INTRODUCTION: This systematic literature review aimed to evaluate the feasibility of xenogeneic bone blocks for ridge augmentation compared with autogenous blocks by analyzing block survival rates, block resorption, subsequent implant survival rate, post-surgical complications, and histomorphometric findings. MATERIALS AND METHODS: Electronic searches were conducted in the Medline (PubMed), Web of Science and Cochrane databases, complimented by a manual search in specialist journals, for relevant articles published up to March 2020. Inclusion criteria were human studies in which the outcomes of xenogeneic bone block grafts were evaluated by means of their survival rates and subsequent implant survival rates. RESULTS: Sixteen articles fulfilled the inclusion criteria and were analyzed. 333 patients were recruited with a total of 337 xenogeneic bone blocks and 82 autogenous bone blocks, showing block failure rates of 6.82% and 6.1%, respectively. Bone gain, in both height and width, was similar among xenogeneic and autogenous bone blocks, but autogenous bone blocks suffered greater resorption. Implant survival rates were slightly lower for xenogeneic bone blocks. Histological and histomorphometric analysis observed more bone formation and less residual bone substitute with autogenous bone blocks than xenogeneic bone blocks. CONCLUSIONS: Atrophic alveolar crest reconstruction with xenogeneic bone block grafts would appear to offer a viable alternative to autogenous bone block grafts, obtaining similar block graft failure rate, fewer sensitive postoperative complications but a slightly lower implant survival rate. Further investigations generating long term data are needed to confirm the feasibility of xenogeneic bone blocks in different clinical scenarios.
INTRODUCTION: This systematic literature review aimed to evaluate the feasibility of xenogeneic bone blocks for ridge augmentation compared with autogenous blocks by analyzing block survival rates, block resorption, subsequent implant survival rate, post-surgical complications, and histomorphometric findings. MATERIALS AND METHODS: Electronic searches were conducted in the Medline (PubMed), Web of Science and Cochrane databases, complimented by a manual search in specialist journals, for relevant articles published up to March 2020. Inclusion criteria were human studies in which the outcomes of xenogeneic bone block grafts were evaluated by means of their survival rates and subsequent implant survival rates. RESULTS: Sixteen articles fulfilled the inclusion criteria and were analyzed. 333 patients were recruited with a total of 337 xenogeneic bone blocks and 82 autogenous bone blocks, showing block failure rates of 6.82% and 6.1%, respectively. Bone gain, in both height and width, was similar among xenogeneic and autogenous bone blocks, but autogenous bone blocks suffered greater resorption. Implant survival rates were slightly lower for xenogeneic bone blocks. Histological and histomorphometric analysis observed more bone formation and less residual bone substitute with autogenous bone blocks than xenogeneic bone blocks. CONCLUSIONS: Atrophic alveolar crest reconstruction with xenogeneic bone block grafts would appear to offer a viable alternative to autogenous bone block grafts, obtaining similar block graft failure rate, fewer sensitive postoperative complications but a slightly lower implant survival rate. Further investigations generating long term data are needed to confirm the feasibility of xenogeneic bone blocks in different clinical scenarios.