Background: This study was aimed to investigate if the adjunctive use of erythritol air-polishing powder applied with the nozzle-system during subgingival instrumentation (SI) has an effect on the outcome of non-surgical periodontal treatment in patients with moderate to severe periodontitis. Methods: Fourty-two individuals with periodontitis received nonsurgical periodontal therapy by SI without (controls, n = 21) and with adjunctive air-polishing using nozzle + erythritol powder (test, n = 21). They were analyzed for the clinical variables BOP (primary outcome at six months), probing depth (PD), attachment level, four selected microorganisms and two biomarkers at baseline, before SI as well as three and six months after SI. Statistical analysis included nonparametric tests for intra- and intergroup comparisons. Results: In both groups, the clinical variables PD, attachment level and BOP significantly improved three and six months after SI. The number of sites with PD ≥ 5 mm was significantly lower in the test group than in the control group after six months. At six months versus baseline, there were significant reductions of Tannerella forsythia and Treponema denticola counts as well as lower levels of MMP-8 in the test group. Conclusions: Subgingival instrumentation with adjunctive erythritol air-polishing powder does not reduce BOP. But it may add beneficial effects like reducing the probing depth measured as number of residual periodontal pocket with PD ≥ 5 mm when compared with subgingival instrumentation only. Clinical relevance: The adjunctive use of erythritol air-polishing powder applied with the nozzle-system during SI may improve the clinical outcome of SI and may reduce the need for periodontal surgery. Trial registration The study was retrospectively registered in the German register of clinical trials, DRKS00015239 on 6th August 2018, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL.

Hitherto no study has been published on the effect of the adjunctive administration of essential oils following scaling and root planing (SRP). This study describes the effect of a mouthrinse consisting of essential oils (Cymbopogon flexuosus, Thymus zygis and Rosmarinus officinalis) following SRP by clinical and microbiological variables in patients with generalized moderate chronic periodontitis. Forty-six patients (aged 40–65 years) with moderate chronic periodontitis were randomized in a double-blind study and rinsed their oral cavity following SRP with an essential oil mouthrinse (n = 23) or placebo (n = 23) for 14 days. Probing depth (PD), attachment level (AL), bleeding on probing (BOP) and modified sulcus bleeding index (SBI) were recorded at baseline and after 3 and 6 months. Subgingival plaque was taken for assessment of major bacteria associated with periodontitis. AL, PD, BOP and SBI were significantly improved in both groups after three (p < 0.001) and 6 months (p ≤ 0.015). AL improved significantly better in the test than in the control group after 3 and 6 months (p < 0.001), so did PD after three months in the tendency (p = 0.1). BOP improved better in the test group after 3 months (p = 0.065). Numbers of Treponema denticola (p = 0.044) and Fusobacterium nucleatum (p = 0.029) decreased more in the test than in the control group after 3 months, those of Tannerella forsythia after 6 months (p = 0.039). Prevotella micra (p < 0.001, p = 0.035) and Campylobacter rectus (p = 0.002 , p = 0.012) decreased significantly in both groups after 3 months. The adjunctive use of a mouthrinse containing essential oils following SRP has a positive effect on clinical variables and on bacterial levels in the subgingival biofilm. 332-12-24092012, DRKS 00009387, German Clinical Trials Register, Freiburg i. Br., 16.09.2015