Local Minocycline Effect on Inflammation and Clinical Attachment During Periodontal Maintenance: Randomized Clinical Trial

Background: Minocycline microspheres (MMs) are being used to treat residual inflamed periodontal pockets during periodontal maintenance therapy (PMT), but evidence for efficacy from randomized clinical trials is lacking. The purpose of this study is to evaluate the effect of MMs plus scaling and root planing (SRP) on these sites. Methods: Sixty patients with chronic periodontitis on 6‐month PMT intervals to be followed for 1 year were randomized (51 completed the study) into two statistically similar groups, SRP + MM (aged 66.8 years) and SRP alone (aged 67 years), to treat a ≥5 mm posterior interproximal pocket during PMT with a history of bleeding on probing (BOP). Group treatments were applied to the site at baseline and 6 months. Clinical attachment levels (CALs; primary outcome), probing depths (PDs), plaque, and BOP also were recorded at baseline and 6 and 12 months. In addition, gingival crevicular fluid was analyzed for an inflammation index ratio of interleukin (IL)‐1β/IL‐1 receptor antagonist (ra) using enzyme‐linked immunosorbent assays. Results: All clinical parameters improved significantly (P <0.005) from baseline in both groups with no differences between groups at any time point. CAL decreased 17% (0.9 ± 0.8 mm) and 13% (0.7 ± 0.9 mm) in SRP + MM and 11% (0.7 ± 1.1 mm) and 21% (1.2 ± 0.9 mm) in SRP at 6 and 12 months, respectively. The odds of having BOP decreased 90% (down to 38% of patients) and 95% (26%) in SRP + MM and 82% (42%) and 82% (41%) in SRP at 6 and 12 months, respectively. IL‐1β/IL‐1ra decreased a significant 61% (P = 0.009) only in SRP + MM at 6 months. Conclusions: SRP of inflamed moderate pockets during 6‐month PMT, with or without MMs, improves CALs, along with PDs and BOP over a 1‐year period. The use of MMs did not result in an additional benefit over SRP alone.