Effect of periodontitis history on implant success: a long-term evaluation during supportive periodontal therapy in a university setting

The aim of this retrospective study was to evaluate the long-term implant survival in patients with a history of chronic periodontitis, during supportive periodontal therapy (SPT), compared to periodontally healthy patients. Twenty-nine periodontitis patients (test) with SPT for >= 9 years and implant-supported restorations (5 years follow-up) were recruited and pair-matched with 29 periodontally healthy patients (control). Subjects in both groups were examined following active periodontal therapy and/or implantation (T1) (test 69 implants, control 76 implants) and at end of SPT or supportive postimplant therapy (T2). Differences between the groups in implant survival (primary outcome), mean marginal bone loss (MBL) and pocket probing depths (PPDs) (secondary outcomes) were evaluated. Implant survival over 5 years was 97.1% in test compared to 97.4% in control group (p = 0.562). MBL was significantly different (test 18.7 +/- 18.2%; control 12.5 +/- 21.3%) (p < 0.05). PPDs increased at T2 in both groups (test: T1 3.4 +/- 1.0 mm; T2 4.2 +/- 1.6 mm; control: T1 1.0 +/- 1.2 mm; T2 2.9 +/- 0.8 mm; p < 0.05 between groups). Prognostic factors for implant loss appeared to be the presence of residual periodontal pockets of 4 mm (OR 1.90), bone height (OR 1.81) and age (OR 1.16) at T1. In terms of implant survival, no differences were observed between periodontitis and periodontally healthy patients. However, patients with history of periodontitis showed higher MBL and PPDs compared to periodontally healthy patients. The presence of a good periodontal maintenance program with preceding successful active periodontal treatment seems to be indispensable components of successful implant treatment in patients with history of chronic periodontitis.