Occurrence of Progressive Bone Loss Around Anodized Surface Implants and Resorbable Blasting Media Implants: A Retrospective Cohort Study

Background: This study evaluates occurrence of progressive bone loss (PBL) around implants with different implant surfaces. Methods: Retrospective examination of 2,517 implants was performed in 903 patients, including 1,147 anodized‐surface implants in 454 patients and 1,370 resorbable blasting media (RBM)‐surface implants in 449 patients, which were placed from January 2006 to December 2010. Through regular check‐up radiographs and records, presence of PBL (up to >50% of fixture length) was investigated. Implant removal for any reason was regarded a failure. Results: In total, 2,186 implants (979 anodized implants and 1,207 RBM implants) in 793 patients were included in this study. PBL was more frequently observed among anodized implants (n = 36 in 21 patients; 4%) than among RBM implants (n = 19 in 14 patients; 2%), and this difference was statistically significant (P <0.001). Occurrence of PBL was significantly influenced by surface modification and implant diameter (odds ratio OR] of anodized surface = 4.40, 95% confidence interval CI] = 1.78 to 10.89, P = 0.001; OR of wide implants = 9.62, 95% CI = 1.13 to 81.68, P = 0.038; determined by mixed‐effects logistic regression analysis with random patient effect). However, total survival rate was significantly influenced by implant diameter and not by surface modification (P = 0.019), although effect of implant diameter was observed to be significant on anodized implants (P = 0.030). Conclusion: Implant surface modification and implant diameter are significantly associated with occurrence of PBL.