In situ clinical evaluation of a stabilised, stannous fluoride dentifrice.

OBJECTIVES: To compare the erosion protection efficacy of a stabilised, stannous fluoride (SnF2 ) dentifrice versus a sodium fluoride (NaF) dentifrice using a modified in situ clinical model. METHODS: This study, a randomised parallel group in situ design with in vivo product use and ex vivo acid challenge, compared: A, a dentifrice containing 1,450 ppm F as NaF; B, a dentifrice containing 1,450 ppm F (1,100 ppm F as SnF2 + 350 ppm F as NaF); and T, tap water. Sample size was n = 4 per group (total of 12 subjects) and within each subject appliances were placed on each side of the mouth (left and right). Enamel specimens were placed in different positions of the mouth (front, mid-front, mid-rear, rear) in each appliance (total = 8 specimens per subject). Product treatment was twice per day (lingual brushing for 30 seconds followed by swishing for 90 seconds with the resultant product/saliva slurry) in vivo for 15 days, and ex vivo acid treatment (0.02 m citric acid 5 minutes four times per day; total exposure time = 300 minutes). Data were analysed using a general linear repeated measures model with treatment, side and position as fixed effects. Within subjects, correlations were modelled assuming a different correlation and variance for treatment B relative to the other groups. Pairwise treatment differences were performed using a 5% two-sided significance level. RESULTS: Enamel loss (in µm) was significantly lower (P < 0.005) for treatment B versus treatments A and T. Treatment B reduced enamel surface loss by 86.9% relative to treatment A. There was no statistical difference in mean enamel loss (P = 0.51) between treatments A and T. Enamel loss was not statistically different for side (left vs. right; P = 0.44) or position (front, mid-front, mid-rear, rear; P = 0.36). CONCLUSION: This modified in situ erosion model confirmed the enhanced erosion protection benefits of a stabilised SnF2 dentifrice versus a conventional NaF dentifrice, validating the ability of the model to safely and effectively demonstrate differences in the erosion protection potential of oral care products.

Clinical response of two brush-applied peroxide whitening systems.

OBJECTIVE: A randomized, examiner-blind parallel design study was conducted to evaluate the clinical efficacy and tolerability of two brush-applied, peroxide-based tooth whiteners. METHODOLOGY: A total of 38 subjects were randomized to Colgate Simply White, an 18% carbamide peroxide paint-on liquid in an applicator bottle, or Crest Night Effects, a 19% sodium percarbonate system in unit dose sachets that dries to form an adherent film. Treatment was for 14 days. The 18% carbamide peroxide gel was applied twice daily, while the 19% sodium percarbonate film was applied for overnight use. Subjects were evaluated at baseline, and again after 7 and 14 days of treatment using digital images to assess tooth color, and oral examinations to establish safety. Whitening efficacy was determined by evaluating the reduction in tooth yellowness (delta b*), increase in tooth brightness (delta L*), reduction in tooth redness (delta a*) and overall tooth color change relative to pure white (delta W*). RESULTS: After 14 days, the mean change in yellowness (delta b*) was -1.43 +/- 0.20 for the 19% sodium percarbonate film, and -0.44 +/- 0.06 for the 18% carbamide peroxide gel. Mean change in brightness (delta L*) was 1.13 +/- 0.13 and 0.55 +/- 0.13 in the film and gel groups, respectively. Between-group comparisons showed highly significant (p < or = 0.003) whitening for the 19% sodium percarbonate film compared to the 18% carbamide peroxide gel for all 14-day color measurements (delta b*, delta L*, delta a* or delta W). Both products were well-tolerated, with no subjects discontinuing treatment early due to a causal adverse event. CONCLUSION: In a direct clinical comparison of two brush-applied products over 14 days, Crest Night Effects provided significant and meaningful improvement in tooth color, representing more than double the whitening measured for the Colgate Simply White.

Delivery, substantivity and clinical response of a direct application percarbonate tooth whitening film.

PURPOSE: A novel overnight bleaching system containing 19% sodium percarbonate and silicone film forming agents (Crest Night Effects) is described, along with research supporting the substantivity of the product on tooth surfaces and its resulting whitening efficacy. METHODS: Nine adult volunteers were enrolled in a study to determine overnight retention (substantivity) of the product. A non-reactive blue pigment was added to the product to aid in evaluating retention. The participants applied the product to their anterior dentition at night and then had digital images taken. After 7 hours of sleep, the patients were awakened and re-imaged. The percent coverage with blue pigment on the surfaces of the 12 anterior teeth was calculated from the digital images after application and after awakening. The product was also evaluated in a 2-week efficacy study with 16 adult volunteers. Each night the participants brushed their teeth before going to bed as they normally would, dried their teeth with a towel, and then applied the product to their six maxillary and mandibular anterior teeth. The product was left on the teeth overnight and then removed in the morning via toothbrushing. Color (baseline and after 2 weeks of product usage) was determined using digital imaging and the standard L*a*b* measurement scale. RESULTS: In the substantivity study, 84.7% of the subject teeth surfaces were covered on average with the blue pigment-containing film immediately after application. Following overnight use, excellent retention was demonstrated as 77.4% of the initially covered surfaces still had pigment-containing film on them. These means did not differ significantly (P > 0.44). In the clinical efficacy study, there was significant (P < 0.0001) color improvement versus baseline after 2 weeks of treatment as measured by a mean (SD) delta b* of -1.71 (0.85) and mean (SD) delta L* of 1.62 (0.68). The product was well-tolerated, with the primary adverse events being oral irritation (13%) and tooth sensitivity (6%). No participants discontinued product use because of a product-related adverse event.