A randomised clinical in situ study to evaluate the effects of novel low abrasivity anti-sensitivity dentifrices on dentine wear.

OBJECTIVES: To compare the abrasive wear on human dentine in an in situ model associated with use of an experimental low abrasivity anti-sensitivity dentifrice containing 1% alumina and 5% sodium tripolyphosphate (STP) with an experimental ultra-low abrasivity non-alumina 5% STP dentifrice, a higher abrasivity daily-use whitening dentifrice, and water as controls. METHODS: This was a single-centre, single-blind, randomised, split-mouth, four-treatment, two-period, crossover in situ study in 29 healthy subjects. Subjects wore bilateral lower buccal appliances, each fitted with four dentine specimens. Study treatments were applied ex vivo (three times daily). Dentine loss was measured by non-contact profilometry after 5, 10 and 15days' treatment. RESULTS: All 29 subjects were included in the efficacy analysis. Significantly less dentine loss was associated with brushing with the low and ultra-low abrasivity dentifrices than with the higher abrasivity dentifrice at all timepoints (p<0.01). Brushing with ultra-low abrasivity dentifrice or water resulted in statistically significantly less dentine loss compared with brushing with the low abrasivity dentifrice at all timepoints (p<0.05). Dentine loss after brushing with ultra-low abrasivity dentifrice was not significantly different from brushing with water. CONCLUSIONS: The degree of dentine loss observed in this in situ model reflected the abrasivity of the study dentifrices. Brushing with low or ultra-low abrasivity STP-containing anti-sensitivity dentifrices resulted in significantly less dentine loss (equating to dentine wear) than with a higher abrasivity daily-use whitening dentifrice.

A clinical study to measure anti-erosion properties of a stabilized stannous fluoride dentifrice relative to a sodium fluoride/triclosan dentifrice.

OBJECTIVE: To compare the enamel protection efficacy of a stabilized stannous fluoride (SnF2 ) dentifrice to a sodium fluoride (NaF)/triclosan dentifrice following acidic erosive challenge. METHODS: In this in situ, randomized, controlled, double-blind, two-treatment, four-period crossover clinical trial, subjects wore an appliance fitted with human enamel samples 6 h day-1 during each 15-day treatment period. Twice each treatment day they swished with their assigned dentifrice slurry: 0.454% SnF2 /0.077% NaF or 0.32% NaF/0.3% triclosan. After each treatment and two other times daily, subjects swished with 250 ml of orange juice over a 10-min period (acidic erosive challenge). Enamel samples were measured for tooth surface loss using contact profilometry at baseline and days 10 and 15. RESULTS: Thirty-six subjects (mean age 44.8 years, range 23-65 years) were randomized to treatment; 33 subjects completed the final study visit. There were no statistically significant baseline differences (P > 0.44) in the specimen surfaces of the two dentifrice treatment groups via profilometry. At day 10, the SnF2 dentifrice provided a statistically significant (P < 0.0001) reduction in enamel loss by 67% versus the NaF/triclosan dentifrice with estimated medians of 1.22 and 3.68 µm, respectively. At day 15, the SnF2 dentifrice again provided a significantly greater benefit (P < 0.0001) against tooth surface loss versus the NaF/triclosan dentifrice, with 68% less erosion, and estimated medians of 1.60 and 5.03 µm, respectively. Both dentifrices were well tolerated. CONCLUSION: A stabilized SnF2 dentifrice provided superior protection against the initiation and progression of tooth enamel surface loss in situ after erosive challenge compared to a NaF/triclosan dentifrice.