Synthesis Of Calcium Silicate Hydrate And Application Research Of Tooth Remineralization

Silicate base materials become hot research point due to the good biocompatibility and biodegradation. Previously studies have shown that silicate base materials have higher bioactivity than calcium phosphate materials, and the silicate base materials have been widely used for filling or repairing of bone and joint. As a silicate base biomaterials, calcium silicate hydrate just mainly used in cement now. Recently research found that calcium silicate hydrate can be used as drug carrier for drug delivery research. It just said that calcium silicate hydrate have good vitro bioactivity. However, there is no report of systematic research the vitro bioactivity of calcium silicate hydrate. So, it is very important meanings of systematic research of calcium silicate hydrate to make it used as bioactivity materials.In this study, calcium silicate hydrate was prepared by method of chemical precipitation. And research the influence of prepared calcium silicate hydrate of different calcium sources. Then research the effect of pH value and Ca/Si ratio for vitro bioactivity and deposition ability in tooth of calcium silicate hydrate. Lastly, calcium silicate hydrate was remineralization for enamel and dentine.The result of this study as follow:(1) Calcium silicate hydrate powder was successfully prepared by chemical precipitation method using different calcium sources. The morphology of the product is uniform; the size is well-distribution; the size test show that the products particle size were about 450 nm and 360 nm. From the analysis of XRD spectra obtained that using calcium hydroxide as calcium source for preparation of calcium silicate hydrate with high purity, high in vitro bioactivity. But using calcium nitrate as the calcium source preparation of calcium silicate hydrate has miscellaneous peak, and weak in vitro bioactivity.(2) The effect of pH value for calcium silicate hydrate show that calcium silicate hydrate can induce in vitro formation of hydroxyapatite, and having good deposition on enamel at pH values of 9 and 11. However, when pH values increased to 13, the calcium silicate hydrate cannot induce the formation of hydroxyapatite. And it was found that calcium silicate hydrate inducing the formation of relatively uniform mineralized layers in enamel only at pH value of 11. Study effect of Ca/Si ratio for the calcium silicate hydrate of inducing the formation of mineralized layer capacity and deposition in enamel at three conditions of 1:2,1:1,2:1. Research results show that, when the calcium silicon ratio is 1:2, the calcium silicate hydrate with optimal induces the formation of mineralized layer capacity. Therefore, the optimum reaction condition of synthesis of calcium silicate hydrate was that pH value of the system is about 11, and Ca/Si ratio is 1:2.(3) The enamel remineralization study found that calcium silicate hydrate in enamel can induce the formation of bone-like apatite. What is more, along with the remineralization time increased, the remineralization layer thickness is increased. The thickness remineralization layer may reduce enamel wear and corrosion by acid. For dentin remineralization study found that calcium silicate hydrate also can induce the formation of bone-like apatite in dentine. With increase the concentration of calcium silicate hydrate, the quantity of calcium silicate hydrate deposited in dentin surface increasing. The induction of apatite depth in dentinal tubules is also increasing, and even reached 5μm. Calcium silicate hydrate with good dentinal tubules occluding effect may play a role in repair of hypersensitive teeth.