Fluoride Intake Through Dental Care Products: A Systematic Review

Fluoride (F) is added to many dental care products as well as in drinking water to prevent dental decay. However, recent data associating exposure to F with some developmental defects with consequences in many organs raise concerns about its daily use for dental care. This systematic review aimed to evaluate the contribution of dental care products with regard to overall F intake through drinking water and diet with measurements of F excretion in urine used as a suitable biomarker. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using keywords related to chronic exposure to F in the human population with measurements of F levels in body fluids, 1,273 papers published between 1995 and 2021 were screened, and 28 papers were finally included for data extraction concerning daily F intake. The contribution of dental care products, essentially by toothbrushing with kinds of toothpaste containing F, was 38% in the mean regardless of the F concentrations in drinking water. There was no correlation between F intake through toothpaste and age, nor with F levels in water ranging from 0.3 to 1.5 mg/L. There was no correlation between F intake and urinary F excretion levels despite an increase in its content in urine within hours following exposure to dental care products (toothpastes, varnishes, or other dental care products). The consequences of exposure to F on health are discussed in the recent context of its suspected toxicity reported in the literature. The conclusions of the review aim to provide objective messages to patients and dental professionals worried about the use of F-containing materials or products to prevent initial caries or hypomineralized enamel lesions, especially for young children.

Effect of fluoridated water on dental caries and fluorosis in schoolchildren who use fluoridated dentifrice

This cross-sectional study evaluated the prevalence and severity of dental caries and fluorosis in children and adolescents using fluoridated toothpaste, from areas with and without fluoridated water. Parents of 5-year-old children and 12-year-old adolescents from neighbourhoods that are supplied with and without fluoridated water answered questionnaires for determining socio-economic and demographic characteristics and habits related to oral health. The individuals were examined, and dental caries and fluorosis were measured by dmft/DMFT and TF indexes, respectively. Descriptive, bivariate and logistic regression analyses were performed (p < 0.05). Of 692 participants, 47.7% were 5-year-olds and 52.3% were 12-year-olds. The mean dmft/DMFT in the 5-year-olds/ 12-year-olds from Exposed and Not Exposed fluoridated water groups was 1.53 (± 2.47) and 3.54 (± 4.10) / 1.53 (± 1.81) and 3.54 (± 3.82), respectively. Children (OR = 2.86, 95% CI = 1.71-4.75) and adolescents (OR = 1.95, 95% CI = 1.24-3.05), who did not consume fluoridated water, had greater caries experience. Among adolescents, there was an association between fluoridated water and the prevalence of very mild/mild fluorosis (OR = 5.45, 95% CI: 3.23-9.19) and moderate fluorosis (OR = 11.11, 95% CI = 4.43-27.87). Children and adolescents, who consumed fluoridated water, presented lower prevalence and severity of dental caries compared to those who used only fluoridated toothpaste as the source of fluoride. There is an association between water fluoridation and very mild/mild and moderate fluorosis in adolescents.

Fluoridated water impact on tooth decay and fluorosis in 17-20-year-olds exposed to fluoride toothpaste

OBJECTIVE

To determine the impact of water fluoridation on the prevalence and severity of dental caries and fluorosis in individuals aged 17-20 years exposed to fluoride toothpaste.

METHODS

The study population consisted of 660 students from public schools, residents of areas supplied with fluoridated water (exposed group) or not (not exposed group). Students from both groups had access to fluoride toothpaste throughout life. A questionnaire about socioeconomic demographic aspects, conditions related to access and exposure to fluoridated water, and habits related to oral health was applied. Dental caries was measured by the DMFT index and dental fluorosis by the TF index. The chi-square test, t test, and subsequently logistic regression were applied for data analysis.

RESULTS

Caries experience (DMFT≠0) was significantly higher in students from areas not exposed to fluoridated water, after adjustments to clinical conditions, demographic socioeconomic profile, and hygiene habits. The DMFT mean (±SD) was significantly higher in students from areas not exposed to fluoridated water than exposed (3.83 [±3.28] and 2.48 [±2.71] respectively). The prevalence of very mild/mild and moderate fluorosis was 41.1% and 21% for students either exposed to fluoridated water or not, respectively.

CONCLUSION

Exposure to fluoridated water was associated with a lower prevalence and severity of tooth decay, in spite of the use of fluoridated toothpaste. The prevalence of dental fluorosis at all levels was higher in fluoridated areas, however, in both groups, there were few cases with esthetic implications.

Chemical Aspects of Human and Environmental Overload with Fluorine

Over the last 100-120 years, due to the ever-increasing importance of fluorine-containing compounds in modern technology and daily life, the explosive development of the fluorochemical industry led to an enormous increase of emission of fluoride ions into the biosphere. This made it more and more important to understand the biological activities, metabolism, degradation, and possible environmental hazards of such substances. This comprehensive and critical review focuses on the effects of fluoride ions and organofluorine compounds (mainly pharmaceuticals and agrochemicals) on human health and the environment. To give a better overview, various connected topics are also discussed: reasons and trends of the advance of fluorine-containing pharmaceuticals and agrochemicals, metabolism of fluorinated drugs, withdrawn fluorinated drugs, natural sources of organic and inorganic fluorine compounds in the environment (including the biosphere), sources of fluoride intake, and finally biomarkers of fluoride exposure.

Effect of high-fluoride dentifrice and bracket bonding composite material on enamel demineralization in situ

OBJECTIVE

This in situ study evaluated the effect of high-fluoride dentifrice (5000 μg F^-/g) and fluoride-containing bonding composite resin on enamel demineralization adjacent to orthodontic brackets.

METHODS

Ten volunteers wore palatal appliances containing bovine enamel blocks with metallic brackets bonded with fluoride-free or fluoride-containing composite resin. During three phases of 14 days each, three dentifrices with different fluoride concentrations (0, 1100, and 5000 μg F^-/g) were tested. The cariogenic challenge consisted of 20% sucrose solution dripped 8x/day onto the dental blocks. At the end of each phase, biofilm formed was collected for fluoride analysis. Cross section hardness was performed in enamel blocks, and the lesion area was calculated. Data were analyzed by two-way ANOVA followed by Tukey post hoc test (α = 5%).

RESULTS

The only signicant factor for all the variables under study was the dentifrice. Smaller lesion area and higher fluoride concentration on biofilm were found in 5000 μg F^-/g group, irrespective of bonding composite resin (p < 0.001). Neither bracket-bonding composite resin nor the interaction between the factors was statistically significant (p > 0.05) for all the variables.

CONCLUSION

High-fluoride dentifrice is effective in reducing demineralization on enamel adjacent to orthodontic brackets, while the fluoride-containing bonding composite resin does not influence it.

CLINICAL SIGNIFICANCE

Since high-fluoride dentifrice was able to reduce demineralization adjacent to brackets, it can be an option to caries management in orthodontics patients.

Enamel Microabrasion and Dental Bleaching on Teeth Presenting Severe-pitted Enamel Fluorosis: A Case Report

The present clinical case report describes the clinical steps of enamel microabrasion associated with dental bleaching to restore severely-pitted fluorosed teeth. The process of removing the fluorotic superficial stains started by using macroabrasion with a water-cooled fine tapered 3195 FF diamond bur. Rubber dam isolation of the operative field was used to remove the remaining enamel stains and superficial irregularities with the Opalustre microabrasive compound (6.6% hydrochloric acid associated with silicon carbide particles) followed by polishing using fluoridated paste and subsequent 2% neutral fluoride gel topical application. After one month, dental bleaching was performed using 10% carbamide peroxide in custom-formed acetate trays for two hours/day for 42 days. The association of enamel microabrasion with dental bleaching was effective for reestablishing the dental esthetics of a patient with severe dental fluorosis.

Influence of Fluoridated Groundwater and 1,100 Ppm Fluoride Dentifrice on Biomarkers of Exposure to Fluoride

Abstract This research aimed to determine the influence of fluoridated groundwater and 1,100 ppm fluoride dentifrice on biomarkers of exposure to fluoride in preschoolers. A cross-sectional study was performed on thirty preschoolers recruited from naturally fluoridated and non-fluoridated areas (n=15). Total Daily Fluoride Intake (TDFI) from diet and dentifrice, and Daily Urinary Fluoride Excretion (DUFE) was measured over 24 h. Nails samples were collected twice during 30 days. Fluoride analyses were performed using a fluoride-ion-specific electrode. Data were evaluated using the Student and paired t-test, Pearson correlation analysis, multiple linear regression analysis (α≤0.05). Fluoridated groundwater and dentifrice were the dominant sources (r2 > 0.83) of TDFI in children from a naturally fluoridated and a non-fluoridated area, respectively. A positive correlation between TDFI and DUFE (r=0.50), and between [F] in fingernails and toenails (r=0.60) were found in children from a naturally fluoridated area. The [F] in nails of finger and toe were not correlated to TDFI. The consumption of fluoridated groundwater influenced the fluoride concentration in urine. In addition, the use of 1,100 ppm fluoride dentifrice did not influence the fluoride concentration in urine and fingernails.

Does flavoured dentifrice increase fluoride intake compared with regular toothpaste in children? A systematic review and meta-analysis

BACKGROUND

Toothpaste manufacturers encourage through aggressive marketing strategies the overconsumption of fluoridated dentifrices. There are conflicting results regarding fluoride intake from toothpastes in children.

AIM

The aim of this systematic review and meta-analysis was to determine whether dentifrice flavour increases fluoride ingestion by children.

DESIGN

We included clinical trials on children that evaluated the use of flavoured dentifrice - FD vs regular dentifrice - RD to identify the fluoride intake. An electronic search was performed in PubMed, Web of Science, Scopus, The Cochrane Library, LILACS/BBO, and grey literature followed by manual search. The methodological quality of the studies was assessed using the Cochrane Collaboration common scheme for bias and ROBINS-I tool. Data were analysed in subgroups such as low (G1) and ordinary (G2) fluoride concentrations of dentifrices. We carried out heterogeneity and sensitive analyses.

RESULTS

For G1, the fluoride intake from RD was significantly higher than from FD [standardised mean difference = -2.57 (-3.26, -1.89), P < 0.00001]. For G2, the fluoride ingestion from RD was significantly higher than from FD [mean difference = -0.00 (-0.00, -0.00), P = 0.02].

CONCLUSIONS

There is evidence to support the null hypothesis that flavouring from dentifrice does not increase fluoride intake in young children.