Crestal Versus Subcrestal Short Plateau Implant Placement

Plateau implants are widely acknowledged for their high success rates due to their ability to minimize bone stress concentrations. In cases where there is insufficient bone height, crestal implant placement is a viable alternative. Otherwise, subcrestal placement of short implants is recommended as it plays a vital role in preserving crestal bone from overload. In this context, the biomechanical state of the bone is directly influenced by the depth at which the implant is inserted. The objective of this study was to assess the impact of crestal and subcrestal placement of short plateau implants in varying bone quality conditions on peri-implant bone stresses. A 5.0 × 5.0 mm Bicon Integra-CP™ implant was chosen for numerical analysis. Four posterior maxilla models with types III and IV bone, each having a 1.0 mm cortical bone thickness, were utilized. Simulations were conducted at different insertion depths: the implant neck was placed at the crestal level and −1, −2, and −3 mm subcrestal positions. A mean maximal oblique load of 120.92 N was applied to the center of the 7.0 mm abutment. Von Mises equivalent stress distributions in the surrounding bone were examined to identify areas with stress magnitudes exceeding 100 MPa in cortical bone and 5 MPa in cancellous bone.In all scenarios, the highest von Mises equivalent stress values were observed at the implant neck. The results indicated that the 5.0 × 5.0 mm Bicon Integra-CP™ implant, when placed crestally, resulted in safe bone von Mises equivalent stresses and offered promising clinical outcomes. However, in all subcrestal scenarios, the implant placement have led to von Mises equivalent stress values exceeding the acceptable range in cancellous bone due to the absence of contact with cortical bone. Notably, the tested Bicon implant displayed low sensitivity to deteriorating bone quality at the studied subcrestal levels, affirming the positive clinical experience with Bicon plateau implants.