Effect of Nonsurgical Mechanical Debridement With or Without Chlorhexidine Formulations in the Treatment of Peri-Implant Mucositis. A Randomized Placebo-Controlled Clinical Trial

Objectives: To evaluate the treatment of peri-implant mucositis (PM) using a nonsurgical submarginal peri-implant instrumentation (NSPI) with or without chlorhexidine (CHX) solutions. Methods: Fifty-six patients (28 per group) were randomly assigned to the test (NSPI + 0.12% mouthwash and subgingival CHX irrigation plus tongue brushing with 1% CHX gel) or the control group (NSPI + placebo mouthwash and subgingival placebo irrigation plus tongue brushing with placebo gel). At baseline, 1, 3, 6 months, bleeding on probing (BOP), probing pocket depth (PPD), modified gingival index (mGI), modified plaque index (mPlI), full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS), and the proportions of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were recorded. The BOP reduction was set as a primary outcome. Data were analyzed to assess BOP reduction at a 6-month follow-up and to identify significant predictors of implant-site BOP through mixed generalized linear regression. Results: After 6 months in both groups, a significant reduction of BOP, PD, mPlI, mGI, FMBS, and FMPS was noted (p < 0.05). However, at 6 months, the test group was more effective than the controls in reducing median BOP (∆values control/test: 39.3% [95% CI 37.4–42.3] vs. 48.7 [95% CI 46.5–51.2], p = 0.044), as well as mPlI (p = 0.041) and the proportion of Treponema denticola (p = 0.039). Moreover, the implant-sites BOP reduction was significantly influenced by test treatment (p < 0.001), history of periodontitis (p = 0.003), and a high number of cigarettes/day (p = 0.002), the proportion of Porphyromonas gingivalis (p = 0.021) and Tannerella forsythia (p = 0.032). Conclusions: NSPI + CHX showed better results compared to placebo in implant-sites BOP reduction. The high number of cigarettes/day and the proportion of Porphyromonas gingivalis and T. forsythia negatively influenced the BOP reduction in PM-treated patients.