Guided tissue regeneration ensures osseointegration of dental implants placed into extraction sockets. An experimental study in monkeys.

The aim of the present study was to explore the possibility of achieving osseointegration of dental titanium implants, inserted into alveoli immediately after tooth extraction, by covering the recipient site with a teflon membrane. In each of 7 monkeys, mucoperiosteal flaps were raised on the buccal and palatal aspects of the maxillary molars in both sides of the jaw. The second molars were then extracted and self tapping titanium implants of the screw type (Astra Dental Implants) were inserted into the sockets of the largest roots. In the coronal portion of the sockets, a void was always present between the implant and the socket walls. In one side of the jaw, a membrane (Gore-Tex Augmentation Material) was adjusted to cover the implant. The implant in the other side of the jaw served as control and was only covered by the tissue flaps. Microscopic analysis after 3 months of healing revealed that soft tissue was facing the coronal portion of the implants to a varying degree in the control side, while osseointegration was consistently observed to the top of the membrane-covered implants which remained submerged throughout the experimental period. The results suggest that the membrane technique can secure complete osseointegration of implants inserted immediately into extraction sockets.