Impact of Connection Design and Abutment Material on the Stress Created in the Underlying Bone with Different Tightening Torque Values – A Finite Element Analysis Study

A BSTRACT Context: Studies evaluating the stress created on the underlying bone due to variations in the torque values and the type of implant–abutment interface with different abutment materials are still lacking. Aim: The aim of this study was to investigate the impact of connection design and abutment material on the stress created in the underlying bone with different tightening torque values using finite element analysis (FEA). This study aims to inform clinicians on optimal implant selection and torque application for enhanced implant longevity. Materials and Methods: A three-dimensional FEA was conducted on models created from DICOM images of a maxillary anterior segment. The models were constructed using Pro/Engineer Wildfire 2.0 and analyzed in Ansys software. Implants with internal conical–hex, CrossFit, and TorcFit connections were paired with titanium and zirconia abutments. Torque values of 30 Ncm, 35 Ncm, and 40 Ncm were applied, with loading forces of 100 N, 150 N, and 200 N in oblique orientation. Statistical analysis was performed using one-way ANOVA and post hoc Tukey’s test. Results: Significant differences in stress distribution were observed based on torque values, abutment materials, and connection types. Higher torque values led to increased stress at the buccal and palatal aspects, especially at 100 N and 150 N loading forces ( P < 0.05). Titanium abutments exhibited superior stress distribution compared to zirconia at the crest of the implant under a 100 N load. The CrossFit connection demonstrated the most favorable stress distribution pattern, effectively minimizing stress concentrations compared to the internal conical–hex and TorcFit connections. Conclusions: This study highlights the critical impact of torque application, abutment material selection, and connection design on stress distribution around dental implants. Titanium abutments and the CrossFit connection showed optimal performance in managing stress, suggesting that these choices may contribute to improved implant stability and longevity. Precise torque application is essential to mitigate risks of complications such as bone resorption and screw loosening.