PLAQUE-INDUCED PERI-IMPLANTITIS IN THE PRESENCE OR ABSENCE OF KERATINIZED MUCOSA - AN EXPERIMENTAL-STUDY IN MONKEYS

In 5 monkeys a total of 30 transmucosal endosseous dental implants wer e inserted in edentulous areas of the mandible with presence or absenc e of keratinized mucosa. After a healing period of 3 months with optim al plaque control, all implants were exposed to plaque accumulation fo r periods up to 9 months. To secure abundant plaque accumulation on ha lf the number of the implants, cotton wool ligatures were placed aroun d the implants at the entrance to the peri-implant sulcus. Attachment loss was measured clinically and histometrically, and tissue recession was measured clinically. Ligated implants without keratinized mucosa demonstrated significantly more recession and slightly more attachment loss than the other implants. The results of this study suggest that the absence of keratinized mucosa around dental endosseous implants in creases the susceptibility of the peri-implant region to plaque-induce d tissue destruction.