A randomized crossover trial assessing denture adhesive for prevention of food infiltration among partial denture wearers.

PURPOSE: This two-treatment, four-period, double-blind, randomized controlled crossover trial assessed the ability of two denture adhesives, both applied with a thin nozzle in a continuous application pattern, to prevent food infiltration beneath partial dentures. METHODS: Participants with mandibular partial dentures and a history of food particle infiltration were enrolled. All participants used both an optimized calcium/zinc partial salt of polyvinyl methyl ether/maleic acid (PVM/MA) denture adhesive and a calcium/sodium partial salt of PVM/MA test denture adhesive, twice each, throughout four study periods, according to a randomly assigned sequence. At each visit, participants underwent two assessments: once with no denture adhesive (baseline) and once with denture adhesive, 1 hour after adhesive application. For each assessment, participants ate one-half of the top of a poppy seed muffin, and a dental professional counted the seeds retained on the denture and mucosa, which was the primary variable. The change-from-baseline comparison was made for each treatment separately using a paired t-test or Wilcoxon Signed Rank test depending on the normality of the data. A between-treatment comparison for the change from baseline was performed using a crossover ANCOVA with treatment and period as fixed effects and participant as a random effect. The baseline poppy seed count was used as a covariate. RESULTS: 30 participants were enrolled; 29 completed the trial. Both denture adhesives achieved statistically significantly fewer retained seeds versus baseline (P< 0.001). The calcium/zinc adhesive reduced the seed count from baseline by 85.9% (6.18 vs 0.86), and the calcium/ sodium adhesive reduced seed count by 76.6% (6.04 vs 1.43). Comparing the two denture adhesives, the reduction in seed count from baseline was statistically significantly greater for the calcium/zinc adhesive versus the calcium/sodium formulation (P= 0.008). CLINICAL SIGNIFICANCE: These results support the recommendation of denture adhesive use for the prevention of food infiltration beneath partial dentures, with optimized calcium/zinc denture adhesive showing the greatest prevention benefit.

Effects of stannous fluoride dentifrice on gingival health and oxidative stress markers: a prospective clinical trial.

BACKGROUND: Periodontal disease results in oral dysbiosis, increasing plaque virulence and oxidative stress. Stannous fluoride (SnF2) binds lipopolysaccharides to reduce plaque virulence. This study prospectively assessed SnF2 effects on oxidative stress in adults with gingivitis. METHODS: This was a 2-month, single-center, single-treatment clinical trial. Twenty "disease" (> 20 bleeding sites with ≥ 3 pockets 3 mm-4 mm deep) and 20 "healthy" (≤ 3 bleeding sites with pockets ≤ 2 mm deep) adults were enrolled. All participants were instructed to use SnF2 dentifrice twice daily for 2 months. An oral examination, Modified Gingival Index (MGI) examination and Gingival Bleeding Index (GBI) examination were conducted at baseline, 1 month and 2 months. Gingival crevicular fluid (GCF), saliva, oral lavage and supragingival plaque were collected at each visit to evaluate: Endotoxins, Protein Carbonyls, L-lactate dehydrogenase (LDH), Ferric reducing antioxidant power (FRAP), Oxidized low density lipoproteins (oxi-LDL), IL-6 and C-reactive protein (CRP). A subset-analysis examined participants considered at higher risk of cardiovascular disease. Change-from-baseline analyses within each group were of primary interest. RESULTS: The disease group showed statistically significant reductions in GBI at Month 1 (67%) and Month 2 (85%) and in MGI at Month 1 (36%) and Month 2 (51%) versus baseline (p < 0.001). At baseline, the disease group showed greater LDH in GCF and oxi-LDL levels in saliva versus the healthy group (p ≤ 0.01). Total antioxidant capacity (FRAP) in saliva increased versus baseline for the disease group at Months 1 and 2 (p < 0.05), and levels for the disease group were greater than the healthy group at both timepoints (p < 0.05). SnF2 treatment reduced endotoxins (lavage) for both disease and healthy groups at Month 2 (p ≤ 0.021) versus baseline. There was a reduction in oxidative stress markers, namely protein carbonyl in saliva, at Months 1 and 2 (p < 0.001) for both groups and a reduction in cytokine IL-6 (lavage) in the disease group at Month 2 (p = 0.005). A subset analysis of participants at higher coronary disease risk showed reductions in endotoxins in lavage, oxi-LDL, and CRP in saliva at Month 2 (p ≤ 0.04). CONCLUSION: SnF2 dentifrice use reversed gingival inflammation, suppressed endotoxins and reduced some harmful oxidant products in saliva and gingiva. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov NCT05326373, registered on 13/04/2022.

A randomized controlled trial assessing denture adhesive efficacy on denture retention across 13 hours.

PURPOSE: To compare the effects of two denture adhesive formulations on the bite force required to dislodge a maxillary denture in adult participants during a 13-h test period. MATERIALS AND METHODS: Twenty-two participants with a fair-to-poor fitting maxillary denture opposed by natural dentition or a stable mandibular denture were enrolled in this single-center, randomized, double-blind, two-treatment, 4-period crossover study. Participants were randomly assigned a product usage sequence so that each participant used each product twice during the 4-day test period. The test product was a denture cream adhesive formulated with an optimized calcium/zinc partial salt of polyvinyl methyl ether/maleic acid (Fixodent Ultra technology); the control product was a cream adhesive formulated with a calcium/zinc partial salt of polyvinyl methyl ether/maleic acid (Fixodent Original technology). On each study day, bite force at dislodgement was measured with a gnathodynamometer at baseline, representing the "no adhesive" score. Then, after standardized product application to the participant's existing maxillary denture by site staff, bite force measurements were retaken at 1, 3, 5, 7, 9, 11, and 13 h. The change from baseline and the 13-h area under the bite-force-change-from-baseline curve were analyzed via an analysis of variance. RESULTS: Twenty-one participants completed all test periods; one additional participant completed three test periods so 22 participants were included in the analysis. There were 15 females and 7 males with a mean age of 70 years. The mean 13-h area under the bite-force-change-from-baseline curve was 8% greater (p = 0.010) for the test adhesive (114.3 lb) than for the control adhesive (105.9 lb). Both adhesives showed a statistically significant increase in bite force (p < 0.001) at each time point compared to no adhesive. CONCLUSIONS: The optimized calcium/zinc partial salt of polyvinyl methyl ether/maleic acid test adhesive provided superior maxillary denture retention relative to that of the control adhesive across 13 h. Both adhesives increased bite force at dislodgement compared to no adhesive.

Rapid Antigingivitis Efficacy of a Novel Stannous Fluoride Dentrifice: Results from a 12-Week Randomized Controlled Clinical Trial.

OBJECTIVE: To assess the anti-gingivitis and anti-plaque efficacy of a novel bioavailable stannous fluoride (SnF2) dentifrice to a negative control. METHODS: This was a 12-week randomized, controlled, double-blind, two-treatment, parallel group clinical study. One hundred generally healthy adults with evidence of plaque and gingivitis were enrolled into the study. Subjects were randomly assigned to one of two dentifrice treatments: (1) novel SnF2 dentifrice containing the amino acid glycine as a stabilizing chelant (Procter and Gamble) or (2) a negative control sodium monofluorophosphate dentifrice. Gingivitis was assessed using the Löe-Silness Gingivitis Index (LSGI) at baseline, Week 1, and Week 12 while plaque was evaluated according to the Turesky Modification of the Quigley-Hein Plaque Index at baseline and Week 12. RESULTS: One hundred subjects completed the trial. Subjects using the novel SnF2 dentifrice demonstrated statistically significantly fewer bleeding sites and a lower LSGI score versus those using the negative control as early as Week 1 (P less than .001). The benefit increased throughout the study, with the SnF2 dentifrice showing 33.4% fewer bleeding sites and a 16.5% lower LSGI score versus the negative control at Week 12 (P less than .001). Subjects with localized or generalized gingivitis (≥10% bleeding sites) had 6 times better odds of transitioning to generally healthy (less than 10% bleeding sites) after using the SnF2 dentifrice for 12 weeks versus the negative control. Plaque scores for the SnF2 dentifrice were also statistically significantly lower (P less than .001) than those for the negative control at Week 12. CONCLUSION: The novel SnF2 dentifrice with the amino acid glycine produced statistically significant improvements in gingival health that were seen as early as 1 week and numerically increased throughout the study.

Clinical Parameters and Oral Fluid Biomarkers in Gingivitis Subjects using an Electric Toothbrush with Irrigator vs a Manual Toothbrush Alone over 8 Weeks: A Randomised Controlled Clinical Trial.

PURPOSE: To compare clinical outcomes and oral fluid biomarkers in gingivitis subjects using an electric toothbrush/irrigator combination (test) or a manual toothbrush alone (control) over 8 weeks. MATERIALS AND METHODS: Subjects were randomly assigned to two groups of n = 30. In both groups, toothbrushing was performed twice daily at home and no additional interdental cleaning aids were allowed. Plaque Index (PLI), Gingival Index (GI), whole saliva (WS), and gingival crevicular fluid (GCF) samples were collected at weeks 2, 4, and 8. RESULTS: Subjects' mean age was 23 years and 52% were female. Overall baseline means were 1.31 for PLI, 1.07 for GI, and 34.9 for number of bleeding sites. At every follow-up visit, both groups differed statistically significantly (p < 0.001) from baseline for all clinical parameters. The test group demonstrated statistically significantly (p < 0.001) greater reductions in GI vs the control group by 18% at week 2, 17% at week 4 and 24% at week 8. The test group also demonstrated statistically significantly (p < 0.002) greater reductions in the number of bleeding sites vs the control group by 33% at week 2, 34% at week 4 and 43% at week 8. Between-group comparisons for both WS and GCF revealed numerical trends for decreased levels of interleukin (IL)-1ß in GCF after 4 and 8 weeks, but these were not statistically significant. CONCLUSION: In subjects using the electric toothbrush/irrigator combination, increased clinical improvements may be found accompanied by similarly improved trends for oral fluid biomarkers such as IL-1ß.

Handheld optical coherence tomography for clinical assessment of dental plaque and gingiva.

SIGNIFICANCE: Optical coherence tomography (OCT) offers high spatial resolution and contrast for imaging intraoral structures, yet few studies have investigated its clinical feasibility for dental plaque and gingiva imaging in vivo. Furthermore, the accessibility is often limited to anterior teeth due to bulky imaging systems and probes. AIM: A custom-designed, handheld probe-based, spectral-domain OCT system with an interchangeable attachment was developed to assess dental plaque and gingival health in a clinical setting. APPROACH: Healthy volunteers and subjects with gingivitis and sufficient plaque were recruited. The handheld OCT system was operated by trained dental hygienists to acquire images of dental plaque and gingiva at various locations and after one-week use of oral hygiene products. RESULTS: The handheld OCT can access premolars, first molars, and lingual sides of teeth to visualize the plaque distribution. OCT intensity-based texture analysis revealed lower intensity from selected sites in subjects with gingivitis. The distribution of the dental plaque after one-week use of the oral hygiene products was compared, showing the capability of OCT as a longitudinal tracking tool. CONCLUSIONS: OCT has a strong potential to display and assess dental plaque and gingiva in a clinical setting. Meanwhile, technological challenges remain to perform systematic longitudinal tracking and comparative analyses.

A randomized controlled trial of a power brush/irrigator/mouthrinse routine on plaque and gingivitis reduction in orthodontic patients.

OBJECTIVES: To assess plaque and gingivitis reduction in orthodontic patients after 4 weeks' use of an oscillating-rotating power brush, irrigator, and mouthrinse. MATERIALS AND METHODS: This was a randomized, examiner-blind, clinical trial comparing plaque and gingivitis outcomes for an experimental power brush/irrigator/mouthrinse oral hygiene routine vs a dental prophylaxis followed by regular manual brushing (positive control). Fifty-one participants with fixed orthodontic appliances in the upper and lower jaw and a minimum of 15 gingival bleeding sites were randomly assigned to experimental or positive control treatment. Both groups were instructed to use their products at least twice daily. At baseline, week 1, and week 4, plaque was evaluated using digital plaque imaging analysis and a conventional subjective index. Gingival inflammation and bleeding were also measured. Analysis of covariance was used to compare groups. RESULTS: Fifty-one participants (mean age = 13.9 years) were randomized; 50 (25 per group) completed the study. At baseline, group means were not statistically different (P > .1) for gingival inflammation or bleeding. At week 4, the experimental and control groups had a 10.0% to 32.7% and 5.9% to 6.7% reduction vs baseline, respectively, in plaque (across both methods); 12.6% and 8.3% reduction, respectively, in gingival inflammation; and 50.6% and 37.8% reduction, respectively, in bleeding. At week 4, group differences favoring the experimental group were statistically significant (P < .05) for gingival inflammation, gingival bleeding, and plaque (by conventional and digital imaging indexes). CONCLUSIONS: Use of a power brush/irrigator/mouthrinse resulted in statistically significantly greater plaque and gingivitis reductions than prophylaxis followed by manual brushing in patients with fixed appliances over 4 weeks.

A randomized clinical trial to evaluate the plaque removal efficacy of an oscillating-rotating toothbrush versus a sonic toothbrush in orthodontic patients using digital imaging analysis of the anterior dentition.

OBJECTIVE: To compare the plaque removal efficacy of an oscillating-rotating electric toothbrush with an orthodontic brush head versus a sonic toothbrush in adolescent patients with fixed orthodontic appliances. MATERIALS AND METHODS: This was a randomized, examiner-blind, replicate single-use, two-treatment, four-period, crossover study with a washout period between visits of approximately 24 hours. Forty-four adolescent patients with fixed orthodontic appliances in both arches were randomized based on a computer-generated randomization schedule to one of four toothbrush treatment sequences. The primary outcome was plaque score change from baseline, measured using digital plaque imaging analysis. RESULTS: Baseline plaque levels for both brush treatments were high, covering more than 50% of the tooth area. Effective plaque removal was observed with both brush treatments (P < .001); however, the reduction in plaque with the oscillating-rotating toothbrush was statistically significantly greater (P = .017) compared with the sonic toothbrush. CONCLUSIONS: The study provides evidence for more effective plaque-removing efficacy of the oscillating-rotating toothbrush versus the sonic toothbrush among orthodontic patients.

Using Electromagnetic Articulography to Measure Denture Micromovement during Chewing with and without Denture Adhesive.

PURPOSE: To study the effects of denture adhesive upon denture micromovements in three dimensions during the chewing of hard, sticky, and tough food items observed using a novel method involving an electromagnetic articulograph (EMA) speech research system. MATERIALS AND METHODS: Ten volunteers (mean age 60.9 ± 10.4 years) with fair- or poor-fitting complete maxillary dentures were enrolled. Chewing experiments were conducted using two treatments (adhesive or no-adhesive control) and three foods: carrots (hard), raisins (sticky), and processed meat stick (tough). Denture micromovement was measured through a novel application of a Northern Digital Wave EMA System. Three-dimensional denture position was captured during mastication using three sensors embedded into a replica denture for each subject. Following individual characterization of a "home" reference position, the Euclidean Distances from Home (DfH) were calculated for each recorded sample of the chewing experiments. The DfH at each sample represented the denture movement for that 1/100th of a second of the activity. The DfH data were then summarized as the mean DfH, the maximum DfH, and total distance traveled by the denture. Several thresholds were also analyzed, including the percent of time that the DfH ≥1.5 mm, ≥2.0 mm, and ≥2.5 mm. RESULTS: With adhesive treatment, the mean DfH of dentures during chewing was reduced by 26.8% for carrot, 30.3% for raisin, and 31.0% for meat stick, when compared with no-adhesive treatment (p < 0.001 for all comparisons). Similar results were also seen for the maximum DfH and total distance travelled endpoints across foods. For the threshold endpoints, adhesive treatment was associated with a statistically significant reduction in denture micromovements at all three thresholds across foods. At the threshold of DfH ≥ 1.5 mm, adhesive treatment was associated with a reduction in micromovement by 61.6%, 56.2%, and 70.0% with carrot, raisin, and meat stick, respectively (p ≤ 0.004 for all comparisons). CONCLUSIONS: Observations of denture movement using the Wave EMA System were able to differentiate systematically between adhesive treatment and no-adhesive treatment for denture micromovements during different chewing challenges. Use of adhesive was associated with statistically significant reductions in denture micromovements for hard, sticky, and tough foods as measured with both distance and threshold endpoints.

Subgingival uptake and retention of stannous fluoride from dentifrice: Gingival crevicular fluid concentrations in sulci post-brushing.

PURPOSE: To examine the delivery of stannous fluoride to subgingival sulci following toothpaste use in a clinical population. METHODS: This was a controlled, single-site study. 23 subjects with at least 20 dental pockets, 2-4 mm with bleeding, who had not used a stannous fluoride dentifrice in the last 3 months were enrolled. After a 2-week washout period, 20 subjects returned for a baseline visit. They were instructed to refrain from brushing the night before the baseline visit. GCF samples were taken from up to 10 sites identified as sampling sites. Subjects were then given a 0.454% stannous fluoride dentifrice and soft manual toothbrush and asked to brush for 1 minute. 30 minutes after brushing, GCF was re-sampled. Subjects continued using the stannous fluoride dentifrice and soft manual toothbrush at home, twice daily for 2 weeks, in place of their usual hygiene products. At Days 1 and 14, subjects returned to the site, and 12 hours post-brushing GCF samples were taken. The samples were analyzed by ICP-MS (inductively coupled plasma mass spectrometry). A Wilcoxon signed-rank test was performed to determine the difference between post-baseline visits and baseline. Statistical tests were 2-sided using a 5% significance level. RESULTS: 20 subjects completed the trial. Significant levels of tin, a marker for stannous fluoride, were detected 30 minutes after brushing at sampling sites of 2-4 mm. The median tin level in gingival crevicular fluid (GCF) was 24.59 ng/µl, which was highly significant versus baseline (P< 0.0001). Tin levels sampled in GCF 12 hours after brushing on Days 1 and 14 were highly significant versus Baseline (P< 0.0001), showing an increasing trend with continued use. CLINICAL SIGNIFICANCE: Stannous fluoride was found to penetrate sampling sites from 2-4 mm and was retained for 12 hours. Subgingival uptake and retention of stannous fluoride following toothbrushing may play a role in detoxification effects on microbial biofilms and may contribute to the therapeutic efficacy of stannous fluoride dentifrices in promoting gingival health.

Clinical effects of stannous fluoride dentifrice in reducing plaque microbial virulence III: Lipopolysaccharide and TLR2 reporter cell gene activation.

PURPOSE: This study expanded the analysis of subgingival dental plaques from previous research to include the evaluation of cohort, site and treatment effects on chemically measured endotoxin and activation of Toll-like receptor (TLR) based gene expression in two additional reporter cell lines: a TLR2 specific cell line and a THP-1 (multi TLR reporter) cell line. METHODS: Participants from high and low bleeding cohorts were sampled at baseline for both supra and subgingival dental plaque at both healthy as well as clinically diseased sites and then provided with intervention hygiene products including a stabilized SnF2 dentifrice and a new soft bristle manual toothbrush. Following 2 and 4 weeks of assigned dentifrice use, participants returned for a re-evaluation of gingival inflammation and bleeding and repeat samplings of dental plaque. Subgingival sampled plaques were chemically analyzed for endotoxin concentration using a Thermo Scientific Pierce LAL chromogenic endotoxin quantitation kit. Samples were also used for inoculation of two reporter cell assays (an HEK293 TLR2 reporter cell line and a THP-1 monocyte cell line). Reporter cell activation was analyzed via luminescence changes of secreted embryonic alkaline phosphatase. RESULTS: The endotoxin content of subgingival plaque could be measured directly with dye assays and plaque isolates activated gene expression in both TLR reporter cell lines. Higher disease cohorts and sites with gingival inflammation generally showed more endotoxins and higher levels of plaque virulence as compared to low disease cohorts or plaque sampled from clinically healthy sites. SnF2 dentifrice treatment was associated with broad scale reductions in endotoxin content and virulence potentiation properties of dental plaque samples collected subgingivally from patients. CLINICAL SIGNIFICANCE: These results collectively support the use of dye or various reporter cell lines in the characterization of plaque virulence in diseased populations and as a potential route for analysis in clinical evaluations of treatment interventions. Subgingival plaque 'detoxification' including effects on microbial pathogenicity as well as metabolic activity may be considered important mechanisms contributing to clinical benefits of SnF2 dentifrice.

Clinical Effects of Stabilized Stannous Fluoride Dentifrice in Reducing Plaque Microbial Virulence II: Metabonomic Changes.

OBJECTIVES: The clinical effects of stannous fluoride (SnF2) dentifrice in reducing symptoms of gingivitis and reducing the virulence of subgingival plaque through suppression of activation of gene expression in toll receptor based reporter cells were previously reported. This study expanded analysis of the clinical study to include evaluation of dentifrice effects on salivary metabolites using 1H Nuclear Magnetic Resonance (1H NMR) systems biology-based metabonomics. METHODS: The clinical design was reported previously (J Clin Dent2017;28:16-26). Participants included a cohort exhibiting high and low levels of gingival disease as presented at initiation of the study. Participants provided morning lavage saliva samples at baseline. Following this, participants were provided with a hygiene intervention, including a stabilized SnF2 dentifrice and a new soft bristle manual toothbrush. Following two and four weeks of assigned dentifrice use, participants again collected morning lavage saliva samples. Samples were analyzed by 1HNMR spectroscopy on a Bruker 600MHz NMR spectrometer. System-wide analyses were carried out by partial least squared (PLS) comparisons of aggregate spectra, and discrete metabolites with established spectral signatures were likewise directly compared. RESULTS: PLS analysis showed significant differences in saliva composition for saliva collected from high bleeding and low bleeding cohorts. Clear shifts in saliva composition were observed in system-wide PLS analysis following intervention of SnF2 dentifrice for both cohorts. A number of discrete spectral changes were consistently observed with SnF2 dentifrice intervention, most notably including reductions in propionic acid and butyric acid, key short chain fatty acids associated with anaerobic metabolism in dental plaques. CONCLUSIONS: These results collectively demonstrate that SnF2 dentifrice treatment was associated with broad scale modifications in saliva composition following intervention in both high and low diseased cohorts. Changes in overall salivary composition and specific reductions in saliva concentrations of propionic and butyric acid reductions occurred coincident with clinical improvements in gingivitis and gingival bleeding. These results provide support for the hypothesis that the effectiveness of SnF2 dentifrice in improving gingival health is associated with a modification of microbiome metabolism, including suppression of short chain fatty acid metabolites.

A Comparison of Oral Hygiene Products and Professional Care: A six-week randomized clinical trial.

Purpose: To investigate the anti-gingivitis efficacy of a novel oral hygiene routine consisting of a two-step stannous fluoride dentifrice and hydrogen peroxide whitening gel system, an interactive oscillating-rotating electric toothbrush, and expanded polytetrafluoroethylene floss.Methods: A total of 52 participants (n=52;mean age 35.8±11.23 years) were enrolled in the study and randomized 1:1 to the experimental hygiene group or control (dental prophylaxis followed by use of standard sodium fluoride dentifrice and a manual toothbrush). Participants were instructed to brush twice daily; those in the experimental group were instructed to floss once daily. Oral examinations were conducted at Baseline, Week 2, Week 4, and Week 6.Results: Both groups experienced significant declines in the mean number of bleeding sites from Baseline at all time points, evident as early as Week 2. Bleeding sites continued to decline throughout the trial in the experimental group, whereas they showed an increasing trend between Weeks 2 and 6 in the control group. The experimental group had 55% fewer bleeding sites at Week 2, 85% fewer bleeding sites at Week 4, and 98% fewer bleeding sites at Week 6 (p<0.0001 for all) as compared to the control group. At Week 6, 84% of participants in the experimental group had no bleeding, while all participants in the control group had bleeding.Conclusion: The experimental oral hygiene group showed significantly greater reductions in gingival bleeding than the control oral hygiene group, with benefits seen as early as Week 2 and increasing over the six-week study.

Clinical Effects of Stabilized Stannous Fluoride Dentifrice in Reducing Plaque Microbial Virulence I: Microbiological and Receptor Cell Findings.

OBJECTIVES: Lipopolysaccharides (LPSs) and lipoteichoic acids (LTAs), or bacterial endotoxins, bind with Toll-like receptors (TLRs) that are expressed on host cells of the periodontium, thereby contributing to the periodontal pathogenicity of oral bacteria. Stannous fluoride (SnF2), an antibacterial fluoride that treats and controls gingivitis, has been shown to react with lipophilic domains/anionic charges in LPS and LTA. The effects of bacterial species and dental plaque on toll receptors can be studied using genetically engineered cell lines containing linked toll receptors on their surfaces. This randomized, examiner-blinded study examined the clinical effects of stabilized SnF2 dentifrice intervention on gingivitis and dental plaque virulence in populations exhibiting high and low levels of clinical gingivitis. METHODS: Recruited populations were evaluated for gingival inflammation (MGI) and gingival bleeding (GBI) at baseline and assigned into two cohorts of 20 each, those with high (GBI > 20 sites) and low (GBI < 3 sites) levels of observed bleeding/gingivitis. Participants were sampled at baseline for both supra- and subgingival dental plaque at both healthy (no bleeding, PD = 2 mm), as well as clinically diseased sites (bleeding, PD = 3-4 mm), and then provided with an intervention hygiene product including a stabilized SnF2 dentifrice and a new soft bristle manual toothbrush. Following two and four weeks of assigned dentifrice use, participants returned for a re-evaluation of gingival inflammation and bleeding and repeat samplings of dental plaque. Plaque samples were analyzed by anaerobic culturing of gram negative anaerobes (GNA), as well as by incubation of subgingival sampled plaques with TLR4 transfected HEK293 cells, where gene expression was assessed by measurement of a SEAP alkaline phosphatase reporter as a marker of toll receptor activation. RESULTS: Clinical assessments showed statistically significant reductions in MGI (24-26%) and GBI (42-53%) gingivitis in both diseased and healthy cohorts following four weeks of dentifrice intervention. For all clinical examinations, MGI and bleeding sites were statistically significantly different (lower) in the low bleeding versus the higher bleeding cohort. Supragingival and subgingival GNAs were significantly reduced (p < 0.05) in both high and low disease cohorts at bleeding and healthy sites following four weeks of stabilized SnF2 dentifrice use. TLR activation from subgingival sampled plaque was reduced following four weeks of stabilized SnF2 dentifrice use in both high and low disease cohorts and in both healthy, as well as diseased sites. CONCLUSIONS: Collectively, these results support the potential for stabilized SnF2 dentifrice to provide clinical gingivitis benefits via mechanisms beyond control of plaque mass, potentially directly decreasing the pathogenicity of plaque biofilms by blocking reactivity of LPS and LTA ligands with tissue receptors associated with inflammation. Importantly, benefits could be seen in both diseased sites, as well as sites not yet exhibiting symptoms of inflammation, supporting the activity of SnF2 not just in treating diseased sites, but in preventing disease development. These learnings may influence treatment planning for patients susceptible to gingivitis.

Effect of a Multidirectional Power Toothbrush and a Manual Toothbrush in Individuals Susceptible to Gingival Recession: A 12-Month Randomized Controlled Clinical Study.

BACKGROUND: Clinical studies have explored the relationship between toothbrushing and development of gingival recession (GR), but relevant GR data for the multidirectional power toothbrush (PT) are lacking. The aim of this study is to evaluate the effect of brushing with either a multidirectional PT or American Dental Association reference manual toothbrush (MT) on mid-buccal preexisting GR (PreGR) during 12 months. METHODS: This was a 12-month prospective, single-masked, parallel-group, randomized, controlled clinical study. Healthy participants without periodontitis with at least two teeth showing PreGR ≥2 mm were randomized to a group brushing with either an MT or PT. The primary outcome parameter was change at sites with PreGR ≥2 mm. All clinically based GR measurements were performed by one calibrated examiner at baseline, 6, and 12 months. Secondary outcomes were changes of GR at all mid-buccal sites (with or without PreGR), changes in percentage of GR sites demonstrating a change of ≥1 mm, and changes in probing depths. RESULTS: A total of 107 participants completed the study (PT: 55, MT: 52). During the 12-month study period the mean recession at sites with PreGR ≥2 mm decreased significantly from 2.2 to 2.1 mm in both groups (P <0.05). The extent of GR parameters did not differ between MT and PT groups at any time point. GR evaluated clinically and on stone casts was well correlated. CONCLUSION: Neither the PT nor MT led to an increase in PreGR during 12 months of daily use.

Quantitation of endotoxin and lipoteichoic acid virulence using toll receptor reporter gene.

PURPOSE: To apply quantitative Toll-like receptors (TLR) cell assays to compare lipopolysaccharides (LPSs) and lipoteichoic acids (LTAs) from different oral bacterial strains for potential pathogenicity in vitro. METHODS: The potency of LPS and LTA from different bacteria on activation of TLR reporter genes in HEK-tlr cell lines was examined. P. gingivalis LPS mix, P. gingivalis 1690 LPS, P. gingivalis 1435/50 LPS, E. coli LPS (E. coli K12), B. subtilis LTA, S. aureus LTA, E. hirae LTA and S. pyogenes LTA were examined in both TLR2 and TLR4 HEK cell line reporter assays. Solutions of LPS and LTA from selected bacteria were applied in a dose response fashion to the TLR reporter cells under standard culture conditions for mammalian cells. Reporter gene secreted-embryonic-alkaline-phosphatase (SEAP) was measured, and half maximal effective concentration (EC50) was determined for each sample. Concentration dependent TLR activation was compared to similar responses to LPS and LTA for commercial BODIPY-TR-Cadaverine and LAL biochemical (non cell based) assays. RESULTS: All LPS from P. gingivalis activated both TLR2 and TLR4 responses. E. coli LPS is a strong activator for TLR4 but not for TLR2 responses. In contrast, both B. subtilis and S. aureus LTA provoked responses only in TLR2, but not in the TLR4 assay. Interestingly, E. hirae LTA and S. pyogenes LTA did not stimulate strong TLR2 responses. Instead, both E. hirae LTA and S. pyogenes LTA mounted a reasonable response in TLR4 reporter gene assay. Both LPS and LTA showed deactivation of fluorescence in BODIPY-TR-Cadaverine while only LPS was active in LAL. As with biochemical assays, an EC50 could be determined for LPS and LTA from various bacterial strains. The EC50 is defined as a concentration of LPS or LTA that provokes a response halfway between the baseline and maximum responses. Lower EC50 means higher potency in promoting TLR responses, and in principle indicates greater toxicity to the host. CLINICAL SIGNIFICANCE: InvivoGen TLR2 and TLR4 assays distinguish specific types of microbial products, such as LPS and LTA from different bacteria. Application of EC50 determinations creates a means for quantitative and comparisons of LPS and LTA virulence in a cellular-based assay and combinations of TLR reporter cell assays along with biochemical evaluation of LPS#47;LTA in BODIPY-TR-Cadaverine and LPS in LAL assays provides a means to quantitate virulence of plaque samples with respect to both LPS and LTA. These learnings have long-term implications for patient care in that understanding the virulence of patients' plaque provides important information to assess risk of oral diseases.

Lipopolysaccharide and lipoteichoic acid binding by antimicrobials used in oral care formulations.

PURPOSE: To study the reactivity of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) with the cationically charged agents cetylpyridinium chloride, stannous fluoride, and the non-cationic agent triclosan. We also assessed the effect of these agents to inhibit LPS and LTA binding to cellular Toll-like Receptors (TLRs) in vitro. METHODS: The ability of these antimicrobials to bind with LPS and/or LTA was assessed in both the Limulus amebocyte lysate and BODIPY-TR-cadaverine dye assays. Mass spectroscopy was then used to confirm that stannous fluoride directly binds with LPS and to determine stoichiometry. Lastly, we looked for possible inhibitory effects of these antimicrobial agents on the ability of fluorescently conjugated LPS to bind to TLR4 expressed on HEK 293 cells. RESULTS: Cetylpyridinium chloride (CPC) and stannous salts including stannous fluoride interfered with LPS and LTA reactivity in both dye assays, while triclosan had no effect. Mass spectroscopy revealed direct binding of stannous fluoride with E. Coli LPS at 1:1 stoichiometric ratios. In the cellular assay, cetylpyridinium chloride and stannous fluoride, but not triclosan, inhibited LPS binding to TLR4. CLINICAL SIGNIFICANCE: These results support a potential mechanism of action for stannous fluoride and CPC formulated in oral products in which these ingredients bind bacterial toxins and potentially render them less toxic to the host. These results may influence home care recommendations for patients at risk for plaque-related diseases.

Lipopolysaccharide and Lipoteichoic Acid Virulence Deactivation by Stannous Fluoride.

OBJECTIVES: Oral bacterial pathogens promote gingivitis and periodontal disease. Bacterial endotoxins, also known as lipopolysaccharides (LPSs) and lipoteichoic acids (LTAs), are known to enhance bacterial pathogenicity through binding with Toll-like receptors (TLRs), a group of pattern recognition receptors critical to the activation of innate immunity, that are expressed on host cells. Both LPS and LTA contain lipophilic domains and anionic charges that may be susceptible to reactivity with stannous fluoride, a commonly used ingredient clinically proven for the treatment and prevention of gingivitis. This study examined the effects of stannous fluoride on Toll-like receptor activation in response to bacterially derived LPS and LTA in select cell lines and secretion of inflammatory cytokines from human primary peripheral monocytes likewise exposed to LPS. METHODS: TLR4 and TLR2 transfected HEK293 cells and THP1-Dual™ cells were exposed to bacterial LPS and LTA in the presence of increasing concentrations of stannous fluoride. Gene expression was assessed by measurement of secreted embryonic alkaline phosphatase (SEAP) reporter gene for HEK293 cells and SEAP and luciferase for THP-1 cells. Cell viability was confirmed using PrestoBlue. Human primary monocytes were treated with LPS with various concentrations of supplemented stannous fluoride, and cytokine expression was directly measured. RESULTS: Stannous fluoride inhibited gene expression response of TLR4 and TLR2 in HEK293 cells and THP1-Dual™ cells in a dose response fashion, producing complete inhibition at micromolar concentrations. The addition of stannous fluoride suppressed production of TNF-a, IFN-g, IL12p70, IL10, IL-1b, IL2, and IL-6, and also increased secretion of Il-8 in dose response fashion. Viability assays confirmed no effects of LPS or stannous fluoride on viability of HEK293, THP-1, and primary human monocytes. CONCLUSIONS: These results support the potential for stannous fluoride to provide clinical gingivitis benefits by directly decreasing the pathogenicity of plaque biofilms by blocking reactivity of LPS and LTA ligands with tissue receptors associated with inflammation. These learnings may influence recommendations for patients at risk for plaque-related diseases.

Response of chronic gingivitis to hygiene therapy and experimental gingivitis. Clinical, microbiological and metabonomic changes.

PURPOSE: To compare the clinical, microbiological and metabonomic profiles of subjects with high and low levels of chronic gingival bleeding during a controlled oral hygiene regimen intervention including sequential phases of rigorous therapeutic oral hygiene followed by experimental gingivitis (EG). METHODS: Two cohorts of qualified study subjects with differences in gingival bleeding on probing levels at their baseline clinical examination were entered into the study. These two cohorts were followed through three separate study phases including a 1-week baseline phase, a 2-week phase of rigorous oral hygiene including dental prophylaxis, and a 3-week EG phase of no oral hygiene to encourage relapse of gingivitis. The 58 subjects were assessed during each phase of the study for clinical presentation of gingivitis and concurrently had plaque sampled for real-time polymerase chain reaction (RTPCR) microbiological characterization and salivary lavage samples for 'systems biology' metabonomics assessment by 1H-NMR. RESULTS: Subjects presenting with different levels of gingival bleeding on probing when they entered the study responded differently to rigorous oral hygiene and EG. Specifically, the high bleeding cohort responded sluggishly to rigorous oral hygiene and exhibited markedly greater relapse to gingivitis during EG. RTPCR analysis showed changes in bacterial populations that were associated with study phases, particularly the increases in putative periodontal pathogens during EG. However, the microbiological profiles of high- and low-susceptibility gingival bleeding patients were largely similar. Metabonomic analysis likewise revealed significant changes in metabolite composition during study phases associated with differences in plaque toxicity, especially the short chain carboxylic acids propionate and n-butyrate, which tracked clinical changes in gingivitis severity. Systems analysis of metabonomic changes suggested differences between cohorts, although analysis to date has not elucidated whether these differences are causative (population predictive) or simply diagnostic of clinical status within populations.

Plaque reduction efficacy of an oscillating-rotating power brush with a novel brush head utilizing angled bristle tufts.

PURPOSE: To evaluate an oscillating-rotating power brush with a novel brush head utilizing angled bristle tufts versus a manual brush for plaque removal. METHODS: This was a single-center, randomized, open-label, examiner-blind, two-treatment, parallel-group study. Subjects brushed with their assigned toothbrush and a marketed dentifrice twice daily at home for 6 weeks. Plaque measurements were evaluated at baseline and week 6 using the Turesky Modified Quigley-Hein Plaque Index (TQHPI). Data was analyzed using the analysis of covariance (ANCOVA) with baseline as the covariate. RESULTS: Ninety-four subjects completed the study, with 46 in the manual group and 48 in the power group. The oscillating-rotating brush with the novel brush head demonstrated statistically significantly greater reductions in whole mouth and interproximal plaque measures compared to the manual toothbrush. The benefit for the oscillating-rotating brush over the manual control brush was 164.5% for whole mouth plaque and 167.4% for interproximal plaque (P < 0.001) measured 12 hours after brushing. Both brushes produced statistically significant reductions in plaque measures relative to baseline (P < 0.001 for both measures). There were no adverse events reported or observed for either brush. CONCLUSIONS: The oscillating-rotating brush with the novel brush head produced reductions in whole mouth and interproximal plaque more than twice that of the manual toothbrush.