Biomechanical effect of crestal bone osteoplasty before implant placement: a three-dimensional finite element analysis.

This study investigated the biomechanical effects of crestal bone osteoplasty and flattening procedures carried out in edentulous knife-edge ridges to restore bone width before implant placement on the virtually placed implants using finite element methods. Three-dimensional models representing a knife-edged alveolar bone with two different crestal cortical bone thicknesses (1.6mm, thin group; 3.2mm, thick group) were created. Gradual crestal bone osteoplasty with 0.5mm height intervals was simulated. Cylindrical implants with abutments and crowns were constructed and subjected to oblique loads. Maximum stress was observed at the cervical region around the implant neck. Different osteoplasty levels showed different stress values and distributions. Highest compressive stress was observed in the flat models (60.8 MPa and 98.3 MPa in thick and thin groups, respectively), lowest values were observed when osteoplasty was limited to the sharp edge (36.8 MPa and 38.9 MPa in thick and thin groups, respectively). The results suggested that eliminating the sharp configuration in knife-edge ridges improved stress and strain outcomes, but flattening the alveolar crest and/or uncovering the cancellous bone resulted in a marked increase in compressive stress and strain values in the peri-implant bone that may influence the longevity of implants placed in these ridges.