DIMENSION OF THE PERIIMPLANT MUCOSA - BIOLOGICAL WIDTH REVISITED

The objective of the present study was to determine the dimension of t he mucosal-implant attachment at sites with insufficient width of the ridge mucosa. 5 beagle dogs were used. Extractions of all mandibular p remolars were performed and 3 months later, 3 fixtures of the Branemar k System(R) were installed in each side. Following 3 months of healing , abutment connection was carried out. On the right or left side of th e mandible, abutment connection was performed according to the Branema rk System(R) manual - (control side). On the contralateral. side (test side), an incision not extending through the periosteum was made at t he crest of the ridge. The soft tissue was dissected and a critical am ount of connective tissue on the inside of the flap was excised. The p eriosteum was Subsequently incised, abutment connection performed, and the trimmed flaps sutured. The sutures were removed after 10 days. Af ter a 6-month period of plaque control, the animals were sacrificed, b iopsies sampled and processed for light microscopy. The length of the junctional epithelium varied within a rather narrow range; 2.1 mm (con trol side) and 2.0 mm (test side). The height of the suprabony connect ive tissue in this model varied between 1.31+/-0.3 mm (test side) and 1.8+/-0.4 mm (control side). At sites where the ridge mucosa prior to abutment connection was made thin (less than or equal to 2 mm), wound healing consistently included bone resorption. This implies that a cer tain minimum width of the periimplant mucosa may be required, and that bone resorption may take place to allow a stable soft tissue attachme nt to form.