Class IV Cavity Preparation Flashcards

Define class IV cavities.

What are the types of tooth preparation in class IV?

What is the characteristics of conventional tooth preparation?

What is the purpose of beveled conventional tooth preparation?

When is a modified class IV preparation used?

What additional features can enhance retention in class IV preparations?

How are the walls prepared in class IV?

Why are the walls prepared parallel and perpendicular to the long axis of the tooth?

All weakened enamel is removed, and the initial axial wall depth is established at _______________ mm into dentin.

Bevel the CSM of all ________________ of the preparation.

The bevel is prepared at a __________-degree to the external tooth surface with a flame-shaped or round diamond instrument.

The width of the bevel should be _______________.

What instrument is used to bevel sharp CSM if fracture is confined to enamel?

Class IV Cavity Preparation Overview

Class IV cavities are located on the proximal surfaces of anterior teeth, involving the incisal angles.

Types of Tooth Preparation

Conventional Tooth Preparation: Features a 90-degree cavity shape margin (CSM) with the gingival margin primarily on cementum.
Beveled Conventional Tooth Preparation: Utilized for larger cavities to enhance retention and aesthetic integration.
Modified Class IV Preparation: Designed for smaller class IV needs with a focus on minimal invasiveness.

Retention Mechanisms

In addition to an etched enamel margin, retention can be augmented using:
- Grooves or shaped undercuts
- Dovetail extensions
- Threaded pins for improved stability

Wall Preparation Techniques

Walls are prepared to be as parallel and perpendicular as possible to the long axis of the tooth.
This orientation provides greater resistance to biting forces, reducing the risk of tooth or restorative material fracture.

Initial Axial Wall Depth

The depth of the initial axial wall must range from 0.2 to 0.5 mm into the dentin for effective cavity preparation.

Enamel Margin Handling

All accessible enamel margins must be beveled to facilitate a smooth transition and enhance the bonding surface.

Bevel Specifications

The bevel is prepared at a 45-degree angle to the external tooth surface using a flame-shaped or round diamond instrument.
The width of the bevel should range from 0.25 to 2 mm, balancing retention and aesthetics.

Fractured Enamel Retention

If enamel fractures are restricted to the enamel layer, retention can usually be achieved by beveling the sharp cavity shape margin with a flame-shaped diamond instrument, followed by bonding procedures for stability.

Test your knowledge on Class IV cavity preparations with these flashcards. This quiz covers definitions, types of tooth preparations, and specific technical details regarding dental procedures. Perfect for dental students and professionals looking to refresh their knowledge.