A novel silicate-doped calcium-based composite dental pulp capping agent

The development of a dental pulp capping agent (DPCA) requires suitable setting time, acceptable compressive strength, favorable bioactivity, and to facilitate cementum tissue regeneration. Calcium phosphate cement (CPC) is widely used for its self-setting, biodegradability, biocompatibility, and formability. However, a relative low strength and lack of bioactivity have limited its application. Herein, dicalcium silicate (Ca2SiO4, C2S) was introduced into CPC to prepare a novel silicate-doped CPC/C2S composite DPCA by self-setting in situ and its setting time, compressive strength, bioactivity, and biomineralization behaviors were investigated. The results indicated that the mechanical strength and setting time of DPCA were higher than those of pure CPC. C2S transformed into a C-S-H gel without disturbing the hydration of DPCA after soaking in SBF for 5 days. Moreover, much more bone-like hydroxyapatite layers were formed, and DPCA exhibited higher bioactivity mainly in virtue of the rapid formation of C-S-H. DPCA with 15 wt% C2S. suggested to be the optimized composite, exhibited significantly improved bioactivity and high compressive strength, indicating that DPCA with 15 wt % C2S might have a significant pulp capping therapy advantage over the pure CPC. (C) 2009 Curtin University of Technology and John Wiley & Sons, Ltd.