Linings and caries in retrieved permanent teeth with amalgam restorations

Area of Science:

• Dental materials science
• Cariology
• Restorative dentistry

Background:

• Cavity linings are used in dental restorations to protect the pulp and reduce microleakage.
• The effectiveness of cavity linings in preventing secondary caries adjacent to amalgam restorations is not fully understood.

Purpose of the Study:

• To investigate the correlation between the presence, position, and integrity of cavity linings and the incidence of caries adjacent to amalgam fillings.

Main Methods:

• Microscopic examination of 57 extracted permanent teeth with amalgam fillings to detect cavity linings.
• Assessment of caries incidence adjacent and not adjacent to restorations.
• Evaluation of cavity lining washout at the cavosurface margin.

Main Results:

• Cavity linings were detected in 74% of teeth, with 53% showing adjacent caries.
• No significant difference in adjacent caries incidence was observed between lined and unlined cavities.
• Washout of cavity linings occurred in 36% of lined teeth, which showed a significantly higher incidence of adjacent caries (31% of lined specimens).

Conclusions:

• The presence of cavity linings alone does not reduce the incidence of adjacent caries.
• Washout of cavity linings is associated with a significantly higher risk of secondary caries.
• Maintaining the integrity of cavity linings is crucial for preventing recurrent caries.