The document discusses factors that contribute to the stability of complete dentures, including retention, stability, and support. Stability specifically refers to the denture's ability to withstand horizontal forces and resist displacement. Key factors that affect stability include the quality and height of the residual ridge, accuracy of the impression, orientation of the occlusal plane, arrangement of teeth, and contour of the polished surfaces. An optimal outcome relies on incorporating retentive, stabilizing, and supportive features into the prosthesis.

1. STABILITYSTABILITY
ININ
COMPLETE DENTURESCOMPLETE DENTURES
INDIAN DENTAL ACADEMY
Leader in continuing dental education
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2. INTRODUCTION:
A number of forces and factors combine to
retain complete dentures in the mouth, not all these
factors act at the same time, instead, some act only
when they are needed to meet or resist a certain
dislodging forces.
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3. The factors that include to retain complete dentures
in the mouth are
1}Retention
2}Stability and
3}Support
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5. STABILTY:
“It is the quality of denture to be firm,steady or
constant to resist displacement of functional stresses
and not to be subject to change of positions when
forces are applied”- G.P.T
It is the ability of the denture to withstand
horizontal forces.
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6. Factors affecting stability of the denture are:
Stability begins with an impression that does not
displace the tissue but depends primarily on the
following
1}vertical height of residual ridge
2}quality of soft tissue covering the ridge
3}quality of impression
4}occlusal rims
5)Arrangement of teeth
6)Contour of the polished surfaceswww.indiandentalacademy.comwww.indiandentalacademy.com

7. Vertical height of the residual ridge:
The residual ridge should have sufficient vertical
height to obtain good stability.
highly resorbed ridges offer the least stability.
the ridge should provide a firm soft tissue base
with adequate sub mucosa to offer good stability.
Flabby tissues with excessive sub mucosa offer poor
stability.
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8. Quality of impression
An impression should be as accurate as possible
The impression surface should be smooth and
duplicate all the detail accurately.
It should be devoid of voids and any rough surfaces
It should be dimensionally stable and should not wrap
on removal
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9. Occlusal plane: the occlusal plane should be oriented
parallel to the ridge.
If the occlusal plane is inclined,then the sliding forces
may act on the denture,reduce its stability.
The occlusal plane should divide interarch space
equally.
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10. teeth arrangement:teeth arrangement:
The position of teeth and their occlusion play anThe position of teeth and their occlusion play an
important role in the stability of the denture.important role in the stability of the denture.
Balanced occlusion facilitates the even distributionBalanced occlusion facilitates the even distribution
of forces across the denture.of forces across the denture.
Absence of balanced occlusion may produceAbsence of balanced occlusion may produce
unbalanced forces on any one slide of the dentureunbalanced forces on any one slide of the denture
leading to loss of stability.leading to loss of stability.
teeth in the denture should be arranged in theteeth in the denture should be arranged in the
neutral zone.neutral zone.
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11. Contour of polished surface:
The polished surfaces of the denture
should be harmonious with the oral structures.
They should not interfere with the action of the oral
musculature..
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12. SUPPORT
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13. Definition
The resistance to vertical forces of mastication,occlusal
forces and other forces applied in a direction towards the
denture bearing area.
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14. MECHANISM OF COMPLETE DENTURE SUPPORT
With complete dentures,the mucous membrane is forced to
serve the same purpose as periodontal ligament that provide
natural teeth.
In order to provide good support,the denture base should
cover as much denture bearing area as possible.
This helps to distribute forces over a wide area.this ability of
the denture to distribute forces over wide areas due to an
increase in the denture base area is termed the SNOWSHOE
effect.
Confining the occlusal forces to stress bearing areas and
relieving the non stress bearing areas will aid to improve
support.
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15.  Optimum out come of complete dentureOptimum out come of complete denture
treatment depends upon the successfultreatment depends upon the successful
integration of the prosthesis with theintegration of the prosthesis with the
patients oral function plus psychologicalpatients oral function plus psychological
acceptance of the denture by the patient.acceptance of the denture by the patient.
 This is achieved by incorporatingThis is achieved by incorporating
retentive,stabilizing and supportiveretentive,stabilizing and supportive
features in the prosthesis.features in the prosthesis.
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