Treatment of Peri-Implant Mucositis with Repeated Application of Chlorhexidine Chips or Gel during Supportive Therapy—A Randomized Clinical Trial

RUNNING HEAD: Peri-implant maintenance with CHX ABSTRACT: Background: To assess the effect of chlorhexidine (CHX) chip application in patients with peri-implant mucositis as compared to CHX gel application. Methods: In peri-implant sites with mucositis, CHX gel was applied in the control group (GC) and CHX chips in the test group (CC) at baseline and after three months. At baseline and after six months, peri-implant pocket depths (PPD), bleeding-on-probing (BOP) and activated matrix metalloproteinase-8 (aMMP8) were assessed. Longitudinal changes were tested for inter-group differences. Results: Thirty-two patients were treated. BOP was more reduced (p = 0.006) in CC than in GC, with means and standard deviations of 46 ± 28% and 17 ± 27%, respectively. PPD was more reduced (p = 0.002) in CC than in GC with 0.65 ± 0.40 mm and 0.18 ± 0.32 mm, respectively. Regarding BOP, the percentages of improved, unchanged and worsened sites accounted for 32%, 61% and 7% in GC and 46%, 53% and 1% in CC, respectively. For probing pocket depth, the according values were 26%, 66% and 8% (GC) versus 57%, 38% and 5% (CC). Conclusions: During supportive therapy, repeated CHX chip application might resolve marginal peri-implant inflammation in terms of bleeding better than CHX gel.