Definite Implant Position as Novel Readout for Effectiveness of Ridge Preservation Indicates to Beneficial Effect of Combined Treatment with Platelet-Rich Fibrin (PRF) and Xenogenic Biomaterial in Bone Regeneration

Methods of ridge preservation following tooth extraction, aiming to maintain alveolar bone volume and support tissue regeneration, have been extensively researched. Continuously, new approaches and materials are being explored in this context. To scientifically evaluate outcomes, the pre-implant situation is usually assessed radiologically, histologically, and/or clinically. However, the influence of ridge preservation on implant placement itself is rarely examined in depth, and if at all, the focus has been on implant stability or survival rates. Based on the assumption that preoperative radiological assessment, including cone beam computed tomography, provides only an indirect and inherently limited approximation of actual intraoperative bone condition, undetected factors such as insufficient bone density, mechanically unfavorable trabecular structure, or incompletely resorbed residual biomaterial may necessitate a shift of the implant from the preferred position originally occupied by the tooth root. We therefore established a method that evaluates and categorizes implant position in three dimensions based on radiological data post-implantation. Our data, derived from a multicenter randomized clinical trial (RCT), demonstrate that the greatest positional deviations are observed without preservation, whereas the combination of biomaterial and PRF most frequently allowed for central implant placement. The proposed method proves well suited for evaluating the outcome of ridge preservation procedures. The findings demonstrate that both the absence and presence, and further the type, of preservation have a measurable influence on the final implant positioning.