A randomised oral fluoride retention study comparing intra-oral kinetics of fluoride-containing dentifrices before and after dietary acid exposure.

OBJECTIVE: This exploratory, randomised, single-blind, crossover, study evaluated fluoride and calcium ion concentrations and pH following use of one of two 1450 ppm fluoride (NaF), 5% w/w KNO3 dentifrices: (1) test dentifrice (with cocamidopropyl betaine) with an orange juice (OJ) rinse; (2) test dentifrice with a deionized (DI) water rinse or (3) comparator dentifrice (with sodium lauryl sulphate and tetrasodium pyrophosphate) with an OJ rinse. DESIGN: Eighteen participants used their assigned dentifrice, rinsed with DI water, then expectorate was collected. Sixty min post-brushing, participants rinsed with OJ or DI water then expectorate was collected. Saliva samples were collected pre-brushing and at 1, 5, 10, 15, 30 and 60 min post-brushing and following the 60 min OJ/DI water rinse. The pH of samples was taken. RESULTS: Significant differences (p < 0.05) were found in salivary fluoride ion concentrations between test and comparator dentifrices at 30 and 60 min and following the 60 min OJ rinse, favouring the former. Significant differences were also found between test and comparator dentifrices for salivary calcium ion concentration at 1, 5 and 10 min (p < 0.0001), favouring the former, and between test or comparator + OJ rinse and test + water rinse (p < 0.005), favouring the latter. No pH differences were shown prior to OJ/water rinse. Products were generally well-tolerated. CONCLUSIONS: Results confirmed that acid-labile fluoride is released from the oral cavity following a dietary acid challenge and showed that formulation excipients may impact on retention of such.

Randomized exploratory study to measure ion release from calcium sodium phosphosilicate-containing dentifrice.

This exploratory study investigated salivary concentrations of silicon, calcium, sodium, and phosphorous over a 60-min time period following the use of a calcium sodium phosphosilicate (CSPS)-containing dentifrice. Participants brushed with a dentifrice containing 5% (w/w) or 0% (w/w) CSPS or swilled with a slurry containing 5% (w/w) CSPS/glycerol. Saliva samples were collected before, and 2, 5, 15, and 60 min after, product use and were analysed using inductively coupled plasma optical emission spectroscopy. Intra-oral pH measurements were also taken. Primary analysis was of centrifuged saliva supernatant containing only dissolved material. At most time points, the CSPS-containing dentifrice and slurry generated significantly more salivary silicon than the dentifrice containing 0% CSPS. At 2-15 min after brushing there was significantly more salivary calcium after use of the CSPS-containing dentifrice and slurry, compared with the 0% CSPS dentifrice; a significant reduction, from baseline, in salivary calcium after use of dentifrice containing 0% CSPS; and an increase in salivary sodium after use of dentifrices containing either 5% or 0% CSPS, but no differences between them. Salivary phosphorous concentration decreased significantly with all treatments 2-5 min after use. There were no significant between-treatment differences in intra-oral pH. Products were generally well tolerated. This study establishes that it is possible to measure changes in salivary ionic composition derived through oral retention of CSPS, delivered via a dentifrice.

A randomised clinical evaluation of a fluoride mouthrinse and dentifrice in an in situ caries model.

OBJECTIVES: Fluoride mouthrinses provide advantages for fluoride delivery by maintaining elevated intra-oral fluoride concentrations following fluoride dentifrice use. This in situ caries study investigated potential anti-caries efficacy of a 220 ppm fluoride mouthrinse. METHODS: This was an analyst-blinded, four-treatment, randomised, crossover study using partially demineralised, gauze-wrapped, human enamel samples mounted in a mandibular partial denture. Participants brushed twice daily for 14 days with either a 1150 ppm fluoride or a fluoride-free placebo dentifrice and either rinsed once daily with the 220 ppm fluoride mouthrinse or not. Following each treatment period, percent surface microhardness recovery (%SMHR) and enamel fluoride uptake (EFU) were assessed. RESULTS: Fifty three participants completed the study. Compared with the placebo dentifrice/no rinse treatment, the fluoride-containing regimens demonstrated greater enamel remineralisation (%SMHR) and fluoridation (EFU): fluoride dentifrice/fluoride rinse (%SMHR difference: 21.55 [95% CI: 15.78,27.32]; EFU difference 8.35 [7.21,9.29]); fluoride dentifrice/no rinse: 19.48 [13.81,25.15]; 6.47 [5.35,7.60]; placebo dentifrice/fluoride rinse: 16.76 [11.06,22.45]; 5.87 [4.72,7.00] (all P < .0001). There were no significant differences in%SMHR between fluoride regimens. The fluoride dentifrice/fluoride rinse regimen was associated with higher EFU than the fluoride dentifrice/no rinse (1.88 [0.75,3.01], P = .0013) and placebo dentifrice/fluoride rinse regimens (2.48 [1.34,3.62], P < .0001). Treatments were generally well-tolerated. CONCLUSIONS: The in situ caries model demonstrated that the fluoride mouthrinse is effective in promoting enamel caries lesion remineralisation and fluoridation whether used following a fluoride or non-fluoride dentifrice. Additive (potential) anti-caries benefits of a fluoride rinse after a fluoride dentifrice were confined to enhancements in lesion fluoridation (EFU). CLINICAL SIGNIFICANCE: In conjunction with a fluoride dentifrice, fluoride mouthrinses enhance enamel fluoridation, which may be useful in caries prevention.

Erosion Remineralization Efficacy of Gel-to-Foam Fluoride Toothpastes in situ: A Randomized Clinical Trial.

This single-center, randomized, placebo-controlled, four-treatment, four-period crossover study compared the enamel remineralization effects of low- and medium-abrasivity gel-to-foam toothpastes and a reference toothpaste (all 1,450 ppm fluoride as NaF) versus placebo toothpaste (0 ppm fluoride) using a short-term in situ erosion model. Subjects (n = 56) wearing a palatal appliance holding acid-softened bovine enamel specimens brushed their teeth with the test toothpastes. Thereafter, the specimens were removed for analysis of percent surface microhardness recovery (%SMHR) and percent relative erosion resistance (%RER) at 2, 4, and 8 h. Both low- and medium-abrasivity gel-to-foam fluoride toothpastes and the reference toothpaste provided significantly greater %SMHR than placebo at all assessment time points (all p < 0.05). No statistically significant difference of %SMHR was observed between the fluoride treatment groups at any time point. Similarly, all fluoride products provided significantly superior %RER versus placebo (all p < 0.0001), whereas no significant difference of this parameter was noted between the fluoride treatment groups. Increasing numerical improvements of %SMHR and %RER were observed in all four treatment groups over time (2, 4, and 8 h). The present in situ model is a sensitive tool to investigate intrinsic and fluoride-enhanced rehardening of eroded enamel. All three fluoride toothpastes were more efficacious than placebo, and there were no safety concerns following single dosing in this short-term in situ model.

A randomized, crossover trial to evaluate the effect of two mouthrinses on plaque regrowth in the absence of brushing.

This study assessed the effects on plaque in the absence of brushing of two twice-daily mouthrinses, one with an enzymatic-based formulation (Biotène) and one with an antimicrobial chlorhexidine-based formulation (Peridex), and sterile water. Plaque levels were assessed in 23 participants using a 4-day, nonbrushing plaque regrowth model after twice-daily rinsing with sterile water (negative control), the enzyme-based mouthrinse, or the chlorhexidine-based mouthrinse (positive control). Peridex showed significantly greater prevention of plaque regrowth when compared with water and the enzyme-based Biotène mouthrinse. After 4 days, the enzyme-based mouthrinse was associated with a small but nonsignificant reduction in plaque regrowth compared with water. This study confirmed that Peridex is effective at prevention of plaque regrowth. Twice-daily rinsing with a Biotène formula that contained enzymes showed a small but nonsignificant trend toward prevention of plaque regrowth versus rinsing with water.

A randomized clinical study investigating the staining profile of an experimental stannous fluoride dentifrice.

PURPOSE: The primary objective of this study was to investigate the staining profile of an experimental test dentifrice containing 0.454% w/w stannous fluoride compared to that of a marketed control dentifrice containing 0.76% w/w sodium monofluorophosphate (Colgate Cavity Protection) following regular and repeat use, with twice daily brushing over 8 weeks. As an exploratory objective, the staining profile of the test dentifrice was compared to that of a marketed comparator dentifrice containing 0.454% w/w stannous fluoride (Crest Pro-Health - Clean Mint). METHODS: This was a single-center, examiner-blind, randomized, three arm, parallel group study, stratified by pre-baseline stain score [total Lobene Stain Index (LSI) (area x intensity) score < 31, > or = 31] and smoking status. Following initial screening, 137 healthy subjects, aged 18 years and above, with 12 gradable anterior teeth returned for baseline assessments. At the baseline visit, subjects received an oral soft tissue (OST) examination and an assessment of extrinsic dental stain using the LSI on the facial and lingual surfaces of the 12 anterior teeth, LSI area, LSI intensity and LSI area x intensity (the LSI area x intensity score was termed the pre-baseline LSI score). Subjects who met study requirements received a dental prophylaxis of the anterior teeth to remove all visible stain from their tooth surfaces such that an LSI (area x intensity) score of 0 was achieved. Randomized subjects brushed with their assigned dentifrice at home twice daily for 1 timed minute and returned after 4 and 8 weeks for an OST examination and dental stain assessment of the anterior teeth using LSI. RESULTS: There were no statistically significant differences in dental stain build-up between the test dentifrice containing 0.454% w/w stannous fluoride and a marketed control dentifrice (Colgate Cavity Protection), after 4 and 8 weeks of twice daily brushing, in terms of LSI area x intensity, LSI area or LSI intensity scores. Exploratory analysis indicated that the marketed stannous fluoride dentifrice (Crest Pro-Health) exhibited more dental stain build-up at 4 and/or 8 weeks compared to the other two study dentifrices. However, post-hoc analysis revealed an imbalance in LSI baseline stain levels between the treatment groups, with higher stain levels in the marketed comparator group, which made it difficult to draw robust conclusions from the exploratory data. This imbalance was not considered to impact the other study analyses. Study treatments were well tolerated.