Injectable calcium phosphate and styrene-butadiene polymer-based root canal filling material.

Abstract

Three-dimensional obturation of the root canal system is mandatory for a successful root canal treatment. Using a filling material with optimal properties may enable the root canal to be sealed well and therefore obtain the desired obturation. To develop a new injectable paste endodontic filling material using calcium phosphate powder and a styrene-butadiene emulsion polymer. The powder phase comprised an equivalent molar ratio of tetracalcium phosphate, anhydrous dicalcium phosphate, bismuth oxide, and calcium chloride. The liquid phase comprised a styrene-butadiene rubber emulsion in distilled water. The powder and the liquid were mixed to achieve a paste consistency. The paste was subjected to various tests including flow, setting time, dimensional change, solubility, and radiopacity to indicate its suitability as a root canal filling material. All these tests were conducted according to the American National Standards Institute-American Dental Association for endodontic sealing materials. After passing these tests, the paste was submitted to an injectability test. The material showed acceptable flowability with 19.1 ± 1.3 min setting time and 0.61 ± 0.16% shrinkage after 30 days of storage. We found the highest solubility at 24 h (6.62 ± 0.58%), then the solubility decreased to 1.09 ± 0.08% within 3 days. The material was more radiopaque than a 3 mm step on an aluminum wedge. Furthermore, the material showed good injectability of 93.67 ± 1.80%. The calcium phosphate powder in styrene-butadiene emulsion met basic requirements for a root canal filling material with promising properties.