In-Vitro Investigation of Fatigue and Fracture Behavior of Transmucosal versus Submerged Bone Level Implants Used in Fixed Prosthesis

Background: The present in vitro study aimed to investigate the fatigue performance of different dental fixtures in two different emergence profiles. Biological failures are frequently reported because the problem canonly be solved by replacing a failing implant with a new one. Clinicians addressed minor mechanical failures, such as bending, loosening or the fracture of screws, abutment, or the entire prosthesis, by simply replacing or fixing them. Methods: Transmucosal and submerged bone-level dental implants underwent fatigue strength tests (statical and dynamical performance) by a standardized test: UNI EN ISO 14801:2016. Two types of emergence profiles (Premium sub-crestal straight implant with a cylindrical-shaped coronal emergence or Prama one-piece cylindrical-shape implant with transmucosal convergent neck and hyperbolic geometry) were tested, and dynamic fatigue were run to failure. Data was analyzed by a suitable statistical tool. Results: The Wöhler curve of 0.38 cm Premium group c2, appeared to be significantly different from that of the 0.38 cm Prama group c3 (nonparametric one-way ANOVA χ² = 6; degree of freedom = 1; probability = 0.0043) but not from that of the 0.33 cm Premium group c1 (nonparametric one-way ANOVA χ² = 0.62; degree of freedom = 1; probability = 0.4328). Fatigue performance of configuration 2 was one and a half times better than that of configuration 3. Group c3 had a better ultimate failure load (421.6 ± 12.5 N) than the other two settings i.e., c1 (324.5 ± 5.5 N) and c2 (396.3 ± 5.6) reaching almost a nonsignificant level. Conclusions: It was observed that a transmucosal implant design could provide the highest resistance to static fracture. On the other hand, an equicrestal implant design could increase dynamic endurance.