Ridge Preservation After Tooth Extraction With Buccal Bone Plate Deficiency Using Tunnel Structured β‐Tricalcium Phosphate Blocks: A 2‐Month Histologic Pilot Study in Beagle Dogs

Background: Reduction in alveolar ridge volume is a direct consequence of tooth extraction. Tunnel β‐tricalcium phosphate (β‐TCP) blocks were manufactured from randomly organized tunnel‐shaped β‐TCP ceramic. Efficacy of these blocks compared to extraction alone for alveolar ridge preservation after tooth extraction with buccal bone deficiency was evaluated. Methods: Maxillary first premolars of six beagle dogs were extracted after removing the buccal bone, and bone defects of 4 × 4 × 5 mm (mesio‐distal width × bucco‐palatal width × depth) were created. Fresh extraction sockets with buccal bone defects were filled with tunnel β‐TCP blocks at test sites. Two months after the operation, histologic and histometric evaluations were performed. Results: Regarding histologic sections, coronal and middle horizontal widths of the alveolar ridge were significantly greater at test sites (3.2 ± 0.5 and 3.6 ± 0.4 mm, respectively) than at control sites (1.2 ± 0.3 and 2.0 ± 0.6 mm, respectively). The amount of woven bone was significantly greater at test sites (62.4% ± 7.9%) than at control sites (26.8% ± 5.3%), although that of connective tissue and bone marrow was significantly greater at control sites (38.1% ± 6.2% and 16.0% ± 6.9%, respectively) than at test sites (10.7% ± 5.7% and 4.1% ± 2.2%, respectively). Regarding basic multicellular units, no statistically significant difference was found between the test and control sites (0.5% ± 0.1% and 0.6% ± 0.1%, respectively). Conclusion: Tunnel β‐TCP blocks represent an effective bone‐graft material for alveolar ridge preservation in fresh extraction sockets with buccal bone defects.