Effects of uncontrolled periodontitis on marginal bone alterations around implants: A case-control study.

BACKGROUND The hypothesis of bacterial infection initiating marginal bone loss around dental implant in analogy with natural tooth is still in debate. PURPOSE The aim of this retrospective study was to investigate the effects of uncontrolled periodontitis on marginal bone alterations around implants compared with the periodontal health group at a mean follow-up of at least 6 years. MATERIALS AND METHODS Thirty consecutive uncontrolled periodontally compromised patients (PCP) and 30 periodontally healthy patients (PHP), with a total of 96 Straumann implants (PCP = 55, PHP = 41) were matched for age, gender, smoking, and implant characteristics. The inclusion criteria for PCPs were continuing tooth loss due to uncontrolled periodontal disease and no supportive periodontal maintenance after implant therapy. Peri-implant conditions were examined and the number of teeth lost during the follow-up periods was recorded in both groups. Radiographic marginal bone loss of implants and adjacent teeth was calculated having the restoration time point as baseline. RESULTS No implant loss occurred in both groups. The mean number of teeth lost during the follow-up periods was 0.67 ± 0.80 in the PHP group, 3.93 ± 2.36 in the PCP group with statistical significance. The average overall bone loss was significantly greater at teeth than that around implants in the PCP group (0.54 ± 0.27 versus 0.22 ± 0.25 mm, P < .001), while no statistically significant differences were observed in the PHP group (0.18 ± 0.08 versus 0.22 ± 0.18 mm, P = .317). No statistically significant differences were observed between PC and PH patients when comparing the peri-implant marginal bone loss. No significant correlations were found between teeth loss and crestal bone loss at implants sites in both groups. CONCLUSION This study indicated that the marginal bone level around implants seemed more stable in comparison to that around the natural teeth when exposed to uncontrolled periodontal disease.