Density, Polymerization Shrinkage, Filler Content and Coefficient of Thermal Expansion of Composite Resins for Crown and Bridge

Abstract

Density, polymerization shrinkage, filler content, constituent elements of filler and thermal expansion of ten composite resins (A3 enamel and dentin pastes) for crown and bridge were measured. Density of composite pastes was 1.493-2.528g/cm³, and that of set composites was 1.588-2.561g/cm³. Polymerization shrinkage of composites was 1.17-5.98 vol%. Inorganic filler content was 44.9-88.3wt%. Si or Al was the main component element of inorganic filler, and Ba, La, Sr, Zr and Zn were added as X-ray opaque materials. Thermal expansion was 16.8-96.4×10^-6/℃ (30-80℃). With an increase in inorganic filler, polymerization shrinkage and thermal expansion decreased.