Timing of fluoride toothpaste use and enamel-dentin demineralization

It is well established that fluoride (F) prevents caries development by inhibiting demineralization and enhancing remineralization processes. However, it is not known which of these protective mechanisms is more important. In this double-blind, crossover in situ study conducted in three phases of 14 days each, 12 volunteers wore palatal appliances containing enamel and root dentin slabs, on which biofilm was allowed to accumulate under exposure to 20% sucrose solution 8×/day. F toothpaste was used once a day, either before the daily demineralizing episodes (in the morning) or after them (at night). Non-F placebo toothpaste was used in the control group. F toothpaste significantly reduced enamel and dentin demineralization compared with the control (p < 0.05). F toothpaste was more effective when used after the demineralization episodes than before, and this difference was statistically significant for dentin (p < 0.05). The results suggest that brushing with F dentifrice at night to remineralize daily mineral losses may be preferable to brushing in the morning to inhibit the demineralizing episodes of the day.     

Enhanced enamel benefits from a novel fluoride toothpaste

Objectives : Through the understanding of tooth enamel science and insights into the beneficial role calcium can play in the caries process, a novel fluoride toothpaste has been developed containing micro‐calcium. This paper describes a series of in vitro studies to assess delivery of the micro‐calcium to a plaque biofilm, delivery of radiolabelled micro‐calcium to subsurface enamel lesions and the rehardening of acid softened enamel by this novel toothpaste. Two clinical studies evaluated the delivery of calcium to the mouth. Methods : Uptake of micro‐calcium to a plaque biofilm was assessed using a Calgary Biofilm Device and measuring the calcium levels delivered to the biofilm from the micro‐calcium containing toothpaste, a calcium carbonate toothpaste, a silica toothpaste or water controls. Sound and subsurface enamel lesions were treated with ⁴⁵Ca labelled micro‐calcium toothpaste in an in vitro pH cycling study and the uptake of labelled calcium determined. Acid softened enamel specimens were treated with either the micro‐calcium containing toothpaste, a calcium carbonate toothpaste or a non‐fluoride silica toothpaste in an in vitro remineralisation protocol and the changes in surface microhardness measured. Calcium delivery in vivo was determined in two double‐blind, randomised cross‐over studies. Subjects brushed their teeth for one minute with either the micro‐calcium containing toothpaste or a silica toothpaste. Immediately after brushing and at fixed time intervals up to one hour, unstimulated saliva samples were taken and the total calcium concentration determined. Results : Significantly (p<0.05) more calcium was delivered to a plaque biofilm from the micro‐calcium containing toothpaste than the controls. The radiolabelled micro‐calcium study demonstrated the uptake of calcium to subsurface enamel lesions. In the remineralisation study, acid softened enamel became significantly harder (p<0.05) following treatment with the micro‐calcium containing toothpaste than compared to the control toothpastes. It was shown in the two clinical studies that more calcium was delivered to the mouth following the use of the micro‐calcium containing toothpaste than compared to the silica toothpaste. The product differences were in excess of 50% and were of statistical significance (p<0.001). Conclusions : The studies show that the new toothpaste containing micro‐calcium delivered elevated levels of calcium to the mouth, promoted enhanced remineralisation of demineralised enamel lesions and thus can help repair early signs of tooth decay.     

Anticaries effect of toothpaste with nano-sized sodium hexametaphosphate

Objective

To evaluate the effect of a fluoride toothpaste containing nano-sized sodium hexametaphosphate (HMPnano) on enamel demineralization on the biochemical composition and insoluble extracellular polysaccharide (EPS) in biofilm formed in situ.

Methods

This crossover double-blind study consisted of four phases (7 days each), in which 12 volunteers wore intraoral appliances containing four enamel bovine blocks. The cariogenic challenge was performed using 30% sucrose solution (6×/day). Blocks were treated 3×/day with the following toothpastes: no F/HMP/HMPnano (Placebo), conventional fluoride toothpaste, 1100 ppm F (1100F), 1100F + 0.5% micrometric HMP (1100F/HMP), and 1100F + 0.5% nano-sized HMP (1100F/HMPnano). The percentage of surface hardness loss (%SH), integrated loss of subsurface hardness (ΔKHN), and enamel calcium (Ca), phosphorus (P), and fluoride (F) were determined. Moreover, biofilms formed on the blocks were analyzed for F, Ca, P, and insoluble extracellular polysaccharide (EPS) concentrations. Data were analyzed using one-way ANOVA, followed by Student–Newman–Keuls’ test (p < 0.001).

Results

1100F/HMPnano promoted the lowest %SH and ΔKHN among all groups (p < 0.001). The addition of HMPnano to 1100F significantly increased Ca concentrations (p < 0.001). The 1100F/HMPnano promoted lower values of EPS when compared with 1100F (~ 70%) (p < 0.001) and higher values of fluoride and calcium in the biofilms (p < 0.001).

Conclusion

1100F/HMPnano demonstrated a greater protective effect against enamel demineralization and on the composition of biofilm in situ when compared to 1100F toothpaste.

Clinical relevance

This toothpaste could be a viable alternative to patients at high risk of caries.

     

Sodium trimetaphosphate enhances the effect of 250 p.p.m. fluoride toothpaste against enamel demineralization in vitro

This in vitro study investigated the effect of sodium trimetaphosphate (TMP), added to toothpaste containing 250 p.p.m. fluoride, on enamel demineralization. Bovine enamel blocks (n = 96) were subjected to five pH cycles over a 7‐d period and treatment with suspensions of toothpastes containing 0, 250, 500, and 1,100 p.p.m. fluoride (as sodium fluoride), as well as with 250 p.p.m. fluoride containing TMP at 0.25, 0.5, 1.0, and 3.0%. Treatment with toothpaste suspensions was performed under agitation twice a day, for 1 min. Surface and cross‐sectional hardness, and fluoride firmly bound to enamel, were quantified. Data were subjected to one‐way anova , followed by Tukey's test. Low‐fluoride toothpastes containing TMP at 0.25–1.0% resulted in enamel mineral loss similar to that seen for the toothpaste containing 1,100 p.p.m. fluoride. Also, the addition of TMP to the toothpaste containing 250 p.p.m. fluoride promoted enamel fluoride concentrations similar to those obtained for the 500 p.p.m. fluoride group. The toothpaste containing 250 p.p.m. fluoride and 0.25% TMP led to the lowest mineral loss among all groups. It was concluded that the addition of as little as 0.25% TMP to a toothpaste containing 250 p.p.m. fluoride can reduce enamel demineralization to levels similar to those seen for a conventional toothpaste containing 1,100 p.p.m. fluoride, in vitro.     

Effect of luting cement on dental biofilm composition and secondary caries around metallic restorations in situ

Since the importance of luting cement on secondary caries in enamel and dentin is unknown, an in situ crossover study was conducted in three phases over 21 days using a fluoride-containing toothpaste. One hundred and twenty-six metallic restorations were cemented into the dentinoenamel junction of slabs of human teeth with zinc phosphate (ZP), resin-modified glass ionomer (GI) or resinous cement (RC). The slabs were inserted onto flanges of the removable partial acrylic dentures of 14 volunteers and covered with gauze to enhance dental plaque accumulation. The volunteers used fluoride toothpaste (1.100 microg F/g, w/w). After 21 days, the biofilm that formed on the slabs was collected for biochemical and microbiological analyses, and the demineralization in enamel-dentin around the restorations was evaluated. The fluoride concentration of biofilm in the GI group was higher (p<0.05) than the ZP and RC groups. Also, the concentration of Zinc in biofilm formed on the slabs cemented with ZP was higher (p<0.05) than the other groups. However, the effect of the luting material on enamel or dentin demineralization was not statistically significant (p>0.05). The data suggest that when fluoride toothpaste is used, the anticariogenic property of the luting cement may not be relevant to the reduction of secondary caries.     

Initial in situ secondary caries formation: effect of various fluoride-containing restorative materials

This study evaluated the effects of various restorative materials (Ariston pHc; Dyract; Vitremer; Tetric Ceram; Compoglass F, F2000; Hytac and Ketac Molar) on initial secondary caries formation in situ. Eighty-eight enamel slabs from sound human molars were sterilized (ethylene dioxide) and embedded in epoxy resin. Standardized tooth preparations were filled with the various restorative materials according to manufacturers' recommendations. One specimen from each group was inserted into one of two buccal aspects of an intraoral appliance worn by 11 volunteers for four weeks, day and night. Oral hygiene was performed without additional fluoride application. During meals and oral hygiene procedures, the appliances were stored in sucrose solution (10%). After in situ exposure, the samples were prepared for microradiographic assessment. Mineral content and lesion depth were evaluated by a dedicated software package (TMR 1.24). Lesion depth and mineral loss of the carious lesions close to Ariston pHc was significantly lower when compared to distant parts of the same lesions (p < 0.05; t-test, Bonferroni-Holm correction). All other materials containing fluoride showed no caries protective effect on surrounding enamel (p > 0.05; t-test, Bonferroni-Holm correction). A hydroxyl-, calcium- and fluoride-containing restorative material hampers demineralization next to the restoration, whereas, fluoride release of various fluoride-containing restorative materials does not affect demineralization of adjacent enamel in situ.     

Mechanism of action of tin‐containing fluoride solutions as anti‐erosive agents in dentine – an in vitro tin‐uptake,tissue loss,and scanning electron microscopy study

Ganss C, Hardt M, Lussi A, Cocks A‐K, Klimek J, Schlueter N. Mechanism of action of tin‐containing fluoride solutions as anti‐erosive agents in dentine – an in vitro tin‐uptake, tissue loss, and scanning electron microscopy study. Eur J Oral Sci 2010; 118: 376–384. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci Solutions containing tin and fluoride exhibit remarkable anti‐erosive properties with tin ions as a major agent. To elucidate its mechanism of action in dentine, the tin uptake on and in the tissue was investigated and related to histological findings and substance loss. Samples were treated twice daily, each treatment lasting for 2 min, with fluoride solutions [pH 4.5; 1,500 parts per million (p.p.m.) F] containing 2,100, 1,400, or 400 p.p.m. Sn as SnCl₂. In experiments 1 and 2, samples were eroded with citric acid (pH 2.3) six times each day, each treatment lasting for 5 min; in experiment 2, the demineralized organic matrix was continuously digested by collagenase; in experiment 3, no erosive challenges were performed. Sample surfaces and cross‐sections were investigated using energy dispersive X‐ray spectroscopy, scanning electron microscopy, and profilometry. Surface retention of tin was found in almost all treatment groups and was highest in experiment 2. On cross‐sections, tin was retained within the organic matrix; in mineralized areas, tin was found mainly within a depth of 10 μm. Test solutions inhibited substance loss significantly; in experiment 2, the effect was dose‐dependent. Erosion inhibition seemed to depend mainly on the incorporation of tin in the mineralized dentine when the organic portion was preserved, but on surface precipitation when the organic portion was continuously digested.     

The effect of copper on demineralization of dental enamel

Previous studies have concluded that copper might inhibit enamel demineralization in vitro. Our aim was to assess the effect of copper (Cu2+), with and without amine fluoride, on human dental enamel under cariogenic challenge in situ. In a double-blind randomized four-leg crossover trial, 14 individuals wore a removable appliance containing 2 enamel slabs, 1 containing an artificial caries lesion. During each leg, the appliance was exposed twice daily to one of the test solutions: 1.25 mM CuSO4, amine fluoride (250 ppm F), copper and amine fluoride combined, or a placebo (water). A cariogenic challenge was provided in all cases by 5 daily exposures to 10% sucrose. Slabs were assessed before and after 21 days' exposure by Knoop microhardness and transverse microradiography. Significantly less demineralization was observed with Cu2+ and fluoride in combination than with fluoride treatment alone (p < 0.05), whereas copper alone had no significant protective effect.     

Risk-benefit balance in the use of fluoride among young children

This study aimed to evaluate the risk-benefit balance of several fluoride exposures. Fluoride exposure history of randomly selected children was collected for calculation of exposure to fluoridated water, toothpaste, and other fluoride sources. We evaluated the risk-benefit balance of fluoride exposure by comparing dental fluorosis on maxillary central incisors, recorded at the time of the study with the use of the Thylstrup and Fejerskov Index, and deciduous caries experience, recorded at age six years, of the same group of South Australian children who were from 8 to 13 years old in 2002-03. Population Attributable Risk for fluorosis and Population Prevented Fraction for caries were estimated. Fluorosis prevalence was found to be 11.3%; caries prevalence, 32.3%; mean dmfs, 1.57 (SD 3.3). Exposure to fluoridated water was positively associated with fluorosis, but was negatively associated with caries. Using 1000-ppm-F toothpaste (compared with 400- to 550-ppm-F toothpaste) and eating/licking toothpaste were associated with higher risk of fluorosis without additional benefit in caries protection. Evaluation of the risk-benefit balance of fluoride exposure provides evidence to assist in the formulation of appropriate guidelines for fluoride use.     

The anti‐caries efficacy of a silica‐based fluoride toothpaste containing zinc citrate,triclosan, vitamin E and sunflower oil

Aim : To evaluate the ability of a new fluoridated toothpaste, containing 1450 ppm fluoride (as sodium fluoride), vitamin E and sunflower oil, to reduce the acid‐dissolution of sound dental enamel (demineralisation study), promote remineralisation of demineralised enamel (remineralisation study) and deliver and incorporate fluoride into demineralised enamel (fluoride uptake), when compared to a clinically‐tested fluoride toothpaste and a non‐fluoride negative control toothpaste. Methods : The de‐ and remineralisation studies both utilised pH cycling protocols. In the demineralisation study, sound enamel sections were used and efficacy was measured by calcium analysis of experimental solutions. For the remineralisation study, artificial carious lesions were microradiographed before and after pH‐cycling. For fluoride‐uptake, lesions were immersed in slurries of the toothpastes and subsequently, an acid‐etching technique was used to sample the lesions. Results : Expressed as mean values (SD), for the new fluoride toothpaste, the positive and negative controls respectively were: demin study, calcium demineralisation rate = 0.0980 (0.010), 0.110 (0.009) and 0.493 (0.043) μg Ca.mm‐2.h‐1; remin study, Δ;Z = 20.7 (16.6), 24.6 (14.9) and ?34.7 (13.1) %; F‐uptake = 27.8 (1.56), 29.6 (2.00) and 1.06 (0.430) μg F.cm‐2. Compared with the negative control, both the positive control and the test toothpaste significantly reduced enamel demineralisation and increased both remineralisation and fluoride uptake to enamel. There were no significant differences between the new fluoride toothpaste and positive control. Conclusion : Fluoride delivered from the new silica‐based toothpaste containing vitamin E and sunflower oil was as effective as that delivered from a clinically proven toothpaste.     

Effect of frequency of sucrose exposure on dental biofilm composition and enamel demineralization in the presence of fluoride

It has been suggested that enamel would resist higher frequencies of sucrose exposure if fluoride from water or dentifrice is being used. However, the effect of increasing frequencies of sugar on dental biofilm composition is not well known. Ten volunteers living in a fluoridated area wore palatal appliances bearing human enamel slabs during 14 days. The slabs were exposed to 20% sucrose solution 0 (control), 2, 4, 6, 8 or 10 times/day and the volunteers used fluoride dentifrice 3 times/day. Enamel demineralization was significantly greater than control for sucrose frequencies higher than 6 times/day. However, biofilm mass, total microbiota, total streptococci, lactobacilli counts and insoluble extracellular polysaccharide concentration increased, while Ca, P(i) and F concentration in whole biofilm decreased significantly, with frequencies of sucrose exposure lower than 6 times/day. The findings confirm that fluoride can reduce enamel demineralization if sucrose consumption is not higher than 6 times/day, but changes in the biochemical and microbiological composition of the biofilm are observed with lower frequencies of sucrose use.     

Fluoride concentrations in enamel and dentin of primary teeth after pre- and postnatal fluoride exposure

The aim of this study was to determine any existing difference in the amount of fluoride incorporated in the surface, body enamel and dentin of two groups of deciduous teeth, either exposed to pre- and postnatal fluoride supplements or to postnatal fluoride only. One hundred and eighty five subjects with intact deciduous incisors were selected from a randomized, double blind study of the caries preventive efficacy of prenatal fluoride (F) supplementation. Surface and body enamel samples were obtained by the acid etch biopsy technique. Dentin microsamples were obtained by drilling to a depth of 100 microm using the microdrill biopsy technique. It was concluded that fluoride exposure during the prenatal period offered no additional measurable fluoride uptake by dental tissues other than that attributable to postnatal fluoride alone.     

A study of developmental defects in enamel in 10-year-old high social class children residing in a non-fluoridated area

This study investigated the relationship between reported exposure to fluoride in the form of toothpaste and fluoride supplements, the level of observed developmental defects in enamel and the caries experience in a sample of 10-year-old children. Using a modified and simplified version of the developmental defects of enamel index, 300 10-year-old children who had been continually resident in non-fluoridated high social class areas were examined. The examination was followed by a questionnaire to parents on their child's fluoride supplement and toothpaste usage, and toothbrushing habits in early childhood. The prevalence of developmental defects in enamel was lower than that reported elsewhere. A large number of children had diffuse developmental defects but had no history of exposure to fluoride supplements. The only differentiating factor between this group and a similar group with no diffuse defects was in the amount of toothpaste dispensed during toothbrushing prior to the age of six. There was no association between caries experience and the presence or absence of developmental defects. It was concluded that parents of children from a high social class background should supervise the brushing of their children's teeth and use only a pea-sized amount of toothpaste.     

The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers,environmental registers and administrative registers

Kirkeskov L, Kristiansen E, Bøggild H, von Platen‐Hallermund F, Sckerl H, Carlsen A, Larsen MJ, Poulsen S. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers. Community Dent Oral Epidemiol 2010; 38: 206–212. © 2010 John Wiley & Sons A/S Abstract – Objectives: To study the association between fluoride concentration in drinking water and dental caries in Danish children. Methods: The study linked registry data on fluoride concentration in drinking water over a 10‐year period with data on dental caries from the Danish National Board of Health database on child dental health for 5‐year‐old children born in 1989 and 1999, and for 15‐year‐old children born in 1979 and 1989. The number of children included in the cohorts varied between 41.000 and 48.000. Logistic regression was used to assess the correlations, adjusting for gender and taxable family income as a proxy variable for socioeconomic status. Results: Fluoride concentration in drinking water varied considerably within the country from very low (<0.10 mg/l) to more than 1.5 mg/l. Only little variation was found over the 10‐year study period. Dental caries in both 5‐year‐olds and 15‐year‐olds decreased over the study period. An inverse relation between the risk of dental caries and fluoride concentration in drinking water was found in both primary and permanent teeth. The risk was reduced by approximately 20% already at the lowest level of fluoride exposure (0.125–0.25 mg/l). At the highest level of fluoride exposure (>1 mg/l), a reduction of approximately 50% was found. Similar findings were found if analysis was limited to children residing in the same place during the entire study period. Conclusions: The study confirmed previous findings of an inverse relation between fluoride concentration in the drinking water and dental caries in children. This correlation was found in spite of the extensive use of fluoridated toothpaste and caries‐preventive programs implemented by the municipal dental services in Denmark. Linking Danish health registers with environmental and administrative registers offers an opportunity for obtaining sample sizes large enough to identify health effect, which otherwise could not be identified.     

Effect of acidulated phosphate fluoride gel application time on enamel demineralization of deciduous and permanent teeth

Although the effect of acidulated phosphate fluoride gel (APF gel) on caries reduction in permanent teeth is based on evidence, the relevance of the clinical application time is still under debate. Also, the effect of 4- versus 1-min application has not been evaluated in deciduous enamel. In a blind, crossover, in situ study of 14 days, 16 adult volunteers wore palatal appliances containing slabs of human permanent and deciduous enamel. At the beginning of each phase, the slabs were submitted to one of the following treatments: no APF application (negative control); APF gel (1.23% F) application for 1 or 4 min. Biofilm accumulation on the slab surface was allowed and the slabs were subjected eight times a day to 20% sucrose, simulating a high cariogenic challenge condition. On the 15th day of each phase, fluoride retained as CaF(2) and fluorapatite (FAp) was determined on the enamel of the slabs and demineralization was assessed by cross-sectional microhardness. Fluoride as CaF(2) and FAp, formed by APF gel application on the enamel slabs not subjected to the cariogenic challenge, was also determined. APF gel reduced demineralization in both enamel types (p < 0.05), but the difference between 1 and 4 min was not statistically significant (p > 0.05). CaF(2) and FAp formed and retained on deciduous and permanent enamel was significantly higher in APF gel groups (p < 0.05), but no significant difference was found between 1 and 4 min (p > 0.05). The findings suggest that 1 min of APF gel application provides a similar effect on inhibition of demineralization as 4 min, for both permanent and deciduous enamel.     

The effects of low-fluoride toothpaste supplemented with calcium glycerophosphate on enamel demineralization

Objectives

The aim of the present study was to evaluate the effects of different concentrations of calcium glycerophosphate (CaGP) in toothpastes with low-fluoride (low-F) concentrations on enamel demineralization by using a bovine enamel and pH cycling model.

Materials and methods

Experimental toothpastes containing 0 or 500 μg F/g (NaF) and CaGP concentrations of 0, 0.1, 0.25, 0.5, 1, and 2 % were manufactured. A commercial toothpaste was used as a positive control (1,100 μg F/g). After polishing and hardness tests, enamel blocks were subjected to pH cycling for 5 days and toothpaste treatment twice daily. The treatment regimen involved soaking all blocks in the corresponding slurry for 1 min (2 ml/block). Surface and cross-sectional hardness and fluoride concentrations in enamel were analyzed. The hardness data were analyzed using a one-way ANOVA followed by a Bonferroni post hoc test. Fluoride concentrations were analyzed using a Kruskal–Wallis followed by a Student–Newman–Keuls post hoc test.

Results

The mineral loss with the toothpaste containing 500 μg F/g and 0.25 % CaGP was lower than that in the other groups (p?<?0.05). Fluoride concentrations in the enamel treated with 0.1, 0.25, and 0.5 % CaGP toothpastes were similar to those in the enamel treated with the 500 μg F/g toothpaste (p?>?0.05). A greater concentration of CaGP reduced the fluoride levels in enamel (p?<?0.05).

Conclusions

The results from the present in vitro study show that a low-F (500 μg F/g) toothpaste is capable of maintaining the efficacy of 1,100 μg F/g toothpaste when supplemented with 0.25 % of CaGP.

Clinical relevance

The developed toothpaste prevents caries as a standard one and is safe for individuals of any age group.     

Enamel mineralization disturbances in 12-year-old children with known early exposure to fluorides

Abstract Enamel changes and caries experience were studied in 134 12-year-old children with a known early exposure to fluoride tablets and/or fluoride containing toothpaste. The influence of birth weight and breast-feeding period was also analyzed. A clinical intact enamel was found in 32% of the children. Enamel fluorosis was found in 45% and localized opacities or hypoplasias in 40% Children who had consumed fluoride tablets for a period of at least 12 months from the age of 6 months ran a 5.4 times greater risk of developing enamel fluorosis than children with no such consumption. No such risk could be shown in children who at 6 or 12 months of age started to use fluoride toothpaste. There was no statistically significant reduction in the prevalence of smooth surface caries or fillings in children with an exposure to fluoride tablets.     

Effect of fluoridated milk on enamel and root dentin demineralization evaluated by a biofilm caries model

Although some studies suggest an anticaries effect of fluoridated bovine milk (F-milk) on enamel, evidence is still considered weak. Even more uncertain, the effect of F-milk on root caries remains largely unknown. This study evaluated the effect of F-milk on enamel and on root dentin demineralization using a validated Streptococcus mutans biofilm model, simulating a high cariogenic challenge. S. mutans (UA159) biofilms were formed on bovine enamel and root dentin saliva-coated slabs after measuring initial surface microhardness (SH). Biofilms were exposed to 10% sucrose 8×/day and treated 2×/day with either: (1) 0.9% NaCl (negative control), (2) bovine milk, (3) F-milk (5.0 ppm F as NaF) or (4) NaF 0.05% (anticaries-positive control). Medium pH was monitored twice/day, as a biofilm acidogenicity indicator. After 5 days for enamel and 4 days for dentin, biofilms were recovered to analyze: biomass, soluble proteins, viable microorganisms, and extra- and intracellular polysaccharides. Enamel and dentin demineralization were estimated by percentage of SH loss. Results were compared by ANOVA and Tukey's test. Neither acidogenicity nor biofilm composition differed among treatment groups in biofilms formed on enamel or dentin (p > 0.05). F-milk, however, significantly reduced enamel and dentin demineralization when compared with the negative control (p < 0.05). Also, F-milk was as efficient as 0.05% NaF to reduce enamel (p > 0.05), but not dentin demineralization (p < 0.05). These findings suggest that milk containing 5.0 ppm of fluoride is effective to control enamel caries and that it may be effective on root dentin caries prevention.     

In vitro efficacy of a whitening toothpastecontaining calcium carbonate and perlite

Objectives : The studies described in this paper aimed to assess the stain removal efficacy, fluoride efficacy and abrasivity to enamel and dentine of a new whitening toothpaste containing calcium carbonate and perlite, using appropriate in vitro models. Methods : Stain removal efficacy was assessed using the pellicle cleaning ratio (PCR) method. Fluoride efficacy was assessed using remineralisation, demineralisation and fluoride‐uptake methods. Abrasivity was assessed using an enamel and dentine wear method. Results : The results showed that the new whitening toothpaste was able to remove extrinsic tooth stain more effectively than three commercially available toothpaste formulations. The fluoride efficacy was superior to a non‐fluoridated control and was not significantly different to a clinically tested fluoride‐containing toothpaste. The abrasivity data showed that the calcium carbonate/perlite toothpaste is no more abrasive to enamel or dentine than two other commercially available whitening toothpastes. Conclusions : The studies show that the new whitening toothpaste is effective in extrinsic stain removal, has an efficacious fluoride source and does not have an undue degree of abrasivity to enamel or dentine compared to other relevant commercially available products.