Effects of bone morphogenetic protein‐6 on periodontal wound healing/regeneration in supraalveolar periodontal defects in dogs

Objective Application of a synthetic BMP‐6 polypeptide in a rat periodontal fenestration defect model enhanced periodontal wound healing/regeneration including new bone and cementum formation. The purpose of this study was to translate the relevance of these initial observations into a discriminating large animal model. Methods Critical‐size (4–5 mm) supraalveolar periodontal defects were created at the 2 nd and 3 rd mandibular premolar teeth in 11 Beagle dogs. Experimental sites received BMP‐6 at 0.25, 1.0 and 2.0 mg/ml soak‐loaded onto an absorbable collagen sponge ( ACS ) carrier or ACS alone (control) each condition repeated in four jaw quadrants. The animals were euthanized at 8 weeks when block biopsies were collected and processed for histologic/histometric analysis. Results BMP‐6 at 0.25, 1.0 and 2.0 mg/ml soak‐loaded onto the ACS yielded significantly enhanced new bone (0.99 ± 0.07 versus 0.23 ± 0.13 mm/BMP‐6 at 0.25 mg/ml) and cementum (2.45 ± 0.54 versus 0.73 ± 0.15 mm/BMP‐6 at 0.25 mg/ml) formation including a functionally oriented periodontal ligament compared with control ( p  < 0.05). A significant inverse linear association between BMP‐6 dose and new bone ( β  = −0.21 ± 0.09 mm, p  = 0.016) and cementum height ( β  = −0.34 ± 0.15 mm, p  = 0.023) was observed. Minimal root resorption was observed without significant differences between groups. Ankylosis was not observed for any of the experimental groups. Conclusions Surgical application of BMP‐6 / ACS onto critical‐size supraalveolar defects enhanced periodontal wound healing/regeneration, in particular cementogenesis including a functionally oriented periodontal ligament; the low BMP ‐6 0.25 mg/ml concentration apparently providing the most effective dose.