Histologic aspects of the bone and soft tissues surrounding three titanium non-submerged plasma-sprayed implants...

The authors report the histological features found around three non-submerged titanium plasma-sprayed implants retrieved, after a 10-month loading period, from an autopsy case. At the time of implant insertion, the clinician had noted a wide vestibular dehiscence of the central implant, and it was decided to use a bioabsorbable membrane for guided bone regeneration in this area. After specimen processing, it was possible at low magnification to observe that in the most vestibular slides, the central implant was almost completely surrounded by connective tissue, while in the most lingual slides, the quantity of bone around the implant tended to increase. The other two implants had a bone-implant contact percentage of about 60%. Only in a few areas was mineralized bone in direct contact with the metal surface, while around the major portion of the implant perimeter a layer of unmineralized, red-stained, osteoid material was present. No inflammatory infiltrate was present in the epithelium and in the supracrestal connective tissues. The fibers of this tissue had a different orientation: in the most coronal portion of the implants (smooth surface), they tended to run parallel implant's surface, while in the most apical region (plasma-sprayed surface), they tended to be arranged in a perpendicular fashion. These results, in man, were strikingly similar to those previously reported in dogs and monkeys.