Fabrication of Carbonate Apatite Cement as Endodontic Sealer

Abstract

Carbonate Apatite (CO3Ap) cement has been widely used for bone substitute. It is known that CO3Ap crystals have the close composition to natural bone. It is expected that CO3Ap cement may play an essential role in endodontics treatment, particularly as an endodontic sealer due to its potential to obturate root canal system to a more hermetic and stable environment. Therefore, the aim of this study is to fabricate CO3Ap cement as a new material for endodontic sealer. The CO3Ap cement sealer was prepared by mixing dicalcium phosphate anhydrous (DCPA), vaterite and calcium hydroxide [Ca(OH)2] with 0.2 mol/L Na2HPO4 containing 1% sodium carboxymethyl cellulose (NaCMC) and 32 µg thymoquinone, with liquid to powder ratio of 0.6. The set cement was incubated at 37°C under 100% relative humidity for 72 h. In this study, five compositions of powder ratio were prepared. The diametral tensile strength (DTS) evaluation indicated that CO3Ap cement made of 60% DCPA, 30% Vaterite and 10% Ca(OH)2 has the highest mechanical strength compared with the other compositions. X-ray diffraction (XRD) analysis of the set cement with the highest DTS value indicated that CO3Ap crystals were successfully formed. The set cement with the highest DTS value showed the highest density compared with the other compositions evidenced from scanning electron microscope (SEM) images. In conclusion, the CO3Ap cement was successfully fabricated by mixing DCPA, vaterite and Ca(OH)2. The CO3Ap cement prepared from 60% DCPA, 30% Vaterite and 10% Ca(OH)2 demonstrated the highest DTS value compared with the other compositions.