Quantitative analysis of the effects of brushing, flossing, and mouthrinsing on supragingival and subgingival plaque microbiota: 12-week clinical trial.

BACKGROUND: Translational microbiome research using next-generation DNA sequencing is challenging due to the semi-qualitative nature of relative abundance data. A novel method for quantitative analysis was applied in this 12-week clinical trial to understand the mechanical vs. chemotherapeutic actions of brushing, flossing, and mouthrinsing against the supragingival dental plaque microbiome. Enumeration of viable bacteria using vPCR was also applied on supragingival plaque for validation and on subgingival plaque to evaluate interventional effects below the gingival margin. METHODS: Subjects with gingivitis were enrolled in a single center, examiner-blind, virtually supervised, parallel group controlled clinical trial. Subjects with gingivitis were randomized into brushing only (B); brushing and flossing (BF); brushing and rinsing with Listerine® Cool Mint® Antiseptic (BA); brushing and rinsing with Listerine® Cool Mint® Zero (BZ); or brushing, flossing, and rinsing with Listerine® Cool Mint® Zero (BFZ). All subjects brushed twice daily for 1 min with a sodium monofluorophosphate toothpaste and a soft-bristled toothbrush. Subjects who flossed used unflavored waxed dental floss once daily. Subjects assigned to mouthrinses rinsed twice daily. Plaque specimens were collected at the baseline visit and after 4 and 12 weeks of intervention. Bacterial cell number quantification was achieved by adding reference amounts of DNA controls to plaque samples prior to DNA extraction, followed by shallow shotgun metagenome sequencing. RESULTS: 286 subjects completed the trial. The metagenomic data for supragingival plaque showed significant reductions in Shannon-Weaver diversity, species richness, and total and categorical bacterial abundances (commensal, gingivitis, and malodor) after 4 and 12 weeks for the BA, BZ, and BFZ groups compared to the B group, while no significant differences were observed between the B and BF groups. Supragingival plaque vPCR further validated these results, and subgingival plaque vPCR demonstrated significant efficacy for the BFZ intervention only. CONCLUSIONS: This publication reports on a successful application of a quantitative method of microbiome analysis in a clinical trial demonstrating the sustained and superior efficacy of essential oil mouthrinses at controlling dental plaque compared to mechanical methods. The quantitative microbiological data in this trial also reinforce the safety and mechanism of action of EO mouthrinses against plaque microbial ecology and highlights the importance of elevating EO mouthrinsing as an integral part of an oral hygiene regimen. TRIAL REGISTRATION: The trial was registered on ClinicalTrials.gov on 31/10/2022. The registration number is NCT05600231.

Quantitative analysis of the effects of essential oil mouthrinses on clinical plaque microbiome: a parallel-group, randomized trial.

BACKGROUND: The rich diversity of microorganisms in the oral cavity plays an important role in the maintenance of oral health and development of detrimental oral health conditions. Beyond commonly used qualitative microbiome metrics, such as relative proportions or diversity, both the species-level identification and quantification of bacteria are key to understanding clinical disease associations. This study reports the first-time application of an absolute quantitative microbiome analysis using spiked DNA standards and shotgun metagenome sequencing to assess the efficacy and safety of product intervention on dental plaque microbiome. METHODS: In this parallel-group, randomized clinical trial, essential oil mouthrinses, including LISTERINE® Cool Mint Antiseptic (LCM), an alcohol-containing prototype mouthrinse (ACPM), and an alcohol-free prototype mouthrinse (AFPM), were compared against a hydroalcohol control rinse on clinical parameters and the oral microbiome of subjects with moderate gingivitis. To enable a sensitive and clinically meaningful measure of bacterial abundances, species were categorized according to their associations with oral conditions based on published literature and quantified using known amounts of spiked DNA standards. RESULTS: Multivariate analysis showed that both LCM and ACPM shifted the dysbiotic microbiome composition of subjects with gingivitis to a healthier state after 4 weeks of twice-daily use, resembling the composition of subjects with clinically healthy oral conditions recruited for observational reference comparison at baseline. The essential oil-containing mouthrinses evaluated in this study showed statistically significant reductions in clinical gingivitis and plaque measurements when compared to the hydroalcohol control rinse after 6 weeks of use. CONCLUSIONS: By establishing a novel quantitative method for microbiome analysis, this study sheds light on the mechanisms of LCM mouthrinse efficacy on oral microbial ecology, demonstrating that repeated usage non-selectively resets a gingivitis-like oral microbiome toward that of a healthy oral cavity. TRIAL REGISTRATION: The trial was registered on ClinicalTrials.gov on 10/06/2021. The registration number is NCT04921371.

Efficacy of flossing and mouth rinsing regimens on plaque and gingivitis: a randomized clinical trial.

BACKGROUND: To investigate the effects of combinations of mechanical (brushing and flossing) and chemotherapeutic regimens which included essential oils (EO) non-alcohol and alcohol-containing mouthrinses compared to brushing only in the prevention and reduction of plaque, gingivitis, and gingival bleeding. METHODS: This was a randomized, virtually supervised, examiner blind, controlled clinical trial. Following informed consent and screening, subjects (N = 270) with gingivitis were randomly assigned to one of the following regimens: (1) Brush Only (B, n = 54); (2) Brush/Rinse (EO alcohol-containing mouthrinse) (BA, n = 54); (3) Brush/Rinse (EO non-alcohol containing mouthrinse) (BZ, n = 54); (4) Brush/Floss (BF, n = 54); (5) Brush/Floss/Rinse (EO non-alcohol containing mouthrinse) (BFZ, n = 54). Unflavored waxed dental floss (REACH unflavored waxed dental floss), and fluoridated toothpaste (Colgate Cavity Protection) were used. Examinations included oral hard and soft tissue, plaque, gingivitis, gingival bleeding, probing depth and bleeding on probing. RESULTS: After 12 weeks, both BA and BZ and the BFZ group were superior in reducing interproximal plaque (30.8%, 18.2%, 16.0%, respectively), gingivitis (39.0%, 36.9%, 36.1%, respectively), and bleeding (67.8%, 73.6%, 79.8%, respectively) compared to B. The BF group did not provide significant reductions in interproximal plaque but did reduce interproximal gingivitis (5.1%, p = 0.041) at Week 4 and bleeding at Weeks 4 and 12 (34.6%, 31.4%, p < 0.001 respectively) compared to B. The BFZ group did not significantly reduce interproximal plaque, gingivitis or bleeding compared to BZ. CONCLUSIONS: This study demonstrated that the addition of EO non-alcohol containing mouthrinse to the manual toothbrushing and flossing regimen further reduces plaque, gingivitis and bleeding showing that addition of EO mouthrinses (alcohol or non-alcohol containing) to the oral hygiene regimen provides sustained reductions in plaque to help maintain gingival health after a dental prophylaxis. Dental professional recommendation of the addition of an EO non-alcohol containing mouthrinse to daily oral hygiene routines of brushing or brushing and flossing should be considered to aid supragingival plaque control and improve gingivitis prevention. STUDY REGISTRY NUMBER: NCT05600231.

Comparative Effectiveness of Toothbrushing, Flossing and Mouthrinse Regimens on Plaque and Gingivitis: A 12-week virtually supervised clinical trial.

Purpose:Various mechanical and chemotherapeutic methods are used to control dental plaque accumulation and prevent or reduce gingivitis. The purpose of this 12-week clinical trial was to investigate the effects of various combinations of supervised mechanical and chemotherapeutic regimens on the prevention and reduction of plaque, gingivitis, and gingival bleeding.Methods:Volunteers presenting with some evidence of gingivitis and no severe periodontitis were randomized into four groups: brush only (BO); brush/rinse (BR); brush/floss (BF); brush/floss/rinse (BFR) for this examiner-blinded clinical trial. Toothbrush, toothpaste, floss and a mouthrinse containing a fixed combination of four essential oils (EO) and training/instructions were provided to participants as per their assigned group. Participants performed their regimen at home, under virtual supervision, once each weekday; the second daily and weekend uses were unsupervised. Assessments included oral hard and soft tissue, plaque, gingivitis, and gingival bleeding (weeks 4, 12); probing depth and bleeding on probing (week 12).Results:Of 213 enrolled participants, 209 completed the study. After 12 weeks, plaque, gingivitis, and gingival bleeding were significantly reduced in groups BR (35.8%, 50.8%, and 71.0% respectively, p<0.001) and BFR (32.8%, 54.1%, and 78.2% respectively, p<0.001) compared to BO. After 12 weeks, gingivitis and gingival bleeding were significantly reduced in the BF group (9.2%, p=0.013 and 17.5%, p=0.003, respectively), however there were no significant reductions in plaque in the BF group as compared to the BO group (p=0.935).Conclusions:Oral care regimens that included a mouthrinse containing a fixed combination of four EOs (BR and BFR), demonstrated statistically significantly reduced plaque, gingivitis, and gingival bleeding as compared to BO and BF after 12 weeks. The BF regimen statistically significantly reduced gingivitis and gingival bleeding but did not statistically significantly reduce plaque compared to BO after 12 weeks.

Role of Manual Dexterity on Mechanical and Chemotherapeutic Oral Hygiene Regimens.

Purpose:Effective use of mechanical plaque control devices can depend on individual manual dexterity levels. The purpose of this component of a 12-week, virtually-supervised clinical trial was to investigate the role of manual dexterity on clinical outcomes for gingivitis, as measured by the relationship between manual dexterity scores on the Purdue Pegboard Test (PPT) and the effects of various mechanical and chemotherapeutic oral hygiene regimens.Methods:This was a single-center, examiner blinded, randomized, four-treatment arm, parallel group, 12-week plaque and gingivitis study. At baseline, healthy adult volunteers with evidence of gingivitis were assessed for manual dexterity and were then examined for plaque, gingivitis and bleeding. After a dental prophylaxis, participants were randomized into four treatment groups: brush only (BO); brush/rinse (BR); brush/floss (BF); and brush/floss/rinse (BFR). The flossing groups received instruction in flossing. The PPT was used to assess manual dexterity and was performed by a licensed occupational therapist. Virtual supervision was required once each weekday and the oral hygiene regimen was unsupervised on evenings and weekends.Results:Of the 213 subjects enrolled, 209 completed the trial. Improvements from baseline to week 12 in interproximal percent nonbleeding healthy sites (Expanded Bleeding Index (EBI)=0 and Modified Gingival Index (MGI)=0 or 1) were dependent on the participant's dexterity score. Participants with the lowest dexterity scores (9 or lower) in the BFR treatment group demonstrated the greatest improvement interproximally based on the indices (EBI and MGI). In comparison, the BF test group subjects with dexterity scores 9 or lower had limited change in improvement interproximally. There was a direct correlation between flossing effectiveness and dexterity scores.Conclusions:Less manual dexterity can limit dental flossing effectiveness. Flossing is a difficult daily task that requires functional bilateral dexterity to be perform correctly. Individuals with lower levels of manual dexterity were shown to benefit from the addition of an essential oil mouthrinse to a regimen of toothbrushing and flossing in this clinical trial. The addition of an essential oil mouthrinse improved interproximal gingival health and mitigated the manual dexterity variable.

Habits, Practices and Beliefs Regarding Floss and Mouthrinse among Habitual and Non-Habitual Users.

Purpose:The purpose of this survey was to investigate how flossing and rinsing behaviors impact individual beliefs about oral disease risk, the efficacy of floss and mouthrinse, and the perceived benefits and barriers of floss and mouthrinse.Methods:Participants in this required component of a 12-week plaque and gingivitis randomized clinical trial on flossing and rinsing regimens completed a paper questionnaire prior to randomization and baseline/screening measurements.Results:All of the clinical trial participants (n=213) completed the questionnaire. Respondents were grouped as habitual or non-habitual users of floss or mouthrinse if the product was used at least once daily; 16% (n=34) were habitual users of floss and 17% (n=36) were habitual users of mouthrinse. Perceived barriers included fear of gingival bleeding and pain, forgetting, and not including flossing or rinsing as part of the daily oral care routine. Non-habitual users were less likely to believe in the intangible benefits of flossing or rinsing and much more likely to perceive barriers to using floss or mouthrinse. Risk perception of developing oral disease was not shown to predict product usage. Respondents viewed their risk of developing gingivitis as relatively low despite this diagnosis being confirmed clinically among the participants.Conclusions:While respondents strongly believed that brushing, flossing, and mouthrinse use carry unique benefits and that combining all three methods would be optimal, these respondents still had high perceived barriers to using floss and mouthrinse regularly and consequently these habits were not included in their daily oral hygiene regimen. Understanding the perceptions regarding oral health behaviors may help drive more effective interventions and assist practitioners in improving their patients' oral health outcomes.