Full-crown castings made with water-saturated and dry casting ring liners

Area of Science:

• Dental Materials Science
• Prosthodontics
• Biomaterials Engineering

Background:

• Asbestos use in casting ring liners is declining due to carcinogenicity.
• Cellulose paper is emerging as a safer alternative to asbestos paper.
• Accurate fit of dental castings is crucial for crown longevity and patient comfort.

Purpose of the Study:

• To evaluate the effect of different cellulose paper ring liner conditions (dry vs. water-saturated) on the marginal fit of dental castings.
• To compare the fit of castings fabricated with dry liners, water-saturated liners, and no liners.

Main Methods:

• Standardized wax patterns were created for full crowns using brass dies.
• Marginal gaps of wax patterns were measured.
• Wax patterns were divided into three groups: dry liner, water-saturated liner, and no liner.
• Castings were fabricated and their marginal fit to the die was measured at the same points.

Main Results:

• A statistically significant difference was found between wax patterns and castings in all groups (p = 0.0051).
• No statistically significant difference in comparative casting fit was observed between the groups.
• Mean marginal space was 0.47 mm (dry liner) vs. 0.51 mm (water-saturated liner) vs. 0.52 mm (unlined).
• Dry liners resulted in smaller marginal spaces than water-saturated liners.

Conclusions:

• The use of dry cellulose paper ring liners may enhance the marginal fit of dental castings.
• Dry liners show potential for improving the precision of full crown fabrication.
• Further research may explore optimal conditions for using cellulose liners in casting procedures.