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.

Genomic expression changes induced by topical N-acetyl glucosamine in skin equivalent cultures in vitro.

N-acetyl glucosamine (NAG) has been shown to be effective in reducing the appearance of hyperpigmented spots. From published in vitro mechanistic testing, glucosamine inhibits enzymatic glycosylation, a required processing step in converting inactive human pro-tyrosinase to the active tyrosinase, a key enzyme in the production of melanin. There is also published literature discussing the anti-inflammatory and antioxidant properties of glucosamine compounds. To identify additional mechanisms by which NAG might affect melanin production, an in vitro genomics experiment was conducted in SkinEthic skin equivalent cultures, which were topically dosed with NAG vs. a vehicle control. Relative to vehicle, NAG reduced melanin production, and the expression of several pigmentation-relevant genes were affected (down-regulated or up-regulated) by NAG treatment. Thus, there are several mechanisms that may be operative in the observed pigmentation effects.