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.

Measuring enamel erosion: a comparative study of contact profilometry, non-contact profilometry and confocal laser scanning microscopy.

OBJECTIVES: To compare three instruments for their ability to quantify enamel loss after acid erosion. METHODS: 6 randomized parallel groups of bovine enamel samples were subjected to citric acid (higher acidity) or orange juice (lower acidity) erosion and remineralisation in a cycling model. Two protected shoulders were created on each of the samples using tape, to serve as reference for analysis. The time of exposure to each acid was varied, along with presence or absence of agitation. After treatment, samples were measured on 3 instruments capable of measuring step height: a contact profilometer (CP); a non-contact profilometer (NCP); and a confocal laser scanning microscope (CLSM) by three different examiners. Additionally, 3D (volume) step height was also measured using the CLSM. RESULTS: Increasing acid concentration and exposure time resulted in greater erosion, as did agitation of samples while in acid solution. All instruments/methods identified the same statistically significant (p<0.05) pair-wise differences between the treatments groups. Further, all four methods exhibited strong agreement (Intra-class correlation ≥ 0.96) in erosion level and were highly correlated, with correlations of 0.99 or higher in all cases. SIGNIFICANCE: All instruments/methods used in this study produced very similar conclusions with regard to ranking of enamel loss, with data showing very high agreement between instruments. All instruments were found to be equally suited to the measurement of enamel erosion.

A randomized clinical trial to compare plaque inhibition of a sodium fluoride/potassium nitrate dentifrice versus a stabilized stannous fluoride/sodium hexametaphosphate dentifrice.

AIM: To compare the plaque inhibition efficacy of a sodium fluoride/potassium nitrate (NaF/KNO3 with 1450 ppm F) test dentifrice to a 0.454% stannous fluoride/sodium hexametaphosphate/sodium fluoride positive control dentifrice (SnF2/SHMP with 1450 ppm F). METHODS AND MATERIALS: Twenty-five subjects were randomized to a two-period, two-treatment, double blind crossover sequence using NaF/KNO3 (Sensodyne ProNamel dentifrice) and SnF2/SHMP (blend-a-med* EXPERT GUMS PROTECTION dentifrice). Each treatment was conducted with a standard manual toothbrush (Oral-B P35 Indicator). Digital plaque image analysis (DPIA) was used on three consecutive days to evaluate: (a) overnight plaque formation (A.M. pre-brushing); (b) following 40 seconds of brushing with the test product (A.M. post-brushing); and (c) mid-afternoon (P.M.). Images were analysed using an objective computer algorithm to calculate the total area of visible plaque. A four-day washout period was instituted for the crossover phase. RESULTS: All 25 subjects completed the study. The SnF2/SHMP positive control dentifrice provided statistically significantly lower levels of plaque area coverage versus the NaF/KNO3 test dentifrice at each timepoint. For the SnF2/SHMP dentifrice, plaque coverage was 23.0% lower (p< 0.0001) at A.M. pre-brushing, 17.3% (p= 0.0163) lower at A.M. post-brushing, and 22.6% (p= 0.0004) lower at the P.M. measure relative to the NaF/KNO3 dentifrice. CONCLUSION: The SnF2/SHMP dentifrice (blend-a-med EXPERT GUMS PROTECTION) inhibits plaque regrowth both overnight and during the day to a significantly greater degree than the NaF/KNO3 dentifrice (Sensodyne ProNamel). CLINICAL SIGNIFICANCE: Dentists recommending an effective home use dentifrice for patients experiencing dentinal hypersensitivity and/or dental erosion may previously have needed to compromise on other key benefits, such as plaque control. blend-a-med EXPERT GUMS PROTECTION is a dentifrice when integrated into an oral hygiene routine can provide a proven treatment for hypersensitivity, dental erosion, and a reduction in the regrowth of plaque.

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.