Effect of the association of microparticles and nano-sized β-calcium glycerophosphate in conventional toothpaste on enamel remineralization: In situ study

OBJECTIVES

This in situ study aimed to assess the remineralizing effect of a fluoride toothpaste supplemented with β-calcium glycerophosphate in both micro (β-CaGPm) and nano-sized forms (β-CaGPn).

METHODS

This blind and cross-over study was performed in 4 phases, each spanning 3 days. Twelve volunteers utilized palatal appliances containing four bovine enamel blocks with artificial caries lesions. Volunteers were randomly assigned to the following treatment groups: Placebo (no F-β-CaGPm-β-CaGPn); 1100 ppm F alone (1100F); 1100F plus 0.5% micrometric β-CaGP (1100F-0.5%β-CaGPm); and 1100F plus 0.25%nano-sized β-CaGP (1100F-0.25%β-CaGPn). Participants were instructed to brush their natural teeth with the palatal appliances in the mouth for 1 min (3 times/day), ensuring that the enamel blocks were exposed to the natural toothpaste slurries. Following each phase, evaluations were conducted to determine the percentage of surface hardness recovery (%SHR), integrated recovery of subsurface hardness (ΔIHR), profile subsurface lesion through polarized light microscopy (PLM), as well as fluoride (F), calcium (Ca), and phosphorus (P) concentrations within the enamel. Data were analyzed by ANOVA and Student-Newman-Keuls test (p < 0.001).

RESULTS

Treatment with 1100F-0.25%β-CaGPn resulted in %SHR ∼69 % and ∼40 % higher when compared to 1100F and 1100F-0.5%β-CaGPm (p < 0.001). The reduction in lesion body (ΔIHR; PLM) was ∼40 % higher with 1100F-0.25%β-CaGPn (p < 0.001) compared to 1100F. The addition of β-CaGPm and β-CaGPn did not influence enamel F concentration (p > 0.001). Treatment with 1100F-0.25%β-CaGPn led to an increase in the concentration of Ca and P in the enamel (p < 0.001).

CONCLUSION

The addition of 0.25%β-CaGPn into 1100F formulation increased the bioavailability of calcium and phosphate, promoting a higher remineralizing effect.

CLINICAL SIGNIFICANCE

Toothpaste containing 1100F-0.25%β-CaGPn showed a potential of higher remineralization to 1100 ppm F and 1100 ppm F micrometric β-CaGP could be a strategy for patients at caries activity.

Remineralizing Potential of Low-fluoridated, Nonfluoridated and Herbal Nonfluoridated Dentifrices on Demineralized Surface of Primary Teeth: An In Vitro Study

Aim

The aim of this in vitro study is to evaluate the remineralizing potential of commercially available low-fluoridated, nonfluoridated, and herbal nonfluoridated child formula dentifrices on primary teeth.

Materials and methods

Total of 36 primary teeth were placed in the demineralizing solution for 96 hours to produce artificial carious lesions of approximately 100 μm depth, and then cut longitudinally into 30 sections of 100–150 μm thickness and randomly assigned to three groups. Sections were treated with low-fluoridated, nonfluoridated, and herbal nonfluoridated dentifrice. Lesions were evaluated using polarized light microscopy.

Results

Intragroup comparison of mean lesion depth from pretreatment to posttreatment among the three study groups revealed that maximum reduction in lesion depth was found to be in group I (low-fluoridated) followed in descending order by group III (herbal nonfluoridated) and group II (nonfluoridated), respectively.

Conclusion

Group I (low-fluoridated) and group III (herbal nonfluoridated) demonstrated remineralization of carious lesions by virtue of a decrease in lesion depth, whereas group II (nonfluoridated) showed an increase in lesion depth.

Clinical significance

Fluoride dentifrices are the most widely used products that deliver topical fluoride to the oral environment. The major drawback is the risk of dental fluorosis, which occurs because of ingestion of dentifrices, in preschool children. This necessitates use of preventive measures which include (1) reducing the amount of toothpaste used, (2) supervised brushing in preschool children and (3) developing low-fluoride toothpastes for minimizing risk of dental fluorosis. Further dental professionals must investigate effectiveness of increasingly popular “Herbal” products.

How to cite this article

Tiwari S, Saha S, Dhinsa K, et al. Remineralizing Potential of Low-fluoridated, Nonfluoridated and Herbal Nonfluoridated Dentifrices on Demineralized Surface of Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(3):251-257.

Topical fluoride to prevent early childhood caries: Systematic review with network meta-analysis

OBJECTIVES

To summarize the evidence on prevention of early childhood caries (ECC) by professionally or self-applied topical fluorides using network meta-analysis.

DATA

Randomized-controlled trials with minimum 1-year follow-up assessing caries-preventive effect among children younger than six years.

SOURCES

Eight electronic databases and grey literature.

STUDY SELECTION

After screening and data extraction, risk of bias assessment using Cochrane risk of bias tool 2.0 was done. Twenty-four trials were included, among which 17 were assessed as "high risk" and remaining as "low risk". Fifteen studies evaluated professionally-applied, and the other nine used self-applied topical fluorides. Ten studies on professionally-applied fluorides reporting the net caries increment (dmfs increment) at 2-years follow-up were included in Network meta-analysis (NMA). NMA and ranking the interventions were conducted using a frequentist random-effects approach and surface under the cumulative ranking command, followed by assessing the certainty of evidence using an extension of GRADE approach with CINeMA framework. Among the eight included interventions of professionally-applied fluorides, only two, i.e., 3-monthly 0.9% difluorosilane (DFS) and 6-monthly 5% sodium fluoride varnish were effective in preventing ECC compared to control with 3-monthly DFS application ranking higher than 6-monthly sodium fluoride varnish application.

CONCLUSION

Among all the professionally-applied topical fluoride interventions reviewed, very low to moderate evidence was found with 0.9% DFS application at 3-monthly intervals, which was ranked highest in prevention of ECC. Among the included studies on self-applied topical fluorides, the evidence was inconclusive due to heterogeneity among studies.

CLINICAL SIGNIFICANCE

The 0.9% DFS varnish applied every 3 months is most effective for preventing early childhood caries. The review recommends that good quality studies be conducted in future, comparing two or more interventions for both self- as well as professionally-applied topical fluoride agents with adequate follow-up.

In situ evaluation of 200 ppm fluoride toothpaste content trimetaphosphate, xylitol and erythritol on enamel demineralization and dental biofilm

OBJECTIVE

To evaluate the effect of low-fluoride (F^-) toothpaste and sodium trimetaphosphate (TMP) associated with xylitol and erythritol (XE) on enamel demineralization and biofilm composition.

METHODS

This crossover double-blind in situ study consisted of five phases (seven days each), in which 14 volunteers wore oral appliances containing four enamel bovine blocks. The cariogenic challenge was performed by exposure to a 30% sucrose solution (6x/day). The toothpaste treatments (3x/day) were as follows: placebo (no F^-/TMP/XE); 200 ppm F^- (NaF) (200F); 1,100 ppm F^- (1100F); 16% Xylitol and 4% Erythritol (XE); and 200 ppm F^-, 0.2% TMP, 16% xylitol, and 4% erythritol (200F-TMP-XE). Percentage of surface hardness loss (%SH) and integrated loss of subsurface hardness (ΔKHN), and calcium (Ca²⁺), phosphate (PO₄^3-), and F^- on enamel and biofilm were determined; as well as insoluble extracellular polysaccharide (EPS).

RESULTS

XE and 1100F groups showed no significant difference for %SH and ΔKHN values (p = 0.220 and p = 0.886), and the 200F-TMP-XE group had the lowest mineral loss (p < 0.001). Ca²⁺ and PO₄^3- in the enamel showed the highest values (p < 0.001) for the 200F-TMP-XE group. Higher values of F^- in the enamel and biofilm were observed for the 1100F group (p < 0.001). There was no difference for Ca²⁺ (p = 1.00) and EPS (p =0.918) values between XE and 200-TMP-XE groups in the biofilm, but their values were higher and lower than the 1100F (p = 0.002 and p = 0.029), respectively.

CONCLUSIONS

200F-TMP-XE promoted a greater protective effect against enamel demineralization and significantly affected the composition of biofilm formed in situ compared to 1100F toothpaste.

CLINICAL SIGNIFICANCE

Low-F^- toothpaste containing TMP and polyols can be considered an effective and safe measure to improve the oral health of individuals, especially patients with high caries activity.

Review of Fluoride Intake and Appropriateness of Current Guidelines

Since the classical epidemiological studies by Dean, it has been known that there should be an optimum level of exposure to fluoride that would be able to provide the maximum protection against caries, with minimum dental fluorosis. The "optimal" daily intake of fluoride for children (0.05-0.07 mg per kilogram bodyweight) that is still accepted worldwide was empirically determined. In the present review, we discuss the appropriateness of the current guidance for fluoride intake, in light of the windows of susceptibility to caries and fluorosis, the modern trends of fluoride intake from multiple sources, individual variations in fluoride metabolism, and recent epidemiological data. The main conclusion is that it is very difficult to think about a strict recommendation for an "optimal" range of fluoride intake at the individual level in light of existing knowledge of 1) the mechanisms of action of fluoride to control caries, 2) the mechanisms involved in dental fluorosis development, 3) the distinct factors that interfere in the metabolism of fluoride, and 4) the windows of susceptibility to both dental caries and fluorosis development. An "optimal" range of fluoride intake is, however, desirable at the population level to guide programs of community fluoridation, but further research is necessary to provide additional support for future decisions on guidance in this area. This list includes the effect of factors affecting fluoride metabolism, clinical trials on the effectiveness of low-fluoride dentifrices to prevent caries in the primary dentition, and validation of biomarkers of exposure to fluoride.

Average area under the curve: An alternative method for quantifying the dental caries experience in longitudinal studies

OBJECTIVES

Field-traditional decayed, missing, filled surfaces (dmfs) increments require complete follow-up, only using initial and final visits. Repeated dmfs scores complicate sophisticated statistical models, limiting their utility. Elsewhere, area under the curve (AUC) uses all repeated measures to summarize data. This study applied AUC methodology to caries data, creating average AUCs for dmfs trajectories (dmfs^aAUC ) and comparing increments and dmfs^aAUC values.

METHODS

Longitudinal data were obtained from high-caries risk (i.e. poor, rural, African American community in Perry County, Alabama) infants, 8 to 18 months at baseline. Baseline and five annual visual oral examinations provided dmfs scores. Differences in baseline and final dmfs scores constituted increments. The trapezoidal rule was applied to dmfs trajectories to calculate AUC values which were adjusted for varying follow-up times, producing dmfs^aAUC values. Participants sharing incremental or dmfs^aAUC values had their trajectories and second caries measurements compared. Within-participant increment and dmfs^aAUC differences were evaluated (paired t test, α = 0.05). Comparative analyses required complete follow-up.

RESULTS

The dmfs^aAUC provided forty-eight additional person-years, increasing the potential sample size by 20% (N = 85). Sixty-six children, 5.7 to 6.3 year-olds at study's end, contributed 121 331 person-days to five-year increment and dmfs^aAUC calculations. Trajectories and dmfs^aAUC values varied for participants with equivalent increments; comparable trajectories and different increments resulted from participants with similar dmfs^aAUC values. Within-participant disease amounts were similar.

CONCLUSIONS

When desired, dmfs^aAUC can replace increments as a more data-inclusive summary of longitudinal caries burden, incorporating intermediate visits, incomplete follow-up and time.

Fluoride toothpastes of different concentrations for preventing dental caries

BACKGROUND

Caries (dental decay) is a disease of the hard tissues of the teeth caused by an imbalance, over time, in the interactions between cariogenic bacteria in dental plaque and fermentable carbohydrates (mainly sugars). Regular toothbrushing with fluoride toothpaste is the principal non-professional intervention to prevent caries, but the caries-preventive effect varies according to different concentrations of fluoride in toothpaste, with higher concentrations associated with increased caries control. Toothpastes with higher fluoride concentration increases the risk of fluorosis (enamel defects) in developing teeth. This is an update of the Cochrane Review first published in 2010.

OBJECTIVES

To determine and compare the effects of toothpastes of different fluoride concentrations (parts per million (ppm)) in preventing dental caries in children, adolescents, and adults.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 15 August 2018); the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 7) in the Cochrane Library (searched 15 August 2018); MEDLINE Ovid (1946 to 15 August 2018); and Embase Ovid (1980 to 15 August 2018). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials (15 August 2018). No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials that compared toothbrushing with fluoride toothpaste with toothbrushing with a non-fluoride toothpaste or toothpaste of a different fluoride concentration, with a follow-up period of at least 1 year. The primary outcome was caries increment measured by the change from baseline in the decayed, (missing), and filled surfaces or teeth index in all permanent or primary teeth (D(M)FS/T or d(m)fs/t).

DATA COLLECTION AND ANALYSIS

Two members of the review team, independently and in duplicate, undertook the selection of studies, data extraction, and risk of bias assessment. We graded the certainty of the evidence through discussion and consensus. The primary effect measure was the mean difference (MD) or standardised mean difference (SMD) caries increment. Where it was appropriate to pool data, we used random-effects pairwise or network meta-analysis.

MAIN RESULTS

We included 96 studies published between 1955 and 2014 in this updated review. Seven studies with 11,356 randomised participants (7047 evaluated) reported the effects of fluoride toothpaste up to 1500 ppm on the primary dentition; one study with 2500 randomised participants (2008 evaluated) reported the effects of 1450 ppm fluoride toothpaste on the primary and permanent dentition; 85 studies with 48,804 randomised participants (40,066 evaluated) reported the effects of toothpaste up to 2400 ppm on the immature permanent dentition; and three studies with 2675 randomised participants (2162 evaluated) reported the effects of up to 1100 ppm fluoride toothpaste on the mature permanent dentition. Follow-up in most studies was 36 months.In the primary dentition of young children, 1500 ppm fluoride toothpaste reduces caries increment when compared with non-fluoride toothpaste (MD -1.86 dfs, 95% confidence interval (CI) -2.51 to -1.21; 998 participants, one study, moderate-certainty evidence); the caries-preventive effects for the head-to-head comparison of 1055 ppm versus 550 ppm fluoride toothpaste are similar (MD -0.05, dmfs, 95% CI -0.38 to 0.28; 1958 participants, two studies, moderate-certainty evidence), but toothbrushing with 1450 ppm fluoride toothpaste slightly reduces decayed, missing, filled teeth (dmft) increment when compared with 440 ppm fluoride toothpaste (MD -0.34, dmft, 95%CI -0.59 to -0.09; 2362 participants, one study, moderate-certainty evidence). The certainty of the remaining evidence for this comparison was judged to be low.We included 81 studies in the network meta-analysis of D(M)FS increment in the permanent dentition of children and adolescents. The network included 21 different comparisons of seven fluoride concentrations. The certainty of the evidence was judged to be low with the following exceptions: there was high- and moderate-certainty evidence that 1000 to 1250 ppm or 1450 to 1500 ppm fluoride toothpaste reduces caries increments when compared with non-fluoride toothpaste (SMD -0.28, 95% CI -0.32 to -0.25, 55 studies; and SMD -0.36, 95% CI -0.43 to -0.29, four studies); there was moderate-certainty evidence that 1450 to 1500 ppm fluoride toothpaste slightly reduces caries increments when compared to 1000 to 1250 ppm (SMD -0.08, 95% CI -0.14 to -0.01, 10 studies); and moderate-certainty evidence that the caries increments are similar for 1700 to 2200 ppm and 2400 to 2800 ppm fluoride toothpaste when compared to 1450 to 1500 ppm (SMD 0.04, 95% CI -0.07 to 0.15, indirect evidence only; SMD -0.05, 95% CI -0.14 to 0.05, two studies).In the adult permanent dentition, 1000 or 1100 ppm fluoride toothpaste reduces DMFS increment when compared with non-fluoride toothpaste in adults of all ages (MD -0.53, 95% CI -1.02 to -0.04; 2162 participants, three studies, moderate-certainty evidence). The evidence for DMFT was low certainty.Only a minority of studies assessed adverse effects of toothpaste. When reported, effects such as soft tissue damage and tooth staining were minimal.

AUTHORS' CONCLUSIONS

This Cochrane Review supports the benefits of using fluoride toothpaste in preventing caries when compared to non-fluoride toothpaste. Evidence for the effects of different fluoride concentrations is more limited, but a dose-response effect was observed for D(M)FS in children and adolescents. For many comparisons of different concentrations the caries-preventive effects and our confidence in these effect estimates are uncertain and could be challenged by further research. The choice of fluoride toothpaste concentration for young children should be balanced against the risk of fluorosis.

Exposição a fluoreto por crianças na faixa etária crítica para fluorose dentária, residentes no semiárido brasileiro

Resumo Há uma preocupação com o aumento da prevalência de fluorose dentária, que depende da dose de fluoreto (F) a que as crianças são submetidas durante a formação dos dentes. A temperatura ambiental afeta a ingestão de água e, portanto, seria importante avaliar se as crianças que vivem em uma região de clima semiárido estão expostas a uma dose excessiva de F. Assim, o objetivo do presente estudo foi determinar a dose total de F a que as crianças são expostas durante a idade crítica para a fluorose dentária, tendo dieta (água e alimentos) e dentifrício como fontes de F, em uma região de clima semiárido no Brasil. Metodologia: foram selecionadas 26 crianças com idade de 25,2 ± 9,1 meses, residentes em Feira de Santana-BA. Foram coletadas amostras de dieta-duplicada, água, produtos de escovação e dentifrícios. A concentração de F foi determinada após o devido preparo das amostras, utilizando um eletrodo específico. Resultados: a média e o desvio padrão de dose (mg F / kg / dia) em função da dieta, dentifrício e total foram, respectivamente: 0,016 ± 0,010; 0,030 ± 0,039 e 0,047 ± 0,043. Conclusões: as crianças avaliadas, residentes em uma região de clima semiárido, não estão expostas a uma dose de risco de fluorose dentária.

Nyvad Criteria for Caries Lesion Activity and Severity Assessment: A Validated Approach for Clinical Management and Research

The Nyvad classification is a visual-tactile caries classification system devised to enable the detection of the activity and severity of caries lesions with special focus on low-caries populations. The criteria behind the classification reflect the entire continuum of caries, ranging from clinically sound surfaces through noncavitated and microcavitated caries lesions in enamel, to frank cavitation into the dentin. Lesion activity at each severity stage is discriminated by differences in surface topography and lesion texture. The reliability of the Nyvad criteria is high to excellent when used by trained examiners in the primary and permanent dentitions. The Nyvad criteria have construct validity for lesion activity assessments because of their ability to reflect the well-known caries-controlling effect of fluoride. Predictive validity was demonstrated by showing that active noncavitated lesions are at higher risk of progressing to a cavity or filled state than do inactive noncavitated lesions. Lesion activity assessment performed successfully as a screening tool to identify individuals with a poor caries prognosis. Because of their predictive validity, the Nyvad criteria are superior to other current caries lesion descriptors for the detection of changes in the lesion activity status over time. The Nyvad criteria fulfill all the formal requirements for a robust caries lesion classification and are recommended for evidence-based caries management in clinical practice and in research.

Evaluation of low fluoride toothpaste using primary enamel and a validated pH-cycling model

AIM

To develop and validate pH-cycling model for primary enamel, which was then used to evaluate the anti-caries potential of fluoride toothpastes.

DESIGN

Human primary enamel slabs were subjected to pH-cycling model for 10 days and maintained for 6 h in demineralizing solution and 18 h in remineralizing solution daily. Twice/day, the slabs were treated. To validate it, the treatments were water or solutions containing 62.5, 125, 250, and 375 μg F/mL. Commercial toothpastes containing no fluoride, 500, 1100, and 1450 μg F/g were evaluated. Demineralization was assessed by percentage of surface hardness loss (%SHL) and cross-sectional hardness (ΔS). Fluoride dose-response effect was analysed by quadratic regression and the effects of toothpastes by Tukey's test.

RESULTS

Dose-response effect was found between fluoride concentration and %SHL (R²  = 0.7047; P < 0.01) or ΔS (R²  = 0.4465; P < 0.01). %SHL and ΔS (mean ± SD) for the group treated with 500 μg F/g toothpaste was 36.6 ± 8.0 and 6298.5 ± 1221.3, respectively, which were significantly higher than those treated with 1100 (25.2 ± 8.7; 4565.7 ± 1122) and 1450 μg F/g (24.2 ± 5.2; 2339.1 ± 879.7) toothpastes.

CONCLUSION

The developed pH-cycling model may be used to evaluate and compare the anti-caries potential of toothpaste formulations with low fluoride concentration because it presents dose-response effects on the reduction of primary enamel demineralization.

Fluoride toothpaste efficacy and safety in children younger than 6 years: a systematic review

BACKGROUND

The authors conducted a systematic review to assess the efficacy and safety of fluoride toothpaste use in children younger than 6 years.

METHODS

The authors defined research questions to formulate a search strategy. They screened studies, extracted data and assessed risk of bias systematically. They conducted meta-analyses to determine the effects of brushing with fluoride toothpaste.

RESULTS

Use of fluoride toothpaste brushing had a statistically significant effect on mean decayed, missing and filled primary tooth surfaces and decayed, missing and filled primary teeth for populations at high risk of developing caries (standard mean difference [95 percent confidence interval {CI}], -0.25 [-0.36 to -0.14] and -0.19 [-0.32 to -0.06], respectively). The effects of using different fluoride concentration toothpastes on caries varied. Study findings showed either a decrease in the odds of having fluorosis (odds ratio [OR] [95 percent CI] = 0.66 [0.48-0.90]) when the use of fluoride toothpaste was initiated after 24 months or no statistically significant difference (OR [95 percent CI] = 0.92 [0.71-1.18]). Beginning use after 12 or 14 months of age decreased the risk of fluorosis (OR = 0.70 [0.57-0.88]).

CONCLUSIONS

Limited scientific evidence demonstrates that for children younger than 6 years, fluoride toothpaste use is effective in caries control. Ingesting pea-sized amounts or more can lead to mild fluorosis. Practical Implications. To minimize the risk of fluorosis in children while maximizing the caries-prevention benefit for all age groups, the appropriate amount of fluoride toothpaste should be used by all children regardless of age. Dentists should counsel caregivers by using oral description, visual aids and actual demonstration to help ensure that the appropriate amount of toothpaste is used.

Non-surgical treatment of dentin caries in preschool children--systematic review

Background

Untreated dentin caries in primary teeth is commonly found in preschool children worldwide. Recently, the use of simple non-surgical approaches to manage the situation has been advocated.

The aim of the study was to systematically review and evaluate the literature on effectiveness of non-surgical methods in arresting or slowing down the progression of active dentin caries in primary teeth in preschool children.

Methods

A systematic search of the main electronic databases (Pubmed, Cochrane Collaboration, EMBASE) was conducted to identify peer reviewed papers published in English in the years 1947–2014. Keywords and MeSH terms used in the search were “dental caries”, “primary dentition” and various non-surgical treatments (fluoride, sealant, resin infiltration, xylitol, chlorhexidine, CPP-ACP, ozone, etc.). The inclusion criteria were clinical studies conducted in children under 6 years old, and reported findings on caries arrest or caries progression in primary teeth. Retrieved papers were read by two reviewers independently to assess suitability for inclusion, and the final decision was made by consensus. Quality of the included studies was assessed and data were extracted for analysis.

Results

The search identified 323 papers for screening. Among these, 290 papers did not satisfy the study inclusion criteria. Consequently, 33 full papers were retrieved and reviewed. Finally, 4 studies were included. Three studies reported that topical applications of silver diammine fluoride (SDF) solution could arrest dentin caries in preschool children. One study supported that having a daily toothbrushing exercise in kindergarten using toothpaste with 1000 ppm fluoride could stabilize the caries situation in young children.

Conclusions

There is limited evidence to support the effectiveness of SDF applications or daily toothbrushing with fluoride toothpaste in arresting or slowing down the progression of active dentin caries in primary teeth in preschool children. More well-designed randomized controlled trials are required to confirm these findings.

Development of caries adjacent to composite restorations after exposure to dentifrices with different fluoride concentrations

Objective To evaluate the development of recurrent caries after exposure to fluoride dentifrices with different concentrations. Material and method: 48 samples of bovine incisors (4x4mm2) were exposed to pH cycling for 7 days before the preparation of the cavities (2mm deep). The samples were restored with a microhybrid resin composite. Then, the samples were exposed to thermal cycling (350 cycles) and they were randomly allocated into 4 treatment groups (n = 12): Group A - non-fluoridated dentifrice (negative control); Group B - 500 ppm dentifrice; Group C - 750 ppm dentifrice; group D - 1100 ppm dentifrice (positive control). The samples were treated with solutions of each dentifrice (9.6 ml water/1.6 g dentifrice) for 60 seconds and then were immersed in demineralizing (3 h) and remineralizing (2 h) solutions 3 times a day. Next, the samples were immersed in a remineralizing solution for 18 hours. Then, the blocks were sectioned for examination of the length of the outer caries lesion, using polarized light microscopy. The ANOVA parametric test complemented by the Tukey test with a confidence level of 95%, were used in the statistical analysis. Result: A smaller lesion length was observed in the group treated with the fluoride concentration of 1100 ppm F, but there were no differences between toothpastes with fluoride concentrations of 500 and 750 ppm F. Conclusion: The use of fluoride dentifrices (1100 ppm) reduces the development of caries adjacent to dental restorations.

Effects of ion-releasing tooth-coating material on demineralization of bovine tooth enamel

We compared the effect of a novel ion-releasing tooth-coating material that contained S-PRG (surface-reaction type prereacted glass-ionomer) filler to that of non-S-PRG filler and nail varnish on the demineralization of bovine enamel subsurface lesions. The demineralization process of bovine enamel was examined using quantitative light-induced fluorescence (QLF) and electron probe microanalyzer (EPMA) measurement. Ion concentrations in demineralizing solution were measured using inductively coupled plasma atomic (ICP) emission spectrometry and an ion electrode. The nail varnish group and the non-S-PRG filler group showed linear demineralization. Although the nail varnish group and the non-S-PRG filler group showed linear demineralization, the S-PRG filler group did not. Further, plane-scanning by EPMA analysis in the S-PRG filler group showed no changes in Ca ion distribution, and F ions showed peak levels on the surface of enamel specimens. Most ions in the demineralizing solution were present at higher concentrations in the S-PRG filler group than in the other two groups. In conclusion, only the S-PRG filler-containing tooth-coating material released ions and inhibited demineralization around the coating.

Reproducibility and diagnostic outcomes of two visual-tactile criteria used by dentists to assess caries lesion activity: a cross-over study

The aim of this study was to evaluate the reproducibility and differences in diagnostic outcomes by practicing dental clinicians previously inexperienced in using the Nyvad criteria and the ICDAS II criteria with the Lesion Activity Assessment system (ICDAS II + LAA). Four volunteer dentists were randomly allocated to one of two groups. Both groups of dentists examined the same voluntary sample (n = 140) of caries active young adults using Nyvad and ICDAS II + LAA criteria in different sequences. The first group used the Nyvad criteria during period 1, followed by ICDAS II + LAA during period 2; the second group did the examinations in the opposite sequence. Before the period 1 and 2 examinations, dentists from both groups were trained with the Nyvad or ICDAS II + LAA criteria, depending on the group to which they were assigned. Intra-examiner agreement for lesion severity was high for both diagnostic instruments (weighted kappa 0.62-0.80). For lesion activity the intra-examiner unweighted kappa values ranged from 0.31 to 0.61 for ICDAS II + LAA and from 0.36 to 0.51 for Nyvad. The mean number of active non-cavitated caries lesions was significantly higher for ICDAS II + LAA (6.14 ± 5.4) than for Nyvad (3.90 ± 3.9) (p < 0.001). Active cavitated/dentinal caries lesions were significantly higher for ICDAS II + LAA (4.14 ± 4.1) than for Nyvad (2.13 ± 3.1) (p < 0.001). Both the Nyvad and ICDAS II + LAA diagnostic criteria showed high reproducibility for lesion severity assessment. The mean number of active caries lesions among high caries risk subjects was significantly higher using the ICDAS II + LAA criteria, which may subsequently lead to more caries treatment.

TRIAL REGISTRATION

ISRCTN65592532.

Anticaries effect of dentifrices with calcium citrate and sodium trimetaphosphate

Because of the growing concerns regarding fluoride ingestion by young children and dental fluorosis, it is necessary to develop new dentifrices.

OBJECTIVE

The aim of this study was to evaluate the effect of dentifrices with calcium citrate (Cacit) and sodium trimetaphosphate (TMP) on enamel demineralization.

MATERIAL AND METHODS

Enamel blocks (n=70), previously selected through surface hardness analysis, were submitted to daily treatment with dentifrices diluted in artificial saliva and to a pH-cycling model. The fluoride concentration in dentifrices was 0, 250, 450, 550, 1,000 and 1,100 µg F/g. CrestTM was used as a positive control (1,100 mg F/g). Cacit (0.25%) and TMP (0.25%) were added to dentifrices with 450 and 1,000 µg F/g. Surface hardness was measured again and integrated loss of subsurface hardness and fluoride concentration in enamel were calculated. Parametric and correlation tests were used to determine difference (p<0.05) and dose-response relationship between treatments.

RESULTS

The addition of Cacit and TMP did not provide a higher fluoride concentration in enamel, however it reduced (p<0.05) mineral loss when compared to other dentifrices; the dentifrice with Cacit and TMP and a low fluoride concentration presented similar results when compared to a dentifrice with 1,100 mg F/g (p>0.05).

CONCLUSIONS

Dentifrices with 450 and 1,000 µg F/g, Cacit and TMP were as effective as a gold standard one.

Caries Clinical Trial Methods for the Assessment of Oral Care Products in the 21st Century

Traditionally, caries clinical trials of oral care products have focused on the prevention of caries in children and adolescents at the “cavitation” level. Because of a general reduction in caries incidence and the use of positive control comparators, studies have grown both in size and duration to improve statistical power. Currently, they tend to be of 2 to 3 years’ duration, with up to 2,000 high-risk individuals per group. During the past decade, there has been a shift in emphasis from a restorative approach to the treatment of dental caries to a therapeutic approach focused on the remineralization of early caries lesions. However, caries clinical trials of oral care products have not often reflected this paradigm change. This manuscript reviews alternative caries clinical trial methods for oral care products. It is concluded that methods focused on the detection and monitoring of enamel caries and root caries, by visual approaches such as ICDAS and instrumental methods such as QLF, Diagnodent, and Electrical Caries Monitors, provide viable alternatives to traditional methods. In particular, such approaches more accurately reflect the modes of action of many therapeutic agents and formulations and may reduce the cost and duration of product innovation.

Combination effect of fluoride dentifrices and varnish on deciduous enamel demineralization

The aim of this study was to evaluate the anticaries potential of 500 or 1100 ppm F dentifrices combined with fluoride varnish using a pH-cycling regimen. Seventy primary canines were covered with nail polish, leaving a 4×4 mm window on their buccal surface, and randomly assigned into 7 groups (n = 10): S: sound enamel not submitted to the pH-cycling regimen or treatment; N: negative control, submitted to the pH-cycling regimen without any treatment; D1 and D2: subjected to the pH-cycling regimen and treated twice daily with 1100 or 500 ppm F dentifrice, respectively; VF: fluoride varnish (subjected to F-varnish before and in the middle of the pH-cycling regimen); and VF+D1 and VF+D2. After 10 days, the teeth were sectioned, and enamel demineralization was assessed by cross-sectional hardness at different distances from the dental surface. Data were analyzed using a two-way ANOVA followed by Tukey's test. Dentifrice with 1100 ppm F and the combination of F-varnish with the dentifrices significantly reduced enamel demineralization compared with the negative control (p < 0.05), but the isolated effects of F-varnish and dentifrice with low concentration were not significant (p > 0.05). The effect of combining F-varnish with the dentifrices was not greater than the effect of the dentifrices alone (p < 0.05). The data suggest that the combination of F-varnish with dentifrices containing 500 and 1100 ppm F is not more effective in reducing demineralization in primary teeth than the isolated effect of dentifrice containing 1100 ppm F.

Reliability of the Nyvad criteria for caries assessment in primary teeth

This study assessed the interexaminer and intra-examiner reliability of the Nyvad caries classification system in primary teeth and calculated the mean examination time. The criteria were based on visual and tactile examinations to differentiate active and inactive lesions at cavitated and non-cavitated levels. Eighty children (3-7 yr of age) were examined under standardized conditions by calibrated examiners. At the tooth surface level, reliability was expressed as percentage agreement and kappa coefficient, using four diagnostic thresholds: sound vs. diseased; sound or inactive lesion vs. active lesion; intact surface vs. surface discontinuity; and sound or non-cavitated lesion vs. cavitated lesion. Interexaminer and intra-examiner kappa values were, respectively: 0.82/0.86; 0.80/0.86; 0.90/0.94; and 0.95/0.98. At the individual level, reliability of estimates of the caries prevalence and of the decayed or filled surface (dfs) counts were assessed at three diagnostic thresholds: sound vs. diseased; sound or inactive lesion vs. active lesion; and sound or non-cavitated lesion vs. cavitated lesion. For caries prevalence, interexaminer and intra-examiner kappa values were, respectively: 0.84/0.94; 0.69/0.74; and 0.95/0.97. The mean examination time was 226.5s (SD = 128.5). The use of the Nyvad caries diagnostic criteria in primary teeth showed reliable results. The examination time was acceptable.

In situ remineralization of white-spot enamel lesions by 500 and 1,100 ppm F dentifrices

The aim of this study was to evaluate the remineralization potential of three silica-containing NaF dentifrice systems in an intraoral model. Subjects (N = 30) in this randomized, three-phase, 28-day, crossover study served as their own control. Each participant wore a customized orthodontic appliance attached to a mandibular molar and contained one tooth block with caries-like lesion. For each phase, participants engaged in twice-daily brushing for 2 min with one of the following dentifrices: 500 ppm F, 500 ppm F plus functionalized β-tricalcium phosphate (fTCP), and a clinically proven 1,100 ppm F. After each phase, appliances were removed, and specimens were analyzed using surface microhardness (SMH), transverse microradiography (TMR), and cross-sectional microhardness (CSMH). Statistically significant (p < 0.05) remineralization of white-spot lesions relative to baseline occurred for each dentifrice as determined with SMH and TMR. No significant differences (p > 0.05) in SMH were found among the three groups, but trending revealed the 500 ppm F plus fTCP produced 26% and 27% greater SMH recovery relative to 500 and 1,100 ppm F, respectively. Similarly, no significant differences (p > 0.05) in TMR were found among the groups. However, the 500 ppm F plus fTCP dentifrice produced 10% and 38% greater mineral recovery relative to 500 and 1,100 ppm F, respectively, while reducing the lesion depth 30% and 52%, respectively. Significant differences (p < 0.05) in CSMH existed among the three dentifice groups at different enamel depths, but statistical differences (p < 0.05) in relative lesion size were only found between 500 ppm F plus fTCP and 500 ppm F. The combination of fTCP and fluoride in a single-compartment, water-based dentifrice can cooperate with fluoride to produce significant remineralization. These results suggest that the combination of 500 ppm F with fTCP may provide comparable anticaries benefits relative to a 1,100 ppm F dentifrice.

Consumo de dentifrício e fatores associados em um grupo populacional brasileiro

Este estudo transversal avaliou o consumo de dentifrício fluoretado e fatores associados em Passo Fundo, Rio Grande do Sul, Brasil. Seiscentos e oitenta e oito domicílios foram selecionados. Um questionário estruturado foi respondido pela mãe para obter dados demográficos, hábitos e consumo de dentifrício. O consumo foi avaliado por intermédio da duração de um tubo de dentifrício e considerado baixo (duração > 1 mês) e alto (duração < 1 mês). Modelos de regressão logística avaliaram a associação do consumo com variáveis independentes. Foi observado que 61,2% dos domicílios apresentaram alto consumo de dentifrício. No modelo multivariado, idade da mãe > 50 anos (OR = 1.62; IC95% 1,02-2,61), frequência de escovação da mãe (OR = 2,53; IC95%: 1,53-4,16), número de moradores que utilizam escova (OR = 5,69; IC95%: 3,68-8,81) e motivo cosmético para escolha do dentifrício (OR = 1,64; IC95%:1,03-2,61) representaram maior chance de alto consumo de dentifrício. Conclui-se que a maioria dos domicílios apresenta consumo elevado de dentifrício, associado com idade e frequência de escovação da mãe, número de moradores e motivos de escolha.

Fluoride: its role in dentistry

In spite of decades of research on fluoride and the recognition of its role as the cornerstone of dental caries reduction in the last fifty years, questions still arise on its use at community, self-applied and professional application levels. Which method of fluoride delivery should be used? How and when should it be used? How can its benefits be maximized and still reduce the risks associated with its use? These are only some of the challenging questions facing us daily. The aim of this paper is to present scientific background to understand the importance of each method of fluoride use considering the current caries epidemiological scenario, and to discuss how individual or combined methods can be used based on the best evidence available.

What we know and do not know about fluoride

There is much that we know about fluoride as it relates to human health in general and dental health in particular. Some of the information that is known concerning water fluoridation and dental fluorosis is listed. What we do not know about fluoride is discussed in more detail, namely the efficacy of lower levels of fluoride in drinking water, the effect of discontinuing fluoride in drinking water in the absence of additional preventive measures, the prevalence of fluorosis and whether or not this presents a cosmetic problem. Other issues discussed include the actual amount of fluoride ingested from all sources, whether low-fluoride dentifrices are as efficacious as conventional dentifrices in caries protection and reducing enamel fluorosis, the role of socioeconomic factors in determining caries prevalence, and the effects of bottled water use on caries prevalence in fluoridated communities.

Effects of Regular and Low-fluoride Dentifrices on Plaque Fluoride

Previous studies have indicated that the use of low-fluoride dentifrices could lead to proportionally higher plaque fluoride levels when compared with conventional dentifrices. This double-blind, randomized, crossover study determined the effects of placebo, low-fluoride, and conventional dentifrices on plaque fluoride concentrations ([F]) in children living in communities with 0.04, 0.72, and 3.36 ppm F in the drinking water. Children used the toothpastes twice daily, for 1 wk. Samples were collected 1 and 12 hrs after the last use of dentifrices and were analyzed for fluoride and calcium. Similar increases were found 1 hr after the children brushed with low-fluoride ( ca. 1.9 mmol F/kg) and conventional ( ca. 2.4 mmol F/kg) dentifrices in the 0.04- and 0.72-ppm-F communities. Despite the fact that the increases were less pronounced in the 3.36-ppm-F community, our results indicate that the use of a low-fluoride dentifrice promotes a proportionally higher increase in plaque [F] when compared with that achieved with a conventional dentifrice, based on dose-response considerations.

Fluoride toothpastes of different concentrations for preventing dental caries in children and adolescents

BACKGROUND

Caries (dental decay) is a disease of the hard tissues of the teeth caused by an imbalance, over time, in the interactions between cariogenic bacteria in dental plaque and fermentable carbohydrates (mainly sugars). The use of fluoride toothpaste is the primary intervention for the prevention of caries.

OBJECTIVES

To determine the relative effectiveness of fluoride toothpastes of different concentrations in preventing dental caries in children and adolescents, and to examine the potentially modifying effects of baseline caries level and supervised toothbrushing.

SEARCH STRATEGY

A search was undertaken on Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and several other databases. Reference lists of articles were also searched. Date of the most recent searches: 8 June 2009.

SELECTION CRITERIA

Randomised controlled trials and cluster-randomised controlled trials comparing fluoride toothpaste with placebo or fluoride toothpaste of a different concentration in children up to 16 years of age with a follow-up period of at least 1 year. The primary outcome was caries increment in the permanent or deciduous dentition as measured by the change in decayed, (missing), filled tooth surfaces (D(M)FS/d(m)fs) from baseline.

DATA COLLECTION AND ANALYSIS

Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were resolved by discussion and consensus or by a third party. The primary effect measure was the prevented fraction (PF), the caries increment of the control group minus the caries increment of the treatment group, expressed as a proportion of the caries increment in the control group. Where it was appropriate to pool data, network meta-analysis, network meta-regression or meta-analysis models were used. Potential sources of heterogeneity were specified a priori and examined through random-effects meta-regression analysis where appropriate.

MAIN RESULTS

75 studies were included, of which 71 studies comprising 79 trials contributed data to the network meta-analysis, network meta-regression or meta-analysis.For the 66 studies (74 trials) that contributed to the network meta-analysis of D(M)FS in the mixed or permanent dentition, the caries preventive effect of fluoride toothpaste increased significantly with higher fluoride concentrations (D(M)FS PF compared to placebo was 23% (95% credible interval (CrI) 19% to 27%) for 1000/1055/1100/1250 parts per million (ppm) concentrations rising to 36% (95% CrI 27% to 44%) for toothpastes with a concentration of 2400/2500/2800 ppm), but concentrations of 440/500/550 ppm and below showed no statistically significant effect when compared to placebo. There is some evidence of a dose response relationship in that the PF increased as the fluoride concentration increased from the baseline although this was not always statistically significant. The effect of fluoride toothpaste also increased with baseline level of D(M)FS and supervised brushing, though this did not reach statistical significance. Six studies assessed the effects of fluoride concentrations on the deciduous dentition with equivocal results dependent upon the fluoride concentrations compared and the outcome measure. Compliance with treatment regimen and unwanted effects was assessed in only a minority of studies. When reported, no differential compliance was observed and unwanted effects such as soft tissue damage and tooth staining were minimal.

AUTHORS' CONCLUSIONS

This review confirms the benefits of using fluoride toothpaste in preventing caries in children and adolescents when compared to placebo, but only significantly for fluoride concentrations of 1000 ppm and above. The relative caries preventive effects of fluoride toothpastes of different concentrations increase with higher fluoride concentration. The decision of what fluoride levels to use for children under 6 years should be balanced with the risk of fluorosis.

Fluoride ingestion from food items and dentifrice in 2-6-year-old Brazilian children living in a fluoridated area using a semiquantitative food frequency questionnaire

OBJECTIVES

The aim of this study was to evaluate the fluoride intake of 2-6-year-old Brazilian children using a semiquantitative food frequency questionnaire (FFQ) which also estimated fluoride intake from dentifrice.

METHODS

The FFQ was previously validated through application to 78 2-6-year-old Brazilian children and then administered to 379 children residing in an optimally fluoridated community in Brazil (Bauru, State of São Paulo). The FFQ was applied to the parents and used to estimate the food intake of the children. The constituents of the diet were divided into solids, water and other beverages. The fluoride content of the diet items was analyzed with the fluoride electrode. The questionnaire also estimated fluoride intake from dentifrice.

RESULTS

The average (+/-SD) fluoride intake from solids, water, other beverages and dentifrice was 0.008 +/- 0.005; 0.011 +/- 0.004; 0.009 +/- 0.014 and 0.036 +/- 0.028 mg F/kg body weight/day, respectively, totalizing 0.064 +/- 0.035 mg F/kg body weight/day. The dentifrice and the diet contributed with 56.3% and 43.7% of the daily fluoride intake, respectively. Among the children evaluated, 31.2% are estimated to have risk to develop dental fluorosis (intake>0.07 mg F/kg body weight/day).

CONCLUSIONS

The dentifrice was the main source of fluoride intake by the children evaluated. However, the fluoride concentration in food items also significantly contributed to the daily ingestion by 2-6-year-old children. The questionnaire used seems to be a promising alternative to duplicate diet to estimate the fluoride intake at this age range and may have potential to be used in broad epidemiological surveys.

pH-cycling models to evaluate the effect of low fluoride dentifrice on enamel de- and remineralization

Since the currently available pH-cycling models do not differentiate the anti-caries potential of dentifrices with low fluoride (F) concentration, two models were developed and tested in the present. Bovine enamel blocks were subjected to the models and treated with F solutions containing from 70 to 280 microg F/mL in order to validate them in terms of dose-response effect. The models were also tested by evaluating the dentifrices Colgate Baby (500 microg F/g, as a low fluoride dentifrice), Tandy (1,100 microg F/g, as an active F-dentifrice) and Crest (1,100 microg F/g, as positive control). Enamel mineral loss or gain was assessed by surface and cross-sectional microhardness, and lesion depth was analyzed by polarized light microscopy. The pH-cycling models showed F dose-response effect either reducing enamel demineralization or enhancing remineralization. The low F dentifrice presented anti-caries potential, but it was not equivalent to the dentifrices containing 1,100 microg F/g. These data suggest that the models developed in this study were able to evaluate the anti-caries potential of low F dentifrice either on resistance to demineralization or on enhancement of remineralization.