Erosion protection benefits of stabilized SnF2 dentifrice versus an arginine-sodium monofluorophosphate dentifrice: results from in vitro and in situ clinical studies.

OBJECTIVES: The aim of these investigations was to assess the ability of two fluoride dentifrices to protect against the initiation and progression of dental erosion using a predictive in vitro erosion cycling model and a human in situ erosion prevention clinical trial for verification of effectiveness. MATERIALS AND METHODS: A stabilized stannous fluoride (SnF2) dentifrice (0.454 % SnF2 + 0.077 % sodium fluoride [NaF]; total F = 1450 ppm F) [dentifrice A] and a sodium monofluorophosphate [SMFP]/arginine dentifrice (1.1 % SMFP + 1.5 % arginine; total F = 1450 ppm F) [dentifrice B] were tested in a 5-day in vitro erosion cycling model and a 10-day randomized, controlled, double-blind, two-treatment, four-period crossover in situ clinical trial. In each study, human enamel specimens were exposed to repetitive product treatments using a standardized dilution of test products followed by erosive acid challenges in a systematic fashion. RESULTS: Both studies demonstrated statistically significant differences between the two products, with dentifrice A providing significantly better enamel protection in each study. In vitro, dentifrice A provided a 75.8 % benefit over dentifrice B (p < 0.05, ANOVA), while after 10 days in the in situ model, dentifrice A provided 93.9 % greater protection versus dentifrice B (p < 0.0001, general linear mixed model). CONCLUSION: These results support the superiority of stabilized SnF2 dentifrices for protecting human teeth against the initiation and progression of dental erosion. CLINICAL RELEVANCE: Stabilized SnF2 dentifrices may provide more significant benefits to consumers than conventional fluoride dentifrices.

A Randomised trial to investigate the erosive effect of hot drinks.

Research on dental erosion has largely been undertaken at room temperature despite fruit juice drinks often being consumed at elevated temperatures in the United Kingdom, notably during periods of convalesce. The aim of the study was to evaluate the erosive potential of two fruit juices containing acidic non-alcoholic drinks at elevated temperatures in situ on human enamel after 5, 10 and 15 days. A commercially available conventional apple and blackcurrant fruit juice drink was compared to a blackcurrant juice drink modified to have low erosive potential, and mineral water consumed at approximately 59 °C. Twenty-one healthy volunteers aged 18 or over participated in a single-centre, single-blind (blinded to the investigator), three-treatment crossover study. Subjects were randomised to a treatment sequence using a Latin square design. Subjects wore upper removable appliances containing one human enamel specimen from 9 am to 5 pm for 15 days for each beverage. Measurements of enamel loss were recorded after 5, 10 and 15 days by contact surface profilometry. The low erosive blackcurrant drink caused significantly less enamel loss (P < 0·05) than the commercially available conventional apple and blackcurrant fruit juice drink and was not statistically significantly different to mineral water at any of the time points in the study. Consuming the modified low erosive blackcurrant drink at an elevated temperature resulted in negligible enamel loss in situ, consistent with room temperature findings.

In situ randomised trial investigating abrasive effects of two desensitising toothpastes on dentine with acidic challenge prior to brushing.

OBJECTIVES: To determine if brushing dentine with 2 moderate RDA desensitising toothpastes, results in a significant dentine wear difference and whether this difference continues to be relevant when preceded with an erosive challenge. METHODS: An in situ, single centre, single blind, randomised, split mouth study, evaluated the difference in abrasion of 2 toothpastes (SFM - Sensodyne Fresh Mint(®) RDA 70; CPHM - Crest Pro-Health Clean Mint(®) RDA 120) in 28 healthy volunteers. Two toothpaste treatments were administered 3×/day, for each of the two 15 day periods, subjects wearing bi-lateral, lower buccal appliances each with 4 dentine sections. A 2 min extra-oral acidic challenge preceded toothbrushing for 2 study arms. Contact profilometry measured samples at baseline, days 5, 10 and 15. RESULTS: Brushing with SFM was significantly less abrasive than brushing with CPHM at all time points, with or without a preceding acidic challenge (p<0.0001). The additional dentine loss arising from the erosive challenge prior to brushing with each paste was linear with time and independent of abrasive effect. CONCLUSIONS: The desensiting toothpastes' RDA, directly related to dentine loss with toothbrushing. An acidic challenge prior to brushing did not negate the benefits of reduced wear from the lower RDA paste compared to the higher RDA paste. When brushing eroded dentine, the additional wear appeared independent of abrasive effect. Dentine hypersensitivity sufferers should be recommended to use a low-moderate RDA toothpaste, not to brush more than 2×/day and not immediately following an acidic challenge.

Randomized in situ clinical study comparing the ability of two new desensitizing toothpaste technologies to occlude patent dentin tubules.

OBJECTIVE: To compare the ability of two new desensitizing toothpaste technologies (one a 5% NovaMin-based toothpaste and the other an 8% arginine-based toothpaste) to occlude patent dentin tubules in a clinical environment relative to a negative control of water and a control toothpaste after four days of twice-daily brushing and dietary acidic challenges. METHODS: The study design was a single-center, single-blind, randomized, split-mouth, four-treatment, two-period, crossover, in situ clinical study. Healthy subjects wore two lower intra-oral appliances, retaining four dentin samples for four treatment days for each period of the clinical study. Samples were brushed twice daily with a test product (days 1-4), with an additional acidic challenge introduced on two selective days. Scanning electron microscopy (SEM) images were taken of the dentin surface, and dentinal tubule occlusion assessed using a categorical scale. RESULTS: The results demonstrated that the 5% NovaMin toothpaste was statistically superior at occluding patent dentin tubules compared to water (p = 0.009) and the control toothpaste (p = 0.02) at day 4. In contrast, the treatment effect resulting from the 8% arginine toothpaste did not demonstrate the same degree of occlusive propensity, showing no significant difference to the water and control toothpaste at the day 4 time point. CONCLUSION: Application of the 5% NovaMin toothpaste to dentin showed better dentin tubule occlusion and retention abilities in an oral environment under dietary acid challenge conditions, more so than the 8% arginine toothpaste technology. Given modern dietary habits and practices, these results highlight differences in the acid resistance properties of occlusion technologies, and a potential impact on clinical performance.

Development of an in situ methodology for the clinical evaluation of dentine hypersensitivity occlusion ingredients.

OBJECTIVE: The aim of these clinical studies was to evaluate an in situ dentine tubule occlusion model, and to determine the occluding effect from novel occluding agents on patent dentine tubules compared to a positive control (8% strontium acetate--Sensodyne Mint) and negative control (a non-occluding agent) after four days of brushing treatment. METHODS: These two in situ clinical studies were of single-center, randomized, crossover, single-blind design. Healthy participants wore two lower intra-oral appliances retaining four dentine samples for four treatment days for each period of the study. Samples were power-brushed each day with the test product. Assessment utilized surface topological analysis with a replica-based methodology under scanning electron microscopy (SEM). RESULTS: Both clinical trials demonstrated that the positive control (8% strontium acetate) occluded dentine tubules significantly better (p = 0.0007; p < 0.0009) than the negative controls in the two studies, respectively. The experimental occluding agents demonstrated varying degrees of success for occluding effect compared to the controls. CONCLUSION: The methodology clearly demonstrates that this in situ clinical model can robustly and reproducibly detect the dentine tubular occlusive effects of positive and negative controls in the treatment of dentine hypersensitivity brushed on the dentine surface. Using this methodology, new occlusion agents for the relief of dentine hypersensitivity can be assessed for occlusive effects on dentine.

Evaluation of a young child's behavior: effects of attractiveness and sex.

Facial drawings of 2- or 4-yr.-old boys or girls differing in attractiveness were attached to an episode which depicted a mild misbehavior. Neither the attribution of responsibility for the behavior nor the choice of an indulgent vs punitive response was associated with the child's attractiveness, sex, or age. These findings suggest that the halo effects of attractiveness discriminations may not be fully operative at these ages.