Initial healing in the dog of submerged versus non-submerged porous-coated endosseous dental implants.

It has previously been reported that porous-coated root form endosseous dental implants, became well integrated when used in the traditional 2-stage surgical approach. In this study, the placement of the implant in a 1-stage (non-submerged) technique was to be explored. Implants were placed in the mandibles of dogs, and 2 designs were used differing only in that one (experimental) had a 3-mm transgingival extension, permitting it to be exposed to the oral cavity from the outset. 12 (3 per animal) non-submerged implants were placed on 1 side of 4 beagle dogs and 12 control (submerged) implants were placed contralaterally. All implants were allowed to heal for 6 weeks, after which histological preparations were made. 2 of 12 non-submerged implants were lost due to post-operative complications; otherwise, all implants healed uneventfully. Histomorphometric analysis revealed bone-implant contact, as assessed by absolute bone contact (ABC) and contact length fraction (CLF), to be greater for the submerged design, suggesting that bone healing may be delayed with the non-submerged approach. As well, at this early stage of healing, for both implant designs, ABC and CLF were significantly greater on proximal than on buccal and lingual aspects.