Synergic effect of chitosan and dicalcium phosphate on tricalcium silicate-based nanocomposite for root-end dental application.

In recent years, cement composites based on calcium silicate have been more generally considered for medical applications. Calcium silicate Cement are among the categories that are used in dental root canal treatment. The aim of this study is to make new calcium silicate cement with dicalcium phosphate and chitosan additives to preserve and strengthen desirable properties of this type of cements. In this study, composite dental cement based on calcium silicate was prepared. Then effect of adding biodegradable and biocompatible polymer such as chitosan on setting properties and its structure were studied. In this study, a combination of calcium silicate, dicalcium phosphate (DCP) and bismuth oxide (BiO) as powder phase and 2% solution of the chitosan dissolved in 1% acetic acid solution as liquid phase, was used. As well as control sample was obtained by mixing the powder with distilled water as the liquid phase. Based on the obtained results, setting time of composite cement was changed from 51 to 67 minutes by adding chitosan polymer. Presence of chitosan also reduced the compressive strength a little. The bioactivity of the cement were studied in a solution of simulated body fluid (SBF) for 14 days. The samples were analyzed by SEM to identify the microstructure and by XRD to determine crystal structure. The composition of cement before incubation in SBF was included early phases (phase calcium silicate and calcium phosphate) that after 14 days of immersion in SBF, they were converted to layer-shaped hydroxy apatite and the presence of chitosan had not any influence on the final phase of hydroxy apatite.