Incidence and pattern of implant fractures: A long-term follow-up multicenter study

Background: Currently, there is incomplete understanding of the fracture patterns in the implant and their association with clinical factors. Purpose: The aim of this study was to investigate the incidence and pattern of implant fracture (IF) by using 9-year, long-term multicenter follow-up data. Materials and Methods: The association of the incidence and differences in fracture patterns with clinical factors (based on patient variables and implant variables) was assessed for statistical significance using the Chi-square and Fisher exact test, as appropriate. Results: Among a total of 19 087 implants in 8501 patients (7838 male and 663 female) placed over 9 years, fractures were observed in 70 implants (0.4%) in 57 patients (50 male and 7 female). Cases with less than 50% bone loss had a higher incidence of horizontal and vertical IFs limited to the crest module, which are defined as Type I fractures (n = 13, 18.6%). In contrast, cases with ≥50% severe bone loss exhibited a higher incidence of Type II vertical fractures (n = 22, 31.4%), extending beyond the crestal portion (P =.001). Type III fractures (n = 5, 7.1%), defined as a horizontal fracture beyond the crestal module, were also observed. Conclusion: Peri-implantitis-induced marginal and vertical bone loss and manufacturing-induced defects were considered to be major factors in IF. Therefore, using clinically verified implant systems and striving to minimize bone loss by preventing and actively treating peri-implantitis is essential to reduce IFs.