Removable Partial Removable Partial DenturesDentures

LCDR Sean R. KellyLCDR Sean R. Kelly

USN, DCUSN, DC

Comprehensive DentistryComprehensive Dentistry

Removable Partial Removable Partial DenturesDentures

LCDR Sean R. KellyLCDR Sean R. Kelly

USN, DCUSN, DC

Comprehensive DentistryComprehensive Dentistry

PurposePurpose

“ “the preservation of that the preservation of that which remains and not the which remains and not the meticulous replacement of meticulous replacement of that which has been lost.”that which has been lost.”

- Muller DeVan (1952)- Muller DeVan (1952)

PurposePurpose

“ “the preservation of that the preservation of that which remains and not the which remains and not the meticulous replacement of meticulous replacement of that which has been lost.”that which has been lost.”

- Muller DeVan (1952)- Muller DeVan (1952)

GoalsGoals Eliminate diseaseEliminate disease

Preserve what remainsPreserve what remains

Establish or increase Establish or increase masticatory efficiencymasticatory efficiency

Develop and restore esthetics Develop and restore esthetics

Maintain or improve phoneticsMaintain or improve phonetics

GoalsGoals Eliminate diseaseEliminate disease

Preserve what remainsPreserve what remains

Establish or increase Establish or increase masticatory efficiencymasticatory efficiency

Develop and restore esthetics Develop and restore esthetics

Maintain or improve phoneticsMaintain or improve phonetics

RPD TerminologyRPD Terminology StabilityStability

RetentionRetention

RetainerRetainer

RPD TerminologyRPD Terminology StabilityStability

RetentionRetention

RetainerRetainer

RPD TerminologyRPD Terminology the quality of a prosthesis to be firm, the quality of a prosthesis to be firm, stable or constant and to resist stable or constant and to resist displacement by functional, horizontal, or displacement by functional, horizontal, or rotational stressesrotational stresses

that quality inherent in the denture that that quality inherent in the denture that resists the vertical forces of dislodgmentresists the vertical forces of dislodgment

any type of clasp, attachment, device, any type of clasp, attachment, device, etc., used for the fixation, stabilization, or etc., used for the fixation, stabilization, or retention of a prosthesis. retention of a prosthesis.

RPD TerminologyRPD Terminology the quality of a prosthesis to be firm, the quality of a prosthesis to be firm, stable or constant and to resist stable or constant and to resist displacement by functional, horizontal, or displacement by functional, horizontal, or rotational stressesrotational stresses

that quality inherent in the denture that that quality inherent in the denture that resists the vertical forces of dislodgmentresists the vertical forces of dislodgment

any type of clasp, attachment, device, any type of clasp, attachment, device, etc., used for the fixation, stabilization, or etc., used for the fixation, stabilization, or retention of a prosthesis. retention of a prosthesis.

IndicationsIndications Great edentulous spanGreat edentulous span

No posterior abutmentNo posterior abutment

Excessive ridge resorption Excessive ridge resorption

AgeAge

CostCost

IndicationsIndications Great edentulous spanGreat edentulous span

No posterior abutmentNo posterior abutment

Excessive ridge resorption Excessive ridge resorption

AgeAge

CostCost

IndicationsIndications Reduced periodontal support Reduced periodontal support of remaining teethof remaining teeth

Need for cross-arch Need for cross-arch stabilizationstabilization

Patient’s desire Patient’s desire

Physically or emotionally Physically or emotionally handicappedhandicapped

IndicationsIndications Reduced periodontal support Reduced periodontal support of remaining teethof remaining teeth

Need for cross-arch Need for cross-arch stabilizationstabilization

Patient’s desire Patient’s desire

Physically or emotionally Physically or emotionally handicappedhandicapped

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IKennedy Class I

Bilateral edentulous areas located Bilateral edentulous areas located posterior to the remaining natural posterior to the remaining natural teeth.teeth.

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IKennedy Class I

Bilateral edentulous areas located Bilateral edentulous areas located posterior to the remaining natural posterior to the remaining natural teeth.teeth.

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IKennedy Class I

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IKennedy Class I

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IIKennedy Class II

Unilateral edentulous area located Unilateral edentulous area located posterior to the remaining natural posterior to the remaining natural teeth.teeth.

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IIKennedy Class II

Unilateral edentulous area located Unilateral edentulous area located posterior to the remaining natural posterior to the remaining natural teeth.teeth.

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IIKennedy Class II

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IIKennedy Class II

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IIIKennedy Class III

Unilateral edentulous area with Unilateral edentulous area with natural teeth both anterior and natural teeth both anterior and posterior to it. posterior to it.

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IIIKennedy Class III

Unilateral edentulous area with Unilateral edentulous area with natural teeth both anterior and natural teeth both anterior and posterior to it. posterior to it.

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IIIKennedy Class III

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IIIKennedy Class III

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IVKennedy Class IV

Single, bilateral edentulous area Single, bilateral edentulous area located anterior to the remaining located anterior to the remaining natural teeth.natural teeth.

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IVKennedy Class IV

Single, bilateral edentulous area Single, bilateral edentulous area located anterior to the remaining located anterior to the remaining natural teeth.natural teeth.

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IVKennedy Class IV

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class IVKennedy Class IV

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class VKennedy Class V

An edentulous area bounded An edentulous area bounded anteriorly and posteriorly by natural anteriorly and posteriorly by natural teeth but the anterior abutment teeth but the anterior abutment (lateral incisor) is not suitable for (lateral incisor) is not suitable for support. support.

- O.C. Applegate (1960)- O.C. Applegate (1960)

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class VKennedy Class V

An edentulous area bounded An edentulous area bounded anteriorly and posteriorly by natural anteriorly and posteriorly by natural teeth but the anterior abutment teeth but the anterior abutment (lateral incisor) is not suitable for (lateral incisor) is not suitable for support. support.

- O.C. Applegate (1960)- O.C. Applegate (1960)

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class VIKennedy Class VI

An edentulous area in which adjacent An edentulous area in which adjacent teeth are capable of support for a teeth are capable of support for a FPD, but possible damage to the pulp FPD, but possible damage to the pulp might occur if crown preparation might occur if crown preparation were attempted. were attempted.

- O.C. Applegate (1960)- O.C. Applegate (1960)

Classification of partially Classification of partially edentulous archesedentulous arches Kennedy Class VIKennedy Class VI

An edentulous area in which adjacent An edentulous area in which adjacent teeth are capable of support for a teeth are capable of support for a FPD, but possible damage to the pulp FPD, but possible damage to the pulp might occur if crown preparation might occur if crown preparation were attempted. were attempted.

- O.C. Applegate (1960)- O.C. Applegate (1960)

Classification of partially Classification of partially edentulous archesedentulous arches ModificationsModifications

Kennedy referred to each additional Kennedy referred to each additional edentulous area, not each additional edentulous area, not each additional missing tooth, as a modification area missing tooth, as a modification area and included them in the and included them in the classification by the number of such classification by the number of such areas. areas.

Classification of partially Classification of partially edentulous archesedentulous arches ModificationsModifications

Kennedy referred to each additional Kennedy referred to each additional edentulous area, not each additional edentulous area, not each additional missing tooth, as a modification area missing tooth, as a modification area and included them in the and included them in the classification by the number of such classification by the number of such areas. areas.

Classification of partially Classification of partially edentulous archesedentulous arches ModificationsModifications

Classification of partially Classification of partially edentulous archesedentulous arches ModificationsModifications

Rules to govern the Rules to govern the classification systemclassification system Follows (vs precedes) extractionsFollows (vs precedes) extractions

If 3rd’s are missing & not to be If 3rd’s are missing & not to be replaced, then not consideredreplaced, then not considered

A 3rd molar used as an abutment is A 3rd molar used as an abutment is considered in the classificationconsidered in the classification

A 2nd molar not to be replaced is A 2nd molar not to be replaced is not considered in the classificationnot considered in the classification

Rules to govern the Rules to govern the classification systemclassification system Follows (vs precedes) extractionsFollows (vs precedes) extractions

If 3rd’s are missing & not to be If 3rd’s are missing & not to be replaced, then not consideredreplaced, then not considered

A 3rd molar used as an abutment is A 3rd molar used as an abutment is considered in the classificationconsidered in the classification

A 2nd molar not to be replaced is A 2nd molar not to be replaced is not considered in the classificationnot considered in the classification

Rules to govern the Rules to govern the classification systemclassification system The most posterior edentulous The most posterior edentulous area(s) always determine(s) the classarea(s) always determine(s) the class

Edentulous areas not determining Edentulous areas not determining the class are modifications.the class are modifications.

Extent of the modification is not Extent of the modification is not considered, only the numberconsidered, only the number

No modifications for a class IVNo modifications for a class IV

Rules to govern the Rules to govern the classification systemclassification system The most posterior edentulous The most posterior edentulous area(s) always determine(s) the classarea(s) always determine(s) the class

Edentulous areas not determining Edentulous areas not determining the class are modifications.the class are modifications.

Extent of the modification is not Extent of the modification is not considered, only the numberconsidered, only the number

No modifications for a class IVNo modifications for a class IV

Components of a RPDComponents of a RPD Major connectorMajor connector

Minor connector(s)Minor connector(s)

Indirect retainersIndirect retainers

RestsRests

Direct retainers (clasp)Direct retainers (clasp)

Denture baseDenture base

TeethTeeth

Components of a RPDComponents of a RPD Major connectorMajor connector

Minor connector(s)Minor connector(s)

Indirect retainersIndirect retainers

RestsRests

Direct retainers (clasp)Direct retainers (clasp)

Denture baseDenture base

TeethTeeth

Components of a RPDComponents of a RPDComponents of a RPDComponents of a RPD

Components of a RPDComponents of a RPD Major connectorMajor connector

Connects the components on one side of Connects the components on one side of the arch to the components on the the arch to the components on the opposite side of the arch. It must:opposite side of the arch. It must:

- be rigid- be rigid

- provide vertical support- provide vertical support

- provide indirect retention- provide indirect retention

- protect soft tissue- protect soft tissue

- provide patient comfort- provide patient comfort

Components of a RPDComponents of a RPD Major connectorMajor connector

Connects the components on one side of Connects the components on one side of the arch to the components on the the arch to the components on the opposite side of the arch. It must:opposite side of the arch. It must:

- be rigid- be rigid

- provide vertical support- provide vertical support

- provide indirect retention- provide indirect retention

- protect soft tissue- protect soft tissue

- provide patient comfort- provide patient comfort

Components of a Components of a RPDRPDComponents of a Components of a RPDRPD Palatal major Palatal major

connector should be connector should be located at least 6mm located at least 6mm away from gingival away from gingival margins and parallel to margins and parallel to their mean curvature. their mean curvature. All adjoining minor All adjoining minor connectors should cross connectors should cross gingival tissues gingival tissues abruptly and should abruptly and should join major connectors join major connectors at nearly a right angle.at nearly a right angle.

Components of a RPDComponents of a RPD Major connector - MandibularMajor connector - Mandibular

A lingual bar should be located at least 4 A lingual bar should be located at least 4 mm inferior to gingival margins, more if mm inferior to gingival margins, more if possible. The vertical height of a finished possible. The vertical height of a finished lingual bar should be at least 4 mm for lingual bar should be at least 4 mm for strength and rigidity. If less than 8 mm strength and rigidity. If less than 8 mm exists between gingival margins and exists between gingival margins and movable floor of mouth, a linguoplate, a movable floor of mouth, a linguoplate, a sublingual bar or a continuous bar is sublingual bar or a continuous bar is preferred as a major connector.preferred as a major connector.

Components of a RPDComponents of a RPD Major connector - MandibularMajor connector - Mandibular

A lingual bar should be located at least 4 A lingual bar should be located at least 4 mm inferior to gingival margins, more if mm inferior to gingival margins, more if possible. The vertical height of a finished possible. The vertical height of a finished lingual bar should be at least 4 mm for lingual bar should be at least 4 mm for strength and rigidity. If less than 8 mm strength and rigidity. If less than 8 mm exists between gingival margins and exists between gingival margins and movable floor of mouth, a linguoplate, a movable floor of mouth, a linguoplate, a sublingual bar or a continuous bar is sublingual bar or a continuous bar is preferred as a major connector.preferred as a major connector.

Components of a RPDComponents of a RPD Major connector - MandibularMajor connector - Mandibular

Components of a RPDComponents of a RPD Major connector - MandibularMajor connector - Mandibular

Components of a RPDComponents of a RPD Major connectorMajor connector

Components of a RPDComponents of a RPD Major connectorMajor connector

Components of a RPDComponents of a RPD Major Major

connectorconnector

Components of a RPDComponents of a RPD Major Major

connectorconnector

Components of a RPDComponents of a RPD Minor connectorMinor connector

Connects the the major connector with Connects the the major connector with other components of the denture. It has other components of the denture. It has two functions. two functions.

1. Transfers functional stress to the 1. Transfers functional stress to the abutment teeth (prosthesis-to-abutment abutment teeth (prosthesis-to-abutment function).function).

2. Transfers the effect of the 2. Transfers the effect of the retainers, rests, and stabilizing retainers, rests, and stabilizing components to the rest of the denture components to the rest of the denture (abutment-to-prosthesis function).(abutment-to-prosthesis function).

Components of a RPDComponents of a RPD Minor connectorMinor connector

Connects the the major connector with Connects the the major connector with other components of the denture. It has other components of the denture. It has two functions. two functions.

1. Transfers functional stress to the 1. Transfers functional stress to the abutment teeth (prosthesis-to-abutment abutment teeth (prosthesis-to-abutment function).function).

2. Transfers the effect of the 2. Transfers the effect of the retainers, rests, and stabilizing retainers, rests, and stabilizing components to the rest of the denture components to the rest of the denture (abutment-to-prosthesis function).(abutment-to-prosthesis function).

Components of a Components of a RPDRPD Minor connectorMinor connector

1. Form: Sufficient 1. Form: Sufficient bulk to be rigid, but not bulk to be rigid, but not objectionable. Therefore objectionable. Therefore tapered to the teeth to tapered to the teeth to provide smooth transition provide smooth transition from tooth to the minor from tooth to the minor connector.connector.

2. Location: When 2. Location: When contacting an axial surface contacting an axial surface of an abutment, is should of an abutment, is should not be located on a convex not be located on a convex surface; instead it should be surface; instead it should be located in an embrasure in located in an embrasure in which it will be least which it will be least noticeable to the tongue.noticeable to the tongue.

Components of a Components of a RPDRPD Minor connectorMinor connector

1. Form: Sufficient 1. Form: Sufficient bulk to be rigid, but not bulk to be rigid, but not objectionable. Therefore objectionable. Therefore tapered to the teeth to tapered to the teeth to provide smooth transition provide smooth transition from tooth to the minor from tooth to the minor connector.connector.

2. Location: When 2. Location: When contacting an axial surface contacting an axial surface of an abutment, is should of an abutment, is should not be located on a convex not be located on a convex surface; instead it should be surface; instead it should be located in an embrasure in located in an embrasure in which it will be least which it will be least noticeable to the tongue.noticeable to the tongue.

Principles of a RPDPrinciples of a RPD Levers (Class I, II and III)Levers (Class I, II and III)

Principles of a RPDPrinciples of a RPD Levers (Class I, II and III)Levers (Class I, II and III)

Principles of a RPDPrinciples of a RPD RotationRotation

- Horizontal fulcrum- Horizontal fulcrum

- Sagittal fulcrum- Sagittal fulcrum

- Vertical fulcrum- Vertical fulcrum

Principles of a RPDPrinciples of a RPD RotationRotation

- Horizontal fulcrum- Horizontal fulcrum

- Sagittal fulcrum- Sagittal fulcrum

- Vertical fulcrum- Vertical fulcrum

Principles of a RPDPrinciples of a RPD Indirect retainer (Class II lever)Indirect retainer (Class II lever)

Principles of a RPDPrinciples of a RPD Indirect retainer (Class II lever)Indirect retainer (Class II lever)

Components of a RPDComponents of a RPD Indirect retainersIndirect retainers

- When the denture base is forced to - When the denture base is forced to move away from the basal seat, it tends to move away from the basal seat, it tends to rotate around one of the fulcrum lines. rotate around one of the fulcrum lines.

- This movement is resisted by rigid - This movement is resisted by rigid units of the partial denture framework units of the partial denture framework (rests) on the opposite side of the fulcrum (rests) on the opposite side of the fulcrum line from the distal extension base and the line from the distal extension base and the activation of the retentive element of the activation of the retentive element of the direct retainer (clasp)direct retainer (clasp)

- The component should be placed as - The component should be placed as far as possible from the distal extension far as possible from the distal extension basebase

Components of a RPDComponents of a RPD Indirect retainersIndirect retainers

- When the denture base is forced to - When the denture base is forced to move away from the basal seat, it tends to move away from the basal seat, it tends to rotate around one of the fulcrum lines. rotate around one of the fulcrum lines.

- This movement is resisted by rigid - This movement is resisted by rigid units of the partial denture framework units of the partial denture framework (rests) on the opposite side of the fulcrum (rests) on the opposite side of the fulcrum line from the distal extension base and the line from the distal extension base and the activation of the retentive element of the activation of the retentive element of the direct retainer (clasp)direct retainer (clasp)

- The component should be placed as - The component should be placed as far as possible from the distal extension far as possible from the distal extension basebase

Components of a RPDComponents of a RPD RestsRestsThe primary purpose is to provide vertical The primary purpose is to provide vertical support for the partial denture. In doing support for the partial denture. In doing so it also does the following:so it also does the following:

- Maintains components in their - Maintains components in their planned positionsplanned positions

- Maintains established occlusal - Maintains established occlusal relationships by preventing settling of the relationships by preventing settling of the denturedenture

- Prevents impingement of soft tissues- Prevents impingement of soft tissues

-Directs and distributes occlusal loads -Directs and distributes occlusal loads to abutment teethto abutment teeth

Components of a RPDComponents of a RPD RestsRestsThe primary purpose is to provide vertical The primary purpose is to provide vertical support for the partial denture. In doing support for the partial denture. In doing so it also does the following:so it also does the following:

- Maintains components in their - Maintains components in their planned positionsplanned positions

- Maintains established occlusal - Maintains established occlusal relationships by preventing settling of the relationships by preventing settling of the denturedenture

- Prevents impingement of soft tissues- Prevents impingement of soft tissues

-Directs and distributes occlusal loads -Directs and distributes occlusal loads to abutment teethto abutment teeth

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

- - OcclusalOcclusal

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

- - OcclusalOcclusal

- - Interproximal Interproximal OcclusalOcclusal

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

OcclusalOcclusal- Outline is a rounded triangular - Outline is a rounded triangular

shape, the apex toward the center of the shape, the apex toward the center of the occlusal surfaceocclusal surface

- It should be as long as it is wide - It should be as long as it is wide with the base of the triangular shape (at with the base of the triangular shape (at the marginal ridge) at least 2.5 mm the marginal ridge) at least 2.5 mm

- Reduction of the marginal ridge = - Reduction of the marginal ridge = 1.5 mm1.5 mm

- Floor of the rest seat is apical to the - Floor of the rest seat is apical to the marginal ridge and is spoon shaped marginal ridge and is spoon shaped (concave)(concave)

- < 90° between rest & the minor - < 90° between rest & the minor connectorconnector

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

OcclusalOcclusal- Outline is a rounded triangular - Outline is a rounded triangular

shape, the apex toward the center of the shape, the apex toward the center of the occlusal surfaceocclusal surface

- It should be as long as it is wide - It should be as long as it is wide with the base of the triangular shape (at with the base of the triangular shape (at the marginal ridge) at least 2.5 mm the marginal ridge) at least 2.5 mm

- Reduction of the marginal ridge = - Reduction of the marginal ridge = 1.5 mm1.5 mm

- Floor of the rest seat is apical to the - Floor of the rest seat is apical to the marginal ridge and is spoon shaped marginal ridge and is spoon shaped (concave)(concave)

- < 90° between rest & the minor - < 90° between rest & the minor connectorconnector

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

- - Cingulum/LingualCingulum/Lingual

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

- - Cingulum/LingualCingulum/Lingual

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

Cingulum/LingualCingulum/Lingual - A slightly rounded V is prepared - A slightly rounded V is prepared

on the lingual surface at the junction of the on the lingual surface at the junction of the gingival and the middle one third of the gingival and the middle one third of the toothtooth

- Mesiodistal length of preparation - Mesiodistal length of preparation should be a minimum of 2.5 mm, should be a minimum of 2.5 mm, labiolingual width about 2 mm, and incisal-labiolingual width about 2 mm, and incisal-apical depth a minimum of 1.5 mmapical depth a minimum of 1.5 mm

- Should not be done on lower - Should not be done on lower anterior teethanterior teeth

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

Cingulum/LingualCingulum/Lingual - A slightly rounded V is prepared - A slightly rounded V is prepared

on the lingual surface at the junction of the on the lingual surface at the junction of the gingival and the middle one third of the gingival and the middle one third of the toothtooth

- Mesiodistal length of preparation - Mesiodistal length of preparation should be a minimum of 2.5 mm, should be a minimum of 2.5 mm, labiolingual width about 2 mm, and incisal-labiolingual width about 2 mm, and incisal-apical depth a minimum of 1.5 mmapical depth a minimum of 1.5 mm

- Should not be done on lower - Should not be done on lower anterior teethanterior teeth

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

- - IncisalIncisal

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

- - IncisalIncisal

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

IncisalIncisal - Used predominately as auxiliary - Used predominately as auxiliary

rests or as indirect retainersrests or as indirect retainers- Should be approximately 2.5 mm - Should be approximately 2.5 mm

wide and 1.5 mm deep so that the rest will wide and 1.5 mm deep so that the rest will be strong without having to exceed the be strong without having to exceed the natural contour of the incisal edgenatural contour of the incisal edge

Components of a RPDComponents of a RPD Types of RestsTypes of Rests

IncisalIncisal - Used predominately as auxiliary - Used predominately as auxiliary

rests or as indirect retainersrests or as indirect retainers- Should be approximately 2.5 mm - Should be approximately 2.5 mm

wide and 1.5 mm deep so that the rest will wide and 1.5 mm deep so that the rest will be strong without having to exceed the be strong without having to exceed the natural contour of the incisal edgenatural contour of the incisal edge

Components of a RPDComponents of a RPD Direct RetainersDirect Retainers

The primary retentive component. The primary retentive component. Provides mechanical retention by engaging Provides mechanical retention by engaging the abutment tooth. Direct retainers may the abutment tooth. Direct retainers may be: be:

- intracoronal - intracoronal

- extracoronal. - extracoronal.

Components of a RPDComponents of a RPD Direct RetainersDirect Retainers

The primary retentive component. The primary retentive component. Provides mechanical retention by engaging Provides mechanical retention by engaging the abutment tooth. Direct retainers may the abutment tooth. Direct retainers may be: be:

- intracoronal - intracoronal

- extracoronal. - extracoronal.

Components of a RPDComponents of a RPD Direct RetainersDirect Retainers

Components of a RPDComponents of a RPD Direct RetainersDirect Retainers

Components of a RPDComponents of a RPD Direct Retainers - extracoronalDirect Retainers - extracoronal

(clasp assembly)(clasp assembly)

- rest (c)- rest (c)- minor connector- minor connector- clasp arm- clasp arm

- retention (a)- retention (a)- stabilization (b)- stabilization (b)

Components of a RPDComponents of a RPD Direct Retainers - extracoronalDirect Retainers - extracoronal

(clasp assembly)(clasp assembly)

- rest (c)- rest (c)- minor connector- minor connector- clasp arm- clasp arm

- retention (a)- retention (a)- stabilization (b)- stabilization (b)

Components of a RPDComponents of a RPD Direct RetainersDirect Retainers

- Clasps should be bilaterally opposed- Clasps should be bilaterally opposed

- Any clasp assembly must satisfy the - Any clasp assembly must satisfy the basic principle of clasp design, which is basic principle of clasp design, which is that more than 180° of the greatest that more than 180° of the greatest circumference of the crown of the tooth circumference of the crown of the tooth must be includedmust be included

Components of a RPDComponents of a RPD Direct RetainersDirect Retainers

- Clasps should be bilaterally opposed- Clasps should be bilaterally opposed

- Any clasp assembly must satisfy the - Any clasp assembly must satisfy the basic principle of clasp design, which is basic principle of clasp design, which is that more than 180° of the greatest that more than 180° of the greatest circumference of the crown of the tooth circumference of the crown of the tooth must be includedmust be included

Components of a RPDComponents of a RPD Direct Retainers (assembly Direct Retainers (assembly types)types)

- RPI (Rest, Guiding Plate, I Bar, .010”)- RPI (Rest, Guiding Plate, I Bar, .010”)

- Modified T bar (Rest, GP, 1/2 T bar, .010”)- Modified T bar (Rest, GP, 1/2 T bar, .010”)

- RPA (Rest, GP, Akers, .010”)- RPA (Rest, GP, Akers, .010”)

- Combination (Rest, GP, Wrought - Combination (Rest, GP, Wrought wire, .015 - .020”)wire, .015 - .020”)

- Interproximal Cast Circumferential (Rest, - Interproximal Cast Circumferential (Rest, GP, Cast Circumferential clasp, .010”)GP, Cast Circumferential clasp, .010”)

Components of a RPDComponents of a RPD Direct Retainers (assembly Direct Retainers (assembly types)types)

- RPI (Rest, Guiding Plate, I Bar, .010”)- RPI (Rest, Guiding Plate, I Bar, .010”)

- Modified T bar (Rest, GP, 1/2 T bar, .010”)- Modified T bar (Rest, GP, 1/2 T bar, .010”)

- RPA (Rest, GP, Akers, .010”)- RPA (Rest, GP, Akers, .010”)

- Combination (Rest, GP, Wrought - Combination (Rest, GP, Wrought wire, .015 - .020”)wire, .015 - .020”)

- Interproximal Cast Circumferential (Rest, - Interproximal Cast Circumferential (Rest, GP, Cast Circumferential clasp, .010”)GP, Cast Circumferential clasp, .010”)

Components of a RPDComponents of a RPD Direct Retainers (Retention)Direct Retainers (Retention)

Components of a RPDComponents of a RPD Direct Retainers (Retention)Direct Retainers (Retention)

- Rigidity of the material - Rigidity of the material will determine the will determine the diameter of the clasp diameter of the clasp and undercut that is and undercut that is requiredrequired

Components of a RPDComponents of a RPDComponents of a RPDComponents of a RPD

Components of a RPDComponents of a RPDComponents of a RPDComponents of a RPD

Other Other claspclasp

designsdesigns

Components of a RPDComponents of a RPD Direct Retainers - the Direct Retainers - the reciprocal clasp armreciprocal clasp arm

- Should be located at the junction of - Should be located at the junction of the gingival and middle thirds of the the gingival and middle thirds of the abutmentabutment

- Should provide stabilization and - Should provide stabilization and reciprocation against the action of the reciprocation against the action of the retentive arm which would optimally have retentive arm which would optimally have its terminal end placed in the gingival its terminal end placed in the gingival thirdthird

- It should be located so that the - It should be located so that the denture is stabilized against horizontal denture is stabilized against horizontal movementmovement

- It may act as an indirect retainer- It may act as an indirect retainer

Components of a RPDComponents of a RPD Direct Retainers - the Direct Retainers - the reciprocal clasp armreciprocal clasp arm

- Should be located at the junction of - Should be located at the junction of the gingival and middle thirds of the the gingival and middle thirds of the abutmentabutment

- Should provide stabilization and - Should provide stabilization and reciprocation against the action of the reciprocation against the action of the retentive arm which would optimally have retentive arm which would optimally have its terminal end placed in the gingival its terminal end placed in the gingival thirdthird

- It should be located so that the - It should be located so that the denture is stabilized against horizontal denture is stabilized against horizontal movementmovement

- It may act as an indirect retainer- It may act as an indirect retainer

Components of a RPDComponents of a RPD Direct Retainers - the Direct Retainers - the reciprocal reciprocal clasp clasp armarm

Components of a RPDComponents of a RPD Direct Retainers - the Direct Retainers - the reciprocal reciprocal clasp clasp armarm

Components of a RPDComponents of a RPD Denture base Denture base

- The part of the denture (metal or - The part of the denture (metal or resin) that rests on the foundation tissues resin) that rests on the foundation tissues and to which the teeth are attachedand to which the teeth are attached

- Effects the transfer of occlusal forces - Effects the transfer of occlusal forces to supporting oral structuresto supporting oral structures

- Intimate relationship with underlying - Intimate relationship with underlying tissue provides secondary retentiontissue provides secondary retention

Components of a RPDComponents of a RPD Denture base Denture base

- The part of the denture (metal or - The part of the denture (metal or resin) that rests on the foundation tissues resin) that rests on the foundation tissues and to which the teeth are attachedand to which the teeth are attached

- Effects the transfer of occlusal forces - Effects the transfer of occlusal forces to supporting oral structuresto supporting oral structures

- Intimate relationship with underlying - Intimate relationship with underlying tissue provides secondary retentiontissue provides secondary retention

Components of a RPDComponents of a RPD Denture base (Ideal material)Denture base (Ideal material)

- Accurately adapts to the tissue- Accurately adapts to the tissue

- Dense, nonirritating surface capable of - Dense, nonirritating surface capable of receiving and maintaining a good finish receiving and maintaining a good finish

- Thermal conductive- Thermal conductive

- Low specific gravity, lightweight- Low specific gravity, lightweight

- Sufficient strength- Sufficient strength

- Easily kept clean- Easily kept clean

- Esthetic- Esthetic

- Able to reline- Able to reline

- Low cost- Low cost

Components of a RPDComponents of a RPD Denture base (Ideal material)Denture base (Ideal material)

- Accurately adapts to the tissue- Accurately adapts to the tissue

- Dense, nonirritating surface capable of - Dense, nonirritating surface capable of receiving and maintaining a good finish receiving and maintaining a good finish

- Thermal conductive- Thermal conductive

- Low specific gravity, lightweight- Low specific gravity, lightweight

- Sufficient strength- Sufficient strength

- Easily kept clean- Easily kept clean

- Esthetic- Esthetic

- Able to reline- Able to reline

- Low cost- Low cost

Components of a RPDComponents of a RPD Tooth ReplacementTooth Replacement

- Plastic or porcelain teeth processed - Plastic or porcelain teeth processed to to the acrylic denture base the acrylic denture base

- Plastic or porcelain veneer cemented - Plastic or porcelain veneer cemented to to a metal backing a metal backing

- Tube teeth cemented over a post- Tube teeth cemented over a post

- Reinforced Acrylic Pontic (RAP)- Reinforced Acrylic Pontic (RAP)

- Metal pontic- Metal pontic

- Metal pontic with resin facing- Metal pontic with resin facing

Components of a RPDComponents of a RPD Tooth ReplacementTooth Replacement

- Plastic or porcelain teeth processed - Plastic or porcelain teeth processed to to the acrylic denture base the acrylic denture base

- Plastic or porcelain veneer cemented - Plastic or porcelain veneer cemented to to a metal backing a metal backing

- Tube teeth cemented over a post- Tube teeth cemented over a post

- Reinforced Acrylic Pontic (RAP)- Reinforced Acrylic Pontic (RAP)

- Metal pontic- Metal pontic

- Metal pontic with resin facing- Metal pontic with resin facing

Components of a RPDComponents of a RPD Tooth ReplacementTooth Replacement

Components of a RPDComponents of a RPD Tooth ReplacementTooth Replacement

Components of a RPDComponents of a RPD Tooth ReplacementTooth Replacement

Components of a RPDComponents of a RPD Tooth ReplacementTooth Replacement