Investigation of oral malodor prevention by dentifrices as measured by VSC reduction.

The oral malodor reduction efficacy of dentifrices containing stannous fluoride (SnF2) or zinc plus arginine (Zn/Arg) was evaluated using a halimeter to measure volatile sulfur compounds (VSCs) in two randomized, controlled, single-blind, cross-over pilot clinical trials. Study 1 (N= 16) had five 1100 ppm F dentifrices and five treatment periods: negative control (NC): 0.243% sodium fluoride (NaF); SnF2A: 0.454% SnF2+ pyrophosphate; SnF2B: 0.454% SnF2+ sodium hexametaphosphate; SnF2C: 0.454% SnF2+ citrate; and SnF2D: experimental 0.454% SnF2with increased bioavailable Sn. Study 2 (N= 16) had four 1450 ppm F dentifrices and four treatment periods: NC: 0.1% NaF + 0.76% sodium monofluorophosphate; Zn/Arg: NaF + zinc + arginine; SnF2E: 0.454% SnF2+ 0.078% NaF + sodium hexametaphosphate; SnF2F: 0.454% SnF2+ 0.078% NaF + citrate. Each period took 96 h; baseline (day 0) morning to day 4 morning. Subjects brushed 2x/day with the treatment dentifrice. VSC levels were measured in the morning, prior to morning brushing, on days 0 and 4. Changes in VSC scores from day 0 to day 4 were assessed using a mixed-model analysis of covariance for cross-over studies. In study 1, SnF2dentifrices B, C and D showed statistically significant reductions (31.3%, 24.8%, 34%, respectively) in VSC scores versus baseline (p< 0.001); the benefits of these treatments versus NC and SnF2dentifrice A were statistically significant (p⩽ 0.001). In study 2, SnF2dentifrices E and F showed statistically significant reductions (31.2%, 22.1%, respectively) in VSC scores versus baseline (p⩽ 0.010); the benefits of these treatments versus NC and the Zn/Arg dentifrice were statistically significant (p⩽ 0.035). The Zn/Arg dentifrice showed a significant increase of 35.2% (p< 0.001) in VSC scores versus baseline. These studies demonstrated that SnF2dentifrices can provide significant oral malodor reductions, but the benefit is formulation dependent. The presence of SnF2is not sufficient to ensure efficacy. The Zn/Arg dentifrice increased VSC levels, indicating greater malodor.Clinical Trial Numbers: 20190429 and 20191028.

Introducing BAIT (Biofilm Architecture Inference Tool): a software program to evaluate the architecture of oral multi-species biofilms.

Biofilm model systems are used to study biofilm growth and predict the effects of anti-biofilm interventions within the human oral cavity. Many in vitro biofilm model systems use a confocal laser scanning microscope (CLSM) in conjunction with image analysis tools to study biofilms. The aim of this study was to evaluate an in-house developed image analysis software program that we call BAIT (Biofilm Architecture Inference Tool) to quantify the architecture of oral multi-species biofilms following anti-biofilm interventions using a microfluidic biofilm system. Differences in architecture were compared between untreated biofilms and those treated with water (negative control), sodium gluconate ('placebo') or stannous fluoride (SnF2). The microfluidic system was inoculated with pooled human saliva and biofilms were developed over 22 h in filter-sterilized 25 % pooled human saliva. During this period, biofilms were treated with water, sodium gluconate, or SnF2 (1000, 3439 or 10 000 p.p.m. Sn2+) 8 and 18 h post-inoculation. After 22 h of growth, biofilms were stained with LIVE/DEAD stain, and imaged by CLSM. BAIT was used to calculate biofilm biovolume, total number of objects, surface area, fluffiness, connectivity, convex hull porosity and viability. Image analysis showed oral biofilm architecture was significantly altered by 3439 and 10 000 p.p.m. Sn2+ treatment regimens, resulting in decreased biovolume, surface area, number of objects and connectivity, while fluffiness increased (P<0.01). In conclusion, BAIT was shown to be able to measure the changes in biofilm architecture and detects possible antimicrobial and anti-biofilm effects of candidate agents.

Fluoride Uptake Profiles of Selected European Toothpastes into Hard Tissues and Plaque.

OBJECTIVES: To compare the fluoridating potential of selected European toothpastes using a combination of enamel, dentin, and plaque in vitromodels. METHODS: Four in vitromodels were included: 1) Enamel Fluoride (F) Uptake (EFU); 2) Dentin F Uptake (DFU); 3) Enamel Solubility Reduction (ESR); and 4) Plaque F Uptake (PFU). A core set of marketed products was included in all studies, plus a standard toothpaste (1100 ppm F as NaF/silica) and placebo control (the PFU study did not include a placebo control). Test dentifrices: [A] Fluocaril® Bi-Fluoré 250 (1500 ppm F as NaF+1000 ppm F as SMFP); [B] LacerAnticaries (2500 ppm F as SMFP); [C] Elmex® Caries Professional™ (1450 ppm F as SMFP+1.5% arginine); [D] Colgate® Triple Action (1450 ppm F as SMFP); [E] Placebo (0 ppm F); and [F] standard toothpaste (1100 ppm as NaF/silica). In all studies (EFU, DFU, ESR, and PFU), assessments were compared for each pair using the Tukey-Kramer HSD test (p < 0.05). RESULTS: In all studies of fluoride uptake, the Fluocaril dentifrice [A] provided the greatest numerical benefit, regardless of the substrate. Statistical groupings were EFU: A > F = B = C = D > E; DFU: A > F = B = C = D = E; PFU: A = B > F = C = D). In demineralization prevention, the Fluocaril dentifrice [A] also provided the greatest benefit (ESR: A = F = C = B = D > E). In all studies that included a placebo control, all of the F-containing dentifrices performed better than the placebo control. CONCLUSIONS: While these results demonstrate that all of the marketed products tested provide effective anticaries benefits, the Fluocaril Bi-Fluoré 250 dentifrice consistently delivered unsurpassed performance. It delivered the highest level of F to plaque, provided greater measures of efficacy in both remineralization and inhibition of demineralization, and delivered substantial improvement in fluoridation of dentin, suggesting the potential for delivering both coronal and root caries benefits.

Comparative Antiplaque Effect of Two Antimicrobial Dentifrices: Laboratory and Clinical Evaluations.

OBJECTIVES: To compare the effect of a stannous fluoride dentifrice versus a triclosan-containing dentifrice on the reduction of plaque using in vitro and clinical models. METHODS: Both investigations evaluated a novel 0.454% stabilized stannous fluoride dentifrice (Crest® Pro-Health™ smooth formula) versus a sodium fluoride/triclosan positive control dentifrice (Colgate® Total®). The in vitro evaluation utilized the Plaque Glycolysis and Regrowth Model (PGRM), wherein the metabolic effects (acid production/glycolysis inhibition) of the dentifrices were assessed on plaque biofilms grown on glass rods after three days growth and a single dentifrice treatment. Treatments were evaluated via analysis of variance, Student's t-test. The clinical trial was a four-week, single-center, randomized and controlled, double-blind, parallel group study, where 120 adults were randomized to one of the two dentifrices for use at home according to manufacturer's instructions. Plaque was evaluated at baseline and Week 4 with the Rustogi Modified Navy Plaque Index (RMNPI). Statistical analyses were via analysis of covariance. RESULTS: In vitro PGRM: The stannous fluoride dentifrice provided 43.3% glycolysis inhibition compared to 27.5% for the triclosan control, and the pH decrease associated with acid production was significantly less for stannous fluoride (0.87) versus triclosan (1.11); p < 0.05. Clinical trial: One hundred eighteen (118) subjects completed the study with fully evaluable data. Both dentifrice groups demonstrated statistically significant (p < 0.0001) reductions in plaque at Week 4 compared with baseline, with the stannous fluoride dentifrice producing a significantly lower adjusted mean Week 4 plaque score (p < 0.0001) versus the triclosan positive control for whole mouth plaque (23.1% lower) and interproximal plaque (43.5% lower). Both dentifrices were well-tolerated. CONCLUSIONS: The stabilized stannous fluoride dentifrice provided statistically significant reductions in plaque glycolysis in vitro and plaque growth in vivo compared to the triclosan dentifrice. Results for both studies were consistent.

In Vitro and In Vivo Evaluations of the Anticalculus Effect of a Novel Stabilized Stannous Fluoride Dentifrice.

OBJECTIVES: To evaluate the effect of a novel stannous fluoride dentifrice with zinc citrate on calculus inhibition using both in vitro and clinical models. METHODS: Each investigation tested a novel stabilized 0.454% stannous fluoride dentifrice with zinc citrate as an anticalculus agent (Crest® Pro-Health™ smooth formula) compared to a negative control fluoride dentifrice. The in vitro study used the modified Plaque Growth and Mineralization Model (mPGM). Plaque biofilms were prepared and mineralized by alternate immersion of glass rods in human saliva and artificial mineralization solution. Treatments of 25% w/w dentifrice/water slurries were carried out for 60 seconds daily for 6 days, between saliva and mineralization solution immersions. Plaque calcium levels were determined by digestion and inductively coupled plasma optical emission spectroscopy. Student's t-test (p < 0.05) was used for statistical analysis. The clinical study was a parallel group, double-blind, randomized, and controlled trial. Following a dental prophylaxis, subjects entered a two-month run-in phase. At the end, they received a Volpe-Manhold Index (V-MI) calculus examination. Eighty (80) qualified subjects who had formed at least 9 mm of calculus on the linguals of the mandibular anterior teeth were re-prophied and randomly assigned to either the stannous fluoride dentifrice or the negative control. Subjects brushed twice daily, unsupervised, during the three-month test period, returning at Weeks 6 and 12 for safety and V-MI examinations. Statistical analyses were via ANCOVA. RESULTS: In vitro mPGM: The stabilized stannous fluoride dentifrice showed 20% less in vitro tartar formation, measured as calcium accumulation normalized by biofilm mass, versus the negative control (106.95 versus 133.04 µg Ca/mg biofilm, respectively, p < 0.05). Clinical Trial: Seventy-eight (78) subjects completed with fully evaluable data. The stannous fluoride dentifrice group had 15.1% less adjusted mean calculus at Week 6 compared to the negative control group (p = 0.05) and 21.7% less calculus at Week 12 (p < 0.01). Both dentifrices were well-tolerated. CONCLUSIONS: The stannous fluoride dentifrice produced significant anticalculus benefits in vitro and in a clinical trial compared to a negative control.

Immediate and Durable Effects of an Oxalate Strip on Human Dentin In Vitro.

OBJECTIVE: The objective of this research was to evaluate the performance of a polyethylene strip coated with an oxalate-containing gel to occlude patent tubuli in human dentin. METHODS: An in vitro model was adapted from the published literature to create a physiologically relevant microenvironment to study immediate and long-term effects of the strip. Observation techniques included scanning electron microscopy (SEM), SEM of ion-milled surfaces (SEM/FIB), and synchrotron-based x-ray microtomography. In addition, the reduction in hydraulic conductance induced by the strip was quantified. RESULTS: Significant deposition of crystalline oxalate was observed in treated dentin. Crystal density and occlusionary performance were found to be strong functions of strip application time and of the number of applications. Quantitative reduction in hydraulic conductance correlated well with crystal accumulation, also demonstrating a strong dependence on time and number of applications. The robustness of an oxalate crystal barrier formed with a single 10-minute strip application was tested over a 30-day period, during which dentin samples were subjected to a series of dissolution and mechanical challenges. Oxalate crystal density was shown to be modestly impacted, with substantial flow resistance maintained throughout the 30-day challenge period. CONCLUSION: The performance of an oxalate gel-coated strip is strongly affected by product-dentin contact time, producing an effective and durable occlusive barrier when applied as an adhesive strip.

Relative Performance of Antisensitivity Dentifrice, Rinse, and Oxalate Strips: An In Vitro Comparison of Common Global Over-the-Counter Products.

OBJECTIVE: The objective of this research was to evaluate the performance of a polyethylene strip coated with an oxalate-containing gel to occlude patent tubuli in human dentin. METHODS: An in vitro model was adapted from the published literature to create a physiologically relevant microenvironment to study immediate and long-term effects of the strip. Observation techniques included scanning electron microscopy (SEM), SEM of ion-milled surfaces (SEM/FIB), and synchrotron-based x-ray microtomography. In addition, the reduction in hydraulic conductance induced by the strip was quantified. RESULTS: Significant deposition of crystalline oxalate was observed in treated dentin. Crystal density and occlusionary performance were found to be strong functions of strip application time and of the number of applications. Quantitative reduction in hydraulic conductance correlated well with crystal accumulation, also demonstrating a strong dependence on time and number of applications. The robustness of an oxalate crystal barrier formed with a single 10-minute strip application was tested over a 30-day period, during which dentin samples were subjected to a series of dissolution and mechanical challenges. Oxalate crystal density was shown to be modestly impacted, with substantial flow resistance maintained throughout the 30-day challenge period. CONCLUSION: The performance of an oxalate gel-coated strip is strongly affected by product-dentin contact time, producing an effective and durable occlusive barrier when applied as an adhesive strip.