RIGID AND NON RIGID CONNECTORS IN FIXED PARTIL

RIGID AND NON RIGID CONNECTORS IN FIXED PARTIL DENTURE Department of Prosthodontics Dentistry Explorer

Fixed partial denture • A partial denture that is luted or other wise securely retained to natural teeth , tooth roots or dental implant abutment that furnish the primary support to the prosthesis -GPT Dentistry Explorer

Connectors • the portion of a fixed dental prosthesis that unites individual components , the retainer (s) and pontics together. Dentistry Explorer

Types • Rigid connectors • Non rigid connectors • Tenon mortise connector • Loop connector • Split pontic connector • Cross pin and wing connector Dentistry Explorer

Rigid connector • Is a non moving connection that joins the retainers and pontics Dentistry Explorer

• These connectors are used when entire load on the pontic is to be transferred directly to the abutment. Dentistry Explorer

Technique of fabricating rigid connectors • Rigid connection can be made by casting as part of multi unit wax pattern or by soldering the design of rigid connector is incorporated into wax pattern. • By soldering using an intermediate metal whose melting temperature is lower than that of the parent metal. • By welding in which two parts are joint by melting the adjacent surfaces by heat and /or pressure. A filler metal whose melting temperature is about the same as that of the parent metal can be used or two metal areas are mainly joined. Dentistry Explorer

Non rigid connectors /stress breaker in fixed partial denture • These connectors are indicated in cases where single path of insertion cannot be achieved due to non-parallel abutment. • These connector allow limited movement between retainer and pontic. • Intra coronal retainers are non rigid connectors that confines within proximal and axial contour or within crown of tooth. • It consist of a matrix component part housed with in the coronal portion of abutment tooth. Dentistry Explorer

Types of intra-coronal system • Key and keyway system • Locking mechanism • Frictional mechanism • Spring retained types Dentistry Explorer

Principle of non-rigid connector • This connector employs a stress breaking principle, which consists of a keyway (female part) and a key way (male part). • This connector when placed between pontic and retainer permits some amount of movement. Dentistry Explorer

Indication • Resilient intra-coronal used for removable bounded prosthesis. • Non-resilient intra coronal used for fixed movable design. Dentistry Explorer

Advantage • Early alignment • Allows individual movement of tooth. • Force distribution can be controlled. • Contour of tooth is not altered as in extra-coronal types. • Can overcome problem of non-parallel abutments. Dentistry Explorer

Disadvantage • Used only for posterior fixed prosthesis. • Cannot be used when opposing teeth are missing because the key tends to displace. • Cannot be used in long span bridges. • The size of intra coronal retainer can encroach upon pulp chamber. • Requires extensive tooth preparation. Dentistry Explorer

• Mc. Collam attachment. • Chayes attachment. • Stern precision attachment. • Crismani attachment. • Schatzman attachment. • Ace attachment. Dentistry Explorer

Method • A wax pattern for retainer is fabricated on working cast. • If plastic is used for the keyway, a deep surface of die wax pattern to create space for placement of plastic keyway. • Path of insertion should be accurate while preparing distal box. • The working cast with wax pattern is surveyed to locate the ideal path of insertion by locking the extension of key into the surveying arm of surveyor. Dentistry Explorer

• The surveying table is adjusted till the assembly seats well into distal box. • This key and keyway assembly is luted in place invested burned out and cast. Dentistry Explorer

Types • Tenon –mortise connector • Loop connectors • Split pontic connector • Cross-pin and wing connector Dentistry Explorer

Tenon-mortise connector • TMC with male and female component or dove tail connectors • It consists of a Mortise(female) prepared within the contours of retainers and a Tenon(male) attached to the pontic. Dentistry Explorer

Loop connectors • Used when an existing diastema is to be maintained in a planned fixed prosthesis. • Consist of loop on the lingual aspect which connect retainer and/or pontics. • The palatal connector seen in a spring cantilever fixed partial denture is a type of loop connector. Dentistry Explorer

Split pontic connectors • Connector is incorporated within the pontic. • Pontics is split into mesial and distal segment. • Each of these segments are attached to their respective retainers. Dentistry Explorer

Cross pin and wing connectors • Used for tilted abutments • A wing is attached to the distal retainer • The wing should align with the long axis of the mesial abutment • The wing along with distal retainer is termed as retainer wing component Dentistry Explorer

• The pontic is attached to the mesial retainer and is designed to fit to the wing in the retainer wing component • The pontic along with the mesial retainer is termed as the retainer pontic component Dentistry Explorer

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