HISTOLOGICAL AND MICRORADIOGRAPHIC EVALUATION OF HYDRATED AND HARDENED ALPHA-TRICALCIUM PHOSPHATE CALCIUM-PHOSPHATE DIBASIC MIXTURES

Bone tissue response to pre-hardened alpha-tricalcium phosphate (alpha -TCP) and calcium phosphate dibasic (DCPD) mixture by hydration was st udied histologically and microradiographical ly after implanting on th e inferior aspect of the mandible in rabbits. In I-month implants, new bone formation was observed along the surface of the material near th e host bone, and connection of new and host bone through thin bone bri dges was seen in some places. In 3-month implants, newly formed bone f illed the greater part of the gap between material and host bone, and in B-month implants, it surrounded almost all the surface of the mater ial. New bone was in direct contact with the material in all implant p eriods. The bone response was essentially consistent with that to hydr oxyapatite (HA). Resorption of the material was noticed in 3- and 6-mo nth implants. It was concluded that pre-hardened alpha-TCP/DCPD mixtur e has good biocompatibility with bone tissue equal to HA and that it r esorbs when implanted in rabbit. Further research should be performed to evaluate the material changes of resorption and formation of the wh ite zone.