Effects of bone grafting, performed with corticotomies and buccal tooth movements, on dehiscence formation in dogs.

Abstract

A randomized split-mouth experiment was performed in dogs to determine the effects of bone grafting, together with corticotomies and buccal tooth movements, on dehiscence formation. Bilateral full-thickness mucoperiosteal buccal flaps were raised, and corticotomies were performed with a piezosurgery unit adjacent to the maxillary second premolars in 7 dogs. The experimental (graft+) sidereceived a demineralized freeze-dried allograph and a resorbable collagen membrane. The second premolars were expanded with archwires for 9weeks, followed by 3weeks of consolidation. Soft tissue measurements included probing depths, attachment loss, and recession. Tooth movements were monitored using intraoral, radiographic, and model measurements. Bone surrounding the second premolars was evaluated with microcomputed tomography. New bone formation was analyzed histologically using calcein and alizarin fluorescent labels, and hematoxylin and eosin stains. Postsurgical healing progressed normally with no signs of infection. The graft+ and control (graft-) second premolars underwent similar amounts of expansion (about 2.5mm intraorally; about 1.7mm radiographically) and tipping, with no statistically significant side differences. The soft tissue periodontium was not affected on either side. There were bony dehiscences on both the graft+ and graft- sides, with slightly but significantly (P=0.038) more bone loss over the mesial root on the graft- side. Bone material density was significantly (P=0.028) greater on the graft+side. Buccal bone apposition was evident surrounding graft particles, and mineralized particulate graft material was present at the apical aspect of the roots on the graft+side. Bone grafting does not prevent dehiscence formation because only a limited amount of new bone is formed, primarily at the more apical aspects of the tooth's roots.