Mona K. Marei, BDS, CAGS, MSC.D, Ahmed El-Sabrooty, BDS,
Ahmed Y. Ragab, BDS, Mohamed A. El-Osairy, BDS
 Alexandria University, Alexandria, Egypt.

 
This study was performed to evaluate the effect of adding tin or aluminum powder with average particie size of 10/u.m to heat curing acrylic resin in a concentration of 5% by volume. Four physical and mechanical properties were tested for the purpose of this evaluation: thermal con­ductivity, impact strength, compressive strength, and warpage. The addition of 5% by volume of either metal powder to polymethylmethacrylate (PMMA) improved the four tested proper­ties. However, tin powder was superior to aluminum powder in improving the impact and compressive strength of PMMA, while aluminum powder was superior to tin powder in impro­ving thermal conductivity of PMMA and decreasing its warpage. Both metal powders caused undesirable discoloration to the heat curing acrylic resin. The use of metaUfilled resin is there­fore recommended in the areas where it is not displayed to get the benefit of improved physical and mechanical properties of PMMA.

Saudi Dental Journal 1994;6(2):69-77.