Class IV Cavity Preparation Flashcards

Questions and Answers

Define class IV cavities.

Located on the proximal surfaces of anterior teeth involving the incisal angles.

What are the types of tooth preparation in class IV?

Conventional tooth preparation (correct)

Beveled conventional tooth preparation (correct)

Modified class IV preparation (correct)

None of the above

What is the characteristics of conventional tooth preparation?

-90-degree CSM and gingival margin mostly on cementum.

What is the purpose of beveled conventional tooth preparation?

Type of class IV tooth preparation used for large cavities. Signup and view all the answers

When is a modified class IV preparation used?

Used for smaller class IV needs. Signup and view all the answers

What additional features can enhance retention in class IV preparations?

All of the above Signup and view all the answers

How are the walls prepared in class IV?

As much as possible parallel and perpendicular to the long axis of the tooth. Signup and view all the answers

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

To provide greater resistance to biting forces that could cause fracture of the tooth or restorative material. Signup and view all the answers

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

0.2 to 0.5 Signup and view all the answers

Bevel the CSM of all ________________ of the preparation.

accessible enamel margins Signup and view all the answers

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

45 Signup and view all the answers

The width of the bevel should be _______________.

0.25-2mm Signup and view all the answers

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

Flame-shaped diamond instrument. Signup and view all the answers

Study Notes

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.

Description

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.