Upload
dr-almas-m-arshad
View
249
Download
6
Embed Size (px)
Citation preview
REMOVABLE PARTIAL
DENTURE – Parts, Functions,
Principles of designDr. Almas Muhammad ArshadHouse OfficerProsthodontic DepartmentUCD, UOL
OBJECTIVES OF PROSTHODONTIC REPLACEMENT•Restoration of esthetics•Restoration of function•Preservation of health
REMOVABLE PARTIAL DENTURE:
“A removable prosthesis that replaces missing teeth in a
partially dentate arch, and can be removed or replaced by the
patient himself.”
TYPES1. Acrylic partial denture
Temporary dentures
2. Cast partial denture
• Interim denture• Enhance the esthetics, stabilization and/or function for a
limited time• Later replaced by definitive prosthesis
• Transitional denture• An interim denture in which artificial teeth are added as
natural teeth lost
• Treatment denture• Used for the purpose of treatment or conditioning of
tissue• Post surgery
TEMPORARY REMOVABLE PARTIAL DENTURES
PARTS OF RPD:Removable partial denture
Connectors
Major
Minor
Rest Retainers
Direct
Indirect
Denture Base
MAJOR CONNECTORSUnificationDistribution of applied forces•Provides cross-arch stability to help resist
the displacement by functional stresses.
MANDIBULAR MAJOR CONNECTORS:• Lingual Bar (All situations where min 8mm space coverage is req)
• Sub-lingual bar (Distance of floor or mouth to gingival margin is < 6mm)
• Continuous Bar (Wide diastema)
• Labial Bar (Severe lingual inclinations)
MAXILLARY MAJOR CONNECTORS:• Single palatal strap (Bilateral short span edentulous spaces)
• Single palatal bar (Interim partial dentures)
• Anterior posterior palatal strap (All Kennedy situations, Multiple saddle areas)
• Anterior posterior palatal bars (Kennedy Class II and IV)
• Complete Palatal plate (Distal extension conditions, Cleft palate, Heavy occlusal forces)
• U shaped (Inoperable tori, Least suitable design)
MINOR CONNECTORS
• Functions • Transfers functional stresses to abutment teeth• Maintain a path of insertion
BaseOther Components (Clasps, rests, Indirect retainers)
RESTS AND REST SEAT• Provides vertical support• Transfers the forces along the long axis of teeth• Positional maintenance• Rest Seat:• The prepared surface on the abutment teeth
to receive the rest
• Types:•Occlusal • Incisal •Cingulum
DIRECT RETAINERSComponent of RPD that functions to retain and prevent the dislodgement of the denture
Intracoronal
Precision Semi precision
Extracoronal
Clasps Prefabricated attachments
TYPES OF CLASP:Cast circumferential clasp Bar Clasp
PRE FABRICATED ATTACHMENTS
INDIRECT RETAINERSStabilizationPrevents the rotational displacement of rpd
Functions through lever action on opposite side of the fulcrum line
FULCRUM LINEAn imaginary line around which the denture tends to rotate.
DENTURE BASE• Support, retention, stress distribution, esthetics•Maxillary denture base Maxillary Tuberosity
area•Mandibular denture base Retromolar pad
ARTIFICIAL TEETH• Types of artificial teeth:• Acrylic• Porcelain•MetalTube teeth
PRINCIPLES OF RPD DESIGN
• Design of removable partial denture should be
1. Simple2. Comfortable3. Harmless to the remaining teeth
PRINCIPLES OF RPD DESIGN
BIOLOGICAL CONSIDERATION•Teeth and periodontal tissue• Inclination of abutment•Status of residual ridge•Types of edentulous ridge•Occlusion
Good Support but poor stability
Poor SupportPoor Stability
Poor support
and poor to fair
stability
MECHANICAL CONSIDERATION•Retention•Stability •Support
1. How the RPD is supported?• Tooth Supported• Kennedy class 3 and 4
• Tooth – Tissue Supported• Kennedy Class 1 and 2• Away from abutment Tissue Support• Adjacent to edentulous area Tooth support• Quality of Ridge and accuracy of impression
is the key
2. Connecting the tooth and tissue support units•Major Connector – Rigid for proper distribution of load•Minor connector•SUPPORT
3. How the RPD is to be retained• Natural Sources• Frictional resistance • Interfacial surface tension• Palatal vault• Occlusion
• Clasp assembly (avoiding torqueing forces)• Splinting• RETENTION
4. Connecting the Retention units to the supporting units
Indirect Retainers - STABILIZATION
5. Outlining and joining the edentulous area to already established design
SEQUENCE OF DESIGN
RetainersMinor connector
Major connectorRests
RPD
References•McCraken’s Removable partial prosthodontics A.B Carr David T Brown 12th edition
THAN
K YO
U