Comparison of different maintenance strategies within supportive implant therapy for prevention of peri-implant inflammation during the first year after implant restoration. A randomized, dental hygiene practice-based multicenter study.

Purpose: This randomized clinical multicenter study compared different professional preventive approaches on peri-implant inflammation under supportive implant therapy (SIT).

Methods: 105 participants (167 implants) were randomly allocated to four groups. All participants were under SIT with a 3-month recall interval. Plaque removal was performed by using manual curettes, a sonic-driven scaler, and a prophylaxis brush (Group A), supplemented by chlorhexidine (CHX) varnish on the implant surfaces (Group C) or by using manual curettes, air polishing with glycine powder, and a prophylaxis brush (Group B), supplemented by treatment with CHX varnish on the implant surfaces (Group D). The peri-implant probing depths (PPD), mucosal recession (MR), and bleeding on probing (BOP) on implants were determined at baseline. After 12 months, the final PPD, MR, and BOP on implants were assessed. The statistical evaluation consisted of Kruskal-Wallis-test, Wilcoxon-test and Chi-squared test modified according to McNemar (P< 0.05).

Results: 62 subjects (n= 101 implants) were available for assessment. In Groups A, C, and D, no significant implant-related differences between baseline and follow-up were found in PPD, MR, and BOP. Group B showed a significant difference (P= 0.022) between baseline (1.77 ± 1.58 mm) and follow-up (2.31 ± 1.54 mm) in PPD. The location of implant (P= 0.02), the type of implant (P= 0.01), and the age of subject (P= 0.04) had significant influences on BOP.

Clinical Significance: All strategies were effective in preventing peri-implant inflammation. The supplemental application of chlorhexidine varnish had no significant additional benefit.