abutment evaluation

ABUTMENT EVALUATION

Dr shabeel pn

ROYAL DENTAL COLLEGE

ABUTMENT

a tooth, a portion of a tooth, or that portion of a dental implant that serves to support and/or retain a prosthesis

- GPT

SIGNIFICANCE

The forces applied to the missing teeth are transmitted through the Pontic, Connectors and Retainers to the Abutment teeth and are therefore called upon to withstand the forces normally directed to the missing teeth, in addition to those usualy applied to the abutment

CONSIDERATIONS

Better to select VITAL teethEndodontically treated tooth with good seal

& complete obturation If coronal tooth structure is lost, strength

regained by Dowel Core, Pin Retained amalgam or composite resin core

Never in pulp capped teeth

CONDITION OF SUPPORTING TISSUES

Evaluated for three factors

- CROWN - ROOT RATIO

- ROOT CONFIGURATION

- PERIODONTAL AREA

CROWN – ROOT RATIO

LENGTH OF TOOTH OCCLUSAL TO CREST OF ALVEOLAR BONE

LENGTH OF ROOT EMBEDDED IN BONE

OPTIMUM RATIO IS 2:3 RATIO OF 1:1 IS MINIMUM ACCEPTABLE AS THE LEVEL OF ALVEOLAR BONE MOVES

APICALLY, THE LEVER ARM OF THAT PORTION OUT OF BONE INCREASES

ROOT CONFIGURATIONRoots that are Broader bucco-lingually than

mesio distally are preferable Multi rooted posterior teeth with widely separated

roots offer better support than conical or fused roots

A single rooted tooth with irregular configuration or some crvature in the apical third is preferrable

A well aligned tooth will provide better support

PERIODONTAL AREA

It includes root surface area & periodontal status

Regarding Root surface area, Ante in 1926 suggested a law – Ante’s Law

“this law states that abutment teeth should have a combined pericemental area that the tooth or teeth to be replaced”

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