GENERAL PAPER – DIVISION 1

1. Four major specialties in Dental technology:

a. prosthodontics,
b. conservation
c. maxillofacial and
d. Orthodontic technology.
2. Define the following
a. Sole proprietorship: Also known as the sole trader is a type of business entity that is
owned and managed by one person in which there is no legal distinction between the
owner and the business. Or it can be define as a business organization set up, financed,
owned and managed by one person with the aim of making profit.
b. Limited liability Company: Is a private company whose owner are legally responsible
for its debts only to the extent of the amount of capital they invested. Or it is a business
structure that provided the limit liability feature of a co-operation and tax efficiencies and
operational flexibility of a partnership can also be defined as a business organization
established, owned and managed by a number of people, operated as a legal person on
behalf of its owners for profit making purposes.
c. Management: is the act of running and controlling a business or similar organization.
3. Write short not on the following
a. Order form: is a document filled in by customers when ordering goods.
b. Invoice: is a business document that shows that list of goods, sold or bought with prices
at the period. It is often issued by the seller to the buyer following the description of the
goods sold. It contains the following information ; Names and addresses of the seller and
the buyer. Date , list of the goods bought, quantity and unit price of the goods, terms of
payment and delivery of goods
c. Delivery Note: is a simple document used to check the authorized quantity of good being
carried away from the store room. It is usually issued by the supplier of goods as a record
or evidence of good supplied.
d. Professional Ethics: A personal and corporate rules that govern behavior within the
context of a particular profession
e. Jurisprudence: Scientific study of law.

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4. Define oral health: oral health according to WHO is defined as a state of being free from
chromic mouth and facial pain, oral and throat cancer, oral sore, birth defects such as cleft lip
and palate, periodontal (gum) disease, tooth decay and tooth loss and other disease and
disorders that affect the oral cavity.
5. Define the following terms.
a. Communicable disease: is defined as an infection disease transmissible (from person to
person) by direct contact with an affected person or the person’s discharges or by indirect
means (as by a vector).
b. Endemic disease: is a disease is a disease that is constantly present to a greater or lesser
degree in people within a given geographical area. Or a continued prevalence of a
disease in a specific population or area.
c. Pandemic disease: is the worldwide spread of a new disease.
6. State three objective of primary health care
a. To make health services accessible and available to everyone where they live or work.
b. To tackle the health problems causing the highest mortality and morbidity at a cost that
the community can afford.
c. To ensure that whatever technology is used, it must be within the ability of the
community to use effectively and maintain.

SECTION B
1. Give the full meaning and explain the function of the following organization.
a. U.N.O: United Nations Organization

It functions

i. Maintain international peace and security

ii. Solve economic, social and political problems through international co-operation
iii. Promote respect for human rights.
b. A. U: African Union

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 It function

i. To promote and defend African common positions on issues of interest to the

continent and its people.
ii. To promote sustainable development at the economic, social and cultural levels and
the integration of African economics.
iii. To coordinate and harmonize the polices between the existing and future regional
economic communities for the gradual attachment of the objective of the union.
c. U.N.I.C.E.F.: United Nations Children Education Fund.
It functions:
i. Providing basic education infrastructure to the world
ii. Increasing child survival in developing countries
iii. Gender equality through education for girls
iv. Protecting and advocating the rights of children.
v. Protection of children from any form of violence and abuse.
vi. Immunization of infants from different disease.
vii. Provision of adequate nutrition and safe drinking water to children.
d. . A.D.B: African Development Bank
It functions:
i. Making loans and equity investments for socioeconomic development.
ii. Providing technical assistance for development projects and programs
iii. Promoting investment of public and private capital for development.
e. N.A.T.O: North Atlantic Treaty Organization.
It functions:
2. Explain in detail how a dental technologist can be protected against transmissible
diseases and hazards in the dental laboratory environment.
 By the use face mask while working.
 By the use of hand gloves during pouring of impression.
 By sterilizing work bench after work.
 By use of protective clothe like laboratory clothes.
 By sterilizing any impression that comes into the laboratory.
 By changing the polishing pumice often.

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  By proper hand washing technique, hand should be washed properly.
 By vaccinating or immunizing against diseases
 Use of protective glasses: safety glasses should be worn for all grinding and polishing
processes.
3. Michael, a qualified and Registered Dental Technologist received a letter from the
Registrar of the DTRBN after the AGM of 2010 informing him that his name has been
struck-off the relevant part of the Register of Qualified Dental technologists in the
country.
a. i. apply or accept a job in response to an advertisement describing the profession as
Dental Technician or such lesser or unbefitting description

ii. dresses indecently.

iii. He engaged in indecorous acts.

b. i. suspension

ii. Withdrawal of his license for a specified period.

iii. Payment of a stipulated amount as fine.

4. Define citizenship and governance.

Citizenship is the status of person recognized under the custom or law as being a
member of a country.

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 GENERAL PAPER- DIVITION 2 (TWO)

1. What is the theme of 2013 National conference/AGM of the ADTN held in Umuahia?

AGM 2013 theme is capacity building: A tools for management of career challenges in
Dental Technology 2marks

2. Define an electrolyte?

Electrolyte are chemical compounds that conduct electricity by changing into ions when
melted or dissolved into a solution. 2marks

3. What is organic chemistry?

a. Science of oxygen compounds
b. Chemistry of carbon compound. (answer)
c. Science of hydro-carbon solution
d. Chemistry of nitrogen compound.
4. Who is the United Nation’s Secretary General?
a. Emaka Anyaoku
b. Koffi Annan.
c. Ban Ki Moon (answer)
d. Anyim Pius Anyim
5. Which of the following numbers are prime numbers?

1,3,9,11,13 and 15

1, 3, 11, 13 and 15.

6. Which club holds the current European championship?

Sevilla

7. Write the full meanings of the following acronyms

a. LCD: Liquid Crystal Display
b. CRT: Cathode Ray Tube
c. CPU: Central Processing Unit

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 d. ROM: Read only Memory.
8. Define the following phenomena.
a. Reality: is the state of having existence or substance or the state of things as they are
quality of being real.
b. Concepts: is a general notion or idea.
c. Constructs: is to build and make something physical. Also to create something such as a
story or theory by organizing ideals and words.
d. Variable: is not being consistent or having a fixed pattern. able to be changed or adapted
9. Mention three principal categories of micro-organisms in Dentistry.
a. Bacteria.
b. Virus.
c. Fungi.
10. List and explain four (4) factors of production.
a. Land: is a free gift of nature that is fixed and reward for it is rent.
b. Labour: is a variable factor and the reward is wages and salaries
c. Capital: is used to start up a business and reward for it is interest.
d. Entrepreneur: is the organizer of the other factors, he bear the risk and takes decisions.
11. Who is an entrepreneur?

An entrepreneur is a person who organizes and manages any enterprise especially business
usually with considerable initiative and risk with hope of making profit.

12. Explain the functions of each member of the Dental Team.

a. Dental surgeon: carries out surgeries in the oral cavity.
b. Dental technologist: Design and fabricate prostheses and appliances for missing
tooth/teeth and associated tissues in the oral cavity.
c. Dental therapy: carries out preventive procedures on people to preserve the dentition
and its surrounding tissues by giving oral hygiene instructions, oral health education,
scaling and polishing. Etc.
d. Dental nurse: assists the surgeon and gives p[ost- operative instructions.

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13. What is SRV in store management?

SRV is store requisition Voucher (store receipt voucher)

14. When do you say a business has broken-even?

It is a point at which total revenue equals total costs or expenses at this point, there is no
profit or loss.

15. Explain the major functions of each arm of government

a. Executive administers and enforces law enacted by the legislature.
b. Legislative is responsible for enacting the law i.e. making law
c. Judiciary deals with the administration of justice and interprets laws.
16. How many types of partial dentures do you have?
We have
a. fixed and
b. removable partial dental

GENERAL PAPER DIVISION 3A

SECTION

1. What is the different between hard and soft water.

Hard water is a type of water that does not readily form lather with soap. While soft water is
one that form lather readily with soap.

2. What is meant by PH of a solution?

The PH of a solution is an acronym for potency of hydrogen. It is used to determine the

acidity and alkalinity of a solution.

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3. What is surface tension?

Surface tension is the force acting parallel to the surface of a liquid due to the force of
intermolecular attraction acting on the surface. It is force that makes a liquid behave like an
elastic skin.

4. List three characteristic of a computer.

Characteristics of a computer are speed-(fast), accuracy, high storage capacity, versatility,

automation, diligence, reliability, convenience, flexibility and business.

5. What is the main aim of psychology?

The main aim of psychology is to understanding the mind, describe behaviour, predict
behaviour and influence i.e. changing behaviour.

6. What is ‘’fostering’’ in relation to medical sociology?

Fostering in medical sociology means taking care of a child that is not related to you by
blood from childhood to adulthood.

7. Define communicable and non-communicable disease?

Communicable disease: is defined as an infection disease transmissible (from person to

person) by direct contact with an affected person or the person’s discharges or by indirect
means (as by a vector).

Non-communicable disease is disease that cannot be easily transmitted.

8. What is meant by the term calorie?

Calorie is amount of energy needed to raise the temperature of 1g of water 1.c

9. What is meant by each of the following terms?

a. Adhesion: is the force of attraction between molecules of different substances.
b. Cohesion : is referred to as the forceof attraction between molecule of the same
substance

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 c. Atmospheric pressure: is the force due to the vertical column of air on a unit area of the
substance
10. Define valency

Valency of an element is the number of hydrogen atoms that combine with or replace one
atom of an element.

11. What is meant by specific gravity?

Specific gravity: is the ratio of the density of a substance to the density ( mass of the same
unit volume) of a reference substance.

12. What are convention of heat and radiation of heat

Convention of heat: is referred to as the transmission of heat from one part of a liquid to
the other by the movement of heat molecules.

SECTION B

1. Explain how a dental technologist can be protected against transmissible diseases and
hazards in the laboratory.
 By the use face mask while working.
 By the use of hand gloves during pouring of impression.
 By sterilizing work bench after work.
 By use of protective clothe like laboratory clothes.
 By sterilizing any impression that comes into the laboratory.
 By changing the polishing pumice often.
 By proper hand washing technique, hand should be washed properly.
 By vaccinating or immunizing against diseases
 Use of protective glasses: safety glasses should be worn for all grinding and polishing
processes.
2. A dental has suffered a lot of setback in profit realization, in what way do you think
knowledge of laboratory management will help you re-engineer the laboratory.

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 The knowledge of laboratory management will help to re-engineer the laboratory in so many
ways, namely,

 Dental laboratory management enables a dental technologist to believe in himself and

earn a better wage.
 It teaches how to manage time, material and products.
 It facilitates the speed of information about the profession and new technique in the
profession.
3. a). Quote the decree and law that established the Dental Technologists’ Registration
Board of Nigeria.

To fully benefit from dental laboratory, there is need to approach the relationship

from two perspective

i. From practice perspective.

ii. Understanding motivations and procedures in the laboratory
iii. Minimizing non-profitable chair time.
iv. Creating restoration that has appropriate maximum life expectancy.
v. Providing restoration that will meet functional and aesthetic expectation.

b). rule 12 is ‘’ working environmental condition” explain the content therein.

 Dental technologist should cover his/herself with protective clothing while working in
the restorative centre.
 There should be sufficient space within the centre for patients, their guardians’ and the
staff.
 Proper hygienic and well ventilated environment should be maintained.
 Eating, drinking and smoking in work area should be avoided, in view of peculiar
nature of the dust produced during manipulation of dental materials such as metals, and
acrylic resin.
4. When two (2) pieces of pure gold are pressed together at room temperature, they will
unite.

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 a. true or false
b. if true explain the process
c. if false what happens during the process
a). true
b) The process is cold-welding. Gold is a soft material, when pressed together at
room temperature the crystalline structure will inter lock and fuse together.
5. Discuss the penalties that are available for unprofessional conduct as provided by the
code of ethics of dental technology profession.
a. . The board will set up a disciplinary committee to look into any violation of this code of
ethics at national or local level as the case may be in accordance to section 21 and other
relevant provision of dental technologist’s act 1987.
b. It should be the duty of the disciplinary committee to recommend the appropriate
punishment in each case in regard to the nature and circumstances of the breaches to the
board, who will pronounce the punishment ranging from suspension to withdrawal of
license of the said Dental Technologist

GENERAL PAPER DIVISION 3B

SECTION

1. What is a Proforma invoice? 2marks

Proforma invoice is the estimated document sent by a seller to a buyer in advance of a

shipment or delivery of goods.

2. Define an electrolyte 2marks

Electrolyte is a substance that dissociates into ions in solution and acquires the capacity to
conduct electricity. OR it is also chemical compound that ionizes when dissolved or molten
to produce an electrically conductive medium.

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3. What is the theme of 2013 National Conference /AGM of the ADTN held at umuahia

AGM 2013 theme is capacity building: A tools for management of career challenges in
Dental Technology

4. Who is an entrepreneur 2marks

An entrepreneur is a person who organizes and manages any business OR enterprise usually
with consideration initiative and risk.

5. List and explain four factors of production 4marks

i. Land : is the economic resource encompassing natural resources found within a
nations economy. It is limited and fixed factor of production that exists naturally.
ii. Labour: is represents the human capital available to transform raw or natural
resources into consumer goods.
iii. Capital : is represents the monetary resources companies use to purchase other
factors of production.
iv. Entrepreneur: is a way of organizes and controls all the other factor of production.
6. Define valency 2marks

Valency of an element is the number of hydrogen atoms that combine with or replace one
atom of an element.

7. State three objectives of primary health care 3marks

 To expand 24/7 access of essential service.
 To facilitate co-ordination with other health services.
 To increase the emphasis on health promotion, disease and injury prevention and chronic
disease management.
8. What is a communicable disease 2marks

Communicable disease: is defined as an infection disease transmissible (from person to

person) by direct contact with an affected person or the person’s discharges or by indirect
means (as by a vector).

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9. Define oral health 2marks

Oral health is a state of being free from chronic mouth or facial pain, oral and throat cancer,
oral sore, birth defects such as cleft lip & palate, periodontal (gum) disease, tooth decay,
tooth loss and other disease that affect the oral cavity.

10. Write short notes on the following 4marks

a. Professional Ethics: A personal and corporate rules that govern behavior within the
context of a particular profession
b. Sole proprietorship: Also known as the sole trader is a type of business entity that is
owned and managed by one person in which there is no legal distinction between the
owner and the business. Or it can be define as a business organization set up, financed,
owned and managed by one person with the aim of making profit.
c. Management: is the act of running and controlling a business or similar organization.
d. Occupational hazard: is a risk experienced in the work place such as chemical,
biological, physiological and physical hazards.

SECTION B
1. a). what is citizenship and governance?
i. citizen : is status of a person recognized under the custom or law as being a member
of a country.
ii. Governance : is establishment of policies and continuous monitoring of their proper
implementataion, by the members of the governing body nof the members and thir
primary duty of enhancing the prosperity and viability of the organization.

b). explain the relationship between the Executive, Legislature and judiciary arms
of government and their roles in governance of a country.

Relationship between the executive, legislature and judiciary arms of government.

 Executive enforces and recommends law

 Legislature makes the law of the land.

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  Judiciary interpret laws of the land; they are all related as they all work towards
creating an orderly and lawful society.

2. Explain in detail how a Dental Technologist can be protected again transmissible

disease and hazards in the dental laboratory environment.
 By the use face mask while working.
 By the use of hand gloves during pouring of impression.
 By sterilizing work bench after work.
 By use of protective clothe like laboratory clothes.
 By sterilizing any impression that comes into the laboratory.
 By changing the polishing pumice often.
 By proper hand washing technique, hand should be washed properly.
 By vaccinating or immunizing against diseases
 Use of protective glasses: safety glasses should be worn for all grinding and polishing
processes.
3. Discuss the penalties that are available for unprofessional conduct as provide by the
code of ethics of Dental technology Profession.
 . The board will set up a disciplinary committee to look into any violation of this code of
ethics at national or local level as the case may be in accordance to section 21 and other
relevant provision of dental technologist’s act 1987.
 It should be the duty of the disciplinary committee to recommend the appropriate
punishment in each case in regard to the nature and circumstances of the breaches to the
board, who will pronounce the punishment ranging from suspension to withdrawal of
license of the said Dental Technologist
4. a). what is Ebola?

Ebola: is acute hemorrhagic fever, it is an infectious and generally fatal disease marked by
fever and severe internal bleeding, spread through contact with an infected body fluid.

b). what are the causes of Ebola?

Ebola is caused by virus

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c). how can it be prevented

It can be prevented by not travelling to endemic areas where virus is found, by not having
sexual contacts with an infected person. Health care workers can prevent the infection by
wearing masks, gloves and goggles when they come in contact with people who may have
Ebola.

5. a). what is NHIS?

NHIS is National Health Insurance scheme; it is a social health insureance programme

designed by the federal government of Nigeria to complement sources of financing the health
sector and to improve access to health care for the majority of Nigerians.

b). who is a health care provider?

Health care provider is doctor of medicine or osteopathy, podiatrist, dentist, chiropractor,

clinical social worker who is authorized to practice by the state and performing within the
scope of their practice as defined by the state.

c). what are the benefits of the NHIS?

Benefits of the NHIS are free health care for all, accessible health care to all

DENTAL LABORATORY TECHNIQUE- DIVISION 1

SECTION A
1. Identify and name these teeth 13
Upper left permanent central incisor and upper left permanent canine.
2. Name 3 classes of dental impression material
i. Based on mode of setting and elasticity.
ii. Based on type of impression and area of use.
iii. Based on their use.
iv. Based on amount of pressure applied.

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3. Explain the following terms

a. Drifting: refers to the migrating (movement) to open spaces left by missing teeth.
b. Abutment: is a tooth or a portion of a tooth or that part implant that serves as a support
and retains prosthesis.
c. Saddle: is the part of denture that rests on the oral mucosa carrying the teeth and to
which the teeth are attached.
d. Pontic : pontic is an artificial tooth on a fixed prosthesis that replaces a missing natural
tooth
4. What is splint

A splint is a rigid or flexible device that maintains in position a displaced or moveable part,
also used to keep in place and protect an injured part e.g. gunning splint.

5. List 3 marking that may be found on the registered bite block of an edentulous patient
i. Median line
ii. Canine line
iii. Lower smile line and
iv. upper smile line
6. What are compensating curves as related to full/full set up? 2marks

Compensating curves as relates to full/full set- the anteroposterior curvature (curve of spee)
and the medio-lateral curvature in the alignment of the occluding surfaces and incisal edges
of artificial teeth that are used to achieve balanced occlusion.

7. What is the difference between occlusion and articulation? 2marks

Occlusion is any contact between the incisal or masticating surfaces of the upper and lower
teeth, while Articulation is the dynamic contact relationship between occlusal surfaces of the
teeth during function.

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8. Where is the cusp of carabelli found?

Cusp of carablli is found on the mesiopalatal cusp of the permanent upper first molar.

9. What is the Kennedy classification of this dentition 543/23478? 2marks

Kennedy class II modification 2

10. Define overbite and overjet 3marks

Overbite is define as the vertical overlap of the upper and lower anteriors

Overjet is the horizontal distance between the upper and lower anteriors.

SECTION: B
1. An impression of patient, whose 21/12 has been marked for extraction in the
prescription card, was brought to your laboratory for the fabrication of a prosthesis
that will be fitted on his next visit a after extraction.
a. What type of prosthesis will you fabricate for the patient?

Immediate upper removable partial denture replacing the central and latereal incisors

b. Describe in sequence, the procedure for fabricating this prosthesis using stock teeth.

Starting from reception of the impression, disinfection, pouring, removing the cast, cutting
off the marked teeth on the model, preparing model, tooth selection and setting up, flasking,
boiling out, mixing, packing, curing, deflasking, trimming and polishing, then labeling for
the next visit ready for fitting.

2. A 20 years old patient lost her 3/3 as a result of an accident; state the name and the
constructional procedure of an orthodontic appliance that will forestall drifting of
adjacent teeth of such patient. 25marks

A 20years old patient lost her 3/3 as a result of accident, Name of the appliance is space
maintainer. Constructional procedure of an orthodontic appliance that will forstall drifting of
adjacent teeth of such patient. Introduction – Due to the patient’s age the lost teeth are

17
 permanent canines, so cannot be replaced naturally, hence the appliance to be considered
should be one that will also be made for this patient, which will forstall drifting and also
restore aesthetics and function.

Construction procedure of a partial denture described in detail, up to polishing and labeling,

ready for fitting.

3. a). What is orthodontic?

Orthodontics is a branch of dentistry concerned with growth and development of the face and
dentition, also the diagnosis, prevention and correction of dental and facial irregularities.

b). Differentiate normal occlusion from mal-occlusion

normal occlusion is the arrangement of teeth and their supporting structure that approaches
an ideal arrangement, while malocclusion is define as an abnormal occlusion in which teeth
are not in normal position in relation to adjacent teeth in the same jaw/ or the opposing teeth
when the jaws are closed.

c). Classify Mal-occlusion.

Angle’s classified malocclusion into three major classes;

i. class 1- Normal occlusion

ii. class 2- Mesiocclusion
iii. class 3- distocclusion

d). What are myfounction appliance?

Myofunctional appliance are those appliances using, removing or modifying the forces
general by orofacial musculature, tooth eruption and dentofacial growth. It is also fixed or
removable which use forces generated by stretching of muscle, facial and / or periodontium
to change skeletal or dental relationship e.g. twin block, bionator etc.

4. Write short notes on:

a. Repair: denture repair is a laboratory procedure carried out to fix broken or cracked
denture. This is mostly done using self-cured acrylic resin.

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 b. Relining: is defined as the procedure used to resurface the fitting surface of a denture
with a new base material to make the denture fit more accurately. It is mostly indicated
on loose fitting denture. Also auto-polymerizing acrylic resin is the material of choice
for relining.
c. Rebasing: is a process of replacing the whole baseplate of a denture with a new denture
base material. It consists of removing the denture base and replacing it with new
material. Though the indication is similar to relining, but it is mostly done when tissue
damage is excessive and also if the patient’s vertical dimension is changed.
d. Addition: Tooth addition refers to the procedure of adding a denture tooth to an existing
denture when the patients natural tooth/teeth requires extraction. This can be done before
or after the extraction. This procedure saves time and money for the patient.
e. Festooning: is the act of carving the base material of a denture to reproduce the natural
gum patterns around the teeth. This enhances the aesthetics of the denture giving it a
more natural look.
5. a). explain the concept of maxillo-facial prosthetics and technology.

Maxillofical prosthetics and technology is a branch of dental technology that deals with
fabrication of prostheses for the correction of congenital and acquired defects of the head and
neck.

b). what are the indications for Max- fac Rehabilitation 25marks

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 DENTAL MATERIAL SCIENCE –DIVISION 1 SECTION A

1. State use of Alizarin- S in dentistry 2marks

Alizarin S is used as a colouring agent

2. Which of the following is not a physical property of dental materials?

a. Color
b. Strength
c. Density
d. Thermal conductivity (answer) 2marks

3. Why does science classify some metals as noble metals?

Because they are metals that are resistant to oxidation and corrosion.

4. Name any three dental materials used for denture base fabrication

Methyl methacrylate, polymethyl methacrylate, stock teeth.

5. Define an alloy

Alloy is a metal made by combining two or more metals/non-metal

6. State the Gay Lussac’s law

Gay Lussac’s law states that at constant pressure, the volume of a fixed number of

partials of gas directly proportional to the absolute temperature.

7. Define the following terms

a. Colloids: are homogeneous non-crystalline substance consisting of large molecules.
b. Gel : is a colloid in a semi-solid form.
c. Sol : is a colloidal suspension of very small solid particles in a continuous liquid
medium.

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8. Why is stainless steel resistant to corrosion?

Because of the addition of 12% or more of chromium.

9. What is crazing and bleaching with regards to denture construction?

Crazing: is a network of minute cracks on the surface of resin due to stress relief.

Beaching : is used to denote lightening of the pigment of dental resin and cloulding

of clear denture base material.nit simply means discolouration of acrylic resin denture

surface .

10. Calculate the fineness of carat gold

Fineness of 18 carat gold
24 carat =1000 fineness
18carat = 18×1000 = 750fineness

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11. What is weld-decay?
Weld- decay is a corrosion process that mainly occurs as a result of senstitization in the heat
affected zones of metal during operations. It occurs in stainless steel or certain nickel-base
alloys.
12. Distinguish between the activator and the initiator in the polymerization of acrylic
resin.
Activator in heat cure is heat while initator is the free radicals which attack double bonds of
acrylic monomers and set off a chain reaction.

SECTION B
1. a). what is investment material in dentistry?

Investment material is described as refractory material which is suitable for forming a mould
in which a molten metal is cast. They are used to envelope wax patterns for the purpose of
creating mould prior to metal casting.

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 b). discuss the ideal properties, types and uses of this material.

i. Even particle size, fine enough to reproduce the surface details of the pattern
ii. Refractory in nature to nature to withstand high temperature burning out and casting
without decomposition.
iii. Reasonable setting time.
iv. Sufficient hygroscopic and thermal expansion to compensate for shrinkage of the
alloy being cast.
v. Smooth consistency when mixed.
vi. Sufficient strength at high temperature to resist casting pressure when the molten
metal enter the mould.
c. Type of investment material
i. Gypsum bonded investment material
ii. Silicon bonded investment material
iii. Phosphate bonded investment material
2. Discuss Binary alloys, based on the following.
a. Solid solution : is alloy formed by metals which are mutually soluble in all proportions
in both the liquid and solid state.
b. Eutectics: are formed by metals which are mutually soluble in the molten state but
insoluble in solid state.
c. Intermetallic compound. Is an alloy formed metals which have chemical affinity for
each other.
3. a). State the composition of reversible hydrocolloid impression materials.
Agar-Agar
Agar -13-17%. (Main constituent)
Water -84% (dispersion medium)
K2SO4-1-2% ( It counters the retarding effect of borates)
Borax – 0.2-0.5%. (Improves strength of the gel)
Inert fillers e.g. was-0.5-1%. (acts as plasticizer).
Alkyl benzonates -0.1%. Acts as preservative.

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 b). give the chemical formal
i. water glass =NaSiO3
ii. Rochelle salt = KNaC4H4O44H2O.
iii. Borax =Na2B4O7 10H2O
iv. Methyl- methacrylate - CH2=C(CH3) COOH3
v. Kaolin(china clay) = Al2Si2O5(OH)4
4. Discuss the constituents of chrome cobalt alloys. What are the effects of each of these
constituents?
Constituents of chrome cobalt alloys and its uses.
Cobalt – 36-60%. ( Hardens and etrengthens the alloy at high temperature).
Chromium 25-30% (corrosion resistance).
Nickel- 0.30%. ( tarish resistance, increase, strength and hardness).
Molybdenum – 5-6%. ( provides hardness and reduces grain size and strength, act as
scavenger).
Carbon-0.2-0.4% ( provides strength )
Tungsten- 0.5% ( provides strength )

Discuss the mechanical properties of this alloy.

5. How are stainless steel alloys classified? Discuss the composition of all the classes of this
alloy. What are those properties that make stainless steel alloy stand out as a material
to be used in the dental laboratory.
Stainless steel are classified as ferritic, martensitic and austentic stainless steel.
Composition of the classification are;
Ferritic stainless steel; chromium – 12-27%
Carbon - 0.20%
Nickel - 1%
Martensitic stainless steel; chromium 11.5-17%
Nickel – 0-0.25%
Carbon – 18%
Austensitic stainless steel; chromium – 18%
Nickel – 8%

23
 Carbon carbon – 0.08-0.15%
Properties of stainless steel alloy that made it stand out as a material to be used in dental
laboratory
 Corrosion resistance
 Tarnish resistance
 Hardness and strength

ORAL ANATOMY/ PHYSIOLOGY DIVISION 2

SECTION A
1. Define the human cell.
The human cell is the basic structural and functional unit of the human body
2. Write the following in full
a. TMJ = Temporo-mandibular joint
b. RBC = Red blood cell
c. WBC =White blood cell
d. BULL =Buccal upper lingual lower
3. Explain briefly the following terms association with anatomical descriptions
a. Anterior = Anterior refers to the front human body or situated toward the front of the
body
b. Median = Situated in the middle, especially of the body
c. Proximal = Situated closer to the point of attachment.
d. Distal = Situated away from the point of attachment. Or a way from central point.
4. Define the following:
a. Ac id = chemical agents that release hydrogen ion when added to water.
b. Base = chemical agents with potential for accepting hydrogen ions.
c. Electrolytes = Electrolytes are chemical compounds that conduct electricity by changing
into ions when melted or dissolved into a solution.

24
 d. Acid-base balance = A state of equilibrium between acidity and alkalinity of the body
fluid.
5. State two causes of tooth movement
a. Habits e.g. thumb sucking
b. Spaces
c. Trauma
6. What is inflammation
Inflammation is the tissue response to infection or injury with pain, heat, redness and
swelling as the basic symptoms.
7. Define dental caries
Dental caries is defined as a localized, post-eruptive, pathological process of external origin
involving softening of the hard tooth tissue and processing to the formation of a cavity.
(WHO).
8. What are tumours
Tumours are abnormal mass of tissue resulting from uncontrolled progressive multiplication
of cells.
9. List 3 muscles of mastication
a. Masseter.
b. Pterygoid.
c. Temporalis
SECTION B
1. a). what is cleft palate?
Cleft palate is an opening the roof of the mouth (palate) due to a failure of the palatal shelves
to unite fully. It is also a congenital defect of the palate in which longitudinal fissure exists in
the roof of the mouth.
b). describe the factor that could be responsible for such deformity
factors responsible for cleft palate (a).inherited factor, Environmental risk factor
c). describe the construction of a temporary that can be used for such deformity
smoking

25
2. a) what do you understand by T.M.J
T.M.J is the temporomandibular joint, a bilateral hinge joint that connects the lower jaw
(mandible) to the temporal bone of the skull.
b). State the function of T.M.J
It helps in movement of the lower jaw
It helps us in chewing our food.
It help us to speaks well
d. Explain the cause(s) of T.M.J dysfunction
Accident
Habits
3. With the aid of diagram (s), discuss major anatomies of the oral cavity.
4. a). Define homeostasis and its relevance to man
homeostasis is the maintenance of relatively stable internal physiological conditions such as
body temperature.
b). Explain the importance of homeostasis to the internal environment of human body.
The importance of homeostasis to the internal environment of human body involves
maintaining a constant internal environment by providing the cells with what they used to
survive (oxygen, nutrients and removal of waste) it is necessary for the well-being of
individual cells and of the centre body. It is important for survival in hot or cold climates.
5. a). what are muscles? List the muscles of facial expression
Muscles are a band of fibrous tissue in human body that has ability to contract to produce
movement or maintaining the position of parts of the body facial muscles of expression are
frontalis, nasalis, orbicularis oculi, orbicularis oris, and buccinators.
b). explain the importance of the relevant muscles in denture retention
Orbicularis oris
Buccinators

26
 DENTAL MATERIAL SCIENCE – DIVISION 1B
SECTION A
1. State the use of Tensiometer

Tensiometer is an instrument used to measure the surface tension of liquids.

2. Define hooke’s law

Hook’s law states that the strain in a material is proportional to the applied stress within the
elastic limit of that material
3. What is Galvanic shock?
Galvanic shock is an unusual type of dental pain caused by an electrochemical circuit formed
when adjacent or opposing dental restorations made of dissimilar metal alloys comes into
contact in the presence of saliva.
4. Define corrosion
Corrosion is the process by which something deteriorates or rusts because of oxidation.
5. What is Brinell Hardness Number (BHN)?
Brinell hardness number (BHN) is the numerical value assigned to the hardness of metals and
alloys.
6. What is the chemical formula of Densite
Chemical formula of densite = CaSO42H2O
7. State the difference between stress and strain
i. Stress is the internal resistance of a material to applied force while Strain is the
change in shape of an object in response stress.
ii. Stress is the force per unit area while strain is deformation produced in the body.
iii. Stress is how hard materials are being pulled while strain is how far the bar has
stretched.
8. Name three examples of elastic impression materials
i. Alginate impression
ii. Rubber-base impression material
iii. Polysulphide impression material, polyether impression material

27
9. List three abrasives used in dental laboratory
i. Diamond
ii. Garnet
iii. Emery
iv. Sand and
v. quartz
10. State the composition of type IV gold alloy
11. Give two (2) examples of scavenger in an alloy.
Two example of scavenger is flux and some metals in an alloy e.g. Zn

SECTION B

1. State in detail, the ideal properties of dental material under the following sub-heading
i. Physical properties
a. Dental materials should be able to flow and record the details in the oral cavity
b. It should be able to undergo high temperature without distortion.
c. Dental materials should be abrasion resistance
d. They should be resistance to tarnishing and corrosion
e. They should have colour perception that is resemblance with the natural one.
ii. Chemical properties
a. Dental material should not cause galvanic shock/pain to the patient.
b. They should not react with the oral fluids and food.
c. They should be resistant to absorption of fluid.
iii. Biological properties.
a. Dental material should be biocompatible i.e. they should not be toxic for a patient.
b. It should not irritate oral cavity and tooth tissue
c. It should be non-allergenic
d. They should be non-mutagenic or carcinogenic.

28
 iv. Rheological properties.

This is the study of deformation and flow characteristics of material. Dental materials should
have ability to flow and be withdrawn from the oral cavity without deformation.

2. State clearly the differences between Alpha and Beta hemiydrates material in terms of:
a. Manufacture

Alpha hemihydrates Beta hemihydrates

Alpha hemihydrates is manufactured when Beta hemihydrates is manufactured when
finely ground gypsum is heated in an auto finely ground gypsum is heated in open
clave to temperature between 120-130.0 container in an open air to temperatures
until steam pressure is built up to between between 110-120.C.
15-17 ib pis ¾ of its water of crystallization During this heating. ¾ of its water of
is driven off in a controlled manner and crystallization is driven off in a shattered
crystalline form of autoclaved calcium manner and a crystalline form of calcium
sulphate hemihydrates appears . this is sulphate hemihydrates appear. This is
known as stone known as plaster of Paris.

b. Uses

Alpha hemihydrates Beta hemihydrates

i. It is for making model. i. It is used for basing a model
ii. It is used for making dies ii. It is used for mounting model on
articulator.
iii. It is used for flasking denture wax pattern.

c. Physical properties

Alpha hemihydrates Beta hemihydrates

i. It comes in different colours like i. It is usually white.
yellow, blue, pink, green. ii. It is porous and irregular in
ii. It is less porous and regular in shape.
shape.

29
 iii. After setting, it is stronger. iii. After setting, it has medium
strength.

3. a). Discuss in detail, an ideal investment material used in casting an alloy for a four unit
bridge.
An ideal investment material used in casting an alloy for a four unit bridge is gypsum bonded
investment material; they are used for casting gold alloy and can withstand temperature up to
700oC. Its melting point is 1200oC.
b). what are then two major components of an ideal investment material stating the
roles of each component?
Two major components of an ideal investment material and their roles are;
Refractory: silica. is a material that can withstand high temperature and it regulates thermal
expansion of the material.
Binder: example gypsum, phosphate, and ethyl silicate. They are material that will set and
bind the particles of refractory substances together.
4. Write short notes on each of the following.
a. Hardness: is the resistance offered by a surface of a material to scratching, abrasion,
indentation, deformation or breaking. It can be measured using Brinell hardness test or
Vickers test.
b. Impact strength: is a resistance of material to a sudden force without breakage or
fracture.
c. Soldering: is the process of joining two metal parts by heating at a temperature below
that of the metal.
d. Fluxes: Is relatively low fusing substance that prevents the formation of oxide on the
surface of the material it is used upon. It is often used during soldering.
e. Elasticity: is the ability of a body to resist a distorting influence or stress and to return to
its original size and shape when the stress is removed.
5. a). define and classify co-polymers.
Co-polymer is a polymer made by reaction of two different monomers with units of more
than one kind. It can be classified based on the arrangement such as alternating co-polymer,
periodic, statistical, block, linear, and branched co-polymer.

30
 b).factors that affect the rate of polymerization of the material
Chemical stages of polymerization of PMMA; activation, initiation, propagation and
termination.
Physical stages are sandy or granular stage, stringy, dough, rubbery and hard stage.
Factors that affect the rate of polymerization of the material are temperature, particle size,
and high polymer/monomer ratio.

DENTAL LABORATORY TECHNIQUE- DIVISION 2

SECTION A
1. What kind of dentition would you find in the mouth of an eight years old child?

Mixed dentition is when there is presence of both deciduous and permanent teeth in the
mouth.

2. What is parallelometer?
A model surveyor
3. Differentiate between a model and n impression of an oral cavity.
A model is the positive replica of the oral cavity while an impression is the negative replica
of the oral cavity.
4. What is the kennedy classification of this dentition 873 34
Kennedy Class II modification.
5. Who classified malocclusion in orthodontic? Name

The classes of malocclusions

Dr. Edward Angle

Classification are:

a. Class I
b. Class II

31
 c. Class III

6. What is the purpose of annealing a cold-worked metal structure?

Purpose of annealing a cold-worked metal structure is to make it tougher and less brittle.
7. Identify the teeth in this chart 2 6
1 c
2 upper right permanent lateral incisor
6 upper left permanent first molar.
1 lower left permanent central incisor.
C lower left deciduous canine
8. What is splint? Give two example of splints
A splint is a rigid or flexible device that maintains in position a displaced or moveable part,
also used to keep in place and protect an injured part e.g. gunning splint, periodontal splint.
9. Define partial Dental. Classify Partial denture according to their supports.
Partial denture is a denture prosthesis that restores one or more but not all the natural teeth
and / Or associated parts and that is supported in part by natural teeth or abutments.
It is classified into
i. Tissue borne partial denture ,
ii. tooth borne partial denture and
iii. combination of tissue-tooth borne partial denture

SECTION B

1. Discuss the factors that affect the retention and stability of F/F dentures.
Retention is the quality of a prosthesis to be firm and steady, able to resist displacement by
functional horizontal or rotational stresses.
Factors affecting retention and stability are
Anatomical: size and quality of denture bearing area,
Physiological: e.g. saliva viscosity, ptyalism can lead to gagging and xerostomia can cause
soreness and irritation.
Physical: interfacial surface tension, capillary attraction, atmospheric pressure and peripheral
seal, and

32
 Mechanical factors: retentive undercuts, magnets, denture adhesives, suction chambers and
discs

2. Describe the procedure for the construction of an active appliance for the retraction of
1 1 in a twelve years old patient.

Diagrams are essential

Roberts Retractor, Procedure- wire gauge to be used for each component of the appilance,
e.g., 0.6mm stainless hard wire for labial bow that runs from canine to canine, Adam crib on
the 6 6 and acrylic base plate to carry the components,

Trim with a clearance on the anterior area of the baseplate to give room for retraction of the
centrals, polish, ready for delivery.

3. a). list five (5) requirements of an ideal clasp.

Requirements of an ideal clasp; easy to fabricate, offer adequate retention, little or no
interference with occlusion.

b). removable appliance are made up of three basic components,

what are these components and give examples of each.

Three basic components of a removable appliance are

Base palate e.g. clear acrylic resin base palate,

Active or force component e.g. labial bow, springs, expansion screws and

Retentive component e.g. clasps, cribs, hooks.

4. a). what is maxilla-Facial prosthetics and Technology?

Maxillofical prosthetics and technology is a branch of dental technology that deals with
fabrication of prostheses for the correction of congenital and acquired defects of the head and
neck.

33
 b). under what conditions is this form of rehabilitation preferred to other forms of
management?

5. Write short notes on the following:

a. Advantages of porcelain teeth
Advantages of porcelain teeth: greater translucency, harder hence more durable,
resistance to wear, resist staining.
b. Curve of spee
c. Separating medium
d. Curve of monsoon
e. Denture surfaces.

DENTAL MATERIAL SCIENCE –DIVISION 2

SECTION
1. Give the chemical formula of
i. Feldspar = k2O.Al2O6SiO2
ii. Plaster of Paris = CaSO42H2O
2. What is alizarin (sodium Alizarin sulphate) used for in Dental Technology?
Alizarin is used as a colouring agent.
3. What is emulsifier? What material is the term associated with?
Emulsifier is a chemical compound which enables oily substances to mix homogenously
4. In the cooling curve of pure metal, the plateau represent
a. Cooling of completely solidified metal
b. Cooling of molten liquid metal
c. Constant temperature when the metal is solidifying
d. Cooling of the furnace.
5. List the major constituents of porcelain and their functions.
Major constituent of porcelain and their functions include,

34
 a. Feldspar acts as flux
b. Kaolin acts as binder
c. Quartz is a refractory ingredient
d. Alumina increases strength as well as viscosity of the melt

6. State the difference between metals and metalloids

Metals Metalloids
i. Conduct heat and electricity Do not, but are capable of conducting
heat and electricity.
ii. They are always of high luster May be either be dull or shiny
iii. Metal lose electrons in reaction Metalloids can lose or gain electrons

7. A substance used to promote fusion of metals and assist in prevention of oxidation of

molten metal during the casting or soldering procedure is.
a. Inlay
b. Sodium
c. Flux (answer)
d. Silicon carbide.
8. Setting expansion of casting investment is approximately
a. 0.1-0.2%
b. 0.1-0.5%
c. 0.8-1%
d. 1.1-1.7%
e. 1.7-2%
9. What is trituration?
a. Surface discolouration of metal
b. Mixing of amalgam alloy with mercury. (answer)
c. Same as erosion
d. Same as corrosion
e. Mixing of alloy particles

35
10. What is the function of feldspar during preparation of porcelain in a metal-ceramic
crown?
a. It forms a gas phase that is able to soften and flow slightly at porcelain firing
temperature. (answer)
b. It decreases viscosity of ceramic material so that it can be applied on the metal
substructure with ease.
c. Due to its particle size interrupts crack propagation in the dental porcelain.
d. It forms a carbon layer that flows at porcelain firing temperature.
e. Helps to prevent porcelain cracking
11. Regarding base metal alloys:
a. The casting shrinking of base metal alloys is less than that of gold alloys.
b. Chromium added to base metal alloy acts as a solid solution hardener.
c. Carbide precipitation to a certain extent decreases strength of the alloys.
d. Manganese and silicone are added to base metal alloys to act as accelerator.
e. Cobalt act to provide flexibility to base metal alloy.
12. Which of the following is beta hemihydrates calcium Sulphate?
a. Plaster of Paris (answer)
b. Stone plaster
13. Lack of saliva in the mouth is called…………………………………………
14. Mention two (2) broad categories of stains in the oral cavity.
15. Affix meaning to the following terms.
a. Adduction
b. Abduction
c. Sagittal.
d. Coronal

SECTION B

1. With the aid of a well-labelled diagram, describe the anatomy and physiology of the
TMJ.
2. a) What is the palate?

b). describe the features of the hard palate

36
 c). state the five (5) muscles that make up the soft palate.

3. Halitosis is the unpleasant odour that occurs in the mouth. Discuss?

4. a). what is the relationship between cells tissues, organ and systems in human anatomy

b). list ten (10) different types of cells in human body.

5. Write short notes on

a. Mastication
b. Deglutition
c. Amelogenesis
d. The skull
e. Dentition

DENTAL MATERIAL SCIENCE- DIVISION 3A

SECTION. A.

1. Define alloy and metal

Alloy is defined as a mixture of metals or a mixture of a metal and another element.
Metal is a solid material that is typically hard, shiny, malleable, fusible, and ductile with
good electrical and thermal conductivity. E.g. Fe, Au, Ag, Al. etc.
2. State three factors that can affect the grain size and structure of an alloy.
Factors that can affect grain size and structure of an alloy are; heat, cold working and
position of metal in the electrochemical series.
3. Mention five (5) ideal properties of investment materials
Sufficient permeability to allow air to be displaced from mould while casting.
i. Adequate strength at temperatures as high as the casting temperature of the alloy
ii. Smooth composition and consistency.
iii. Must not crack upon heating.
iv. Should be easily manipulated with a reasonable setting time.
v. Should exhibit sufficient overall expansion on setting

37
 vi. Should be economical.
vii. Should breakaway readily from the surface of the metal after casting.

4. Differentiate between abrasive and polishing material, give examples of each.

An abrasive is a material that is used to shape or finish a work piece through rubbing which
leads to part of the work piece being worn away e.g. diamond, and sand. While polishing
materials are material that are used for the reduction of roughness to surface scratches e.g.
fine particle discs, polishing pastes
5. Name two waxes that burn-out at 500oC with less than 0.1% residue
The two waxes are sheet casting wax and inlay wax
6. Give the chemical formal of the following:
a. Broax = Na2B4O710H2O
b. Kaolin (china clay). = Al2Si2O5(OH)4
7. State the differences between alpha and beta form of gypsum product under the
following headings:
a. Manufacture

Alpha gypsum product Beta gypsum product

Manufacture –in an autoclave at a -open air at a temperature of 110-1200C,
temperature of 120-1300C, water of water of crystallization is given out in a
crystallization is given out in a controlled shattered manner.
manner.

b. Uses

Alpha gypsum product Beta gypsum product

Use – for making models For flasking, for model basing, for
mounting, for making models for repairs.

c. Strength

Alpha gypsum product Beta gypsum product

Strength –high strength Low strength

38
 d. Particle size.

Alpha gypsum product Beta gypsum product

Particle size- finer particles Coarse particle

8. With what class of dental material do you associate the term ‘’sol’’ and ‘’gel’’
Sol and gel are associated with reversible hydrocolloid impression material (Agar-Agar).

SECTION B
1. a). what is investment material in dentistry?
Investment material can be described as a material suitable for forming a mould into which a
metal or alloy is appropriately cast.

b). discuss the types and uses of each

i. Gypsum bonded investment: This type of investment material has gypsum as the binder,
silica (refractory material) and chemical modifiers. It is used for casting gold alloys and can
be heated up to 7000C.

ii. phosphate bonded investment: This type of investment material has phosphate as the
binder and also has silica as a refractory material. This investment can withstand high
temperature.

iii. Silica bonded investment: this type of investment has silica as the binder which may
be derived from ethyl silicate or aqueous dispersion of colloidal silica or sometimes
sodium silicate. This investment material is sometimes used for casting of higher
temperature melting alloys.
2. a). what is the difference between stress and strain?
Stress is the load per unit area acting within a material. It can be thought of as the internal
resistive response of a material to an externally applied pressure. While.
Strain is the change in shape of an object in response to external pressure or internal stress.

39
 b). Name three (3) types of stress
i. Compressive stress
ii. Tensile stress
iii. Shear stress

c). How are they induced in acrylic resin?

Using hot water for denture cleaning and exposing acrylic resin denture to monomer and
other solvents can create local stress on denture surface with resultant release of strain due to
external stress. Also due to improper processing or handing.
3. a). what are the ideal properties of a non-metallic denture base material
i. It should be odourless, tasteless, and non-toxic to the oral tissues.
ii. It should have sufficient strength and resistance to fracture and distortion.
iii. It should be aesthetically acceptable.
iv. It should have low specific gravity so that it is light in the mouth.
v. It should be easily repairable.
b). state the composition of one such base and the reasons for the incorporation of its
constituents.
Example of a non- metallic denture base is acrylic resin.
Composition of the liquid ( monomer)
Methyl methacrylate – As a base
Hydroquinone –as an inhibitor, to inhibit the polymerization at room temperature.
Glycol dimethacrylate- Acts as cross- linking agent.
Ethyl metacrylate- to improve the properties of the denture.
Composition of the power (polymer)
Polymethyl methacrylate-base constistuent.
Benzoyl peroxide- Acts as an initiator, to initiate the polymerization reaction.
Dibutyl phithalate-Acts as a plastericizer, so that the denture can be easily moulded to shape
by heat and pressure.
4. a). Explain the meaning of the following
i. Syneresis

40
 Syneresis is define as the contraction of a material by the exudation of liquid e.g. alginate
impression.
ii. Imbibitions
Imbibitions is defined as the absorption of fluid by a solid or colloid that results in swelling.

iii. Hysteresis
Hysteresis simply means deficiency. It is defined as the temperature time lag between the gel
to sol and sol to gel of agar agar reversible hydrocolloid material.
b). Give the composition of the material with which these phenomena are associated.

Agar Agar composition –

Agar : 12.5% Basic constituent.
Borax: 0.2%- improves the strength of the gel and retards the setting of plaster or stone when
they are used for pouring into the finished impression.
Sulphates: 1.7%- Ensures proper setting of the gypsum model.
Alkyl benzoate :- To prevent the growth of mould in the material on storage.
Colouring and flavouring agents- trace.
Water:- 85.5%-acts as dispersing medium.
5. a). What is electrolytic polishing?
Electrolytic polishing is an electro chemical process that removes material from a metallic
work piece. It is used to polish and passivate metal parts. It is often described as the reverse
of electroplating.
b). discuss how this procedure may be demonstrated in the laboratory.

ORAL ANATOMY AND PHYSIOLOGY –DIVISION 3A

SECTION
1. what is Hamular notch ? 2marks

41
 hamular notch is a depression situated between the maxillary tuberosity and the hamular
process of the medial pterygoid plate.
2. A set of deciduous dentition consist of how many teeth 2marks
20 teeth.
3. What is torus palatines? 2marks
Torus palatines is kind of elevation found specifically at the midline of the hard palate.
4. Define centric occlusion 2mark
Centric occlusion is defined as the occlusion of the teeth when the jaws are in centric
relation. It is the maximum intercupation of the opposing occlusal surface of the teeth.
5. What is the name of the joint by which the lower jar articulates with the skull? 2marks
Temporomandibular joint (TMJ)
6. What is Orbicularis oris?
Orbicularis is a sphincter muscle that encircles the mouth
7. Where are these found?
a. Hyoid bone
Hyoid bone is found at the anterior midline of the neck, a cartilage near the hyoid.
b. Incisive papilla
Incisive papilla- found at the median line behind and between the central incisors.
c. Cusp of carabelli

Cusp of calabelli- found at the mesiopalatal cusp of upper first permanent molar.

d. Fraenal attachment

Frenal attachment- in the vestibule of the mouth(sulci).

e. Retromolar pad 5marks

Retromolar pad- found at the posterior section of the lowere alveolar ridge behind the third
lower molar.

8. State the significance of saliva in denture retention 3marks

Significance of saliva includes. Cohesion, adhesion and surface tension
9. List three types of cell in human body 3marks

42
 Three types of cell in human body are epithelial cells, defence cells and stem cells.
10. What is a connective tissue 2marks
A connective tissue is a tissue that connects supports, binds or separates other tissues or
organs, typically having relatively few cells embedded in an amorphous matrix, often with
collagen or fibres and including cartilaginous, fatty and elastic tissues.

SECTION B

1. a). Mention five (5) muscles of mastication

i. masseter.
ii. Temporalis
iii. Lateral pterygoid.
iv. Medial pterygoid and
v. Sphenomandibular.
b). Discuss the functions of muscle of mastication
Functions
 Masseter muscles elevates the mandible and is primarily active when grinding tough
food. It exerts considerable power when the mandible is close to centric occlusion
position.
 The temporalis muscle is the largest muscle of mastication.
 The pterygoid (lateral and medial) is activated during mandibular retrusion and during
clenching of the mandible, and is concerned with mandibular protrusion, depression and
lateral excursions. Also the medial pterygoids mainly acts in elevating the mandible.
 The sphenormandibular muscle aids elevation and perhaps protrusion of the mandible.

2. write short notes on the following:

a. the morphology of the maxillary first molar

43
 Morphology of maxillary 1st molar- largest molar in the upper quadrant, the crown is
rhomboid in shape, four well developed cusps and sometimes a supplementary cusp known
as cusp of carabelli on the mesiopalatal cusp, it has 3 roots, one palatally and two buccally.

b. Open bite.
Open bite is a dental disorder in which the anterior teeth both upper and lower are forced
outwards to an extent that the teeth of the upper and lower jaw do not touch each other, even
when posterior teeth is in occlusion.

c. freeway space
Free way space is the space between the occluding surfaces of the maxillary and mandibular
teeth when the mandible is in resting position
d. periodontal membrane

periodontal membrane is also called periodontal ligament, it is a fleshly tissue between tooth
and tooth socket that holds the tooth in place, attaches it to the adjacent teeth and enables it to
resist the stresses of chewing. It develops from the follicular sac that surrounds the
embryonic tooth during growth.

e. overbite and overjet 25marks

Overbite is the vertical distance/overlap between the anterior upper and lower teeth.

Overjet is the horizontal distance/overlap between the anterior upper and lower teeth.

3. Describe the tongue in general terms, how does the tongue affect the formation of the
maxillary and mandibular arches. 25marks
Tongue is a muscular organ with its base attached to the floor of the mouth. It is attached to
the inner surface of the mandible near the midline and gains support below from the hyoid
bone. It is pink in colour and covered by a thin lining of non-keratinized mucosa that is
tightly bound down to the underlying muscles. It is characterized by an abundance of
papillae. The tongue affects the formation of the arches in that the arches have to form in the
space between the tongue and the check, so the size and shape of the tongue will affect the
shape of the maxillary and mandibular arches.

44
4. Describe the anatomic relationship between the condylar angle, cuspal angle and incisal
guidance angle when centric occlusion is maintained 25marks
5. Describe the anatomy of the lips and the check and how it aid denture retention and
stability. 25marks
The lips are composed of muscles ( the orbicularis oris muscle) and connective tissues,
covered externally by skin and internally by mucous membrane. The corner of the lips ( the
labial commissures) are usually located adjacent to the maxillary canine and mandibular first
premolar teeth.
The checks extend intra-orally from the labial commissures anteriorly to the ridge of mucous
overly the ascending ramus of the mandible posteriorly. The mucous is non-keratinized and
being tightly adherent to the buccinators muscle, is stretched when the mouth is opened and
wrinkled when closed.
The lips and check anatomy aid in denture retention and stability as the denture is placed on
the ridge between the tongue and lips anterior, checks posteriorly, the muscles of the lips and
the checks helps in stabilizing them. The buccal flanges of the upper denture which slopes up
and out from the occlusal surfaces of the teeth allows the check to rest and support the
denture.

DENTAL LABOURATORY TECHNIQUE DIVISION 3A

SECTION A
1. Why should clasp be tapered? 2marks
To avoid displacement
2. What would be the effect of packing resin before the acrylic had reached the proper
stage. 2marks
Contraction porosity, bleaching, granularity
3. What is the use of periodontal splint 2marks
Periodontal splint is used stabilize periodontally compromised tooth.
4. Define angle class II malocclusion 2marks

45
 Angle class II malocclusion – it is defined as an abnormal arch relationship when the first
permanent molar is anterior places more than normal.
5. What are the functions of occlusal rest 3marks
Function of occlusal rest; stabilizes the denture, it increases retention of a partial denture,
resists vertical force of occlusion, and prevents the lateral forces from acting on the tooth.
6. What is annealing 2marks
Annealing is a low temperature heat treatment which has little effect on the fibrous grain
structure. Its purpose is to induce ductility, soften the metal, relieve internal stress and refine
the structure.
7. What is the essential difference between electrodeposition and electropolishing. 3marks
Electropolishing removes surface metal by ionic dissolution while electrodeposition
adds/deposits layer of metal onto the part by ionic deposition .
8. State possible causes of an acrylic tooth coming off an acrylic denture 2marks
Incomplete wax boil-out, excessive cold mould seal on the tooth surface, under, under
packing.
9. What is an oral screen? 2marks
An oral screen is a myofunctional/ passive removable orthodontic appliance made of
Plexiglas or acrylic resin that fits into the vestibule of the mouth for the correction of mouth
breathing and sometimes retraction of mildly proclined centrals.
10. What is the difference between occlusion and articulation 2marks
Occlusion simply means the contact between teeth. It is the relationship between the
mixillary and the mandibular teeth when they approach each other or at rest. While
Articulation is known as dynamic occlusion, it is the contact between teeth (maxilla and
mandible) when the jaw is in motion.
11. If surplus separating medium is left on a plaster of Paris impression before casting.
What effect will this have on the final model? 2marks
Loss of the fine detail on the model, reduced strength and wrong model

SECTION B

1. a) State three jaw relationships which are commonly identified in full/full set up.

46
 i. Class I = Normal
ii. Class II = Superior
iii. Class III = Inferior

b). Describe how the setting- up of the artificial teeth is affected by each. 25marks.
i. Class I – Anterior overbite/overjet 1-2mm, canine prominence evident, compensating
curve incorporated, balanced occlusion and articulation
.ii. class II – Replace lower first premolar with a canine, add extra canine to upper model
iii. class III – Extra premolar added to lower model.
2. Describe the preparation of a die model for a crown work using
a. Dental stone

Basic principles to be considered are

b. Electrodeposted metal 25marks

3. a). what basic principles have to be considered in the design and construction of a
circumferential clasps used in partial denture construction. The clasp should include
more than 180o of the greatest circumference of the crown of the tooth.

Occlusal rest must be designed to prevent movement of the clasp arms.

Amount of retention should be the minimum necessary to resist reasonable dislodging forces.

Clasp retainers on abutment teeth adjacent to distal extension bases should be designed so
that they avoid direct transmission of tipping and rotational forces to the abutment teeth.

b). how would the survey line marked on the tooth influence the design 25marks
How would survey line marked on a tooth influence the design.
i. It will influence the type and position of the components of the denture.
ii. It determines the path of insertion of the denture.
iii. It indicates the presence of desirable undercuts for retention.
4. Write short note on the following:
i. Retainers

47
 Retainers are custom made devices made usually of wires or clear plastic that holds teeth in
position after surgery or any method of teeth realigning. They are most often used before or
after dental braces to keep teeth in position to prevent relapse.

ii. Sanitary pontic

Sanitary pontic is an artificial tooth on a fixed denture that replaces a missing natural tooth.
The tissue side of the pontic does not contact the ridge at all, to facilitate cleaning.

iii. Crazing
Crazing refers to a network of fine cracks on the surface of a material. Crazing is a
phenomenon that frequently precedes fracture in some glassy thermoplastic polymers.
iv. Beriby layer
Beriby layer is define as a molecular layer of a highly polished surface produced by
use of a series of abrasives of decreasing coarseness.
v. Opacifier

Opacifier is a substance ( an additive such as enamel, pain etc) added to a material in order to
make the system opaque.

5. State the precautions which should be taken when flasking, packing and processing a
full lower denture with acrylic to avoid:
a. Porosity – flasking- Ensure you use flask that have metal to metal contact

Porosity – flasking- Ensure you use flask that have metal to metal contact

-Use open method/ reverse method

-Ensure good water/power ratio of plaster

-Do not cold mould seal when it is hot

Packing –Ensure appropriate monomer/polymer ratio when mixing

-keep jar closed after mixing

48
 -pack at dough stage

-Pack enough dough into the mould

-used required pressure .

Processing –start curing from room temperature and do not exceed the required temperature.

b. Irregular colouring
Irregular colouring : flasking : Avoid excess cold mould seal.
Parking: ensure a homogenous mix of the dough before packing and mix in a dry clean
jaw.
Processing : ensure flask is closed with a metal to metal contact to avoid water from
slipping into the mould.
c. Raised bite 25marks
Raised bite :flasking –allow enough time for comlete setting of plaster before toping.
-Ensure metal to metal contact
Packing –Avoid excessive pressure or inadequate pressure
Pack at dough stage
Avoid over packing without enough pressure.

DENTAL LABORATORY TECHNQIUE – DIVISION 3B

SECTION A
1. Identify and name these teeth. DA 47 2marks
a. 4 = upper left permanent first premolar
b. 7 = upper left permanent second molar
c. A = lower right deciduous central incisor
d. D = lower right deciduous first premolar
2. Name three classes of dental impression materials 3marks

49
 Three classes of dental impression material; accord to flow; viscous and non- viscous ,
accord to set; rigid and elastic, reversible and irreversible mucostatic and mucocompressive.

3. What is the Kennedy classification of this dentition 873 345 2marks

Kennedy class II modification 2.
4. Who classeified malocclusion in orthodontics?
Dr. Edward Angele
Name the classes of malocclusion 4marks
a. Class I –normal occlusion
b. Classe II- superior protrusion
c. Class III – inferior protrusion
5. What are compensating curves as related to full/full set-up 2marks
The curve introduced in the construction of complete denture to compensate for the opening
influences produced by the condylar and incisal guidance during lateral and protrusive
mandibular excursive movements.
6. Define retention and stability 2marks
Retention
Retention is the ability of denture to withstand displacement against its path of insertion.
Stability
Stability is the ability of a denture to withstand horizontal forces and to resist displacement
by functional stresses.
7. Explain the following terms
a. Drifting

Drifting: teeth moving out of position to the or even further into open spaces left behind by
missing teeth

b. Abutment

Abutment is a tooth or portion of tooth that supports or retains a prosthesis.

c. Saddle

Saddle is the part of a denture that rests on the oral mucosa and to which teeth are attached.

50
 d. Pontic 4marks

Pontic is an artificial tooth on a bridge that replaces a missing natural tooth.

8. What is the use of gunning splint? 2marks

Gunning splint is used in reduction and fixation of a fractured mandible.

9. List four ideal properties of dental impression materials 2marks

Ideal properties of dental material;
i. Ease in manipulation
ii. Adequate shelf life for storage
iii. Non-toxic and non-irritant
iv. Compatibility with the cast or die material.
v. Accurate surface reproducibility and dimension.
vi. It should be economical.
vii. It should have adequate strength and good setting time
10. What is electropolishing? 2marks
Electropolishing is the electrolytic removal of a thin layer of metal to produce a bright
surface
11. Explain normalizing 2marks
Normalizing heat treatment is heat treatment carried out to enhance the mechanical properties
of the material by refining the microstructure.

SECTION B
1. State the precautions which should be taken when flasking, packing and processing a
full upper denture with methylacrlate to avoid
a. Raised bite
b. Bleaching
c. Porosity 25marks

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 Porosity – flasking- Ensure you use flask that have metal to metal contact

Porosity – flasking- Ensure you use flask that have metal to metal contact

-Use open method/ reverse method

-Ensure good water/power ratio of plaster

-Do not cold mould seal when it is hot

Packing –Ensure appropriate monomer/polymer ratio when mixing

-keep jar closed after mixing

-pack at dough stage

-Pack enough dough into the mould

-used required pressure .

Processing –start curing from room temperature and do not exceed the required temperature.

d. Irregular colouring
Irregular colouring : flasking : Avoid excess cold mould seal.
Parking: ensure a homogenous mix of the dough before packing and mix in a dry clean
jaw.
Processing : ensure flask is closed with a metal to metal contact to avoid water from
slipping into the mould.
e. Raised bite
Raised bite :flasking –allow enough time for comlete setting of plaster before toping.
-Ensure metal to metal contact
Packing –Avoid excessive pressure or inadequate pressure
Pack at dough stage
Avoid over packing without enough pressure.
2. Write short note on the following
a. Beilby layer

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 Beriby layer is a relatively scratch-free microcrystalline surface produced by a series of
abrasive of decreasing coarseness. It is first seen on the surface of a highly polished metal or
acrylic resin work. It is first described by Sir George Thomas Beriby, a British Chemist.

b. Crazing

Crazing is the production of minute or a mesh of fine cracks on the surface of a material like
processed acrylic resin denture. Crazing can be as a result of heat or action of organic
solvents.

sanitary pontic

Sanitary pontic is a self-cleaning pontic which does not touch the edentulous ridge. It is easy
to keep it cleans.
c. component parts of partial denture 25marks

Component parts of partial denture; partial denture can either be fixed or removable. For a
fixed partial denture the component parts are the pontic, connector and retainer. While the
removable partial denture has the denture base (base plate), denture teeth, major, minor
connectors, rest, direct and indirect retainer.

3. Discuss the factors that affect the retention and stability of full/full denture. 25marks
Factors that affect the retention and stability of full/full denture, define retention and
stability. Then discuss the factors under these headings; anatomical, mechanical and physical.
4. Describe the procedure for the constructions of an active appliance for the retraction of
1 1 in a 10years old patient.
Diagrams are essential. 25marks
Active appliance to retract 1 1 in a 10 year old is Roberts retractor. Describe the procedure
and show diagram of the appliance.
5. Describe the principles of sprueing a wax pattern suitable for the withdrawal method of
investment with gypsum bonded material. 25marks
Principles of sprueing a wax pattern suitable for the withdrawal method of investing with
gypsum bonded material;

53
 Sprue length should not extend 18mm and where possible, shorter sprue of 6-10mm should
be used (adequate sprue length)
Angulation of sprue
Location of sprue
Number of sprue
Thickness of sprue.

DENTAL MATERIAL SCIENCE DIVISION 3B

SECTION A
1. State the different between stress and strain 2marks
Stress is the force acting on a material while strain is the deformation as a result of the force
applied on a material.
2. Name three examples of elastic impression 2marks
Examples of elastic impression materials are
i. Aliginate
ii. Silicone rubber and
iii. Agar- Agar.
3. Define Tarnishing and corrosion 2marks
Tarnishing is a surface discolouration of a metal. While corrosion is a chemical or electro
chemical process in which metal is attacked by environmental agents.
4. Explain Hygroscopic Setting Expansion 2marks
Hygroscopic setting expansion is an increase that occurs when setting investment material is
exposed to additional water.
5. In the cooling curve of pure metal, what does the plateau represent? 2marks
Plateau represents solidification of metal
6. What is Dental Flux? 2marks
Dental Flux is relatively low fusing substance that prevents the formation of oxide on the
surface of metal during soldering.
7. What is sodium Alizarin Sulphate used for, in Dental Technology? 2marks

54
 Sodium Alizarin sulphate is used as colouring agent.
8. Give the chemical formular of plaster of Paris 2marks
CaSO42h2O-CaSO41/2 H2O-1/2H2O.
9. Differentiate between abrasive and polishing materials
Give two example of each. 4marks
Abrasive material is used to cause wear on another material through mechanical means.
While polishing material is a material used to achieve a glossy surface on a material.
Examples of abrasive material are diamond and quartz while examples of polishing material
are pumice and rouge.
10. Name and define two types of stress 2marks
Two type of stress are:
Compressive stress is the internal resistance of a material to external force coming from two
opposite direction
Tensile stress is the internal resistance of a material to elongating force.

SECTION B
1. Discuss the ideal properties of a non-metallic denture base material 25marks
a. It should shelf life
b. It should not irritate the patient
c. It should be aesthetically pleasing.
d. It should be opaque to x-ray.
e. It should be able to resist sudden force
f. It should not melt in the mouth temperature and should not permit bacterial growth
g. Be hard enough to resist abrasion and accommodate high polishing.
h. It should have low specific gravity
i. It should not be toxic
j. It should have high modulus of elasticity.
2. Write short notes on the following:
a. Soldering

Soldering is the process of joining two or more metals using an intermediate metal whose
melting temperature is lower than the metals to be soldered.

55
 b. Thermal expansion

Thermal expansion is the increase in size, especially of investment materials when subjected
high temperature. This helps to compensate for thermal contraction of the alloy being cast.

c. Syneresis

Syneresis is a phenomenon in which hydrocolloid impression materials exudates water or

shrinks slightly when exposed to dry atmosphere.

d. Imbibitions

Imbibitions is defined as the absorption of fluid by a solid or colloid that results in swelling

e. Hysteresis

Hysteresis is a time-temperature lag during the cooling of reversible hydrocolloid from sol to
gel.

3. Describe the constituents, polymerization and uses of auto-polymerizing acrylic resin

Chemical stages of polymerization of PMMA; activation, initiation, propagation and termination.

Physical stages are sandy or granular stage, stringy, dough, rubbery and hard stage.
Factors that affect the rate of polymerization of the material are temperature, particle size,
and high polymer/monomer ratio.

4. State in details, the ideal properties of dental materials under the following subheadings
a. Physical properties
i. Dental materials should be able to flow and record the details in the oral cavity
ii. It should be able to undergo high temperature without distortion.
iii. Dental materials should be abrasion resistance
iv. They should be resistance to tarnishing and corrosion
v. They should have colour perception that is resemblance with the natural one.

56
 b. Chemical properties
i. Dental material should not cause galvanic shock/pain to the patient.
ii. They should not react with the oral fluids and food.
iii. They should be resistant to absorption of fluid.

c. Biological properties
i. Dental material should be biocompatible i.e. they should not be toxic for a patient.
ii. It should not irritate oral cavity and tooth tissue
iii. It should be non-allergenic
They should be non-mutagenic or carcinogenic
d. Rheological properties
This is the study of deformation and flow characteristics of material. Dental materials should
have ability to flow and be withdrawn from the oral cavity without deformation.
e. Mechanical properties
5. List ten abrasive agents used in dental laboratory and discuss their uses 25marks

ORAL ANATOMY AND PHYSIOLOGY DIVISION 3B

SECTION A.
1. What is tooth morphology 2marks
Tooth morphology is the subject which deals with the external and internal structure,
function, location of the teeth in the oral cavity.
2. Name three major salivary glands 3marks
Three major salivary gland are
i. Parotid.
ii. submandibular.
iii. sublingual gland,
3. Draw human skull and label it 5marks
4. List three types of cell human body 3marks
Three types of cells are

57
 a. Stem
b. Blood,
c. Nerve and
d. epithelial
5. What is adhesion and cohesion 2marks
Adhesion is the physical attraction of unlike molecule to one another.
Cohesion is the physical attraction of like molecule to each other.
6. Explain briefly the following terms associated with anatomical descriptions.
a. Median

Median – situated in the middle especially of the body.

b. Proximal

Proximal –situated nearer to the centre of the body or the point of attachment.

c. Distal

Distal – further from the reference point; away from the median plane.

d. Buccal

Buccal – pertaining to or adjacent to the check.

e. Lingual 5marks
Lingual – pertaining to the tongue; next to or toward the tongue.
7. State three causes of tooth movement 3marks
a. Trauma
b. Oral habits
c. Existing space
d. Oral tumors.
8. Define Dental Caries 2marks
Dental caries is a localized, progressively destructive disease of the teeth that starts at the
external surface (usually the enamel) with subsequent cavities formed on the tooth/teeth
involved.

58
 SECTION B
1. With the aid of diagram, discuss major anatomical features of the
oral cavity. 25marks
anatomical feature of oral cavity with diagram; incisive papilla, frenal attachment, upper
alveolar ridge, rugae, palatal torus, hard palate, palatal fovea, soft palate, uvula. retromolar
pad, sulcus, lower alveolar ridge and tongue.
2. a). what are muscles?
Muscles are band or bundle of fibrous tissue in a human body that has the ability to contract,
producing movement in or maintaining the position of parts of the body.
b). list muscles of facial expression
Muscles of facial expression -:
i. frontalis
ii. nasalis
iii. orbicularis ocui,
iv. orbicularis oris and
v. buccinators
c. explain the relevance of muscles to denture retention 25marks
Relevance of muscles to denture retention; The orbiclaris oris which is the main muscle of
the lip has a minimal effect on the denture as the muscles are thin. The buccinators and
levator anguli oris influence the position of the buccal frenum hence there is need for
clearance on the buccal flange of the denture with the flanged shaped in a way that makes the
check muscle help to stabilize the denture.

3. write short note on the following:

a. Freeway space

Freeway space is the space or gap between the occluding surface of the maxillary and
mandibular teeth when the mandible is in a resting position. Also called intercuspal
clearance.

b. Deglutition

59
 Deglutition is the process in the human body that makes something pass through the mouth
to the pharynx into the oesophagus with shutting the epiglottis. It is an important part of
eating and drinking. Its process is of three staged. Also called swallowing.

c. Bite plane

Bite plane: - A component part of orthodontic appliance that is used to open bite for quicker
movement or allow some teeth to erupt while holding others in position. It can be anterior
bite plane, posterior bite plane and sved bite plane, the posterior bite planes may be
positioned unilaterally or bilaterally depending on the function of the bite plane. It is often
made in acrylic resin

d. Dental stains

Dental stains simply means discoloration of the teeth. This can be due to a variety of factors,
which can be classified as intrinsic stains if it originates within the teeth or extrinsic stains if
it is from outside the teeth and it is on the outermost surface of the tooth (enamel). Common
causes of extrinsic stains are tobacco products, coffee, tea and kolanut. This type of stain can
be removed by scaling and polishing or tooth beaching. Common causes of intrinsic stains
are internal trauma to tooth/ teeth, tetracycline, over exposure to fluoride at an early age,
congenital tooth discolouration/ dentogenesis imperfect. The treatment option is porcelain
veneers.

e. Halitosis 25marks
Halitosis is simply bad breath. That is a chronic bad breat that persists even when steps
have been taken to reduce it. It can be as a result of consumption of certain foods, poor
oral hygiene, alcohol; tobacco use, dry mouth or some chronic medical condition.
4. a). Define mastication
Mastication is the process of chewing food for swallowing and digestion.
b). State the role of each tooth in the process of mastication
Role of each tooth in the process of mastication
 Incisors- for shearing and cutting food.
 Canine – for tearing food
 Premolar- for tearing and grinding food.

60
  Molar – grinding of food.
c). Explain the five (5) mandibular movements. 25marks
five mandibular movements:
i. Protrusive
ii. Retrusive
iii. Elevation
iv. Depression and
v. Lateral movement.
5. Describe the formation of the tooth under the following criteria:
a. Amelogenesis

Amelogenesis is the formation of the enamel and begins when the crown is forming during
the bell stage of tooth development. The ameloplast cells are responsible for this process.

b. Dentinogenesis

Dentinogenesis is the formation dentin, a substance that forms the majority of tooth
structure. This is performed by odontoblasts which are special type of biological cell on the
outer wall of dental pulps and it begins at the late bell stage of the tooth development.

c. Cementogenesis
Cementogenesis is the formation of the cementum, one of the three mineratized
substances of a tooth. The cementum covers the root of the tooth and serves to anchor
gingival and periodontal fibres. The cementoblasts is responsible for cementogenesis.
Cementum grows slowly, by surface opposition throughout life.
Hence, the sequence of tooth formation starts from the formation of the cementum,
followed by the dentine and lastly the enamel.

DENTAL LABORATORY TECHNIQUE- DIVISON 4A

SECTION A

61
1. What are the two methods of basing cast? 2marks
i. Reverse method
ii. Boxing
iii. Use of preformed or rubber mould.
2. With the aid of a diagram, name and show the three parts of a clasp. 2marks
Draw and label clasp; Reciprocating arm, support, retentive clasp arm, beacing portion,
minor connector.
3. What is mesiodistal width and inciso-cervical length of the following teeth
21 12
21 12 2marks

4. List the accessories of a Dental surveyor 2marks

Dental surveyor accessories
a. Analyzing rod
b. Chisel
c. Lead marker (carbon)
d. Undercut gauge.
5. What is Normalizing Heat Treatment?
2marks
High temperature treatment given to a ferrous metal to restructure or refine the grain
structure.
6. Define centric occlusion 2marks
Centric occlusion is the maximum intercuspation of the opposing occlusal surface of the
teeth.
The occlusion of the teeth when the jaws are in centric relation.
7. What is the difference between periodontal and gunning splint? 2marks
Periodontal splint is made for a dentate patient while gunning splint is made for edentulous
patient
8. What is anodizing? 2marks
Anodizing is an eletrochchemical process that converted the metal surface into a decorative,
durable, corrosion resistant, anodic oxide finish. Or anodizing is an electrolyte passivation
process used to increase the thickness of the natural oxide layer on the surface of metal parts.

62
9. Mention 4 types of Dental bridge 2marks
Types of Dental Bridge:
i. fixed-fixed
ii. fixed-removable
iii. plain cantilever
iv. spring cantilever
10. Define gingival approaching to as high fusing? 2marks
A clasp that approaches the undercut from the gingival direction.
11. When is porcelain referred to as high fusing?
2marks
High fusing is when the fusing temperature is between 1288-1450oC
12. What is ash figure 5 used for? 2marks
i. high survey line
ii. low survey line
iii. medium survey line
iv. Diagonal survey line.

Ash figure 5 is used for trimming wax or carving wax patterns.

SECTION B
1. a). What is electrolytic polishing ?
Electrolytic polishing is the electrolytic removal of a thin layer of a metal to produce a bright
surface
b). Name 5 polishing agents and 5 abrasive agents used in dental laboratory
five abrasives
i. Diamond.
ii. tungsten
iii. Carbide.
iv. pumice
v. garnet
vi. quartz

63
 vii. carborundum(silicate carbide)
viii. corundum, emery
ix. Sand.
C. discuss the principles of partial denture according to Beckett 25marks
principles;
i. high speed and low pressure
ii. low speed and high pressure
iii. The polishing material should be fine enough to produce a glossier surface.
iv. The pressure applied should be minimal to avoid war page.
v. Water/glycerine should be used to check the effect of heat and dust.
vi. the speed of the wheel should be minimal
2. a). list the components of partial denture.
Major connector, minor connectors, rest, direct retainer, indirect retainer, denture base
artificial tooth replacement.
b). discuss the classification of partial denture according to Beckett.
Beckett classification (based on load distribution)
i. tooth borne
ii. tissue borne
iii. tooth-tissue borne
c). what is the function of occlusal rest and similar component of partial denture?
i. major connectors – connectors the components on one side of the arch to the component on
the opposite side of the arch.
ii. Minor connector – connects the other components of the removable partial denture to
major
iii. Occlusal rest- meant to transmit the occlusal forces acting on the denture along side of the
abutment tooth.
vii. Direct retainer- Helps to prevent the displacement of the denture.
viii. indirect retainer – assists the direct retainer in preventing displacement of denture
base

64
 ix. Denture base – forms the tissue surface of the denture over the edentulous area. Helps
to distribute the forces acting the denture over the entire residual ridge. Holds the
tooth replacements in position.
x. artificial tooth replacement – reproduce the contour and function of the missing teeth

25marks
3. writ short notes on the following
a. opacifier

Opacifier is a material or substance added to another material to prevent the passage of light
thereby making it opaque e.g. porcelain.

b. posterior palatal seal

Posterior palatal seal is the seal created at the posterior border of a maxillary prosthesis.

c. Cohesion and Adhesion

Cohesion is the state whereby similar molecules of matter adhere or stick to one another.

Adhesion is the attraction of dissimilar molecules of matter. These two apply in denture
retention and stability.

d. Viscosity

Viscosity is the resistance to flow or alteration of shape by any substance as a result of

molecular cohesion.

e. Neutral Zone and Residual Ridge. 25marks

Neutral zone is the potential space between the lips and the checks on one side and the
tongue on the other area or position where the forces between the tongue and checks or lips
are equal.

Residual ridge- alveolar ridge left when the natural teeth are lost.

4. a). What is instrumentation?

65
 Instrumentation is the use of measuring instruments to monitor and control a process. Or it is
the art and science of measuring and control of process variables within a production,
laboratory or manufacturing.
b). Mention 10 dental laboratory equipment and their accessories
i. Trimming machine – hand piece, foot pad, wire and electric plug.
ii. Polishing machine –buffs, plastic trough, shield
iii. Model trimmer- Rubber tubing.
iv. Bench press.
v. curing bath
vi. vibrating machine
vii. furnace,
viii. centrifugal casting machine
ix. sand blasting machine
x. induction casting machine
xi. electrolysis machine
xii. porcelain firing machine
xiii. Thermoplastic machine.
c). Mention 10 dental laboratory hand instrument and state their uses 25marks
Dental laboratory hand instrument and their uses: wax knife, lecron, carver, blow pipe, air
syringe, ash figure 5, adam’s or universal plier, loop former, nipper cutter, pair of divider,
mixing bowl, freach saw, carmel hir brush, spatula, plaster knife.
5. Describe the method of mixing, flasking, and processing a methyl methacrylate lower
denture to avoid :
a. Porosity – flasking- Ensure you use flask that have metal to metal contact

Porosity – flasking- Ensure you use flask that have metal to metal contact

-Use open method/ reverse method

-Ensure good water/power ratio of plaster

-Do not cold mould seal when it is hot

Packing –Ensure appropriate monomer/polymer ratio when mixing

66
 -keep jar closed after mixing

-pack at dough stage

-Pack enough dough into the mould

-used required pressure .

Processing –start curing from room temperature and do not exceed the required temperature.

b. Irregular colouring
Irregular colouring : flasking : Avoid excess cold mould seal.
Parking: ensure a homogenous mix of the dough before packing and mix in a dry clean
jaw.
Processing : ensure flask is closed with a metal to metal contact to avoid water from
slipping into the mould.
c. Raised bite 25marks
Raised bite :flasking –allow enough time for comlete setting of plaster before toping.
-Ensure metal to metal contact
Packing –Avoid excessive pressure or inadequate pressure
Pack at dough stage
Avoid over packing without enough pressure.
25marks

DENTAL MATERIAL SCIENCE DIVISION 4A

SECTION A
1. What is space lattice? 1mark
Space lattice is a three dimensional atomic arrangement within a crystalline material.
2. What is a crystalline structure? 2marks

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 Crystalline structure is a regular pattern of atomic arrangement in space and inter-atomic
distances and angles of the atoms in crystals.
3. Why are some metals classified as noble metals? 2marks
Because they are able to resist corrosion and tarnishing in the mouth.
4. List the ideal properties of dental materials 2marks
Any four ideal properties of dental materials are;
a. Dimensional stability
b. ease of manipulation
c. fitness for purpose
d. compatibility with other materials
e. cost etc
5. Define the Newton’s law of motion 2marks
Newton’s third law of motion states that to every action, there is an equal and opposition
reaction.
6. What is weld-decay? 2marks
Weld decay is corrosion of Stainless steel resulting from precipitation of chromium carbide
at the grain boundaries due to overheating.
7. Distinguish between activator and initiator in the polymerization of
acrylic resin. 2marks
Activator helps to break the initiator component into free radical. This could be heat or
chemical. While initiator is the component whose free radicals initiate polymerization
reaction. E.g. Benzoyl peroxide.
8. give the chemical formal of the following
a. water glass - Na2SiO3
b. Rochelle salt -KNaCH4O6
c. Borax - Na2B4O7. 10H2O
d. Kaolin (china clay) – Al2O3.2SiO2.2H2O 4marks
9. define the following:
a. Eutectic alloy

Eutectic alloy is an alloy made up of or formed by metals that are mutually miscible in liquid
state but completely immiscible in solid state. E.g. AgSn.

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 b. Solid solution

Solid solution is alloy formed by metals that are mutually miscible (soluble) in both liquid
and solid state. E.g. Cu-Au.

c. Intermetallic compound

Intermetallic compound is an alloy formed by metals that are miscrible in liquid state and
have tendency to unite and form a definite chemical compound on solidifying. E.g. Hg3Ag3.

d. Dental flux. 4marks

Dental flux is a substance used to prevent formation of oxides or remove oxides as they form
during casting or soldering operation.

10. write short note on the following

a. Elastic limit

Elastic limit is the maximum load a material can absorb without permanent deformation. It is
the greatest stress which a material is capable of developing without any deviation from
proportionality of stress to strain (Hooke’s law).

b. Proportional limit

Proportional limit is the maximum load a material can absorb without permanent
deformation. It is the greatest stress which a material is capable of developing without any
deviation from proportionality of stress to strain (hook’s law).

c. Corrosion

Corrosion is the reaction between metal and its environment to form a metallic compound. It
could be a direct chemical attack or electrolytic corrosion.

d. Tarnishing

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 Tarnishing is the discolouration or loss of surface finish of metal.

SECTION B
1. a). list and discuss the factors that determine the setting time of P.O.P.
Factors that determine the setting time of P.O.P. include; mixing ratio, spatulation , water
temperature, shelf life and chemical modifier.
b). Explain the following terms:
i. Hygroscopic expansion
Hygroscopic expansion is the additional expansion of investment material (especially
gypsum bonded), when immersed in water before the initial setting.
ii. Thermal expansion
Thermal expansion is the increase in size, especially of investment materials when subjected
to high temperature. This helps to compensate for thermal contraction of the alloy being cast.

iii. Setting expansion

Setting expansion is the increase in size of a material. e.g. investment or model material due
to interlocking of crystals, which thrust outwards during setting process.

iv. Inversion change 25marks

Inversion change is a change of allotropic forms of silica (crisobalite & quartz)

from alpha to beta form when subjected to high temperature.

2. a). Mention all types of gypsum products.

i. impression or soluble plaster
ii. plaster of Paris.
iii. Type 1 dental stone
iv. High strength dental stone
b). Briefly explain the production of P.O.P

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 P.O.P is produced by heating calcium sulphate dehydrate in open kettle to a temperature of
110oC to 120oC unit three quarter of its water of crystallization is given up leaving irregular
particles of beta hemihydrates in the pan.
Chemical modifiers are added and ground.
110-120.C
CaSO4-heat – CaSO41/2H2O+11/2H2O.
c). State the compositions and uses of dental stone. 25marks
Composition of Dental Stone
-CaSO4
-K2SO4
-Colouring agent
-Borax
Uses of Dental stone
i. Model making
ii. Making overcast during repair of dentures
iii. As component of investment material
3. a). list the various types of modeling materials.
Modeling materials include,
i. Dental stone (type I & II)
ii. Plaster of Paris
iii. Epoxy resin.

b. State the constituents of blue inlay wax.

Blue inlay wax is compound of paraffin wax, ceresin wax, carnauba wax Bees wax

c. What are the ideal properties of modeling wax? 25marks

Ideal properties of modeling wax

i. It must be easy to manipulate

ii. It must be easy to soften and adapt to model
iii. It must be easy to boil out from the mould
iv. It must have colour contrast with model material
v. It must possess adequate shelf life.

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 vi. It must not soften or distort at mouth temperature etc.
4. write short notes on the following
a. Syneresis and Hysteresis

Syneresis is a phenomenon in which hydrocolloid impression material exudates water or

shrink slightly when exposed to dry atmosphere.

Hysteresis is a time-temperature lag during the cooling of reversible hydrocolloid from sol to
gel.

b. Gelation and Solation

Gelation is the conversion of a colloidal system from sol (semi flud) to gel ( semi solid) by
reduction in temperature.

Solation is the conversion of a colloidal system from gel to sol by application of heat.

c. Rigidity and Elasticity

Rigid materials have high modulus of elasticity.

Elasticity is the ability of a material to return to its original shape after applied load

has been removed.

d. Soldering and Welding 25marks

Soldering is the joining of two metals by fusion of an intermediary alloy (solder) of lower
temperature than that of metals being joined.

Welding is the joining of two metals by combination of heat and pressure without using
intermediary material.

5. a). State 10 requirements of an investment material.

b). State 10 requirements of an impression material. 25marks

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 GENERAL PAPER – DIVISION 4A
SECTION A
1. Mention the act establishing the board (DTRBN). 2marks
Cap D6 of 2004 formerly decree 43 of 1987
2. What is the relationship of Nigeria with W. H.O AND ECOWAS? 2marks
Nigeria is an active member of ECOWAS and WHO, she is also a major provider of
manpower to the organization.
3. What is the different between D.T.R.B.N and A.D.T.N. 2marks
DTRBN is the registration Board, regulates the training and practice of dental technology in
Nigeria. It is government agency, while the association of Dental technologist of Nigeria is a
pressure group made up of dental technologist that works in unity for the benefit of the
profession and its members.
They can protest against government policies that are not favourabl to them in terms of
remuneration, working condition etc.
4. What are the factors to be considered when locating an industry 4marks
factors are:
a. Nearness to source of raw material
b. Nearness to market/ end users
c. Accessibility of labour
d. power supply
e. accessibility (ease of transport)
5. What is scale of preference in economics? 2marks
Scale of preference in economical is a list of goods and services prepared for purchase in
order of priority rating of all individual wants.
6. How many senators do we have in the National Assembly? 2marks
109 senators.
7. Who is entrepreneur? 2marks
An entrepreneur is person who organizes and operates a business venture and assumes much
of the associated risk for productive reason.

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8. Write short notes, on the following
a. Invoice

Invoice- a commercial document issued by a seller to buy indicating the products, quantities
and agreed prices for products or services that the seller has already provided.

b. Delivery Note

Delivery note is a simple document used to check the authorized quantity of goods being
carried away from the store room. It is usually issued by the supplier of goods as a record or
evidence of goods supplied.

c. Requisition Book
Requisition Book is an office with a pre- printed format for making a formal request for
something e.g. office supplies etc. it is an internal document used by departments to
request for material.
d. Quotation

Quotation- quoted price of goods or services. A statement of how much money a particular
piece of work or service will cost.

e. Local purchase order. 5marks

Local purchase order is an official document for the purpose/supply of goods and services at
a fixed price and within a given period of time. It can be used as a document to secure bank
loan.

9. What is the difference between Limited Liability Company and public liability
company? 2marks
Limited Liability Company is owned by an individual while public liability company is a
public government company though not all PLC are government owned. The PLC is also
opened to the public in that everybody can buy shares of the company and become part of the
company while LLC is not open to the public and has a limited number of shareholders.
10. Define Demand and Supply 2marks

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 Demand is the amount of goods and services that consumers are willing and able to buy at
given prices and given time.

SECTION B
1. Write short notes on the following:
a. Communicable disease

Communicable disease is a disease that can be easily transmitted between species or people
by direct contact with affected person or the person’s discharge or indirect means by vectors.

b. Non-communicable disease

Non-communicable disease is disease that cannot be easily transmitted.

c. Endemic disease

Endemic disease –Denoting a temporal pattern of disease occurrence in a population in

which the disease occurs with predictable regularity with only relatively minor fluctuation in
its frequency over time. That is to say a prevalent disease in a particular area or region.

d. Pandemic disease

Pandemic disease – Epidemic over a wide geographical area and affecting a large proportion
of the population at a frequency higher than that expected in a given time period. This is also
to describe outbreak of disease in humans.

e. Epidemic disease

Epidemic disease – A widespread of disease that affects many individuals in a population.

An occurrence of a disease or disorder in a population at a frequency higher than that
expected in a given time period. This is also used to describe outbreak of disease in humans.

2. a). what is primary Health Care?

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 Primary health care (PHC) Refers to essential health that is based or scientifically sound and
socially acceptable methods and technology made universally accessible to individuals and
families in the community through their full participation and at cost which the country can
afford to maintain at every stage of their development in the spirit of self-reliance and self-
determination. PHC services are provided by professionals’ usually general practioners and
nurses in the community.
b). what are the objectives of PHC
i. to make health services accessible and available to everyone wherever they live or work.
ii. To ensure that whatever technology is used, it must be within the ability of the community
to use effectively and maintain.
iii. To tackle the health problems causing the highest mortality and morbidity at a cost that
the community can afford.
iv. To ensure that in implementing the health programmers the community must be fully
involved in planning the delivery and evaluation of the services in the spirit of self-reliance
(WHO 1987)
c).list the various health care systems in Nigeria.
i. Primary health care
ii. Secondary health care
iii. Tertiary health care
iv. private health care providers
d). what are the functional

Health care system in Nigeria and their functions.

i. Primary health care is provided through health clinics and dispensaries scattered
throughout the country.
ii. Secondary health care is dispensed through health care centres and maternity centres.
iii. Tertiary health care is handled through the university teaching hospital.
iv. private health care providers: Nigeria operates a mixed economy, thus private
providers of health care play a significant role in health care delivery

3. a). what are the obligations of a citizen to his/her country?

76
 Citizens obligation to his/her country
i. To submit to the constitutional order.
ii. To take part in the national defence if they are male and 16-60 years of age.
iii. To take care of their children and family members in need of assistance.
iv. To be a responsible steward of their living environment and natural environment and
to redress damage done to the environment.
b). what are your obligations to the profession?
i. to hold paramount the safety, health and welfare of the public (patient).
ii. To make a point of honour to advance the profession by all legitimate methods, by
supporting its institutions and programmes and observing its rules and regulations.
iii. to conduct myself honourably, responsibly, ethically and lawfully so as to enhance the
honour, reputation and usefulness of the profession.
iv. I should not knowingly or recklessly lend name, title or licence to any other person for use
as a Dental technologist.
v. I shall not delegate any service or operation which requires the personal/professional
competence of the dental Technologist to a person not authorized by law to do so.
vi. To perform services only in area of their competence.
c).explain the duties of the Board (DTRBN) to the members of dental technology
profession.
4. a). who is a Dental Technologist?
A dental technologist is a person who by his education, qualification and experience is
qualified to engage in practice of construction and re-construction of dental prostheses and
other acts as by universally acceptable customs as performed by those in the profession.
b). Discuss the duties of the Board (DTRBN) to the members of Dental Technology
profession.
Importance of Dental Technology in medical profession.
i. Oral and maxillofacial Dentistry: Dental technology deals with replacement of
missing facial structures such as obturators for palatal defects, ocular and auricular
prostheses, skeletal plate for jaw reconstruction, and feeding plate for cleft palate.
ii. Prosthetic Dentistry: Design fabrication of crowns and implant supported
crowns/bridges.

77
 iii. Orthodontic dentistry: Design and fabrication of orthodontic appliances such as habit
breakers, space maintainers, space retainers.
iv. Gynecology: construction of vaginal mould.

5. a). What is corruption?

b). Mention 5 corrupt practices

c. List ways that can be used to curb corrupt practices

ANATOMY AND PHYSIOLOGY DIVISION 4A

SECTION A

1. Draw and label the occlusal surface of lower left 1st permanent molar 2marks
Correction diagram showing the five cusps (bucally and 2lingually)
2. Define mastication and deglutition 2marks
Mastication is the act of chewing food preparatory to swallowing and digestion.
Deglutition is the act of swallowing chewed food for digestion.
3. Where can development grooves and marginal ridges are found in the mouth?
Lingual surface of an anterior tooth. Developmental groove can also be seen on occlusal
surface of the posterior
4. list muscles of mastication 2marks
i. Masseter
ii. Temporalis
iii. Medial pterygoid
iv. Lateral pterygoid
5. At what age will the eruption of the following teeth occur 21a a12
21a a12 3marks
a a - 6-7months, 1 1 - 6-7years, 2 2 - 8-9months 2 2 9-10month
a a 1 1

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6. What are the component parts of TMJ? 2marks
bones: – Temporal bones, condyle of mandible,glenoid fossae, articular eminence.
ligaments:- Articular disc, tempromandibular ligament, sphenomandibular ligament and
styomandibular ligament.
7. explain the following terms associated with anatomical description:
a. Median –

median-centre of a structure

b. Mesial

mesial –an aspect towards or nearer to the midline.

c. Distal

Distal –an aspect away from the midline

d. Proximal

Proximal –an aspect that is in close proximity with another part.

e. labial

Labial –aspect of a tooth touching or facing the lip.

f. lingual 4marks

Lingual – aspect of a tooth facing the tongue.

8. List 3 muscles of the tongue. 2marks

Muscles of the tongue: hyoglossus, styloglossus, transverse, Longitudinal, etc.
9. Name three factors that affect the proper development of human teeth 2marks
Congential factor, hereditary, pathological, Physiological factor.
10. Mention 2 muscles of facial expression 2marks
Muscles of facial expression, buccinators, frontalis, orbicularis oris, orbicularis oculi.
11. What is freeway space in relation to human dentition? 2marks

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 freeway space is an interocclusal clearance or a space between the surface of maxillary and
mandibular teeth, when the facial muscles are at rest.

SECTION B
1. a). What is cleft lip?
cleft lip is a fissure or groove in the lip due to inability of the embryonic facial process to
fuse or merge completely.
b). Discuss the factors that could be responsible for such deformity 25marks
discuss the following factors: Genetic factor, environmental factor, lack of folic acid during
pregnancy, smoking by pregnant mother, alcohol consumption, obesity and nutrition,
medication during pregnancy.

2. a). Enumerate the component of blood

Blood cells;- Red blood cell, White blood cells, and Platelets.
b). Mention 5 types of tissue
Types of tissue:-Epithelial, connective, nerve, and bone tissue
c). Draw and label Human cell 25marks
3. a). What is an incompetent lip?
Incompetent lip describes a situation where a lip seal cannot be produced when the facial
muscles are at rest and relaxed.
b). with the aid of diagram, discuss the three facial profile attributed to human being.
Facial profile is the outline form of the face from the lateral or sagittal view.
The three facial profiles attributed to human being;
i. Mesognathic or straight facial profile which has relatively flat appearance.
ii. Retrognathic or concave facial profile with prominent mandible and retruded maxilla.
iii. prognathic or convex facial profile with prominent maxilla and retruded mandible.
4. a). What are the classifications of permanent dentition?
Permanent teeth are classified as following
i. Maxillary
ii. Mandibular
iii. Anterior teeth

80
 iv. Posterior teeth
v. Succedaneous teeth
vi. Non- Succedaneous.
b). with the aid of diagram discuss:
i. Class I jaw relationship
class I jaw relationship is the type of jaw relationship in which the buccal cusps of upper
posteriors are located bucally to the buccal cusps of lowers with an anterior overjet and
overbite of about 1-2mm. The mesiopalatal cusp of upper first molar occluded with the
mesial groove of the lower first molar.
This class is also regarded as normal occlusion.

ii. Class II jaw relationship

Class II jaw relationship is an inferior retrusion or superior protrusion in which the upper jaw
is excessively forward of normal jaw relationship. It may be due to upper jaw being larger
the normal or the lower jaw being smaller than normal.
iii. Class III jaw relationship
Class III jaw relationship is a jaw relationship in which the lower is excessively forward of
the upper jaw, a condition known as inferior protrusion
c. what is incisal guidance angle? 25marks
Incisal guidance angle is the angle formed with the horizontal plane by drawing a line in the
sagittal plane between incises edges of maxillary and mandibular central incisors when the
teeth are in centric occlusion.

5. Draw and label the anatomical features in an open mouth

Antomical feature of open mouth with diagram; incisive papilla, frenal attachment, upper
alveolar ridge, rugae, palatal torus, hard palate, palatal fovea, soft palate, uvula, retromolar
pad, sulcus. lower alveolar ridge and tongue.
b). Discuss how the movement of the jaw is effected at the T.M.J. 25marks
Jaw movement results from the attrition of muscles of mastication. At the TMJ, the
movement of the jaw is effected as follow;

81
 i. Protrusion and retrusion- effected by gliding at both upper and lower synovial cavities
ii. Depression and protrusion (opening) - effected by gliding in both upper synovial
cavities and rotation in both lower synovial cavities.
iii. Elevation and retraction (closing) - same as for opening.

DENTAL MATERIAL SCIENCE - DIVISION 4B

SECTION A
1. Name the liquid and powder used in methyl methacrylate. in what
proportion should they be used? 2marks
liquid- monomer (methyl methacrylate) Power- polymer (polymethyl methacrylate). the
liquid- powder ratio of 1:3 is used.
2. give four proerties required of an ideal material for use in the
construction of the base of a bite block. 2marks
Biocompatibility, Stability, Ease of Manipulation, Cost effective, readily available, good
shalf life.
3. why is it necessary to mix plaster of paris in a clean bowel? 2marks
To prevent the introduction of im,prurities which can act as inibitors or accelerators.
4. State one use of sodium citrate in the dental laboratory 2marks
Plaster removal from finished acrylic resin work.
5. what is meant by the term “carat” 2marks
Quantity of gold in an alloy in a percentage.
6. What is a space Lattice? 2marks
Space lattice is the arrangement of atoms in a crystal.
7. Name the principal constituent of an irreversible hydrocolloid. 2marks

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 Sodium Alginate
8. what is meant by the term “yield point” 2marks
The point at which a material gives way following a constant application of force
9. state two causes of Weld decay in a stainless steel joint 2marks
Prolonged heating

10. what is crazing 2marks

Minute cracks in processed acrylic work due to contact with solvents or stress.
11. Give 2 examples of a polishing material. 2marks
Tripoli, whiting, rouge.
12. What is meant by the term Modulus of Elasticity 2marks
Stress/ strain relationship of a material.

SECTION B
1. Describe the physical and mechanical tests that may be carried out to ascertain
suitability of an alloy for use in partial denture constructions. 25marks
Physical – melting point, colour, conductivity, luster, density.
mechanical – Rigidity, ductility, malleability, tensile strength.
2. What are the constituents and physical properties of
a. dental base plate
b. inlay wax
c. Sticky wax 25marks
3. Explain the theory of electrolytic corrosion. How can this corrosion minimized.
Electrolytic setup in the mouth, saliva as electrolyte and dissimilar electrodes e.g. Amalgam
fillings and non-precious alloy shell crowns, and the anodic electrolyte degrade. To
minimize-use of precious metals, use of similar metals use of non-metallic restorations like
composite, acrylic and flexite.
4. Discuss the reasons for the presence of internal strains in an acrylic denture. 25marks
Reason for internal stress.
5. describe the principle and materials for

83
 a. Abrasion.
b. Polishing.
Principles – pressure, particles size, speed, hardness.
Materials; abrasion e.g. pumice, emery, sandpaper, tungsten carbide, carorundum, corundum.

GENERAL PAPER –DIVISION 4B

SECTION A

1. State the freezing and boiling point of water in degree centigrade and degree
0oC =32oF, 100oC=212oF
2. What is meant by the PH of a solution? 2marks
Potency of hydrogen in a solution is the alkalinity or acidity of a solution.
3. define the term “Osmosis” 2marks
Movement of solvent molecules usually water from are of low concentration to area of higher
concentration through a semi permeable membrane.
4. what is the difference between Hard and Soft
2marks
Hard –presence of CaCO3, does not later easily.
Soft –absence of CaCO3 Later easily.
5. what is the different between the term Anode and Cathode 2mark
Anode is the positively charged electrode. Attracts anion which are negatively charged ions
Cathode is the negatively charged electrode. Attracts cations which are positively charged
ions.

84
6. what part of a gas air blow torch flame should be used in melting gold 2marks
Blue flame is known as the reducing zone.
7. What is the difference between exothermic and endothermic reaction? 2marks
Exothermic reaction gives out heat while endothermic absorbs heat.
8. What is the theme of 2015 National conference/AGM of the ADTN held in calabar?
Entrepreneurship as a new approach to the practice of Dental Technology Profession in
Nigeria.
9. What is opportunity cost? 2marks
Opportunity cost is the foregone alternative.
10. What are the different between EFCC and ICPC? 2marks
EFCC- Economic and financial crime commission
ICPC- independent corrupt practices and other related offences commission.

11. What is global warming 2marks

Global warming is the general increase in atmospheric temperature resulting from depletion
of the ozone layer, the greenhouse effect,
12. Who is the president of Nigeria senate? 2marks
Senator Bukola Saraki

SECTION B
1. Write short notes on:
a. Genetic engineering

Genetic Engineering (genetic modification) set of technologies used to change the genetic
makeup of cells, including the transfer of genes within and across species boundaries to
produce improved organisms.

b. Infection control

Infection control is the prevention of disease transmission from one point to another.

85
 This includes prevention of cross infection.

c. Occupational Hazard
d. Proforma Invoice
Proforma Invoice is a document issue to an intending buyer/ customer stating the
goods/services, the price and items and conditions of the transaction.
2. Discuss the background of the following qualifications:
a. City and Guild of London (part I&II)
b. CDT (Intermediates and final )
c. RDT
3. Entrepreneurship: A new approach to the practice of Dental Technology professionin
Nigeria. Discuss.

4. What is business Plan?

Business plan is a written document that describes in detail how a new business is going to
achieve its goals. A business plan will include written plane from a marketing, financial and
operational view point. Sometimes it is prepared for an existing business that is moving in a
new direction.
Discuss ways by which a dental technologist can generate business ideas.
i. Fabrication of dental prosthesis and appliance for clinics and patients.
ii. Marketing of dental material and equipment.
iii. Manufacturing of dental material and equipment.
5. Discuss the penalties that are available for unprofessional conduct as provided by the
code of ethic of Dental Technology profession.

ORAL ANATOMY AND PHYSIOLOGY DIVISION 4B

86
 SECTION A (TRUE OR FALSE QUESTIONS)
1. the synonymous term for free way space is inter-occlusal clearance 2marks
2. the record of the position of the patient’s maxillary ridge in relation to the condyles is
the face bow record 2marks
3. The reciprocal guidance of the mandibular and maxillary anterior teeth is called incisal
guidance. 2marks
4. Edentulous areas are resorbed in proportion to the amount of time the teeth have being
missing. 2marks
5. Border molding of the impression prevents the muscle of tongue from dislodgram the
denture. 2marks
6. The edentulous arch form bears a direct relation to the contour of the face. 2marks
7. The posterior extensions of the impression for a lower denture may not go beyond the
mylohoid muscle attachment line.
8. The loss of maxillary central incisors cause the greatest damage in facial expression.
9. An increase in vertical dimension may cause the greatest damage in facial expression
10. The external oblique ridge governs the extension of the buccal flange of denture
11. Nature may close the bite with a gradual wear of the natural teeth 2marks
12. The resorption of the edentulous alveolar process is a continuing physiological activity.

ANSWERS TO SECTION A
1. True
2. True
3. True
4. True
5. True
6. True
7. False
8. False
9. True

87
10. False
11. True
12. True

SECTION B
1. how do the following structures influence the design of full/full denture in order that
good retention and Stability may be enhanced:
a. Torus palatinus
b. Frenal attachments
c. Sulci
d. Tongue
2. with the aid of a well label diagram describe the muscles of facial expressions
3. describe the Temporomandibular joint the disorder of this joint sometimes treated by
bite raising. What does this means?
4. write short note on the following
a. Mylohyoid Ridges

mylohyoid ridges are ridges on the lingual surface of the mandible that extends at an angle
from the level of the roots of the last molar to the floor of the mouth and serves as the origin
of the mylohyoid muscle.

b. Cusp of carabelli
c. Cusp of calabelli- found at the mesiopalatal cusp of upper first permanent molar.
d. skull
e. mandible

Mandible is the lower jaw bone that forms the lower part of the skull, along with the maxilla
to form the mouth structure. The movement of the lower jaw open and closes the mouth and
also allows for the chewing of food. The lower set of the teeth in the mouth is rooted in the
lower jaw.

88
5. describe the relationship between condylar angle, occlusal plane, incisal guidance, and
cusp height in relation to the arrangement of teeth.

Incisal guidance angle is angle formed by intersection of plane occlusion and line within
sagittal plane determined by incisal edges of upper and lower incisors when teeth are in
maximum intercuspation. Or the influence of the contacting surfaces of the upper and lower
anterior teeth during mandibular movements.
Condylar guidance is due to path followed by condyle in TMJ obtained by protrusive
registration record. The more the condylar height the more will be the cuspal height.

DENTAL LABORATORYTECHNIQUE- DIVISION 4

SECTION A
1. The aesthetics of an artificial denture begins in the …………………
a. selection of teeth
b. positioning of the teeth
c. finishing Denture
d. impression
2. The impression tray must allow space to ensure a workable thickness approximately.
a. 2mm
b. 4mm
c. 6mm
d. 8mm
3. The area of primary stress in a maxillary denture is on the:
a. Ridge
b. Hard palate
c. Border Area

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 d. Muscle Area
4. The most important disadvantage of acrylic resin denture base is ………
a. Shrinkage
b. Porosity
c. Tooth breakage
d. Water absorption
5. Artificial teeth are best selected from the ………………………….
a. Shape of the face
b. Size of the arch
c. Age of the patient
d. Pre-extraction record
6. The most important factor in the arrangement of teeth is ………………..
a. Mould
b. Leverage
c. Occlusion
d. Occlusion plane
7. The failure of patient to wear artificial denture is mainly caused by ………
a. Lack of patient’s co-operation
b. Faulty construction
c. Irritation of tissue
d. None of the above
8. Loss of several teeth may result into …………..
a. Change in facial contour
b. T.M.J Disturbance
c. Periodontal disturbance
d. All of the above
9. The support of partial denture is usually……….
a. Tooth support
b. Mucosa
c. Occlusal rest support
d. Tooth and mucosa support

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10. One of the most important factots in maintaining stability of artificial denture is
proper……..
a. Occlusion
b. Articulation
c. Selection of teeth
d. Adaption of denture to the tissue
11. Failure of fixed partial prostheses to seat after being soldered is most likely related to…
a. Lack of parallelism between abutment
b. Dimensional change in soldered mass
c. Temporary restoration that failed to maintain proper tooth position
d. Failure to position retainers correctly before soldering
12. An advantage of rubber base impression material over reversible hydro colloid
material is that it……..
a. Will displace soft tissue
b. Will reduce necessary armamentarium
c. Is significantly more accurate
d. Is more accurate if saliva, mucosa and blood are present.

ANSWERS TO SECTION A
1. D
2. B
3. A
4. A
5. D
6. C
7. B
8. E
9. D
10. D
11. D
12. B

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 SECTION B
1. Using Zinc oxide impression as wash, describe the method of repairing a midline
fracture of an ill-fitting full upper acrylic denture. Give reasons for each step you
mentioned. 25marks
2. Dimensional change occur in metal during casting. How may they be compensated?
3. Give a detainled account of how you would replace 1 2 by immediate technique using
stock teeth ready for processing. 25marks
Receive impression, inspect and disinfect impression, mix stone and water, pour the model
material in the proper consistency, vibrate to avoid blow holes, allow it to set and remove the
model, select the correct shade and size of the stock teeth, then prepare the model by
removing the teeth to be extracted carefully at the gingival level from the model, scrape the
area left by the tooth a little deeper to resemble a shallow tooth socket with an area 4-5mm
and 1mm depth, this is done so that the prepared denture will compress the extraction site
and act as a splint. The selected stock teeth are trimmed palatally for easy union with the
denture base material, the model is post dammed to create a posterior palatal seal, wax is
warmed and adapted on the model, the teeth are then setup, wax trimmed and stock teeth
adjusted properly for proper aesthetice and occlusion with the adjacent and opposing teeth,
contoured, smoothened and ready for processing.
4. Describe how you would cast a model from an alginate impression using boxing in
method. 25marks
On receiving the alginate impression in the laboratory, the impression is washed under
running water to get rid of saliva, blood stains and food debris after, disinfect by spraying a
solution of 10parts sodium hypochlorite: 1part water and left undisturbed for 5-10minutes.
Boxing wax or beading wax as they are called is commercially available usually white or
blue in colour, but in the absence of the beading wax. Modeling wax can be used as a
substitute. A 5mm strip of modeling wax is rolled on a flat surface. The wax strip should be
at least 13mm measured vertically from the highest point of impression.
The impression should be stabilized using soft wax to make its surface parallel to the floor,
for the lower impression, the tongue space should be covered with a U-shape pattern sheet of

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 wax. The beading wax is adapted 3-4mm below the height of contour of the impression
flanges with an even width of at least 4mm around the impression. Additional thickness
should be added to the posterior regions of the mandibular impressions. A strip of boxing
wax about 15mm wide is heated and adapted around the beaded impression to form the base
of the model.
Dental stone is mixed to the proper consistency and poured into the boxed impression. When
set, the model is easily separated by peeling off the wax over extended borders of model base
trimmed to an appropriate level.
5. Describe with diagram, the method of obtaining copper plated die from a copper ring
impression. How will the copper plated die be located in the final impression to produce
a removable die? 25marks

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