1
T. E. JACOBSON, D.D.S., AND A. J. KROL, D.D.S.
PRESENTED BY: DR. KALAIARASI.P (PART I PG)
GUIDED BY: DR. RUPAL SHAH (PROFESSOR & HOD)
DR. SANJAY LAGDIVE (PROFESSOR)
Contents 2
About the journal
About the Author
Abstract
Introduction
Factors affecting stability
Review of literature
Critical Evaluation
References
About the journal 3
The Journal Of Prosthetic Dentistry
Publisher- Elsevier
Pubmed Indexed journal
Year of publication- 1983
Volume – 49
Issue- 2
Page no- 166-172
About the Author 4
T. E. Jacobson, D.D.S.
Assistant Clinical Professor, Removable Prosthodontics
A. J. Krol, D.D.S.
Chief of Dental Services, Removable Prosthodontics
University of California, School of Dentistry, San Francisco,
Calif., and Veterans Administration Medical Center, San
Francisco, Calif
Abstract 5
The article has an unstructured abstract
Introduction 6
Complete denture stability is the resistance to horizontal
or rotational forces.
It differs from retention in that stability resists forces in the
horizontal plane whereas retention is the resistance to
vertical dislodging forces.
Stability ensures the physiologic comfort of the patient
while retention contributes to psychological comfort.
Factors 7
affecting Ridge
stability height
Base
Occlusal
adaptatio
factors
n
Stability
Residual
Neuromus
ridge
cular
relationshi
factors
p
Ridge height and conformation 8
Large, square, broad ridges offer a greater resistance to
lateral forces than do small, narrow, tapered ridges.
rounded irregularities of the residual ridge also con
tribute favorably to stability (alveoloplasty must remove
only bony spicules)
Square or tapered arches tend to resist rotation of the
prosthesis better than ovoid arches
The shape of the palatal vault contributes to stability as
limited by the length and angulation of the palatal ridge
slopes. A steep palatal vault may enhance stability.
Boucher* noted that stability is obtained by
incorporating the surfaces of the maxillary and
mandibular ridges, which are at right angle to the
occlusal plane.
*Boucher, C.: Complete denture impressions based on anatomy
of the mouth. J Am Dent Assoc 31:124, 1944.
Base adaptation 9
Friedman* describes the contacting of the labial
and buccal flanges with the labial and buccal
ridge slopes as critical factors contributing to
stability.
Adequate extension of the denture border to
contact maximum of the denture base with facial
and lingual ridge slopes.
Positive and intimate contact of the denture base
with the inclines of the ridges as limited by the
nature of the overlying soft tissues determines the
degree of stability attained
*Friedman, S.: Edentulous impression procedures for maximum
retention and stability. J PR~~THET DENT 214, 1957.
Residual ridge relationship 10
A problem of stability is the offset ridge relations seen in
prognathic and retrognathic patients.
Weinberg* recognizes the need to set teeth in crossbite
when the ridges are in a severe crossbite relation.
The Class III patient frequently displays a lower arch
anterior to the upper arch in centric relation. Sufficient
mandibular posterior occlusion must be developed so
that contact against the maxillary denture extends
posteriorly more than half the distance from the incisive
papilla to the hamular notch.
Without this contact the maxillary denture would tip
anterosuperiorly, traumatizing the maxillary anterior
ridge and loosening the maxillary denture.
Neuromuscular control 11
The musculature can facilitate stability in two ways.
First, the action of certain muscle groups must be
permitted to occur without interference by the
denture base so that they will not dislodge the
prosthesis during function or compromise stability.
Second, the dentist must recognize that normal
functioning of some muscle groups can be used to
enhance stability.
In 1933 Fish, wrote that “it is not so widely
understood that the actual shape of the whole of
the buccal, labial, and lingual surfaces can wreck
the stability of a denture just as completely as a
bad impression or wrong bite.”
Occlusal schemes 12
Regardless of the type of posterior tooth form or
occlusal scheme used, the dentures must be free
of interferences within the functional range of
movement of the patient”
Monoplane (Zero-degree teeth ) may reduce
horizontal forces by eliminating the inclined planes
introduced by the cusp angles of anatomic teeth.
Lingualised occlusion provide both a limited range
of excursive balance and a directing of forces to
the lingual side of the lower ridge during working-
side contacts
Review of literature 13
M.M.Devan in 1954 suggested the neutrocentric
concept of occlusion , which embodied
neutralization of cuspal inclines and centralization
of occlusal forces acting on the denture
foundation for improved denture stability.
Friedman in 1957 ,advocated adapting two layer
of 28 gauge casting wax on the crest of
mandibular ridge for relief and close contact of
custom tray in the rest of the area. In maxilla the
relief is given in the incisive papilla region and in
case of palatal tori only. Also drill a hole in the
centre of the tray for the escape of wash material.
14
Shanahan in 1962, suggested the dynamic
impression technique , where the trial denture base
constructed over the primary cast are loaded with
impression material and impression of tissue is
made by patient assisted movements and doctor
assisted movements . Later the patient is allowed
to use the tray for 2 days , allowing the impression
material to still flow and adjust in accordance with
patient’s tissues. This can help in proper extension
of tray and improved stability.
Beresin, V. E., and Schiesser, F. J.: The Neutral Zone in Complete and 15
Partial Dentures, ed 2. St. Louis, 1978, The C. V. Mosby Co
NEUTRAL ZONE
The neutral zone is that area in
the potential denture space
where the forces of the tongue
pressing outward are neutralized
by forces of the cheeks and lips
pressing inward. Since these
forces are dev eloped through
muscular contraction during the
v arious functions of chewing,
speaking, and swallowing, they
v ary in magnitude and direction
in different indiv iduals. In sev ere
resorbed ridges , working within
the neutral zone enhances
stability
Summary and conclusion 16
Both complete denture stability and retention are
essential in providing successful prosthetic
treatment.
The factors that contribute to these properties are
highly interrelated, and the constant interaction
between stability and retention often makes them
indistinguishable.
The factor of stability involve the tissue, occlusal,
and polished surfaces of the denture.
Care must be taken in the development of all
three of these surfaces to ensure optimal stability of
the final prosthesis.
Critical evaluation 17
Title: It is appropriate.
Abstract: It is non structured and lacks adequate
content.
Introduction: It is crispy and has addressed the
issue aptly.
Discussion: This section gave numerous take home
points but the order of tittles discussed is
haphazardly arranged .
References 18
Friedman, S.: Edentulous impression procedures for maximum retention and stability.
J PR~~THET DENT 214, 1957.
Boucher, C.: Complete denture impressions based on anatomy of the mouth. J Am
Dent Assoc 31:124, 1944.
Fish, W. E.: Using the muscles to stabilize the full lower denture. J Am Dent Assoc
Zlh2163, 1933.
Roberts, A. L.: Principles of full denture impression making and their application in
practice. J PROSTHET DENT 1:213,1951.
Edwards, L. F., and Boucher, C. 0.: Anatomy of the mouth in relation to complete
dentures. J Am Dent Assoc 29331,1942.
Shanahan, T. E. J.: Stabilizing lower dentures on unfavorable ridges. J PROSTHET DENT
12~420, 1962.
Lundquist, D. 0.: An electromyographic analysis of the function of the buccinator
muscle as an aid to denture retention and stabilization. J PROSTHET DENT 9:44, 1959.
Schiesser, Jr., F. J.: The neutral zone and polished surfaces in complete dentures. J
PROSTHET DENT 14:854, 1964.
Beresin, V. E., and Schiesser, F. J.: The Neutral Zone in Complete and Partial
Dentures, ed 2. St. Louis, 1978, The C. V. Mosby Co.
