Periodontal repair in dogs: A biosabsorbable calcium carbonate coral implant enhances space provision of alveolar bone regeneration in conjunction with guided tissue regeneration

Background: Collapse or compression of a barrier device into a periodontal defect or onto the root surface compromises outcomes following guided tissue regeneration (GTR). Bone biomaterials have been suggested to support regeneration of alveolar bone and to improve space provision with GTR devices. The objective of this study was to evaluate space provision, alveolar bone, and cementum regeneration following use of a bioabsorbable, calcium carbonate biomaterial in conjunction with GTR. Methods: Routine, critical size, 5 to 6 mm, supraalveolar, periodontal defects were created in 5 young adult beagle dogs. Alternate jaw quadrants in consecutive animals received GTR and the coral biomaterial (cGTR) or GTR alone. The animals were euthanized 4 weeks postsurgery and tissue blocks processed for histometric analysis. Results: The coral implant particles were surrounded by newly-formed bone or immersed in connective tissue and appeared to resorb and be replaced by bone. There was limited, if any, appreciable cementum regeneration. Space provision was enhanced in cGTR compared to GTR sites (6.1 ± 1.6 versus 2.4 ± 0.8 mm²; P<0.05). Bone regeneration (height) was significantly increased in cGTR compared to GTR sites averaging 1.9 ± 0.6 and 1.2 ± 0.6 mm, respectively (P<0.05). Bone regeneration (area) was 2-fold greater in cGTR sites compared to the GTR control (3.3 ± 1.8 versus 1.4 ± 0.5 mm²), however the difference was not statistically significant (P>0.05). Conclusions: The coral implant significantly enhanced space provision for GTR while alveolar bone formation appeared to be enhanced by its use. Increased healing intervals are needed to fully understand the biologic value of the coral implant as an adjunct to GTR.