WAX PATTERNS IN FPD
www.indiandentalacademy.com
Contents
• Introduction
• History
• Waxes
• Armamentarium
• Wax pattern fabrication
Coping fabrication
Wax pattern removal and evaluation
Proximal surfaces
Axial surfaces
Occlusal morphology
Margin finishing
• Conclusion
• References www.indiandentalacademy.com
INTRODUCTION
HISTORY
www.indiandentalacademy.com
WAXES
Dental waxes are organic polymers consisting
of hydrocarbons and their derivatives.
Molecular weight ranges from 400-4000
www.indiandentalacademy.com
Classification
According to origin
According to use and application
www.indiandentalacademy.com
ACCORDING TO ORIGIN
Natural Synthetic
- Mineral
- Plant
- Insect
- Animal
www.indiandentalacademy.com
ACCORDING TO USE AND &
APPLICATION
Pattern waxes Processing Impression
waxes waxes
www.indiandentalacademy.com
INLAY CASTING WAX
Composition
1. Paraffin-chief content
2. Gum dammar
3. Carnauba wax,Ceresin or Candelilla wax
4. Beeswax
5.Colouring agent
www.indiandentalacademy.com
www.indiandentalacademy.com
CLASSIFICATION
According to ANSI and ADA sp no 4
Type 1 a medium wax. Used for direct
technique.
Type 2 a softer wax.Used for indirect
technique.
www.indiandentalacademy.com
Properties
1. Flow: flow % requirements for ADA sp no 4
Type of inlay 30 37 40 45
wax Max Max Min Max Min Max
Type 1 --- 1.0 --- 20 70 90
Type 2 1.0 --- 50 --- 70 90
www.indiandentalacademy.com
2. Thermal properties
- Thermal conductivity
- Coefficient of thermal expansion
may expand 0.7% with an increase in
0
in temperature of 20 C
and contract as much as 0.35% when it is
cooled from 370 C to 250 C
- Average co-efficient of thermal expansion:
-6 0
350 x 10 /C
www.indiandentalacademy.com
3.Wax distortion
- Elastic memory
This can result from thermal changes,release of stresses
on cooling,time and temperature during storage etc.
Other desirable properties of inlay waxes include:
- Color
- Residue
ADA sp no 4 requires that the melted wax when
vaporized at 5000C shall leave behind no solid residue
in excess of 0.10% of the original weight of the
specimen.
www.indiandentalacademy.com
Armamentarium
• PKT waxing instruments (no 1 to no 5)
• No 7 wax spatula
• Laboratory knife with blade
• Sharp colored pencil (contrasting to wax)
• Sable brush
• Bunsen burner
• Inlay wax
• Occlusal indicator powder
• Die lubricant www.indiandentalacademy.com
www.indiandentalacademy.com
www.indiandentalacademy.com
WAX PATTERN FABRICATION
The following sequence is recommended:
1. Coping fabrication.
2. Wax pattern removal and evaluation.
3. Proximal surfaces.
4. Axial surfaces.
5. Occlusal surfaces.
6. Margin finishing.
www.indiandentalacademy.com
COPING FABRICATION
www.indiandentalacademy.com
WAX PATTERN REMOVAL &
EVALUATION
www.indiandentalacademy.com
PROXIMAL SURFACES
www.indiandentalacademy.com
AXIAL SURFACES
Emergence Profile
www.indiandentalacademy.com
OCCLUSAL MORPHOLOGY
Classification of occlusal arrangements
Cusp fossa Cusp marginal ridge
1. Location of occlusal Occlusal fossae only. Marginal ridges and
contact on opposing teeth. occlusal fossae.
2. Relation with opposing Tooth-to-tooth Tooth-to-two-teeth
tooth.
3. Advantages. Occlusal forces are directed Found in 95% of all adults.
parallel with long axis of the Can be used for single tooth
tooth. These forces are near restorations.
the center of the tooth,
placing very little stress on
the tooth.
4. Disadvantages. Rarely found in natural Food impaction and
teeth. Used when restoring displacement of teeth may
several contacting teeth and arise if functional cusps
teeth opposing them. wedge into a lingual
embrassure.
5. Application. Full mouth reconstruction. Most restorations in daily
practice
www.indiandentalacademy.com
www.indiandentalacademy.com
www.indiandentalacademy.com
www.indiandentalacademy.com
www.indiandentalacademy.com
WAXING TECHNIQUE
There are two wax added techniques for waxing
occlusal surface of restoration.
1st technique given by E.V. Payne
H.L. Lundeen promoted the same technique using
wax of a different color for each of the features.
Usually associated with cusp-marginal ridge
occlusal scheme
2nd technique given by P.K. Thomas
Most often associated with cusp-fossae occlusal
scheme www.indiandentalacademy.com
CUSP MARGINAL RIDGE FOR MAXILLARY TEETH
www.indiandentalacademy.com
CUSP MARGINAL RIDGE FOR MANDIBULAR TEETH
www.indiandentalacademy.com
CUSP-FOSSA ARRANGEMENT
www.indiandentalacademy.com
www.indiandentalacademy.com
MARGIN FINISHING
www.indiandentalacademy.com
WAXING FOR ANTERIOR TEETH
www.indiandentalacademy.com
Wax pattern for the functionally
generated path technique
www.indiandentalacademy.com
www.indiandentalacademy.com
SUMMARY & CONCLUSION
www.indiandentalacademy.com
REFERENCES
• Contemporary Fixed Prosthodontics. 3rd edition,
Rosensteil.
• Fundamentals of Fixed Prosthodontics. 3rd edition,
Herbert T. Shillenburg.
• Philips Science of Dental Materials. 10th edition,
Kenneth J. Anusavice.
• Restorative Dental Materials. 6th edition, Robert J.
Craig.
• Theory and Practice of Ceramo-metal restorations.
Mashiro Kuwata.
www.indiandentalacademy.com
• Periodontal considerations of crown contour. Perel
ML. JPD, 1971; 26: 627-630.
• Current controversies in axial contour design. Anthony
HL, Tjan. JPD, 1980; 44: 536-540.
• Crown contours and gingival response. Lee M.
Jameson, Willam Melone, JPD 1982; 47: 620-624.
• Emergence profile in natural tooth contour. Part 1,
Burney M. Croll, JPD 1989; 62: 4-10.
• Emergence profile in natural tooth contour. Part 2,
Burney M. Croll, JPD 1990; 63: 374-379.
www.indiandentalacademy.com
Thank you
For more details please visit
www.indiandentalacademy.com
www.indiandentalacademy.com
