A randomised in situ trial, measuring the anti-erosive properties of a stannous-containing sodium fluoride dentifrice compared with a sodium fluoride/potassium nitrate dentifrice.

OBJECTIVES: To determine if a stabilised, stannous-containing sodium fluoride dentifrice provides greater enamel protection in situ against intraoral dietary erosive challenges compared with a sodium fluoride/potassium nitrate dentifrice. METHODS: A single-centre, investigator blind, randomised, supervised, two-treatment, non-brushing, four-period crossover in situ study was undertaken, with each test period being 15 days. Thirty-five healthy adult subjects were recruited to participate in the study, which included four erosive acid challenges per day. Subjects were randomised to product treatment, which included either: (1) a stannous-containing sodium fluoride dentifrice (Oral-B(®) Pro-Expert Sensitive) or (2) a sodium fluoride/potassium nitrate dentifrice (Sensodyne(®) Pronamel(®) ). Each study subject wore an intraoral appliance retaining two sterilised, polished human enamel samples for 6 hours/day. Subjects swished with an allocated dentifrice slurry twice a day and with 250 ml of orange juice for 10 minutes (25 ml/minute over a 10-minute period) four times per day. The primary and secondary outcomes for this study were enamel loss measured using contact profilometry at days 15 and 5, respectively, using parametric analysis methods. RESULTS: At day 15, a 38% lower enamel loss (P < 0.0001) was observed, with estimated medians of 2.03 µm (SE 0.247) and 3.30 µm (SE 0.379), in favour of the stannous-containing dentifrice. At day 5, specimens treated with the stannous-containing sodium fluoride dentifrice demonstrated 25% less enamel loss than those treated with the sodium fluoride/potassium nitrate dentifrice. Treatment differences at day 5 were also statistically significant (P < 0.05), with estimated medians of 1.37 µm (SE 0.177) and 1.83 µm (SE 0.223), respectively. CONCLUSIONS: Results of this in situ study suggest the stabilised, stannous-containing sodium fluoride dentifrice could be used to provide significantly greater protection to enamel from erosive acid challenge compared with that provided by conventional fluoride-containing products.

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.

A pilot study to evaluate the impact of digital imaging on the delivery of oral hygiene instruction.

AIMS: To determine whether personalised Oral Hygiene Advice (OHA) using an intra-oral-camera (IOC) combined with standard OHA as provided in general dental practice reduces plaque levels after 4 weeks more than the provision of standard OHA. MATERIALS AND METHODS: 22 healthy adult participants diagnosed with gingivitis took part in this pilot parallel-designed, randomised, examiner-blind, 2x-treatment, study regarding their home-care oral hygiene habits and attitudes to oral health. An IOC-image was taken and plaque, gingival and bleeding scores were recorded. Test group participants received standard OHA with IOC-images to indicate areas for improvement, control group participants received standard OHA. Questionnaires and plaque, gingival and bleeding scores were repeated after 4 weeks. Plaque was scored from the IOC-images and scores compared to clinical plaque scores. RESULTS: Lifestyle habits, attitudes to oral health, plaque (0.63vs0.61, control vs test) and bleeding scores (1.17vs0.96, control vs test) were similar at baseline. After 4-weeks, plaque scores improved more in test as compared to control group (39.4vs20.6%, p<0.05, while gingival and bleeding scores approached significance. There was no difference in lifestyle habits between groups, but the test group reported significantly greater confidence in adhering to their bespoke oral health plan. Agreement between the clinical and IOC plaque scores was good. CONCLUSIONS: Use of IOC further personalises the prevailing standard of oral hygiene advice and generates great patient engagement with pictorial reports to facilitate a more in-depth patient explanation of their gingival health, resulting in significant plaque reduction and improved gingival health compared to the standard OHA alone.

Assessment of tubule occlusion properties of an experimental stannous fluoride toothpaste: A randomised clinical in situ study.

OBJECTIVES: To evaluate the ability of a modified in situ model to differentiate dentinal tubule occlusion properties of toothpaste formulations over 10 days of treatment. METHODS: This was a single-centre, three-treatment period, crossover, randomised, single-blind study with healthy participants wearing two lower oral appliances, each retaining four dentine samples, for 10 treatment days during each period of the study. Samples were power-brushed ex vivo twice on each treatment day with a Test toothpaste containing 0.454% stannous fluoride, a Control fluoride toothpaste containing 0.76% sodium monofluorophosphate, or mineral water. Dentine samples were subjected to in situ acid challenge (orange juice) on Days 9 and 10. Scanning electron microscopy images obtained at baseline and after 1, 4, 8 and 10 days of treatment were graded for degree of surface coverage by four calibrated examiners; the primary study endpoint was Day 8. RESULTS: After 4, but not 8, days' treatment, the degree of tubule occlusion increased in the dentine samples treated with the Test or Control toothpastes compared with the water-treated samples (p < 0.01 and p < 0.05, respectively). Following the acid challenge (Day 10), there was a statistically significantly greater degree of occlusion in the Test toothpaste-treated dentine samples compared with those treated with water (p < 0.01). No other comparisons were statistically significant. All study treatments were generally well-tolerated. CONCLUSIONS: This modified in situ model was unable to demonstrate statistically significant between-treatment differences in dentinal tubule occlusion after 8 days. Conversely, there are recognised developments that could be made to better identify product differences. Clinicaltrials.gov: NCT02768194. CLINICAL SIGNIFICANCE: Dentine hypersensitivity can be managed through brushing with stannous fluoride toothpastes, which occlude patent dentine tubules. Clinical studies measure pain but in situ models are needed to demonstrate occlusion intra-orally. However, this study did not demonstrate superior occlusion with stannous toothpaste; further methodological development is required to investigate its mode of action.

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.