Effect of Filler Ratio on Properties of Nano-hydroxyapatite/SiO_2 Based Bioactive Dental Resin Composites

摘要

Hydroxyapatite (HAP), as an essential component of bone and tooth, is one of the promising bioactive materials. The purpose of this study was to investigate the effects of incorporation of nano-HAP and SiO_2 particles on the properties of bioactive dental composite. Silanized HAP and SiO_2 were mixed with BisGMA/TEGDMA (1/1 wt/wt) monomers at various HAP/SiO_2 mass ratios of 0:7 (no HAP), 5.25/1.75, 3.5/3.5,1.75/5.25, 7:0 (no SiO_2) to yield a series of pastes all containing 70 wt% filler loading. The results showed that flexural strength, elastic modulus and compressive strength gradually decreased with increasing amount of HAP particles, as well as curing depth and polymerization shrinkage, which resulted from the nature of HAP particle material. Water sorption and solubility in water increased slightly with addition of HAP particles. Degree of conversion test could support results above well. Remineralization test in SBF demonstrated dental composite with HAP particles had a good apatite-forming ability. Consequently, dental composite filled with lower amount of nano-HAP (HAP/SiO_2 around 0.25) particles would possess better comprehensive performances.