Class II Amalgam Restoration Flashcards

Questions and Answers

What are two ways to detect caries in Class II?

X-ray (correct)

CT scan

Blood test

Visually during examination (correct)

What is an important thing to keep in mind when looking at Class II lesions in X-rays?

The depth of the penetration of demineralization in enamel and dentin is actually greater than it appears in a bite-wing radiograph.

A caries lesion that appears radiographically to have penetrated about two thirds of the way through the proximal enamel has actually penetrated the dentinoenamel junction (DEJ).

True

If an occlusal caries lesion is present, what determines whether the lesions should be joined or treated with a separate occlusal restoration?

Depends on the distance between the two lesions. Signup and view all the answers

It's usually okay to extend the preparation further into a sound occlusal surface to provide retention of the proximal restoration.

False Signup and view all the answers

What can be done to enhance remineralization after the amalgam restoration has been placed?

Treated with fluoride and acid etched and coated with light-cured resin. Signup and view all the answers

What can be done to enhance remineralization before the amalgam restoration is placed?

Remove demineralized enamel and etch the sound enamel walls. Signup and view all the answers

What is the term for a Class II restoration necessitated only because of a proximal caries lesion limited to the marginal ridge area?

Slot restoration Signup and view all the answers

If the lesion involves the distal surface with access from the occlusal surface, what is it called?

A disto-occlusal slot restoration Signup and view all the answers

Any nicking or scarring of an adjacent tooth should be ___________ before the restoration is placed.

polished away Signup and view all the answers

Carious dentin is removed with which bur?

The largest round bur that will fit into the area. Signup and view all the answers

During preparation, demineralized dentin in the periphery should be:

Completely removed Signup and view all the answers

Which procedure is less likely to result in a pulpal exposure?

Using a slow rotating round bur Signup and view all the answers

Hand instruments such as a _______ may be used to fracture away the shell of enamel.

gingival margin trimmer Signup and view all the answers

In the proximal slot preparation, the walls should meet the proximal surface of the tooth at ___ degrees.

90 Signup and view all the answers

To provide resistance form for the Class II amalgam restoration, the proximal preparation should have a mesiodistal dimension of about ___ mm or more.

1.5 mm Signup and view all the answers

What determines the location of the gingival floor?

Sited by the gingival extent of the carious lesion. Signup and view all the answers

If the extension of Class II preparation into the occlusal groove is necessitated, how wide should be the isthmus?

1/4th of the intercuspal distance Signup and view all the answers

Retention grooves are placed with a round No. or bur.

1/8 or 1/4 Signup and view all the answers

For a proximal slot restoration, retentive undercuts should be at least ___ mm deep.

0.5 mm Signup and view all the answers

When is placement of the retention points or grooves unnecessary?

When the occlusal extension is wide and has parallel walls. Signup and view all the answers

Retention points should be cut parallel faciolingually to the DEJ and to the external surface of the tooth.

True Signup and view all the answers

In proximal slot restorations, what is the only feature that will prevent dislodgment of the restoration proximally?

Retention spots and undercuts Signup and view all the answers

Where is the correct location for the retention grooves for preparation with a deep proximal box?

Just inside the DEJ and NOT in the corners of the box. Signup and view all the answers

What is a keyhole preparation?

Class II amalgam restoration with facial or lingual access instead of occlusal. Signup and view all the answers

When is it recommended to access the Class II lesion from the facial or lingual surface instead?

If a proximal caries lesion is at or apical to the cementoenamel junction. Signup and view all the answers

Which of the following is not a feature of all rubber dam clamps?

Wing Signup and view all the answers

What are the clamps recommended for daily use in dentistry?

W8A, B1, 27, No.W2A, No. 212SA retractor. Signup and view all the answers

Rubber dam material is:

Both A and B Signup and view all the answers

What is the advantage of using wingless clamps?

Less likely to interfere with matrix bands and wedges. Signup and view all the answers

4 prongs of the retainer should contact the tooth, not beyond the ____________.

transitional line angle Signup and view all the answers

What is the clamp of choice for anterior teeth?

No. 212S Signup and view all the answers

What is the clamp of choice for upper and lower molars?

14A Signup and view all the answers

The retainer used for Class V lesions is _________.

212 retainer Signup and view all the answers

Why is it important for the restoration wall to be at a 90° angle with the enamel surface?

To put the bulk of mercury in there. Signup and view all the answers

If the amount of intact marginal ridge in a Class II amalgam restoration is less than 1.6 mm for premolars, what should be the correct orientation of the walls?

Slightly divergent occlusally to prevent undermining. Signup and view all the answers

If the amount of intact marginal ridge is more than 1.6 mm for premolars, what should be the correct orientation of the walls?

Parallel Signup and view all the answers

The reverse S is placed on which side?

Buccal Signup and view all the answers

What is the ideal clearance distance from the adjacent proximal surface F, L, G?

0.2 - 0.3 mm Signup and view all the answers

What hand instruments can be used to shape and smooth the proximal box?

Margin trimmer and hatchet. Signup and view all the answers

Study Notes

Detection of Caries

Caries in Class II restorations can be detected visually or via X-ray.
X-ray examination may not accurately reflect the depth of demineralization; actual penetration may be more extensive.

X-ray Interpretation

A radiographically visible caries lesion near the dentinoenamel junction (DEJ) may have progressed further than expected.

Restoration Techniques

If occlusal and proximal caries lesions are close, they should typically be joined; if not, treat separately.
Avoid extending the preparation into sound occlusal surfaces to maintain tooth strength.

Enhancing Remineralization

After restoration, fluoride treatment can aid remineralization.
Before restoration, demineralized enamel can be removed and the area restored with bonded resin composite.

Types of Restorations

A Class II restoration limited to the marginal ridge is termed a slot restoration.
If access to a distal lesion is from the occlusal surface, it’s classified as a disto-occlusal slot restoration.

Preparation Techniques

Polishing is needed to remove damage from an adjacent tooth before restoration.
Use a large round bur to remove carious dentin thoroughly, ensuring sound dentin supports the enamel margins.

Efficient Tools

Slow rotating round burs reduce the risk of pulpal exposure compared to spoon excavators.
After initial preparation, gingival margin trimmers can help refine enamel edges.

Preparation Angles and Dimensions

Proximal box walls should meet at 90 degrees and converge occlusally for proper retention.
The mesiodistal dimension for resistance form should be around 1.5 mm.

Retention Features

The gingival floor location depends on carious extent or the need for margin separation.
For effective retention, the isthmus width during occlusal extension should be 1/4th of the intercuspal distance.

Retention Grooves

Use round burs of sizes No. 1/8 or 1/4 to create retention grooves.
Retentive undercuts in proximal slot restorations should be significant (at least 0.5 mm deep).

Rubber Dam Clamps

Rubber dam clamps lack wings in wingless designs, indicated by a “W” before the number.
Recommended clamps for everyday use include W8A, B1, 27, W2A, and 212SA retractors.

Materials and Instruments

Rubber dam material may be latex rubber or vinyl; wingless clamps minimize interference with procedures.
Retainers should make contact with the tooth at transitional line angles to avoid injury.

Specific Restorations

For anterior teeth, the preferred clamp is No. 212S; for molars, choose 14A.
Class V lesions are treated with a 212 retainer, ensuring holes are punched slightly buccal.

Surgical Preparation

Restoration walls should form a 90° angle with the enamel surface for optimal mercury placement.
Orientation of walls in Class II restorations depends on intact marginal ridge thickness; walls should diverge if less than 1.6 mm for premolars.

Geometry and Clearance

A reverse S shape is added on the buccal side to ensure proper extension without undermining enamel.
Ideal clearance from adjacent proximal surfaces is 0.2 - 0.3 mm.

Hand Instruments

Use margin trimmers and hatchets for shaping and smoothing the proximal box during preparation.

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Description

This quiz covers essential knowledge for detecting caries in Class II amalgam restorations. It explores methods like visual examination and X-ray, and emphasizes the deeper implications of caries appearance in radiographs. Test your understanding of these critical concepts in dental restoration.