Evaluation of the 45-degree labial bevel with a shoulder preparation

This study compared the margin opening of cemented porcelain-fused-to-metal crowns of three different casting designs: 80-degree bevels with metal collars, 80-degree bevels with porcelain applied to the labial collars, and 45-degree labial bevels with metal and porcelain to a common margin termination. There were no statistically significant differences between the margin opening of the three groups. Porcelain application and firing did not distort the facial margin. The 45-degree bevel with porcelain to the margin has greater esthetic potential and the same margin adaptation as the 80-degree bevel with an all-metal collar.