Titanium endosteal dental implants in the mandibles of beagle dogs: a 2 year study.

Forty of 44 vented endosteal blade implants were well tolerated by the mandibular tissues of beagle dogs, as demonstrated clinically, radiographically, and histologically. Infection and inflammation were not observed. The epithelium did not invade along the neck of the implants more than 2 mm. below the mandibular crest. After 3 to 6 months, except for increasing density of bone at the metal interface, no distinct pattern of reaction could be discerned histologically. Except for heavy collagenous investment in three dogs, there was no sign of the implants being treated as sterile foreign bodies. In this study, histology did not provide good criteria for evaluating the failure of vented endosteal blade implants. In four implants which failed, the most reliable signs of failure were increased mobility and/or sulcus depth around the neck of the abutments. Radiographic evaluation of implants provided the best means of determining bone resorption. Bone resorption was apparent 3 to 6 months after implantation, did not appear to be progressive, and did not indicate implant failure or impending implant failure in those animals in which it occurred. Radiolucent areas observed in 29 of the specimens contained connective tissue, marrow spaces, thin bone trabeculae, and nonpathologic tissues. Although in some of the dogs stress on implants did not cause failure, there is a need for further experimentation involving vented endosteal blades subjected to occlusal loading.