Subgingival ultrasonic instrumentation of residual pockets irrigated with essential oils: a randomized controlled trial.

To evaluate the clinical efficacy of subgingival ultrasonic instrumentation irrigated with essential oils (EOs) of residual periodontal pockets. Sixty-four individuals with chronic periodontitis were invited to participate in this randomized, double-blind, parallel, and placebo-controlled clinical trial. All subjects received non-surgical periodontal therapy. After re-evaluation (baseline), residual pockets (pocket depth ≥5 mm) received test (ultrasonic instrumentation irrigated with EOs) or control therapy (ultrasonic instrumentation irrigated with negative control). Probing pocket depth (PPD), gingival recession (R), clinical attachment level (CAL), bleeding on probing (BOP), and plaque were assessed at baseline and after 4, 12, and 24 weeks. Differences between groups and changes over the course of time were analysed according to a generalized linear model. There was a significant reduction in PPD and BOP, as well as a significant CAL gain in the two groups (p<0.001). Nevertheless, there were no differences between the groups at any time of the study. When only initially deep pockets (PPD ≥7 mm) were analysed, a significantly greater CAL gain (p=0.03) and PPD reduction (p=0.01) was observed in the test group. The adjunctive use of EOs may promote significant CAL gain and PPD reduction in deep residual pockets.