Comparison of histological effects of different bioceramic implants on surgically created periodontal defects in...

The biological response to the resorbable and nonresorbable bone grafting materials implanted in the surgically created defects was compared in 4 Maccaca cyclopsis. Intraosseous angular defects were created on the mesial side of both upper canines and premolars by an air driven fissure bur. The root surface was planed, then hydroxylapatite (HA) and tricalcium phosphate (TCP) were inserted into the right side defects respectively. The left side canine received no implants and served as the control site. The animals were sacrificed 6 and 16 weeks after the experiment. Histologically, the two implant materials were well tolerated by the surrounding tissues and did not elicit any adverse inflammatory reaction. During the 16 weeks periods, TCP was biodegraded through phagocytosis by histiocytes and multinucleated giant cells. The residual particles were incorporated into the new bone matrix and displayed the bone growth guiding property. HA particles were dense and larger in size with low resorption rate, therefore, encapsulation by fibrous tissue was more commonly seen. Although direct bone deposition adjacent to the HA particle surface was apparently found, new bone formation was observed only at the apical portion adjacent to the host alveolar bone. These findings suggested that HA might rather play the role as a biocompatible filler. However, HA was more effective in blocking the downgrowth of the junctional epithelium. Nevertheless, these two implant materials could not hasten the healing process, because new bone formation was observed to be more distinct in the control site.