PULPAL RESPONSE TO CALCIUM-PHOSPHATE MATERIALS IN-VIVO STUDY OF CALCIUM-PHOSPHATE MATERIALS IN ENDODONTICS

The aim of this study was to determine if calcium phosphate (CaP) materials could be used to substitute for calcium hydroxide (CH) as a pulp capping agent. Especially prepared and characterized CaP materials with CH as the reference or control material were used for pulp-capping teeth of pigs, rats, and dogs. The CaP materials included: DCPD (dicalcium phosphate dihydrate), OCP (octacalcium phosphate), beta-TCP (beta-tricalcium phosphate), BCP (biphasic calcium phosphate mixture of 50/50 HA and beta-TCP), and HA (hydroxyapatite) which were used in particle sizes of < 5 mum or < 150 mum. The animals were sacrificed after 21 days to 4 months after pulp-capping. The extracted teeth were immediately prepared for the following analyses: light microscopy, scanning electron microscopy (SEM) using backscattered electrons (BSE), and energy dispersive X-ray (EDX) microanalysis. Three types of mineralizations were observed: dentin bridge formation, dystrophic calcification and mineralization. All the CaP materials showed biocompatibility. Based on these results, it is suggested that the CaP materials tested may be useful for specific clinical applications in endodontics, e.g., pulp capping (microparticles of HA, TCP, BCP), and pulpectomy (HA, OCP, DCPD).