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Removable partial denture (PDF)

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					Removable partial denture
Definition
 Partial denture;A dental prosthesis that
 restores one or more but not all of the
 natural teeth
 Abutment; tooth that serves to support and
    /or retain a prosthesis
Edentulous and Complete Dentures
• Total control of the denture tooth setup
• Completely supported by the oral mucosa
Partially Edentulous & Removable Partial Dentures
• Supported by:
  • Teeth i.e. Tooth Supported
  • Teeth & Mucosa i.e. Extension Bases
• More challenging due to the presence of teeth…
  • Caries, Tooth Wear, Changes in Tooth Positions, VDO Changes, Occlusal
    Plane Discrepancies, Stability of Occlusal Contacts, Loss of Posterior
    Support, Esthetic Compromises




                                Before             After
 RPD INDICATIONS




1. When Fixed Bridges are not a good choice due to:
   a. Long edentulous spans
   b. Lack of a posterior abutment (distal extension)
   c. Structurally and anatomically compromised abutments
      • Absence of adequate periodontal support
      • Poor axial length /retention potential of abutments
   d. Expected Survival / Value - Cost
 RPD INDICATIONS




2. Insufficient bone for Osseointegrated Implants and / or lack of
   patient desire for a fixed restoration
3. Need for cross-arch stabilization
4. Need to correct occlusal plane without restoring every tooth.
5. Need to restore soft and hard tissue contours not just teeth
   a. Anterior Esthetics
   b. Lip Support, Phonetics and Food Bolus Control
6. Age, Health, Attitude and Desires of the patient.
7. Hygiene Potential - Ease of plaque removal
Principles and Objectives of RPD’s:
Stabilize the individual arch and protect remaining structures
Gain Control and Organize Interarch Function:
        VDO, Occlusal Plane, Centric, Guidance and Esthetics
Principles and Objectives of RPD’s:
 Provide cross-arch support
 Unite the remaining teeth to better resist the forces of occlusion
 Restore function and control the direction of the functional load
 on to the remaining teeth and tissue
 Minimize negative forces on existing teeth and soft tissues/bone
Principles and Objectives of RPD’s:
   Basic Steps to Gain Control of the Dental Arches:
1. Evaluate and develop correct vertical dimension of occlusion
2. Identify the most ideal occlusal plane
3. Organize a plan for a stable occlusion
Objectives of partial denture
 1Restoration of masticatory function
 2Restoration of speech
 3Preservation of the remaining tissues
 health
 4Restoration of esthetics
Disadvantage of partial denture
 1 stagnation of food which cause tooth decay
 and depend on
 a patient age……..patient oral hygiene
 2Damage to the abutment and gingival
 a inadequate support
 b food pack
 c too close to gingival margin
 d excessive stresses on the abutment
 3Improper occlusal contact leads to muscle
 spasm
Successful use of a combination of Fixed Prosthodontics and a Removable Partial
                       Denture to Rehabilitate a Patient
Types of Removable Partial Dentures


A.Kennedy-Applegate Classification
B. UCLA Functional Design Classification
Types of Removable Partial Dentures

A. Kennedy-Applegate Classification
 Class I- Bilateral edentulous areas located posterior to remaining
          natural teeth
Types of Removable Partial Dentures

A. Kennedy-Applegate Classification
 Class II- Unilateral edentulous areas located posterior to
      remaining natural teeth
Types of Removable Partial Dentures

 A. Kennedy-Applegate Classification
  Class III- Unilateral edentulous areas with natural teeth both
anterior and posterior
Types of Removable Partial Dentures

 A. Kennedy-Applegate Classification
  Class IV- A single but bilateral (crossing the midline)
edentulous area located anterior to the remaining natural teeth
Applegate”s rule
 1.Classification should follow mouth preparation :
 2.If the third molar is missing and not to be replaced it is not
 considered in the classification
 3.If the third molar is present and to be used as an abutment it is
 considered
 4.If the second molar is missing and the opposing also missing then
 it is not considered
 5.The most posterior edentulous area always determine the
 classification
 6.Additional edentulous areas are referred to as modification
 7.The extent of the modification is not considered only the number
 8.Class 4 has no modification
Types of Removable Partial Dentures


A. Kennedy-Applegate Classification: Class I-IV
B. UCLA Functional Design Classification
   Tooth Borne
   Extension Base
Tooth Borne Removable Partial Dentures


-Abutment teeth border all edentulous areas
-Functional forces are transmitted through
abutment teeth to bone
Objectives of RPD
Objectives of RPD




1. Stabilize the individual arch

2. Organize interarch function by control
  of interarch contacts

3. Preserve remaining natural teeth
To a great extent, the forces occurring
through a removable prosthesis can be widely
distributed, directed, and minimized by the
selection, the design, and the location of
components of the RPD.
Parts of a Removable Partial Denture
Parts of a Removable Partial Denture

 Rests

 Major Connectors

 Proximal Plates/
 Minor Connector


 Denture Base Connectors

 Retainers
Rests: The Definition
 The part of a removable partial denture that
 provides primarily vertical support on the abutment
 teeth.
Major Connector: The Definition
Major Connector: The Definition
 A major connector is a rigid pat of the partial
 denture casting that unites the rests and other parts
 of the prosthesis to the opposite side of the arch.
Minor connector
Minor connector                   The proximal plate is the portion
                                  of the prosthesis that contacts the side
                                  of the tooth and extends onto the
                                  interproximal tissue, which is
                                  considered a minor connector with a
                                  specialized function. It is a thin,
                                  closely fitting metal part of the RPD
                                  framework that covers guide surfaces
                                  (guide planes) of the tooth and
                                  extends onto the adjacent edentulous
                                  mucosa.




    Minor connectors are strong and rigid
    parts of a removable partial denture and
    connect other units, such as rests, with the
    major connector.
Denture Base Connectors
Denture Base Connectors
 Denture base connectors form a structure of metal struts that
 engages and unites the metal casting with the denture base resin.




                     Finish line
             Denture base connector




     1 mm space
                       1 mm thickness of resin
Retainers
 Flexible parts of the framework that are deliberately
 designed to enter undercuts on abutment teeth to resist
 removable of RPDs and to help prevent dislodgement.

The retention remains passive until activated by
placement or removal force on the RPD.
RPD REQUIREMENTS

Support- Resistance to occlusal or vertical
           seating forces.

Stability- Resistance to horizontal or torsional
           forces

Retention- Resistance to vertical dislodging
           forces
                     SUPPORT




From:
• Rests
• Major connectors
• Denture bases
STABILITY




       Active I-bar     From:
                        • Guide planes
                        • Bracing clasp arms
                           •Reciprocation I bar
                        • Lingual plates
                        • Rests
        Reciprocation
                        • Denture bases
        I-bar
RETENTION
                           Indirect retainer (rest)




                                                     on
                                               otati
                                           o fR
                                       s
                                    Axi

                                               Extension Base


            From:
            • Direct Retainers
               •Active I-Bars
            • Indirect Retainers
               •Rests on the other side of the axis of
                rotation from the extension base
            • Proximal Plates(Guide Planes)
Summary: Roles of RPD parts
Summary: Roles of RPD parts
                               Retention Stability Support
 Rests
 Rests                            -         +/-
                                            +/-     +++
 Major Connectors
 Major Connectors                 -         +/-
                                            +/-     ++
 Minor Connectors/Proximal plates +/-
 Minor Connectors/Proximal plates +/-       +++     -
 Denture Base Connectors
 Denture Base Connectors          -         -       -
 Retainers
 Retainers                        +++       +/-
                                            +/-     -
????????
Kennedy’s
Class III



    Kennedy’s Class III, Modification 2
Kennedy Class II       Kennedy Class I mod. 1




         Kennedy Class II mod. 1
Parts of a Removable Partial Denture
Parts of a Removable Partial Denture

 Rests

 Major Connectors

 Proximal Plates/
 Minor Connector


 Denture Base Connectors

 Retainers

				
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posted:2/23/2012
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