Influence of Facial Bone Thickness After Implant Placement into the Healed Ridges on the Remodeled Facial Bone and Considering Soft Tissue Recession: A Systematic Review

Purpose: A systematic review was performed of the dimensional changes in facial cortical bone followingimplant placement into healed ridges, with the aim of establishing a minimum bone thickness that limitssuch changes. The influence of such bone remodeling upon the soft tissues and implant survival wasalso evaluated. Materials and Methods: A search was done of two electronic databases (MEDLINE viaPubMed and CENTRAL), complemented by a manual search and lists of references. The risk of bias andmethodological quality were assessed using the Cochrane Collaboration tool, the Methodological Index forNon-randomized Studies (MINORS), and the Quality Appraisal Checklist for Case Series. Results: The searchyielded 536 publications, of which 11 (four randomized clinical trials, two non-randomized clinical trials,and five case series) were entered in the review. All the included studies reported vertical and horizontalimplant facial bone resorption. Decreased facial bone thickness was correlated with increased verticalbone resorption, which in turn was associated with slight soft tissue retraction. A meta-analysis could notbe performed, due to the heterogeneity of the study designs and measurement sites. Conclusion: Nominimum facial bone thickness was seen that would completely avoid peri-implant bone loss and maintainsoft tissue stability. However, a thickness of approximately 2 mm was associated with diminished verticalbone resorption and less peri-implant mucosal recession