Stress distribution of an anteriorly placed single implant in different clinical scenarios: a 3D finite element analysis

BACKGROUND: Stress distribution around anterior dental implants may vary depending on implant placement timing and loading protocol. This study aimed to evaluate stress distributions around anteriorly placed single implants under different clinical scenarios using three-dimensional finite element analysis (FEA). METHODS: Three clinical scenarios were simulated: (i) healed bone with delayed loading, (ii) healed bone with immediate loading, and (iii) immediate implant placement into a fresh extraction socket with immediate loading. Two abutment angulations (5° and 10°) were evaluated. Horizontal (25.5 N) and oblique (178 N at 30° to the implant long axis) forces were applied to the palatal surface of the restoration. Stress distributions in cortical and trabecular bone were assessed using maximum (P1) and minimum (P3) principal stresses, while von Mises stresses were calculated for the implant and abutment. RESULTS: In cortical bone, the highest tensile stress values occurred under oblique loading in the healed bone-immediate loading scenario (P1: 38.67-38.94 MPa), whereas minimal cortical stresses were observed in the immediate implant placement scenario (P1 ≤ 4.32 MPa). In trabecular bone, the highest stresses were recorded in the immediate implant placement with immediate loading, reaching P1 values of 11.20 MPa (5°) and 12.88 MPa (10°) under oblique loading, followed by healed bone with immediate loading (P1 up to 6.72 MPa). Oblique loading consistently generated higher stress values than horizontal loading. Increasing abutment angulation resulted in slightly higher stress magnitudes without altering stress distribution patterns. CONCLUSIONS: Stress distribution around anterior single implants is primarily influenced by the clinical placement and loading protocol. Immediate implant placement combined with immediate loading resulted in the highest stress concentrations, particularly in trabecular bone, whereas healed bone with delayed loading demonstrated the most favorable stress distribution. Abutment angulation had a secondary effect on stress magnitude.