Evaluation of calcium phosphate cement as a root canal sealer filling material

Calcium phosphate cement for root end sealing was obtained by mixing α-tricalcium phosphate and additives with an aqueous solution of citric. Powder and liquid were mixed at a ratio of 1.25 g/mL. The biocompatibility of this material was investigated primarily by subcutaneous implantation tests. Then calcium phosphate cement was used to fill three adult dogs' root canal, both calcium hydroxide paste and hydroxyapatite paste as control. The animals were killed at 4,12,20 weeks postoperatively respectively. The effects of different materials on the apical closure, restoration of periapical tissues and adaptability to the dentinal surface were examined by optical and electronic microscope. The observation at 20 weeks shows that the calcium phosphate cement has the potentialities of being a root canal sealer filling material available for pulpless teeth with open-apex and destructive periapical tissue.