Firing shrinkage of porcelain-resin composites prepared by laser lithography.

Using porcelain and resin-mixed composites as experimental materials, cubic polymerized composites were prepared by the accumulation of thin slices cured by laser scanning. The composites were then fired, and bulk ceramic bodies were made. The optimal firing conditions of polymerized composites and firing shrinkage were investigated. The results showed that cubic ceramic bodies in a form homologous to that before firing could be reproduced. The volume shrinkage of fired ceramic bodies consisting of 1 g of ceramic powders and 0.3 g of epoxy resin was about 30% under all firing conditions, and there were no significant differences between specimens. It was suggested that with further research and development, three-dimensional forms for clinical use in dentistry could be manufactured by the proposed method.