Name: Retention, stability and support
Uploaded: 2021-12-10
Duration: 45 min 46 s
Description: Retention ,Stability And Support For Complete Denture.

retention stability support. Retention ,Stability And Support For Complete Denture. 

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Retention ,Stability And Support For Complete Denture

Psychological Comfort. Physiological Comfort. Longevity. 

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Objectives. By the end of this session the participants should be able to Define retention ,stability and support Determined the factors affecting. 

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By the end of this session the participants should be able to  Define retention ,stability and support  Determined the factors affecting

RETENTION Definitions The factors affecting the retention of complete dentures STABILITY Definitions Factors affecting the Denture Stability SUPPORT Definitions Type of support Areas of support factors affecting the Denture support. 

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RETENTION   Definitions The factors affecting the retention of complete dentures  STABILITY   Definitions Factors affecting the Denture Stability SUPPORT Definitions Type of support Areas of support factors affecting the Denture support

Compare denture retention, stability and support

Preservation of remaining alveolar ridges Support Stability Retention Esthetics. 

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Preservation of remaining alveolar ridges Support  Stability  Retention  Esthetics

The five objectives of complete denture impression as stated by Carl.O.Boucher in 1944 are

To provide adequate masticatory function To restore natural appearance To restore normal speech Comfort and preservation of supporting structure. 

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To provide adequate masticatory function   To restore natural appearance To restore normal speech  Comfort and preservation of supporting structure

Clinical Complete denture prosthodontics by  Dr.Moustafa  A  Hassaballa . P.no.1

1- It is the resistance of a denture to vertical movement away from the tissues foundation specially in a vertical direction 2- That quality inherent in the prosthesis acting to resist the forces of dislodgement along the path of insertion.. 

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1- It is the resistance of a denture to vertical movement away from the tissues foundation specially in a vertical direction  2-  That quality inherent in the prosthesis acting to resist the forces of dislodgement along the path of insertion.

BOUCHER Described retention as the most spectacular yet probably the least important of all complete denture objectives. This property may indeed be least important, it provides psychological comfort to patient.. 

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BOUCHER Described retention as the most spectacular yet probably the least important of all complete denture objectives.  This property may indeed be least important, it provides psychological comfort to patient.

The act of chewing of food . Adhesive nature of certain food. Gravity(in case of the upper denture). Surrounding musculature (cheeks ,tongue , soft palate) Prematurities in the occlusion when the dentures contact without food being present or during parafunctional activity .. 

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The act of chewing of food .   Adhesive nature of certain food.   Gravity(in case of the upper denture).  Surrounding musculature (cheeks ,tongue , soft palate)  Prematurities in the occlusion when the dentures contact without food being present or during parafunctional activity  .

The dislodging forces acting on a denture are:

1. Physical factors . 2. Anatomical factors. 3. Physiological factors. 4. Mechanical factors. 5. Biological factors .. 

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The factors affecting the retention of complete dentures

1. Physical factors . 2. Anatomical factors.                                                                                                                           3. Physiological factors. 4. Mechanical factors. 5. Biological factors .

Principles Of Complete Denture Retention. Physical. 

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Adhesion Cohesion Surface tension Atmospheric   pressure (peripheral seal) Gravity

Shape of the ridge  Undercuts Anatomy of the border tissues

1-viscosity and volume of saliva 2- Neuromuscular control

Balance Occlusion  Contour of the polished surfaces.

Principles Of  Complete  Denture   Retention

Springs Magnets  Denture adhesive micro valves

1. Physical factors. Adhesion Cohesion Surface tension Atmospheric pressure (peripheral seal) Gravity. 

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Adhesion Cohesion Surface tension Atmospheric pressure (peripheral seal) Gravity

Adhesion. The apparent force of attraction existing between dissimilar bodies in close contact Is the physical attraction of unlike molecules It act when saliva sticks to the denture base and the mucous membrane of the basal seat. 

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The apparent force of attraction existing between  dissimilar  bodies in close contact    Is the physical attraction of  unlike  molecules   It act when saliva sticks to the denture base and the mucous membrane of the basal seat

Effectiveness of adhesion depends on:-. Close adaptation of the denture base to the supporting tissue. The type of the saliva. Shape and surface of the denture bearing area . The direction of the displacing forces.. 

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Close adaptation of the denture base to the supporting tissue.                                                          The type of the saliva. Shape  and surface of the denture bearing area  . The direction of the displacing forces.

https tse4 mm bing net th id OIP QgZAsPJnyYMOWAJKFJtTwCVDw pid 15 1 P 0 w 300 h 300. 

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Cohesion is the physical attraction existing between  similar  bodies in close contact  Is a physical attraction of  like  molecules .

https tse4 mm bing net th id OIP QgZAsPJnyYMOWAJKFJtTwCVDw pid 15 1 P 0 w 300 h 300

Mucosa. Saliva. Adhesion Cohesion Adhesion. Denture. 

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Adhesion    Cohesion                                                                                                                 Adhesion

• Resistance to separation by the film of liquid between the denture base & the supporting tissues . • Dependent on the ability of the fluid to wet the rigid surrounding material. 

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• Resistance to separation by the film of liquid between the denture
base & the supporting tissues .
• Dependent on the ability of the fluid to wet the rigid
surrounding material

Interfacial surface tension  Is the tension or resistance to separation ,possessed by the film of liquid between two well –adapted surfaces

ADHESION Thin film of Saliva between the denture bearing area, and the denture base. COHESION Attraction of like molecules of saliva aiding in retention INTERFACIAL SURFACE TENSION Thin film of saliva resisting displacing forces, and little liquid-air interface. 

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ADHESION
Thin film of Saliva between the
denture bearing area, and the
denture base.
COHESION
Attraction of like molecules of
saliva aiding in retention
INTERFACIAL SURFACE TENSION
Thin film of saliva resisting
displacing forces, and little
liquid-air interface

ADHESION
Thin film of Saliva between the
denture bearing area, and the
denture base.
COHESION
Attraction of like molecules of
saliva aiding in reten tion
INTERFACIAL SURFACE TENSION
Thin film of saliva resisting
displacing forces, and little
liq uid-air in terfa ce

Factor affects the atmospheric pressure:- Perfect peripheral seal. Proper border molding. Selective pressure technique.. 

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Resist dislodging forces applied to denture The retentive force is directly proportional to the area covered by the denture base  Synder et al  :  have shown that a reduction in atmospheric pressure concomitantly reduces the amount of retention

Factor affects the atmospheric pressure:- Perfect peripheral seal.  Proper border molding. Selective pressure technique.

The peripheral seal is the positive contact of the entire perimeter of the denture base to the resilient tissues that outline the basal seat This includes the posterior palatal seal as well as all labial, buccal and lingual vestibules. 

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The peripheral seal is the positive contact of the entire perimeter of the denture base to the resilient tissues that outline the basal seat This includes the posterior palatal seal as well as all labial, buccal and lingual vestibules

Gravity. Gravity acts as retentive forces for the mandibular denture and a displaced for the maxillary denture when patient is in upright posture.. 

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Gravity acts as retentive forces for the mandibular  denture and a displaced for the maxillary denture when patient is in upright posture.

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Shape of the ridge Edentulous ridges are firm and regular and covered by firmly attached , dense mucoperiostem should be vertical ,parallel sides produces the best resistance to un stabilizing forces. 

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Shape of the ridge  Edentulous ridges are firm and regular and covered by firmly attached , dense mucoperiostem should be vertical ,parallel sides produces the best resistance to un stabilizing forces

Image007. Excellent prognosis. Image016. Good prognosis. 

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2 . Undercuts The contour of a cross-sectional portion of a residual ridge or dental arch that prevents the insertion of a dental Prosthesis Any irregularity in the wall of a prepared tooth that prevents the withdrawal or seating of a wax pattern or casting. 

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2 .  Undercuts The contour of a cross-sectional portion of a residual ridge or dental arch that prevents the insertion of a dental Prosthesis  Any irregularity in the wall of a prepared tooth that prevents the withdrawal or seating of a wax pattern or casting

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3.Anatomy of the border tissues The anatomy of the border tissues should be such that it is possible to develop a good denture flange ,the periphery of which can lie in contact with displaceable and elastic tissue. 

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3.Anatomy of the border tissues   The anatomy of the border tissues should be such that it is possible to develop a  good denture flange  ,the  periphery  of which can lie in contact with displaceable and elastic tissue

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Neuromuscular control Refer to the functional forces exerted by the musculature of the patient that can affect denture retention. 

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Neuromuscular control  Refer to the functional forces exerted by the musculature of the patient that can affect denture  retention

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The bilateral, simultaneous, anterior, and posterior occlusal contact of teeth in centric and eccentric positions. 

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Balanced occlusion  Contour of the polished surfaces.

The bilateral, simultaneous, anterior, and posterior occlusal contact of teeth in centric and eccentric positions

Intimate tissues contact ; obtainable by accurate impression Peripheral seale. posterior palatal seal is most important in maintaining seal on the maxillary denture lingual flange area. 

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Intimate tissues contact ; obtainable by accurate impression Peripheral seale.  posterior palatal seal is most important in maintaining seal on the maxillary denture lingual flange area

6.Aids to retention. Springs Magnets Denture adhesive micro valves. 

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Stability. Definition: The quality of a removable dental prosthesis to be firm, steady, or constant, to resist displacement by functional horizontal or rotational stresses Resistance to horizontal movement and the forces that tend to alter the relationship between the denture base and its surrounding foundation. 

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Definition: The quality of a removable dental prosthesis to be firm, steady, or constant, to resist displacement by functional horizontal or rotational stresses  Resistance to horizontal movement and the forces that tend to alter the relationship between the denture base and its surrounding foundation

Retention Residual ridge anatomy Residual ridge relationships Parallelism of the ridges Form and contour of the polished surface Stability of the denture base material Arch arrangement Occlusal plane Occlusal harmony Neuromuscular control. 

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Retention  Residual ridge anatomy Residual ridge relationships Parallelism of the ridges Form and contour of the polished surface Stability of the denture base material  Arch arrangement  Occlusal plane Occlusal harmony Neuromuscular control

The factors that contribute to denture stability include

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Support. The resistance to vertical movement or displacement of the denture towards the denture bearing area . The foundation area on which a dental prosthesis rests.. 

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The resistance to vertical movement or displacement of the denture  towards the denture bearing area .                                                                                                   The foundation area on which a dental prosthesis rests.

Complete denture support. The resistance to vertical movement of the denture base toward the ridge. 

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The surface of the mouth available for  support  of a denture or those areas of the maxillary and mandibular  edentulous ridges that are considered  best suited to carry the forces  of mastication when the denture are in function

The resistance to vertical movement of the denture base toward the ridge

Primary stress- bearing areas Secondary stress- bearing areas Relief areas Valves seal areas. 

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Primary stress- bearing areas  Secondary stress- bearing areas  Relief areas Valves seal areas

Based on clinical and histologic impression the dentist can categorize the denture bearing tissue into four areas

Secondary stress – bearing areas. Aras which by their histological make-up or by the nature of their inclined planes , resist lateral forces of occlusion and can also aid in resistance to vertical forces of occlusion. 

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Those area which are best suited to  resist vertical forces  of occlusion The  histological picture  is abase of  cortical bone protected  by  firmly attached tissue  which is of  sufficient thickness to form a cushion against the forces of occlusion

Aras which by their histological make-up or by the nature of their inclined planes , resist lateral forces  of occlusion and can also aid in resistance to vertical forces of occlusion

Valve seal areas. Area are those soft tissue border areas which the periphery of the denture must contact in order for the factors of retention to be effective Divided. 

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Are those areas which ,when  subjected to occlusal force  ,either   cause discomfort to the patient or instability of the denture and eventual resorption of support bone

Area are those soft tissue border areas which the periphery of the denture must contact in order for the factors of retention to be effective  Divided

Resistant border areas
1.
2.
3.
4.
5.
6.
7.
Labial frenum
Buccal frenum
Distobuccal arch
Pterygomandibular raphe
Retromylohyoid curtain
Alveolingual fold
Lingual frenum

Non-resistant border areas
8. Labial vestibule
9. •Buccal vestibule

Relief Areas Posterior Palatal Seal Valve Seal Areas Primary Stress- bearing Areas Secondary Stress- bearing Areas Fig. 8.6 Classification of the denture-bearing tissues (Denture Foundation).. 

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Relief
Areas
Posterior Palatal Seal
Valve Seal Areas
Primary
Stress-
bearing
Areas
Secondary Stress-
bearing Areas
Fig. 8.6 Classification of
the denture-bearing tissues
(Denture Foundation).

Areas of support:. Anatomy of edentulous maxilla Primary stress bearing area: Horizontal portion of had palate Secondary stress bearing area: ridge crest (2). Non stress bearing area ridge slopes wc—. 

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Anatomy of edentulous maxilla
Primary stress bearing
area:
Horizontal portion of had
palate
Secondary stress bearing
area:
ridge crest (2).
Non stress bearing area
ridge slopes
wc—

Anatomy of edentulous Mandible Primary stress bearing area: buccal shelf & retromaolar pad Secondary stress bearing area Residual ridge & genial tubercles (2) Non stress bearing area Labial and lingual inclines. 

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Anatomy of edentulous Mandible
Primary stress bearing area:
buccal shelf & retromaolar
pad
Secondary stress bearing
area
Residual ridge & genial
tubercles (2)
Non stress bearing area
Labial and lingual inclines