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.
Keywords: Alveolar bone loss; dental implants; logistic regression; radiography, dental; retrospective study; survival analysis.