Histologic and histometric responses to polymeric composite grafts

The present study was designed to determine whether a polymeric composite promotes new attachment in artificially-induced bony defects in the dog model. HTR, hard tissue replacement, is a non-resorbable calcium-layered polymer of polymethyl-methacrylate and hydroxyethyl-methacrylate. It has been reported to be clinically non-inflammatory, osteophilic, and osteoconductive. For the study, 4 beagle dogs, 4 to 6 years old with no periodontal disease were used. Mucoperiosteal flaps were raised including the 2nd, 3rd, and 4th maxillary premolars. Buccal Class II furcation defects were created on these premolars. Reference notches were placed in the roots at the level of the bony defects. Test quadrants were selected by the toss of a coin, and furcations were filled with the polymeric composite particles wetted with sterile saline. Following grafting, the flaps were approximated and sutured. The contralateral side, serving as control, was treated by flap debridement only. Sutures were removed 7 days after surgery. Dogs were sacrificed 4 months following surgery. Mesio-distal histological sections were evaluated by descriptive histology. In addition, surface area determinations (in mm2) of the furcal tissues were carried out using the microscope attached to a digitizer and a computer. In 8 mesio-distal serial sections cut 30 microns apart in both experimental and control teeth, surface area determinations relative to the furcations were made evaluating: 1) the total fill of the furcation; 2) the area filled with alveolar bone; 3) the area occupied by connective tissue; 4) the area occupied by new deposited cementum; and 5) the area filled by epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)