Effect of pH of amine fluoride containing toothpastes on enamel remineralization in vitro

Background

One of the important factors of the demineralization and remineralization equilibrium of enamel is the pH of the surrounding solutions. Effort has been laid in the formulation of different fluoride compounds and the fluoride content in toothpastes but much less is known about the influence of the pH of the toothpastes on their effectiveness. It was therefore the aim of this study to investigate the influence of different pH levels on enamel remineralization in an in vitro experiment using polarization light microscopy and EDX quantitative element analysis.

Methods

A 5 × 5 mm window on the enamel surface of 40 caries free extracted human premolars was demineralized in a hydroxyethylcellulose solution at pH 4.8. The teeth were divided into 8 groups and the lower half of the window was covered with varnish serving as control. Each group was then immersed in toothpaste slurry containing amine fluoride (1400 ppm) at pH 4.1, 4.5, 5.1 and 6.9 or control toothpaste slurry without fluoride at pH 4.3, 4.7, 5.3 and 7.0. Serial sections were cut through the lesions and investigated with polarization light microscopy and quantitative EDX element analysis.

Results

The PLM results showed a decreased porous volume of the body of the lesion after incubation with fluoridated toothpaste at pH 4.53 and 5.16. No differences between the experimental window and the control window were found in the other groups. The quantitative element analysis showed no differences in the element content of any of the groups.

Conclusion

From the results it can be concluded that slightly acidified fluoridated dentifrices may have a certain positive effect on enamel remineralization.     

Evaluation of the anticaries benefit of fluoride toothpastes using an enamel insert model

The remineralization potential of fluoride toothpastes was studied using an in situ enamel insert model. Matched blocks of artificially demineralized human enamel were attached to partial dentures of 16 adult volunteers who brushed their teeth with either a toothpaste containing 1,500 ppm F or one containing 2,500 ppm F for a period of 6 weeks in a balanced, randomized crossover experiment. Computerized image analysis of microradiographs was used to measure the mineral density distribution in the enamel before and after in situ treatment. Both toothpastes demonstrated remineralization of artificial carious lesions. Significantly more remineralization was observed in enamel samples treated with the toothpaste containing 2,500 ppm F compared to that containing 1500 ppm F. This result is consistent with the outcome of a recent caries clinical trial testing the same toothpastes and finding enhanced anticaries efficacy from the higher fluoride level.     

Remineralizing potential of commercially available pediatric dentrifices: An In vitro study

Background

Remineralizing agents are found to be effective in the remineralization of early enamel caries and the remineralized enamel crystallites are more resistant to decalcification and also have the same orientation as the original enamel crystallites. Although child formula fluoridated dentifrices are used safely by young children their remineralizing capability remains questionable.

Superficial fluoride levels and response to in-vitro caries-like lesion induction of enamel from Bristol (U.K.) and Birmingham (U.K.) human deciduous teeth

Surface enamel fluoride levels were measured in deciduous canine teeth from Bristol, with non-fluoridated water supplies, and Birmingham, with fluoridated water supplies. Three populations studied were from Bristol (teeth shed before 1960), Bristol (after 1975) and Birmingham (after 1975). Up to 75 micron from the enamel surface, fluoride concentrations of post-1975 Bristol and Birmingham teeth were, respectively, X 1.3 and 3.4 greater than those of pre-1960 Bristol teeth. The increase in the Bristol teeth is presumably due mainly to the increased use of fluoride-containing toothpastes, that in Birmingham to fluoridated water plus the use of fluoride toothpastes. No difference in the rates of penetration into enamel of acid-gel induced, caries-like lesions were found between the two Bristol populations; Birmingham teeth showed a reduction of 10 per cent in penetration rate. It is suggested that raised fluoride levels in surface enamel do not reduce solubility sufficiently to account, by themselves, for the recent nationwide marked reduction in caries in children. Possibly, the raising of plaque fluoride levels is a more important factor, affecting demineralization, remineralization and bacterial activity.     

The effect of casein phosphopeptide-amorphous calcium phosphate on remineralization of artificial caries-like lesions: an in vitro study

BACKGROUND: The aims of this study were to investigate the efficacy of CPP-ACP containing Tooth Mousse on the remineralization of enamel lesions and to compare its efficacy to that of a fluoride-containing toothpaste. METHODS: Permanent teeth were placed in demineralizing solution for 96 hours to produce artificial caries-like lesions 120-200 microm in depth. They were sectioned into 100-150 microm thick samples and randomly assigned to five groups: for Group A, a fluoridated toothpaste (1100 ppm) was used as a positive control and in Group B, a non-fluoridated toothpaste was used as a negative control. Tooth Mousse containing CPP-ACP was tested by three different means: as a toothpaste (Group C); as a topical coating (Group D); and (Group E) as a topical coating after treating the sections with the same fluoridated toothpaste as in Group A. RESULTS: The lesion depth decreased significantly by 7 per cent in Group A, 10.1 per cent in Groups C and D, and 13.1 per cent in Group E (Paired t- test, p < 0.05), while in Group B the lesion depth increased significantly by 23 per cent. CONCLUSIONS: Based on the data obtained, CPP-ACP containing Tooth Mousse remineralized initial enamel lesions and it showed a higher remineralizing potential when applied as a topical coating after the use of a fluoridated toothpaste.     

Dual-functional adhesive containing amorphous calcium phosphate nanoparticles and dimethylaminohexadecyl methacrylate promoted enamel remineralization in a biofilm-challenged environment

ObjectiveThe cariogenic biofilm on enamel, restoration, and bonding interface is closely related to dental caries and composite restoration failure. Enamel remineralization at adhesive interface is conducive to protecting bonding interface and inhibiting secondary caries. This study intended to assess the remineralization efficiency of adhesive with dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP) on initial caries lesion of biofilm-coated enamel.MethodsArtificial initial carious lesion was created via 72-hour immersion in demineralization solution and cariogenic biofilm was formed after 24-hour culture of Streptococcus mutans (S. mutans). Specimens were then divided into 4 groups: enamel control, enamel treated with NACP, DMAHDM and NACP+DMAHDM respectively. Samples next underwent 7-day cycling, 4 h in BHIS (brain heart infusion broth containing 1 % sucrose) and 20 h in AS (artificial saliva) per day. The pH of BHIS was tested daily. So did the concentration of calcium and phosphate in BHIS and AS. Live/dead staining, colony-forming unit (CFU) count, and lactic acid production of biofilms were measured 7 days later. The enamel remineralization efficiency was evaluated by microhardness testing and transverse microradiography (TMR) quantitatively.ResultsEnamel of NACP+DMAHDM group demonstrated excellent remineralization effectiveness. And the NACP+DMAHDM adhesive released a great number of Ca²⁺ and PO₄^3- ions, increased pH to 5.81 via acid neutralization, decreased production of lactic acid, and reduced CFU count of S. mutans (P < 0.05).SignificanceThe NACP+DMAHDM adhesive would be applicable to preventing secondary caries, strengthening enamel-adhesive interface, and extending the lifespan of composite restoration.     

3种无氟儿童牙膏对乳牙早期釉质龋再矿化作用的体外研究

目的 探究3种市售无氟儿童牙膏即生物活性玻璃儿童牙膏、双黄连儿童牙膏、木糖醇儿童牙膏对乳牙早期釉质龋的再矿化作用。方法 应用离体乳牙制备人工龋模型50例,随机分为5组：活性玻璃组、双黄连组、木糖醇组、NaF组、去离子水组。在体外进行pH循环后,测量各组乳牙的表面显微硬度,并结合偏光显微镜对乳牙的釉质龋损进行形态学观察。结果 活性玻璃组能显著提高乳牙早期釉质龋再矿化后的表面显微硬度（P<0.05）,但其提高的程度不如NaF组（P<0.05）,双黄连组、木糖醇组和去离子水组未能提高再矿化后的显微硬度（P<0.05）。偏光显微镜下,活性玻璃组与NaF组再矿化后乳牙表层釉质的脱矿深度明显变浅。结论 生物活性玻璃儿童牙膏能有效促进乳牙早期釉质龋再矿化,但其再矿化能力小于含氟牙膏,双黄连儿童牙膏和木糖醇儿童牙膏在本次实验中未能体现出再矿化能力。     

The Pre-and Posteruptive Effects of Fluoride in the Caries Decline

The widespread availability of fluoride from many sources is accepted as a major reason for the caries decline among children in developed countries. There is still controversy, however, about its principal mode of action. This article reviews the evidence on fluoride's preeruptive and posteruptive effects, and suggests reasons for its continuing role in the caries decline. Early fluoridation studies accepted that fluoride acted preruptively through incorporation into developing enamel; but further research could not explain why fluoride levels were not clearly higher in enamel exposed to fluoride, nor why there were no clear correlations between caries experience and enamel fluoride concentration. Instead, considerable evidence suggests that fluoride acts mainly, though not entirely, through posteruptive remineralization of demineralized enamel. Caries experience has declined in nonfluoridated as well as in fluoridated areas, though DMF scores are still consistently lower in fluoridated areas. Posteruptive remineralization effects are seen from fluoridated drinking water as well as with fluoride from other sources. The continuing caries decline, beyond the level suggested by early fluoridation field trials, can be attributed either to more efficient remineralization or to long-term, intraoral ecological change, or to both.     

Comparison of new formulas of stannous fluoride toothpastes with other commercially available fluoridated toothpastes: A systematic review and meta-analysis of randomised controlled trials

Aim: The aim of this study was to systematically review and analyse the difference in efficacy of stannous fluoride toothpaste formulations in comparison to other fluoridated toothpastes without stannous fluoride. Materials and methods: A systematic search of the literature was performed according to PRISMA guidelines. A search strategy was developed to answer the study question and was performed in PubMed-Medline databases. Inclusion criteria were randomised controlled clinical trials comparing stannous fluoride toothpaste formulations with other fluoridated toothpastes not containing stannous fluoride. Results: The search in PubMed-Medline databases resulted in 384 articles; 23 articles were downloaded for review, 16 articles were included in the report and six could be used for meta-analysis. All studies were randomised controlled clinical trials that compared clinical outcomes between toothpastes with stannous fluoride combinations and toothpastes with only fluoride. The overall results of the 16 studies favoured the stannous fluoride formulations. However, in a meta-analysis of the randomised controlled clinical trials, it was demonstrated that stannous fluoride toothpaste formulations provided significantly better outcomes based on the Gingival Index (SMD –0.14, 95% CI –0.20, –0.07, P = 0.0001), but not the Modified Gingival Index (SMD –0.30, 95% CI –0.7, 0.09, P = 0.13). Practical implications: The antibacterial properties of stannous seem to provide favourable results when formulated with a fluoridated toothpaste. This systematic review highlights the lack of homogenous research available to rigorously compare stannous fluoride toothpaste formulations with other fluoridated toothpastes without stannous fluoride.Key words: Plaque, prevention, caries, periodontitis, toothpaste, bacteria, gingivitis     

Remineralization agents - new and effective or just marketing hype?

This is a review of the need for better remineralization and of the status of calcium-based remineralizing agents for use in anti-caries toothpastes. Use of fluoride toothpastes has markedly reduced caries. However, the decline may be over or in reverse. There is a limit to what fluoride alone can do; complementary agents are needed. Using plaque as a reservoir for calcium-based agents holds promise. Plaque fluid is already supersaturated with respect to relevant calcium phosphates at neutral pH; extra calcium may lead to surface-blocking and sub-optimal lesion consolidation. However, at cariogenic pH, lesions may be more porous to the ingress of mineral, leading to fuller consolidation, and controlled release of calcium should reduce undersaturation with respect to enamel and accelerate deposition of fluorhydroxyapatite. Clinical data to validate in vitro screening models are scarce. Direct progression to in situ models may often be appropriate. The spectrum of lesion types, from softening to relatively advanced subsurface, and lesion activity should be considered. Far from being 'marketing hype', progress with calcium-based remineralizing agents is both encouraging and scientifically sound. Clinical evidence exists for the efficacy of some agents, but further unequivocal clinical data are needed before these agents might be considered 'effective' when delivered from toothpaste.     

Effect of mucin alone and in combination with various dentifrices on in vitro Remineralization

The aim of this in vitro study was to evaluate the effect of combining various fluoridated dentifrices with mucin on remineralization of bovine enamel. Enamel specimens were embedded in epoxy resin, partly covered with nail varnish, and demineralized in a lactic acid solution (pH 5.0, 14 days). Parts of the demineralized areas of the specimens were then covered with nail varnish. Half of the samples were exposed to a mucin-containing (2.7 g/l) remineralizing solution, the other half to a mucin-free remineralizing solution for 30 days. In each group, the specimens were divided into four subgroups, which were brushed twice a day with a toothpaste containing sodium, stannous/amine, or amine fluoride. The specimens of the fourth subgroup were not brushed, but stored in one of the two solutions. Mineral loss and lesion depth were evaluated from microradiographs. After the remineralization period, specimens that were brushed with one of the dentifrices and stored in the mucin-containing remineralizing solution reacquired more mineral than those brushed and stored in the mucin-free solution (p < 0.05; Bonferroni post hoc test). The results indicate that mucin in combination with various fluorides seems to affect enamel remineralization significantly. Thus, mucin could be considered as an additive to saliva substitutes or mouthwashes in patients with hyposalivation.     

Caries reductions related to the use of fluorides: a retrospective cohort study

AIM: To test whether topical fluoride regimes provided additional caries protection to the first molar teeth of children exposed to fluoridated toothpaste and optimally fluoridated water supplies. PARTICIPANTS AND METHODS: This two-year retrospective cohort study included 660, 8-year-old-children. A cluster sampling technique was used to select three groups of 220 children. Group 1 was selected from schools using fluoride mouthrinses (Programme 1). Group 2 was selected from schools applying fluoride gel (APF 1.23%) in addition to the weekly fluoride mouthrinse (Programme 2). Oral health education and oral hygiene instruction were provided to both groups. The control group was selected from schools in the same area that had not adopted any oral health preventive programme. All children were exposed to optimally fluoridated water and fluoridated toothpaste for the last two years or more. Participants were examined for DMFS scores of their first molars using WHO criteria by one examiner (MLRS). RESULTS: The percentage caries free children in Control, Programme 1 and Programme 2 were 55%, 65% and 65.5%, respectively. The differences between Programme 1 and 2 in relation to the Control Group were statistically significant (P < 0.05). There was no difference between Programme 1 and 2 (P = 0.92). CONCLUSIONS: Weekly fluoride rinsing combined whether or not with fluoride gel applications once every three months, provided additional caries-preventive benefits to children with high levels of caries and exposed to optimally fluoridated drinking water and toothpaste. There was no difference in caries levels between children having fluoride rinses and those having fluoride rinses and fluoride gel.     

Effect of CPP-ACP Paste on Dental Caries in Primary Teeth: A Randomized Trial

This clinical trial tested the effect of daily application of 10% w/v calcium phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste for 1 yr when added to regular toothbrushing with fluoridated toothpaste to prevent dental caries in pre-school children. High-caries-risk children aged 2½ to 3½ yrs in a suburban area of central Thailand were assigned to receive either CPP-ACP (n = 150) or a placebo control (n = 146) in addition to fluoridated toothpaste. The International Caries Detection and Assessment System (ICDAS) was recorded at baseline, 6 mos, and 1 yr. At 1 yr, a significant increase in mean numbers of enamel and dentin caries lesions, as well as dmfs, was found in both groups (p < 0.001). No significant difference was observed between groups on these 3 outcome measures (p = 0.23, 0.84, and 0.91, respectively). The odds of enamel caries lesion transitions to a state of regression or stability, compared with progression from baseline, was also not different between groups [OR = 1.00, 95% CI (0.86, 1.17)]. This trial found that daily application of 10% w/v CPP-ACP paste on school days for 1 yr, when added to regular toothbrushing with a fluoride toothpaste, had no significant added effect in preventing caries in the primary dentition of these pre-school children (ClinicalTrials.gov number CT01 604109).     

The impact of glass ionomer cement and composite resin on microscale pH in cariogenic biofilms and demineralization of dental tissues

ObjectiveSecondary caries is among the most frequent reasons for the failure of dental restorations. Glass ionomer cement (GIC) restorations have been proposed to protect the surrounding dental tissues from demineralization through the release of fluoride and by buffering the acid attack from dental biofilms. In contrast, the lack of buffering by composite resin (CR) restorations has been suggested as a promoting factor for the development of secondary caries.MethodsThe present study employed transversal microradiography and confocal microscopy based pH ratiometry to quantify mineral loss and map microscale pH gradients inside Streptococcus mutans biofilms grown on compound specimens consisting of enamel, dentin and either GIC or CR.ResultsMineral loss in dentin was significantly lower next to GIC than next to CR, but no significant differences in local biofilm pH were observed between the two restorative materials.SignificanceThe cariostatic effect of GIC relies predominantly on the provision of fluoride and not on a direct buffering action. The lack of buffering by CR did not affect local biofilm pH and may therefore be of minor importance for secondary caries development.     

In vitro evaluation of composite containing DMAHDM and calcium phosphate nanoparticles on recurrent caries inhibition at bovine enamel-restoration margins

ObjectiveRecurrent caries is a primary reason for restoration failure caused by biofilm acids. The objectives of this study were to: (1) develop a novel multifunctional composite with antibacterial function and calcium (Ca) and phosphate (P) ion release, and (2) investigate the effects on enamel demineralization and hardness at the margins under biofilms.MethodsDimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP) were incorporated into composite. Four groups were tested: (1) Commercial control (Heliomolar), (2) Experimental control (0% DMAHDM + 0% NACP), (3) antibacterial group (3% DMAHDM + 0% NACP), (D) antibacterial and remineralizing group (3% DMAHDM + 30% NACP). Mechanical properties and Ca and P ion release were measured. Colony-forming units (CFU), lactic acid and polysaccharide of Streptococcus mutans (S. mutans) biofilms were evaluated. Demineralization of bovine enamel with restorations was induced via S. mutans, and enamel hardness was measured. Data were analyzed via one-way and two-way analyses of variance and Tukey’s multiple comparison tests.ResultsAdding DMAHDM and NACP into composite did not compromise the mechanical properties (P > 0.05). Ca and P ion release of 3% DMAHDM + 30% NACP was increased at cariogenic low pH. Biofilm lactic acid and polysaccharides were greatly decreased via DMAHDM, and CFU was reduced by 4 logs (P < 0.05). Under biofilm acids, enamel hardness at the margins was decreased to about 0.5 GPa for control; it was about 1 GPa for antibacterial group, and 1.3 GPa for antibacterial and remineralizing group (P < 0.05).ConclusionsThe novel 3% DMAHDM + 30% NACP composite had strong antibacterial effects. It substantially reduced enamel demineralization adjacent to restorations under biofilm acid attacks, yielding enamel hardness that was 2-fold greater than that of control composites. The novel multifunctional composite is promising to inhibit recurrent caries.     

Caries inhibition in rats by a sodium fluoride, tripolyphosphate toothpaste with whitening and anti-tartar properties

The anti-caries properties of a silica-based, sodium fluoride (NaF) toothpaste containing sodium tripolyphosphate (NaTPP) with tooth whitening and anti-tartar properties (Aquafresh Whitening), in specific pathogen-free Osborne-Mendel rats, were assessed in this study. A silica-based, fluoride-free placebo containing NaTPP, and a NaF-containing silica-based USP reference standard toothpaste were used as negative and positive control toothpastes, respectively. Sixty weanling rats were randomly distributed into groups of 20; all were inoculated with S. mutans 10449S, ate cariogenic diet 2000, and drank demineralized water ad libitum. Each toothpaste, packaged in coded tubes, was applied to the dentitions of the rats' teeth for one minute, twice daily on weekdays, and once daily on weekends and holidays. Both the NaF/NaTPP-containing and the NaF-containing USP standard toothpaste groups had lower total enamel caries scores (41 to 45%) than the group treated with the fluoride-free NaTPP-containing placebo. Similar dimensioned differences were evident both at smooth surface and sulcal enamel sites, and in dentinal sites. All were statistically significant at p < 0.001. There were no statistically significant differences at any tooth surface category site between the two fluoride-containing toothpastes' effects. It is thus apparent that Aquafresh Whitening has the anticaries benefit of a USP reference standard NaF toothpaste.     

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.     

In situ effect of a dentifrice with low fluoride concentration and low pH on enamel remineralization and fluoride uptake

Since the anticaries effect of a dentifrice with low fluoride concentration and low pH is unknown, the aim of the present study was to evaluate in situ the enamel remineralizing ability of this type of formulation. A double-blind crossover design employing 3 phases of 45 days was conducted. Six adult volunteers wore palatal devices containing 6 previously demineralized human dental enamel slabs, which were subjected 3 times a day to one of the following treatments: non-fluoridated dentifrice (negative control); dentifrice containing 1, 100 microg F/g, pH 7.0 (positive control); dentifrice containing 550 microg F/g, pH 5.5 (experimental). At the end of each phase, enamel remineralization was assessed in terms of cross-sectional microhardness, and loosely as well as firmly bound fluoride formation was determined on the enamel surface. Fluoridated dentifrices were more effective than the negative control in forming loosely and firmly bound fluoride on enamel (P < 0.05). However, the positive control formed more loosely bound fluoride than the other treatments (P < 0.05). Microhardness analysis showed that the fluoridated dentifrices were more effective than the negative control (P < 0.05) in remineralizing dental enamel, although no statistically significant difference was observed between them. Thus, the experimental dentifrice was shown to be effective in remineralizing dental enamel, and this may be attributable to its ability to form firmly bound fluoride on enamel.     

Novel pit and fissure sealant containing nano-CaF2 and dimethylaminohexadecyl methacrylate with double benefits of fluoride release and antibacterial function

ObjectivePit and fissure sealants with antibacterial and remineralization properties have broad application prospects in caries prevention. The objectives of this study were to: (1) develop a novel pit and fissure sealant containing CaF₂ nanoparticles (nCaF₂) and dimethylaminohexadecyl methacrylate (DMAHDM); and (2) investigate the effects of nCaF₂ and DMAHDM on biofilm response and fluoride (F) ion release for the first time.MethodsHelioseal F was used as a control. Bioactive sealants were formulated with DMAHDM and nCaF₂. Flow properties, enamel shear bond strength, hardness and F ion releases were measured. Streptococcus mutans (S. mutans) biofilms were grown on sealants. Biofilm metabolic activity, lactic acid production, colony-forming units (CFU), and pH of biofilm culture medium were measured.ResultsAdding 5% DMAHDM and 20% nCaF₂ did not reduce the paste flow and enamel bond strength, compared to control (p < 0.05). Hardness of sealants with 20% nCaF₂ and DMAHDM was higher than control (p < 0.05). The F ion release from 20% nCaF₂ was much higher than that of commercial control (p < 0.05). The sealant with DMAHDM reduced the S. mutans biofilm CFU by 4 logs. The pH in biofilm medium of the new bioactive sealant was much higher (pH 6.8) than that of commercial sealant (pH 4.66) (p < 0.05).SignificanceThe new bioactive pit and fissure sealant with nCaF₂ and DMAHDM achieved high fluoride release and strong antibacterial performance. This novel fluoride-releasing and antibacterial sealant is promising to inhibit caries and promote the remineralizaton of enamel and dentin.     

The Association Between Enamel Fluorosis and Dental Caries in U.S. Schoolchildren

BackgroundThe authors assessed the association between enamel fluorosis and dental caries to determine if there is any beneficial effect of enamel fluorosis in U.S. schoolchildren.

MethodsThe authors used data from a National Institute of Dental Research survey of the oral health of U.S. children conducted in 1986 and 1987 to determine the prevalence of caries and mean decayed, missing or filled surfaces on permanent maxillary right first molars in children 7 to 17 years of age who had a history of a single residence. (To date, this is the only national oral health data set in the United States with detailed information on fluoride exposures.) They examined the association between enamel fluorosis and caries using logistic regression analysis, controlling for potential confounders in communities with water at or above optimal fluoridation levels and in communities with nonfluoridated or suboptimally fluoridated water.ResultsPermanent maxillary right first molars with fluorosis consistently had lower levels of caries experience than did normal molars. Adjusted odds ratios for caries prevalence in molars with fluorosis were 0.71 (95 percent confidence interval [CI], 0.56–0.89) in communities with nonfluoridated or suboptimally fluoridated water and 0.89 (95 percent CI, 0.74–1.06) in communities with water at or above optimal fluoridation levels.ConclusionThis study's findings suggest that molars with fluorosis are more resistant to caries than are molars without fluorosis.Clinical ImplicationsThe results highlight the need for those considering policies regarding reduction in fluoride exposure to take into consideration the caries-preventive benefits associated with milder forms of enamel fluorosis.