Effect of Abutment Angulation and Material on Stress and Strain Distributions in Premaxillary Bone: A Three-Dimensional Finite Element Analysis

Background and Aim: Dental implants with angled abutments are often inserted in the anterior maxillary region due to the status of the residual ridge and aesthetic considerations. The purpose of this study was to assess stress and strain distributions in the premaxillary bone around dental implants by means of finite element analysis (FEA). Materials and Methods: Four three-dimensional (3D) finite element models were designed by using ANSYS 14.5 software: (1) a straight titanium abutment, (2) a straight zirconia abutment, (3) a 20° angled titanium abutment, and (4) a 20° angled zirconia abutment in the anterior maxilla. Standard Straumann® implants with regular necks (4.8×12 mm) were selected. Premaxillary bone with type 3 bone quality was modelled with a 0.5-mm-thick cortical layer. A 178-N oblique load was applied to the cingulum of the models. Afterwards, stress and strain distributions were measured by using ANSYS 14.5 software. Results: Maximum stress and strain concentrated at the implant-abutment joint at the cervical one-third of crestal bone, mainly in the labial surface. The abutment's material had a less substantial effect on the distribution of stress and strain compared to the angle of the abutment. Stress and strain concentration in angled abutments was higher than that in straight abutments. However, angled abutments transferred lower levels of stress and strain to the bone compared to straight abutments. Conclusion: It can be concluded that an angled abutment might decrease the stress and strain in the anterior maxillary bone in comparison with straight abutments.