FUNDAMENTALS OF TOOTH PREPARATION

•Definition of tooth preparation•Need for restoration•Objectives of tooth preparation•Stages and steps of tooth preparation•Factors affecting tooth preparation•Initial and final stages of preparation

Definition of tooth preparation

Mechanical alteration of a defective, injured or diseased tooth to receive a restorative material that re establishes a healthy state for the tooth including esthetic corrections where indicated and normal function and form.

Need for restoration:

Caries Replacement or repair of restorations

with serious defects. Defective open margins Poor esthetics Fractured tooth To maintain form and function

Objectives of tooth preparation:1. Removal all defects and provide

necessary protection to the pulp2. Extend the restoration as conservatively

as possible3. Form the tooth preparation so that under

masticatory force the tooth or restoration will not fracture

4. Allow for esthetic and functional placement of a restorative material.

Stages and steps of tooth preparation

INITIAL TOOTH PREPARATION STAGE: In this stage the mechanical alterations of tooth are extended to sound tooth structure while adhering to a specific limited pulpal or axial depth.

FINAL TOOTH PREPARATION STAGE: This stage includes excavating any remaining , infected carious dentin; removing old restorative material if indicated; protecting the pulp; incorporating additional preparation design features that minimize the tooth or restoration fracture; finishing the preparation walls; then finally cleaning ,inspecting.

Factors affecting tooth preparation