Clinical evaluation of two dental implant macrostructures on peri-implant bone loss: a comparative, retrospective study.

OBJECTIVES: To compare the effect of two implant macrostructures on peri-implant bone level. MATERIAL AND METHODS: This retrospective cohort study was conducted in a private practice. Patients received test (Nobel Speedy Groovy implants) or control implants (Mk III implants) or both. Baseline and corresponding follow-up radiographs, taken with a long-cone technique, were analyzed to evaluate mean bone level changes around implants during a mean follow-up of 69 ± 19 months. A chi-squared test was performed to compare the bone level changes between the two types of implants. A multivariate analysis was used to explain the difference between the two groups. RESULTS: After controlling for inclusion and exclusion criteria, 144 dental implants corresponding to 68 implants in the test group and 76 implants in the control group were placed in 59 patients. Nine dental implants (6.25%) were lost during the observation period: five implants in the test group and four implants in the control group. Consequently, a total of 135 implants placed in 58 patients were available for analysis. Our study shows a significant difference of peri-implant bone level overtime between the test and control groups (P < 0.01). At the end of the observation period, a bone growth was observed in the control group (0.02 ± 0.80 mm), whereas a bone loss was found in the test group (-0.43 ± 1.11 mm). The mean bone level at baseline and the type of periodontal therapy and the maintenance care program were involved in this difference (P < 0.001, P = 0.035, P < 0.001, respectively). CONCLUSION: Our study demonstrates a significant difference in peri-implant bone level between test and control groups. The mean bone level at baseline, the type of periodontal therapy, and the maintenance program may explain peri-implant bone level changes overtime.