Ingestion Of Toothpaste Research Articles

Usage of Fluoridated toothpaste in children and Fluorosis of permanent teeth

Objective: To determine the usage of fluoridated toothpaste in children and the presence of fluorosis in permanent teeth. Study Design: Descriptive cross-sectional study. Place and Duration: This study was undertaken in Hayatabad Model School Hayatabad Peshawar, from 1st March, 2022 to 31st October, 2022. Methodology: Eighty (N=80) school going children of both genders from 11-16 years age with healthy and vital teeth were included in this study. Children with chronic diseases were excluded from this study. Ingestion of childhood fluoride toothpaste and degree of fluorosis was recorded by using a questionnaire. Fluorosis was graded on basis of clinical examination by Dean Index. The data was analyzed using statistical package for social sciences (SPSS) version 20. Numerical variables were presented as mean and standard deviation whereas categorical variables were mentioned as numbers and percentages. Results: Mean age of children was 13.15 with 71.25% females (n=57) and 28.75% (n=23) males. 40.6% children (n=65) had dental fluorosis. Majority of children had mild fluorosis 65% (n=52), followed by moderate fluorosis (12.5%, n=10) and severe fluorosis (3.8%, n=3). 36.3% of the children ingested toothpaste in their early childhood (n=29) whereas 63.7% did not ingest tooth paste (n=51). Conclusion: Dental fluorosis is more common in those children who have a history of ingestion of fluoride tooth paste in their childhood. Keywords: Dental Fluorosis, Fluoride, Dental Caries, Dean Index, Childhood, Tooth Paste, Community Water Fluoridation.

Dose-response relationship between toothpaste soluble fluoride absorbed in the gastrointestinal tract and saliva fluoride secretion

Aim: This study aimed to evaluate if there is a dose-response relationship between toothpaste chemically soluble fluoride absorbed in the gastrointestinal tract and fluoride secreted by saliva, giving support to the use of saliva as surrogate for plasma fluoride. Methods: A 4-phase single blind study was conducted, in which 10 participants were subjected in each phase to one of the assigned treatment groups: group I: fresh sample of a Na2FPO3/CaCO3-based toothpaste with 1,334 μg F/g of total soluble fluoride (TSF) and groups II–IV: aged samples of this toothpaste presenting TSF concentrations of 1,128, 808, and 687 μg F/g, respectively. In all phases, the participants ingested an amount of toothpaste equivalent to 70.0 μg F/Kg body weight, as total fluoride (TF). Saliva and blood samples were collected before (baseline) and up to 180 min after toothpaste ingestion as indicator of fluoride bioavailability. F concentration in saliva and blood plasma was determined with a fluoride ion-specific electrode. The areas under the curve (AUC) of F concentration versus time (AUC = ng F/mL × min) and the peaks of fluoride concentration (Cmax) in saliva and plasma were calculated. Results: A significant correlation between mg of TSF ingested and the AUC (r=0.47; p<0.01), and Cmax (r=0.59; p<0.01) in saliva was found; for TF, the correlation was not significant (p>0.05). In addition, the correlations between plasma and saliva fluoride concentrations were statistically significant for AUC (r=0.55; p<0.01) as for Cmax (r=0.68; p<0.01). Conclusion: The findings support that saliva can be used as a systemic biomarker of bioavailable fluoride present in Na2FPO3/ CaCO3-based toothpaste.

Toothpaste ingestion-evaluating the problem and ensuring safety: systematic review and meta-analysis.

This systematic review and meta-analysis aimed to evaluate the ingestion of toothpaste and its sequelae. The study adhered to the PRISMA guidelines and was registered in the PROSPERO database. A comprehensive search strategy was conducted across multiple databases, resulting in the inclusion of 18 relevant publications. Eligible studies encompassed various designs and included both children and adults as the study population. Data extraction was carried out systematically, and relevant information on study characteristics, interventions, and outcomes were collected. The assessment of bias was performed using the Joanna Briggs Institute's Critical Appraisal Tools showing variations of bias among the included studies. The overall risk of systemic toxicity was found to be low, and no severe or life-threatening events were reported in the included studies. Furthermore, some toothpaste formulations containing higher concentrations of fluoride were associated with an increased risk of dental fluorosis. These findings have several implications for practice and policy. Healthcare providers and dental professionals should emphasize the importance of promoting safe toothpaste use, especially in vulnerable populations such as young children who are more prone to accidental ingestion. Public health campaigns and educational initiatives should aim to raise awareness about appropriate toothpaste usage and the potential risks. In addition, toothpaste manufacturers and regulatory bodies should consider revising guidelines and regulations to ensure the safety of oral care products, including the appropriate concentration of active ingredients. Future research should focus on investigating the long-term effects of toothpaste ingestion, exploring potential interactions between different active ingredients, and evaluating the efficacy of current preventive measures.

THU469 Inhalant Use Resulting In Diffuse Osteosclerosis: Case Report And Review Of The Literature

Abstract Disclosure: C. Hung: None. M. Jesse: None. D. Saxon: None. Osteosclerosis of the bone can develop from excessive fluoride intake. Fluoride sources range from oral intake of fluorinated water, ingestion of toothpaste, to fluorocarbon inhalation. Skeletal fluorosis can manifest with bony changes ranging from increased striation/granulation to thickened trabeculae, and ligaments and tendons can ossify (1). In the literature patients have presented after noticing joint enlargement, worsening chronic joint pains, immobility, and stiffness. Workup generally includes radiographs and dual x-ray absorptiometry (DXA) can reveal increased bone density (2). We describe a patient with osteosclerosis and the workup for this condition. We review the existing literature on fluorinated inhalant use as a cause of osteosclerosis. The patient is a 49-year-old man with type 2 diabetes, chronic pain in multiple joints, hypogonadism, and osteomyelitis status post right above knee amputation was referred to Endocrinology after he was found to have sclerotic bone lesions while undergoing workup for poor mobility. X-ray, CT and MRI scans over the past 7 years showed diffuse bone sclerosis in the spine, pelvis, knee, tibia, and foot. Labs demonstrated normal calcium, albumin, and alkaline phosphatase. DXA confirmed elevated T-scores of +6.8 (1.985 g/cm2) at left femoral neck, +8.6 (2.097 g/cm2) at left proximal femur and +9.8 (2.406 g/cm2) at lumbar spine. The patient confirmed “huffing” computer cleaner for 1 year while having severe depression and had stopped inhalant use 7 years prior to presentation. On literature review we identified case reports of bone sclerosis related to inhalant use. Long-term outcomes and optimal management were described only in case reports. Osteosclerosis from fluorosis should be considered in patients with diffusely increased bone density at multiple sites. 1. Wang Y, Yin Y, Gilula LA, Wilson AJ. Endemic fluorosis of the skeleton: radiographic features in 127 patients. AJR Am J Roentgenol. 1994;162(1):93-8. Epub 1994/01/01. doi: 10.2214/ajr.162.1.8273699. PubMed PMID: 8273699.2.Tucci JR, Whitford GM, McAlister WH, Novack DV, Mumm S, Keaveny TM, et al. Skeletal Fluorosis Due To Inhalation Abuse of a Difluoroethane-Containing Computer Cleaner. J Bone Miner Res. 2017;32(1):188-95. Epub 2016/07/28. doi: 10.1002/jbmr.2923. PubMed PMID: 27449958; PubMed Central PMCID: PMCPMC5977397. Presentation: Thursday, June 15, 2023

Soluble Fluoride in Na2FPO3/CaCO3-Based Toothpaste as an Indicator of Systemically Bioavailable Fluoride

Fluoride chemically soluble in toothpaste is an indicator of fluoride bioavailability when the teeth are brushed, and the same should be expected systemically when toothpaste is ingested. A 4-phases study was conducted, in which 8 participants were subjected in each phase to one of the assigned treatment groups: group I: fresh sample of a Na₂FPO₃/CaCO₃ toothpaste with 1,334 μg F/g of total soluble fluoride (TSF) and groups II–IV: aged samples of toothpaste presenting TSF concentrations of 1,128, 808, and 687 μg F/g, respectively. In all phases, the participants ingested an amount of toothpaste equivalent to 70.0 μg F/kg body weight, as total fluoride (TF). Blood was collected before (baseline) and up to 180 min after toothpaste ingestion as indicator of fluoride bioavailability. Total urine (24 h before and 24 h after ingestion) was collected as indicator of absorbed fluoride that was excreted. F concentration in blood plasma and urine was determined with a fluoride ion-specific electrode. The areas under the curve (AUC) of F concentration versus time (AUC = ng F/mL × min) and the peaks of fluoride concentration in blood plasma (C_max) were calculated. The net amount of fluoride excreted (mg/day) was calculated by subtraction. A significant correlation of the amount (mg) of TSF ingested was found between the AUC (r = 0.76; p < 0.01) and C_max (r = 0.86; p < 0.01) in plasma, and the fluoride excreted (r = 0.65; p < 0.01). For TF, no statistical correlations were found (p > 0.05). Data suggest that the concentration of TSF found in Na₂FPO₃/CaCO₃-based toothpastes is a useful predictor of how much fluoride will be systemically bioavailable when this type of formulation is ingested.

Fractional urinary fluoride excretion and nail fluoride concentrations in normal, wasted and stunted 4–5 year-old children in Nepal

IntroductionIt has been suggested that undernourished children are more likely to develop dental fluorosis. We investigated the effects of nutritional status on systemic fluoride metabolism including the proportion of ingested fluoride excreted through urine (i.e. fractional urinary fluoride excretion - FUFE) and fluoride concentration in nail clippings in children, aged 4−5 years, in Nepal. MethodsNutritional status was evaluated using weight-for-age (wasting) and height-for-age (stunting) indices. Total daily fluoride intake (TDFI) was estimated from diet and toothpaste ingestion and 24 -h urine collected to assess daily urinary fluoride excretion (DUFE). FUFE was calculated by dividing DUFE by TDFI. Nail clippings (finger and toe) were collected and analysed for fluoride concentration. ResultsOf the 100 children who participated, 89 provided information to assess FUFE and 51 children provided nail samples. Overall, 86.5 % of the 89 children were wasted and 39.3 % were stunted.When the samples were pooled into binary (affected and non-affected) categories, mean TDFI and mean DUFE were statistically significantly higher in the 77 wasted children (57.7 and 29.7 μg/kgbw/d, respectively) than the 12 non-wasted children (39.4 and 17.0 μg/kgbw/d, respectively). TDFI and DUFE were also statistically significantly higher in the 35 stunted children (65.1 and 34.5 μg/kgbw/d, respectively) than in the 54 non-stunted children (48.8 and 23.7 μg/kgbw/d, respectively). However, mean FUFE was similar in all groups. There were no statistically significant differences in fluoride concentration of either fingernails or toenails among the different categories of wasting, while mean fingernail fluoride concentration was statistically significantly higher in stunted (5.4 μg/g) than in non-stunted children (3.5 μg/g). ConclusionOur study found no significant effect of nutritional status on the proportion of ingested fluoride excreted in urine (and consequently the proportion retained in the body). These findings suggest that nutritional status may be less likely to be a main risk factor for the development of dental fluorosis than children's dietary habits or total fluoride intake.

Biomarkers for the Assessment of Exposure to Fluoride in Adults

To monitor deficient or excessive intakes of biologically available fluoride (F), various biological samples have been tested for use as biomarkers of human exposure to F. Most such studies have concerned children and often have only involved measurement of F in 1 or 2 types of sample. The present study investigated the relationships of F concentrations in biomarkers of F exposure; including plasma, saliva, hair, finger- and toenails, and daily urinary F excretion (UFE) with the total daily F intake (TDFI) of adults. TDFI was assessed in 60 healthy adults, aged ≥20 years; 31 lived in a low-F water area (LFA, 0.04 mg F/L) and 29 in a high-F water area (HFA, 3.05 mg F/L) of Nigeria. All volunteers provided at least 1 biomarker sample from the above list and completed a questionnaire to evaluate F intake from the diet and toothpaste ingestion. TDFI, UFE and F concentrations of biomarkers were statistically significantly higher in the HFA than in the LFA. There were strong statistically significant positive correlations between TDFI and UFE (ρ = 0.730, p < 0.001); plasma F (ρ = 0.729, p < 0.001); fasting whole saliva F (ρ = 0.653, p < 0.001) and hair F (ρ = 0.603, p < 0.001). The statistically significant positive correlations between TDFI and fingernail F (ρ = 0.502, p < 0.001) and between TDFI and toenail F (ρ = 0.556, p < 0.001) were moderate. In conclusion, this study has indicated the usefulness of 24-h UFE as well as F concentration in plasma, fasting whole saliva and hair as biomarkers of contemporary or sub-chronic F exposure in groups of adults. However, they do not appear to have the necessary sensitivity to predict F exposure in individuals.

Dietary Fluoride Intake by Children: When to Use a Fluoride Toothpaste?

Fluoride is recommended for its cariostatic effect, but excessive fluoride intake may have health risks. Increased prevalence of dental fluorosis in areas with low fluoride content in drinking water has been attributed to the inappropriate excessive intake of fluoride supplements (tablets and drops) and toothpaste ingestion. The aim of the present study was to estimate the fluoride intake and the risk of fluorosis in children (6 months–6 years) in the Castelli Romani area (province of Rome, Italy), which is volcanic, therefore with a higher concentration of fluorine. Measurements of the fluoride content in drinking water, mineral waters, vegetables and commercial toothpaste for children were performed. The fluoride concentrations of all samples were determined using a Fluoride Ion Selective Electrode (GLP 22, Crison, Esp). Data were analyzed by descriptive statistics. Differences between samples were determined by Student’s t-test. The fluoride content in tap water samples collected from public sources averaged from 0.35 to 1.11 ppm. The Pavona area showed the highest content of fluoride with respect to the others (p ≤ 0.05). The fluoride content in mineral water samples averaged from 0.07 to 1.50 ppm. The fluoride content of some vegetables showed increased mean values when compared to control vegetables (p ≤ 0.05). Within the limitations of the present study, considerations should be made when prescribing fluoride toothpaste for infants (6 months–4 years) in the areas with high fluoride content, because involuntary ingestion is consistent.

MEASUREMENT OF THE ACTIVITY CONCENTRATIONS OF GAMMA EMITTING RADIONUCLIDES IN TOOTHPASTE SAMPLES AND ASSESSMENT OF THE CORRESPONDING ANNUAL EFFECTIVE DOSES.

It is inevitable that we are exposed to radiation daily from various sources and products that we consume on daily basis. The use of toothpaste for oral hygiene is one of the most common daily practices by humans and yet very little data are available regarding its radiation content. In this work, we investigated the concentrations of gamma emitting radionuclides in toothpaste samples consumed in Jordan. 40K and 226Ra were detected in almost one-third of the samples, whereas 228Ra was detected in nearly half of them. The corresponding activity concentrations in the detected samples were in the ranges of 68.7-154.2, 4.6-14.1 and 1.3-10.0Bq/kg, respectively. Dose assessment of accidental ingestion of toothpaste for children and adults was made, and its contribution to the annual effective dose was found to be very minimal with maximum doses of ~2.9 and 1.3μSv for children and adults, respectively.

In vitro determination of potentially bioavailable fluoride in diet and toothpaste after ingestion

Aim: To propose a new method to determine in vitro potentially bioavailable fluoride (F) in diet and toothpaste after ingestion. Methods: Diet samples (D) were obtained from 15 portions of a meal served to children in a day care centre. To simulate the ingestion of toothpaste during brushing after meals, a specific amount of toothpaste was added to the diet samples (D + T). F was determined in D and D + T after incubation in a solution that simulated “gastric juice” (0.01 M hydrochloric acid) at 37oC for 30, 60 and 120 min. Microdiffusion facilitated by HMDS was used to determine the total F concentrations in samples D and D + T. The analyses were performed using an ion specific electrode. Results: For D samples, incubation in “gastric juice” for 30, 60 and 120 min resulted in F concentrations (μg F/mL) of 0.75 ± 0.06c, 0.77 ± 0.07c and 0.91 ± 0.09b, corresponding to 75.3, 77.3 and 90.7% of the total F (1.02 ± 0.12a), respectively (p = 0.0001; ANOVA + Tukey). For D + T samples, these values of F concentrations (μg F/mL) were 2.55 ± 0.46b, 2.83 ± 0.44ab and 3.15 ± 0.37a, corresponding to 86.9, 94.8 and 106.7% of the total F (2.99 ± 0.34a), respectively (p = 0.0023; ANOVA + Tukey). Conclusion: Then, it can be concluded that the proposed method of “gastric juice” is a promising protocol for determining potentially bioavailable fluoride in the diet and toothpaste after ingestion. However, additional studies are desirable.

Impact of Reducing Water Fluoride on Dental Caries and Fluorosis

Guidance intended to reduce fluoride toothpaste ingestion in early childhood was introduced in Ireland in 2002. In 2007, water fluoride concentration was adjusted from 0.8–1.0 to 0.6–0.8 ppm. The objective of this study was to determine the difference in caries and fluorosis levels following introduction of these 2 policy measures. A before-and-after study compared caries and fluorosis in random samples of 8-y-olds in Dublin (n = 707) and Cork-Kerry (n = 1148) in 2017 with 8-y-olds in Dublin (n = 679) and Cork-Kerry (n = 565) in 2002. Dentinal caries experience (primary teeth, d3vcmft(cde)) and fluorosis (permanent teeth, Dean’s index of very mild or higher) were clinically measured. Lifetime exposure to community water fluoridation (CWF) was classified as “full CWF”/“no CWF.” Effect of examination year on caries prevalence and severity and fluorosis prevalence was assessed using multivariate regression adjusting for other explanatory variables. There was little change in commencement of fluoride toothpaste use at ≤24 mo following introduction of toothbrushing guidance. Among children with full CWF, there was no statistically significant difference in caries prevalence or severity between 2017 and 2002. In 2017, caries prevalence was 55% in Dublin (full CWF) and 56% in Cork-Kerry (full CWF), and mean d3vcmft(cde) among children with caries was 3.4 and 3.7, respectively. Caries severity was less in 2017 (mean 4.2) than 2002 (mean 4.9) among children with no CWF (P = 0.039). The difference in caries severity between children with full CWF and no CWF was less in 2017 than in 2002 (interaction P = 0.013), suggesting a reduced benefit for CWF in 2017. In 2017, fluorosis prevalence was 18% in Dublin (full CWF) and 12% in Cork-Kerry (full CWF). Fluorosis was predominantly “very mild” with no statistically significant difference between 2017 and 2002. CWF at 0.6 to 0.8 ppm is an effective caries-preventive measure. Results suggested low uptake of toothbrushing guidance, a reduced caries-preventive effect for CWF in primary teeth, and no reduction in fluorosis following introduction of the policy measures.

A case of hemorrhagic gastritis caused by accidental ingestion of fluoride-containing toothpaste

A case of hemorrhagic gastritis caused by accidental ingestion of fluoride-containing toothpaste

Biomarkers for the Assessment of Fluoride Exposure in Children

Due to practical difficulties in quantifying fluoride exposure, the ability of various biomarkers to predict exposure has been investigated previously. However, the results are inadequate for validation of their application and usefulness. This study aimed to investigate the association between contemporary/recent biomarkers of fluoride exposure and total daily fluoride intake (TDFI) of children with large differences in fluoride exposure through drinking water. TDFI was assessed in 61 healthy 4- to 5-year-old children who provided at least 1 biomarker sample; 32 lived in a low-fluoride area (0.04 mg F/L) and 29 lived in a high-fluoride area (3.05 mg F/L). Validated questionnaires were administered to evaluate fluoride intake from diets (including water) and toothpaste ingestion. Daily urinary fluoride excretion (UFE) and fluoride concentrations in plasma, fasting whole saliva, hair, and nails (toenails/fingernails) were evaluated and related to total fluoride exposure. TDFI, UFE, and fluoride concentrations of biomarkers were statistically significantly higher in the high-fluoride area than in the low-fluoride area. There was a strong statistically significant positive correlation between TDFI and UFE (ρ = 0.756, p < 0.001); plasma fluoride concentration (ρ = 0.770, p < 0.001); and toenail fluoride concentration (ρ = 0.604, p < 0.001). The statistically significant positive correlation between TDFI and fingernail fluoride concentration (ρ = 470, p < 0.001) as well as between TDFI and fasting whole saliva fluoride concentration (ρ = 0.453, p = 0.001) was moderate, whereas it was weak between TDFI and hair fluoride concentration (ρ = 0.306, p = 0.027). In conclusion, the current study confirmed the suitability of 24-h urine samples for estimating fluoride exposure in children. The strong correlations between TDFI and fluoride in plasma and toenails also suggest these biomarkers may be considered for health risk assessments of fluoride in children who are susceptible to development of dental fluorosis.

Estimating human exposure to titanium dioxide from personal care products through a social survey approach.

Titanium dioxide (TiO2 ) has been widely applied in personal care products (PCPs), with up to 36% of TiO2 in PCPs is present at the nanoscale. Due to the large quantity produced and the wide application of TiO2 , there is a great potential for human exposure through various routes and therefore a great potential to elicit adverse impacts. This work utilizes a social survey to generate information and estimate TiO2 (bulk and nanoparticle [NP]) exposure to individuals through the daily use of PCPs. Households in the Madison, Wisconsin, USA metropolitan area were surveyed about their PCP usage. Survey results were then combined with usage patterns and TiO2 content in each PCP category to estimate human exposures. Results indicate sunscreen and toothpaste are major contributors to TiO2 dermal exposure. The estimated daily dermal route of exposure ranges from 2.8 to 21.4 mg TiO2 per person per day. Toothpaste has the potential to be ingested though the oral route; 0.15 to 3.9 mg TiO2 per day were estimated to be ingested when 10% toothpaste ingestion was assumed. The results generated in the present case study are generalizable in predicting individual TiO2 exposure from PCPs when the usage pattern is available. In addition, this study can be further used for risk assessment and to refine the use of TiO2 in PCPs. Integr Environ Assess Manag 2019;00:1-7. © 2019 SETAC.

Fluoride Revolution and Dental Caries: Evolution of Policies for Global Use

Epidemiological studies over 70 y ago provided the basis for the use of fluoride in caries prevention. They revealed the clear relation between water fluoride concentration, and therefore fluoride exposure, and prevalence and severity of dental fluorosis and dental caries. After successful trials, programs for water fluoridation were introduced, and industry developed effective fluoride-containing toothpastes and other fluoride vehicles. Reductions in caries experience were recorded in many countries, attributable to the widespread use of fluoride. This is a considerable success story; oral health for many was radically improved. While previously, water had been the only significant source of fluoride, now there are many, and this led to an increase in the occurrence of dental fluorosis. Risks identified for dental fluorosis were ingestion of fluoride-containing toothpaste, water fluoridation, fluoride tablets (which were sometimes ingested in areas with water fluoridation), and infant formula feeds. Policies were introduced to reduce excessive fluoride exposure during the period of tooth development, and these were successful in reducing dental fluorosis without compromising caries prevention. There is now a much better understanding of the public perception of dental fluorosis, with mild fluorosis being of no aesthetic concern. The advantages of water fluoridation are that it provides substantial lifelong caries prevention, is economic, and reduces health inequalities: it reaches a substantial number of people worldwide. Fluoride-containing toothpastes are by far the most important way of delivering the beneficial effect of fluoride worldwide. The preventive effects of conjoint exposure (e.g., use of fluoride toothpaste in a fluoridated area) are additive. The World Health Organization has informed member states of the benefits of the appropriate use of fluoride. Many countries have policies to maximize the benefits of fluoride, but many have yet to do so.

Factors associated with dental fluorosis in three zones of Ecuador.

BackgroundTo determine the prevalence of dental fluorosis in 10-12 year-old school children, in three provinces of the inter-andean Region of Ecuador: Imbabura, Pichincha and Chimborazo, as well as the relationship between certain factors, considering that the latest studies go back to the year 2009.Material and MethodsA cross-sectional and observational study was proposed. A sample of 599 was calculated at 95% of confidence considering population projections for children between 10 and 12 old of three zones of Ecuador. However, 608 school children, who had the acceptance and informed consent of their parents to participate, completed a survey about factors associated with dental fluorosis. Once the survey was completed, the vestibular surfaces of the upper and lower anterior teeth of the infant were photographed, following standardized distance and light procedures. Three evaluators, trained in the detection of fluorosis using the Thylstrup and Fejerskov index, analyzed the photographs. The Stata 13.0 software was used for the statistical analysis, with a level of significance of 5% and with a confidence interval of 95%. To relate the risk factor of fluorosis, a multinomial logistic model was used.ResultsThe prevalence of dental fluorosis was of 89.96%, with a greater presence of grade 2 TF. A positive statistical relationship and statistical significance was detected between dental fluorosis and consumption of bottled beverages. Also the amount of toothpaste used and its ingestion during brushing (p = 0.000) were analyzed.ConclusionsThe populations evaluated, that are related to the consumption of bottled beverages and involuntary toothpaste ingestion, and have a high prevalence of a mild level of fluorosis. Key words:Fluorosis, dental, risk factors, epidemiology.

Fluoride retention in infants living in fluoridated and non-fluoridated areas: effects of weaning.

Limited knowledge is available on total fluoride exposure, excretion and retention in infants, despite the first year of human life being the critical period for dental development and risk of dental fluorosis. This study investigated total daily fluoride intake (TDFI), excretion (TDFE) and retention (TDFR) in infants living in fluoridated and non-fluoridated water areas at pre- and post-weaning stages of development. Healthy infants, aged 0-12 months, were recruited and their TDFI (mg/kg body weight (BW) per d), from diet and toothpaste ingestion, was assessed over a 3-d period using a dietary diary and tooth-brushing questionnaire. TDFE (mg/kg BW per d) was estimated by collecting 48-h urine and faeces. TDFR (mg/kg BW per d) was estimated by subtracting TDFE from TDFI. A total of forty-seven infants completed the study: sixteen at pre-weaning and thirty-one at post-weaning stages, with a mean age of 3·4 and 10·0 months, respectively. TDFI was lower in the non-fluoridated area (P&lt;0·001) and at the pre-weaning stage (P=0·002) but higher in formula-fed infants (P&lt;0·001). TDFE was mainly affected by type of feeding, with higher excretion in formula-fed infants (P&lt;0·001). TDFR was lower in the non-fluoridated area (P&lt;0·001) and at the pre-weaning stage (P&lt;0·001) but higher in formula-fed infants (P=0·001). In conclusion, a relatively large proportion of fluoride intake is retained in the body in weaned infants. This is an important consideration in fluoride-based prevention programmes, with goals to maximise caries prevention while minimising the risk of dental fluorosis.

Fluoride intake and urinary fluoride excretion in 4‐ and 8‐year‐old children living in urban and rural areas of Southwest Nigeria

To estimate and compare total daily fluoride intake (TDFI), daily urinary fluoride excretion (DUFE), daily fluoride retention (DFR), fractional urinary fluoride excretion (FUFE) and fractional fluoride retention (FFR) in 4- and 8 year-old Nigerians and explore associations between these outcomes to improve understanding of fluoride metabolism. Using a cross-sectional observational study, 72 four-year-olds and 72 eight-year-olds were recruited from nursery and primary schools (respectively) in lower and higher water F areas of urban and rural localities in Oyo State, southwest Nigeria. TDFI from diet and toothpaste ingestion was assessed using a validated Food Frequency Questionnaire and visual scale of toothpaste used during toothbrushing. DUFE was measured by collecting a 24-hour urine sample, FUFE estimated as the ratio between DUFE and TDFI, DFR estimated as TDFI-TDFE (where TDFE = DUFE + estimated faecal F excretion (ie TDFI × 10%), and FFR was estimated as [(TDFI-DFR)/TDFI] × 100. Data were analysed using ANOVA with post hoc tests and Student's t tests and strengths of associations between key variables measured. Mean (SD) TDFI, DUFE, DFR, FUFE and FFR were 0.137 (0.169) mg/kg bw/d, 0.032 (0.027) mg/kg bw/d, 0.091 (0.147) mg/kg bw/d, 44% (44%) and 46% (44%), respectively, for 4-year-olds. Corresponding values for 8-year-olds (n = 63) were 0.106 (0.130) mg/kg bw/d, 0.022 (0.017) mg/kg bw/d, 0.073 (0.107) mg/kg bw/d, 36% (30%) and 54% (30%), respectively. Dietary contribution to TDFI was 79% and 75% (respectively), for 4- and 8-year-olds. Mean (SD) TDFI from toothpaste ingestion was 0.021 (0.013) mg/kg bw/d in 4-year-olds, 0.014 (0.010) mg/kg bw/d in 8-year-olds (P = .002) but with no differences between areas. Differences in dietary F intake determined the main differences in F exposure between areas. The positive correlation between TDFI and DUFE was weak for 4-year-olds (r = +.29) and strong for 8-year-olds (r = +.64). A strong positive correlation was observed between TDFI and DFR for both age groups: (r) = +.98 for 4-year-olds and (r) = +.99 for 8-year-olds. Fluoride intake in these 4- and 8-year-old Nigerians was much higher than the "optimal range" of 0.05-0.07 mg/kg bw/d in rural, higher F water areas, with diet as the main contributor. F retention was similar in both age groups, with almost half of TDFI retained in the body. In terms of risk vs benefit for fluorosis and dental caries, this finding should be considered when mitigating against excessive fluoride exposure and planning F-based prevention.

Total daily fluoride intake and fractional urinary fluoride excretion in 4- to 6-year-old children living in a fluoridated area: weekly variation?

Risk of development of dental fluorosis may increase with even a short-term increase in fluoride (F) intake during tooth formation. Considering the wide variations in F concentrations of different food and drinks, it is important to assess short-term differences in F intake and consequently fractional urinary F excretion (FUFE) in children, which provide an indication of F body burden. Therefore, the aim of this study was to investigate weekly variation in total daily F intake (TDFI) and its sources and fractional urinary F excretion (FUFE) in 4- to 6-year-olds living in a fluoridated area in the UK. Sixty-one children were surveyed twice with a 1-week gap between surveys. Dietary F intake was assessed by 'food-diary' and 'duplicate-plate collection'. Toothbrushing expectorate (saliva/toothpaste) was collected to estimate F intake from toothpaste ingestion. TDFI was calculated from dietary F intake and toothpaste ingestion. Daily urinary F excretion (DUFE) was estimated by collecting 24-h urine samples and FUFE was calculated from DUFE and TDFI [FUFE = (DUFE/TDFI) × 100]. The overall mean TDFI, DUFE and FUFE for all children were 0.056 (SD 0.036) mg/kgbw/day, 0.018 (SD 0.007) mg/kgbw/day and 39 (SD 20)%, respectively. The mean (95% CI) difference between the 2 weeks studied was 0.004 (-0.004, 0.011) mg/kgbw/day for TDFI, 0.002 (-0.001, 0.004) mg/kgbw/day for DUFE and 1 (-6, 8)% for FUFE. Mean TDFI and FUFE did not vary statistically significantly with week and therefore one set of data collection from a group of children living in a temperate climate could be sufficient to monitor F exposure and F body burden in community prevention programmes for oral health.

Oral intake of added titanium dioxide and its nanofraction from food products, food supplements and toothpaste by the Dutch population

Titanium dioxide (TiO2) is commonly applied to enhance the white colour and brightness of food products. TiO2 is also used as white pigment in other products such as toothpaste. A small fraction of the pigment is known to be present as nanoparticles (NPs). Recent studies with TiO2 NPs indicate that these particles can have toxic effects. In this paper, we aimed to estimate the oral intake of TiO2 and its NPs from food, food supplements and toothpaste in the Dutch population aged 2 to over 70 years by combining data on food consumption and supplement intake with concentrations of Ti and TiO2 NPs in food products and supplements. For children aged 2–6 years, additional intake via ingestion of toothpaste was estimated. The mean long-term intake to TiO2 ranges from 0.06 mg/kg bw/day in elderly (70+), 0.17 mg/kg bw/day for 7–69-year-old people, to 0.67 mg/kg bw/day in children (2–6 year old). The estimated mean intake of TiO2 NPs ranges from 0.19 μg/kg bw/day in elderly, 0.55 μg/kg bw/day for 7–69-year-old people, to 2.16 μg/kg bw/day in young children. Ninety-fifth percentile (P95) values are 0.74, 1.61 and 4.16 μg/kg bw/day, respectively. The products contributing most to the TiO2 intake are toothpaste (in young children only), candy, coffee creamer, fine bakery wares and sauces. In a separate publication, the results are used to evaluate whether the presence of TiO2 NPs in these products can pose a human health risk.