Fluoride concentrations in drinking water and health risk assessment in the south of Algeria.

Drinking water is the primary source of fluoride intake by humans worldwide. Algeria, Africa's largest country, has been reported to have moderate to high fluoride levels in the water, particularly in the Southern and Saharan regions. In the south of Algeria, dental fluorosis is considered an epidemic that is spreading within the population by health professionals. This study aimed to determine fluoride concentrations in drinking water consumed by Ouargla population (south-east of Algeria) in 2021, assess non-carcinogenic health risk via daily human intake, and calculate the upper acceptable fluoride concentration in drinking water by Galgan and Vermillion formula. Forty-two water samples were collected during the spring season. The fluoride was measured using a validated spectrophotometric method. Hazard quotient of fluoride (HQ) and estimated daily intake (EDI) were calculated. The results reveal a mean fluoride level of 1.07 ± 0.38 mg/L, below WHO recommendation. Fluoride concentrations in water were higher in rural areas than in the central city (p = 0.05). HQ values were less than one for adults but greater than 1 for infants and children, suggesting health risks associated with water consumption for these vulnerable groups (p = 0.007). The main contribution of this study is the establishment of a database concerning fluoride levels and hazard quotient in the south of Algeria. Monitoring drinking water and control fluorosis is essential to avoid potential health risks.

Assessment of the preventive effects of Nd:YAG laser associated with fluoride on enamel caries using optical coherence tomography and FTIR spectroscopy.

OBJECTIVE: This in vitro study characterized and monitored, by Optical Coherence Tomography (OCT) and Fourier Transformed Infrared Spectroscopy (FTIR), the effects of the association of acidulated phosphate fluoride gel (APF-gel) and Nd:YAG (neodymiun:yttrium-aluminum-garnet) laser, as sequencial treatments, in the prevention of incipient enamel caries lesions. METHODS: 120 human enamel samples were randomized into 3 groups (n = 40): APF-gel (1.23% F-, 4 min.); Laser+APF (Nd:YAG laser irradiation-0.6W, 84.9J/cm2, 10Hz, followed by APF-gel); and APF+Laser (APF-gel followed by laser irradiation). The samples were subjected to a 15-day pH-cycling, evaluated by OCT (quantification of optical attenuation coefficient-OAC) and FTIR (analysis of carbonate and phosphate content) before treatments, after treatments, and on the 5th, 10th and 15th days of pH-cycling. The statistical analysis was performed (α = 5%). RESULTS: The Optical Attenuation Coefficient (OAC) assessed by OCT increases with the progression of demineralization, and the Laser+APF presented the highest values of OAC in 10th and 15th days of pH-cycling. Nd:YAG decreased the carbonate content after treatment regardless of the application order of the APF-gel, while APF-gel did not interfere in the composition of enamel. The carbonate content was also changed in the first 5 days of the pH-cycling in all groups. CONCLUSION: Nd:YAG laser irradiation before or after the application of APF-gel did not influence the appearance of incipient caries lesions, showing no synergistic effect. Regardless of the application order of the APF-gel, laser irradiation reduces the carbonate content of the enamel, which also changes during the demineralization process. However, irradiation before the application of APF-gel increased the speed of progression of the lesions, which positively impacts public health as it can prevent caries disease, even in high risk individuals. OCT and FTIR are suitable for assessing this effect.

Laser-induced breakdown spectroscopy as a straightforward bioimaging tool for plant biologists; the case study for assessment of photon-upconversion nanoparticles in Brassica oleracea L. plant.

The main purpose of this work is to thoroughly describe the implementation protocol of laser-induced breakdown spectroscopy (LIBS) method in the plant analysis. Numerous feasibility studies and recent progress in instrumentation and trends in chemical analysis make LIBS an established method in plant bioimaging. In this work, we present an easy and straightforward phytotoxicity case study with a focus on LIBS method. We intend to demonstrate in detail how to manipulate with plants after exposures and how to prepare them for analyses. Moreover, we aim to achieve 2D maps of spatial element distribution with a good resolution without any loss of sensitivity. The benefits of rapid, low-cost bioimaging are highlighted. In this study, cabbage (Brassica oleracea L.) was treated with an aqueous dispersion of photon-upconversion nanoparticles (NaYF4 doped with Yb3+ and Tm3+ coated with carboxylated silica shell) in a hydroponic short-term toxicity test. After a 72-hour plant exposure, several macroscopic toxicity end-points were monitored. The translocation of Y, Yb, and Tm across the whole plant was set by employing LIBS with a lateral resolution 100 µm. The LIBS maps of rare-earth elements in B.oleracea plant grown with 50 µg/mL nanoparticle-treated and ion-treated exposures showed the root as the main storage, while the transfer via stem into leaves was minimal. On the contrary, the LIBS maps of plants exposed to the 500 µg/mL nanoparticle-treated and ion-treated uncover slightly different trends, nanoparticles as well as ions were transferred through the stem into leaves. However, the main storage organ was a root as well.

Influence of Hydroxyapatite Coating for the Prevention of Bone Mineral Density Loss and Bone Metabolism after Total Hip Arthroplasty: Assessment Using 18F-Fluoride Positron Emission Tomography and Dual-Energy X-Ray Absorptiometry by Randomized Controlled Trial.

BACKGROUND: Hydroxyapatite- (HA-) coated implants tend to achieve good osteoinductivity and stable clinical results; however, the influence of the coating on the prevention of bone mineral density (BMD) loss around the implant is unclear. The purpose of this randomized controlled trial was to evaluate the effectiveness of HA-coated implants for preventing BMD loss and to determine the status of bone remodeling after total hip arthroplasty (THA), making comparisons with non-HA-coated implants. METHODS: A total of 52 patients who underwent primary THA were randomly allocated to HA and non-HA groups. BMD was measured by dual-energy X-ray absorptiometry (DEXA) at 1 week postoperation to form a baseline measurement, and then 24 weeks and 48 weeks after surgery. The relative change in BMD was evaluated for regions of interest (ROIs) based on the Gruen zone classifications. 18F-fluoride positron emission tomography (PET) was performed at 24 weeks postsurgery, and the maximum standardized uptake values (SUVmax) were evaluated in the proximal (HA-coated) and distal (non-HA-coated) areas in both groups. RESULTS: There were significant differences in BMD loss in ROIs 3 and 6 (p = 0.03), while no significant difference was observed in ROI 7 at either 24 or 48 weeks postsurgery. There was no significant correlation between PET uptake and BMD (24 or 48 weeks) in either group. CONCLUSION: The influence of a HA coating in terms of BMD preservation is limited. No significant correlation was found between BMD and SUVmax measured by PET, either with or without the use of a HA coating.

Spatial variation and health risk assessment of fluoride in drinking water in the Chongqing urban areas, China.

Fluoride is an essential trace element for humans, and its deficiency or excess in the environment could lead to disease. To investigate the spatial distribution and health risk assessment of fluoride (F-) in drinking water, 302 tap water samples from Chongqing urban areas, China, were collected to analyze F- using an ion chromatograph. The results showed that (1) F- concentration in drinking water ranged from 0.100 to 0.503 mg/L, with an average of 0.238 ± 0.045 mg/L. (2) The spatial autocorrelation analysis showed that high-low clusters were mostly located in Dadukou District and Beibei District, while low-low clusters were mainly in southern Banan District. (3) The fluoride average daily doses of children, teens and adults were 0.030, 0.029 and 0.031 mg/(kg day). (4) Hazard quotients of excessive fluoride (HQe) of children, teens and adults were 0.51 ± 09, 0.49 ± 0.09 and 0.52 ± 0.10, respectively (inferior to 1.00), whereas hazard quotients of inadequate fluoride (HQi) of those groups were 1.21 ± 0.26, 1.23 ± 0.26 and 1.15 ± 0.25, respectively (superior to 1.00). Therefore, average daily fluoride intake of residents with drinking water was inadequate. This could pose dental caries and osteoporosis threats for residents from Chongqing urban areas.

Human health risk assessment: Study of a population exposed to fluoride through groundwater of Agra city, India.

Fluoride (F-), a harmful compound if present in high concentration, is typically found in groundwater. It is important to investigate the F- concentrations in groundwaters of areas where individuals use groundwater for drinking purposes. The objectives of this study were: (a) to estimate the F- exposure, and (b) to assess the non-carcinogenic risk through consumption of groundwater among urban population (different age groups) of Agra city. A total of 28 groundwater samples were collected from Agra city in May 2016, which comprised 22 samples from hand pump and 6 samples from tube wells from shallow aquifers at different sites. The F- concentrations varied from 0.90 to 4.12 mg/L with an average value of 1.88 mg/L. The results obtained reveal that about 64% of the samples exceeded the F- permissible limit of 1.5 mg/L. Nevertheless, 32% of the samples were well within the WHO drinking water guidelines and 3.5% of the samples from the groundwater were below the 1.0 mg/L threshold. The maximum estimated exposure doses were 0.69, 0.31 and 0.12 mg/kg/day for infants, children and adults, respectively. A dental fluorosis becomes evident when the results obtained are compared with an oral reference dose of 0.06 mg/kg/day. The hazard quotient (HQ) was found to be more than 1 for infants and children in all the studied areas which indicates that young consumers are more vulnerable to non-carcinogenic risk due to exposure of F-. On the other hand, the adults at about 71% of the sampled sites may be victims of non-carcinogenic risk. From the results obtained in this study, it is recommended that there be implementation of the appropriate remediation for defluoridation of water to circumvent the population from the probable health risks of F-.

Assessment of oral health-related quality of life as a function of non-invasive treatment with high-fluoride toothpastes for root caries lesions in community-dwelling elderly.

PURPOSE: Non-invasive treatment of root caries lesions (RCLs) may impact oral health-related quality of life (OHRQoL), but no evidence is available. The purpose of the study was to assess changes in OHRQoL among patients exposed to non-invasive treatment of RCLs with conventional or high-fluoride dentifrices. METHODS: To be eligible, subjects had to be ≥60 years of age, independently living, with at least five teeth and one RCL. The 14-item Oral Health Impact Profile for adults in Spanish (OHIP-14Sp), oral examination and sociodemographic data were documented at the beginning of the study (T0). The presence and activity of RCLs were detected and diagnosed. Subjects were randomly assigned to either the control (1,450 ppm fluoride) or the experimental (5,000 ppm fluoride) treatment group. A new set of measurements was obtained at 12 months (T1). Mean comparisons were carried out using the Student's t-test for total OHIP-14Sp scores. To determine whether T1 OHRQoL scores were different regarding sex, age, educational level and socio-economic status, mean OHIP-14Sp scores were obtained and compared with those variables at 12 months. RESULTS: An overall improvement in OHRQoL after the non-invasive treatment of RCLs was verified when T1 was compared with T0 (P < 0.0001). Regarding treatment type, no significant differences were detected between groups (P = 0.114). Subjects with higher income and more years of formal education had better OHRQoL than those with a lower salary (P < 0.0001) and with fewer years of education (P = 0.0006). CONCLUSIONS: Non-invasive treatment for RCLs in community-dwelling elders appears to cause a positive impact on OHRQoL. Better OHRQoL was associated with higher socio-economic status and educational level. No significant differences were detected regarding the fluoride concentration in the dentifrices.

Probabilistic risk assessment of exposure to fluoride in most consumed brands of tea in the Middle East.

The aim of this study was to evaluate the fluoride concentration in seven most consumed brands of tea in the Middle East which was imported to Iran through Zabol County. In the present study, the health risk of exposure to fluoride was estimated using a probabilistic approach. Monte Carlo simulation and sensitivity analysis were applied to quantify uncertainties in risk estimation. The highest mean and 95th percentile of chronic daily intake (CDI) was observed for children group. Iranian tea and Kenya tea had maximum CDI and target hazard quotient (THQ) values among studied brands of tea which followed by Green tea, Taksetare tea, Ceylan tea, Red tea, and White tea. These result indicated that there were significant risks of exposure to fluoride in most of studied brands of tea for children (THQ>1). Sensitivity analysis showed that fluoride concentration and daily intake were the most influential variables in three exposed populations. In conclusion, the fluoride concentration in some studied brands of tea is high and it put children at risk risks of exposure to fluoride.

Attitudes and behavioural factors relating to toothbrushing and the use of fluoride toothpaste among caries-active Swedish adolescents - a questionnaire study.

OBJECTIVE: The aim of this study was to identify attitudes and behaviour relating to fluoride toothpaste and toothbrushing habits among caries-active Swedish adolescents. MATERIALS AND METHODS: This cross-sectional study is based on an earlier clinical, two-year toothpaste intervention study. At the last appointment, 206 adolescents (of 211) answered a questionnaire comprising nine semi-closed questions. RESULTS: The majority (93%) brushed their teeth every day, while 7% did so only occasionally. Most participants (77%) brushed twice a day, while 12% brushed just once a day. About half of those brushing just once a day forgot to brush in the evening. Similarly, more than half of the adolescents (53%) used 1 cm of toothpaste or less on their toothbrush. Moreover, 49% brushed for less than 2 min, 41% brushed for 2 min and 10% for more than 2 min. The majority (73%) rinsed with water after toothbrushing. A difference between boys and girls was also observed; 87% of the girls brushed twice a day, whereas only 67% of the boys did so and boys more frequently forgot in the evening. CONCLUSIONS: Attitudes and behaviour relating to fluoride toothpaste and toothbrushing habits among caries-active Swedish adolescents are still inadequate after two years of toothpaste intervention. There are several areas where improvements can be made, such as frequency of brushing, brushing time, amount of toothpaste and post-brushing procedures. The majority (81%) included 'fresh breath' as a reason for performing oral hygiene and this aspect can be used by dental staff in health promotion.

Probabilistic risk assessment of Chinese residents' exposure to fluoride in improved drinking water in endemic fluorosis areas.

Studies have yet to evaluate the effects of water improvement on fluoride concentrations in drinking water and the corresponding health risks to Chinese residents in endemic fluorosis areas (EFAs) at a national level. This paper summarized available data in the published literature (2008-2016) on water fluoride from the EFAs in China before and after water quality was improved. Based on these obtained data, health risk assessment of Chinese residents' exposure to fluoride in improved drinking water was performed by means of a probabilistic approach. The uncertainties in the risk estimates were quantified using Monte Carlo simulation and sensitivity analysis. Our results showed that in general, the average fluoride levels (0.10-2.24 mg/L) in the improved drinking water in the EFAs of China were lower than the pre-intervention levels (0.30-15.24 mg/L). The highest fluoride levels were detected in North and Southwest China. The mean non-carcinogenic risks associated with consumption of the improved drinking water for Chinese residents were mostly accepted (hazard quotient < 1), but the non-carcinogenic risk of children in most of the EFAs at the 95th percentile exceeded the safe level of 1, indicating the potential non-cancer-causing health effects on this fluoride-exposed population. Sensitivity analyses indicated that fluoride concentration in drinking water, ingestion rate of water, and the exposure time in the shower were the most relevant variables in the model, therefore, efforts should focus mainly on the definition of their probability distributions for a more accurate risk assessment.

School-Based Fluoride Mouth-Rinse Program Dissemination Associated With Decreasing Dental Caries Inequalities Between Japanese Prefectures: An Ecological Study.

BACKGROUND: Dental caries inequalities still severely burden individuals' and society's health, even in countries where fluoride toothpastes are widely used and the incidence of dental caries has been decreasing. School-based fluoride mouth-rinse (S-FMR) programs, a population strategy for dental caries prevention, might decrease dental caries inequalities. This study investigated the association between S-FMR and decreasing dental caries prevalence and caries-related inequalities in 12-year-olds by Japanese prefecture. METHODS: We conducted an ecological study using multi-year prefecture-level aggregated data of children born between 1994 and 2000 in all 47 Japanese prefectures. Using two-level linear regression analyses (birth year nested within prefecture), the association between S-FMR utilization in each prefecture and 12-year-olds' decayed, missing, or filled permanent teeth (DMFT), which indicates dental caries experience in their permanent teeth, were examined. Variables that could explain DMFT inequalities between prefectures, such as dental caries experience at age 3 years, dentist density, and prefectural socioeconomic circumstances, were also considered. RESULTS: High S-FMR utilization was significantly associated with low DMFT at age 12 (coefficient -0.011; 95% confidence interval, -0.018 to -0.005). S-FMR utilization explained 25.2% of the DMFT variance between prefectures after considering other variables. Interaction between S-FMR and dental caries experience at age 3 years showed that S-FMR was significantly more effective in prefectures where the 3-year-olds had high levels of dental caries experience. CONCLUSIONS: S-FMR, administered to children of all socioeconomic statuses, was associated with lower DMFT. Utilization of S-FMR reduced dental caries inequalities via proportionate universalism.

Cost-effectiveness of preventing dental caries and full mouth dental reconstructions among Alaska Native children in the Yukon-Kuskokwim delta region of Alaska.

OBJECTIVE: We conducted a cost-effectiveness analysis of five specific dental interventions to help guide resource allocation. METHODS: We developed a spreadsheet-based tool, from the healthcare payer perspective, to evaluate the cost effectiveness of specific dental interventions that are currently used among Alaska Native children (6-60 months). Interventions included: water fluoridation, dental sealants, fluoride varnish, tooth brushing with fluoride toothpaste, and conducting initial dental exams on children <18 months of age. We calculated the cost-effectiveness ratio of implementing the proposed interventions to reduce the number of carious teeth and full mouth dental reconstructions (FMDRs) over 10 years. RESULTS: A total of 322 children received caries treatments completed by a dental provider in the dental chair, while 161 children received FMDRs completed by a dental surgeon in an operating room. The average cost of treating dental caries in the dental chair was $1,467 (∼258,000 per year); while the cost of treating FMDRs was $9,349 (∼1.5 million per year). All interventions were shown to prevent caries and FMDRs; however tooth brushing prevented the greatest number of caries at minimum and maximum effectiveness with 1,433 and 1,910, respectively. Tooth brushing also prevented the greatest number of FMDRs (159 and 211) at minimum and maximum effectiveness. CONCLUSIONS: All of the dental interventions evaluated were shown to produce cost savings. However, the level of that cost saving is dependent on the intervention chosen.

Comparison of the caries-protective effect of fluoride varnish with treatment as usual in nursery school attendees receiving preventive oral health support through the Childsmile oral health improvement programme - the Protecting Teeth@3 Study: a randomised controlled trial.

BACKGROUND: The Scottish Government set out its policy on addressing the poor oral health of Scottish children in 2005. This led to the establishment of Childsmile, a national programme designed to improve the oral health of children in Scotland. One element of the programme promotes daily tooth brushing in all nurseries in Scotland (Childsmile Core). A second targeted component (Childsmile Nursery) offers twice-yearly application of fluoride varnish to children attending nurseries in deprived areas. Studies suggest that fluoride varnish application can reduce caries in both adult and child populations. This trial aims to explore the effectiveness and cost-effectiveness of additional preventive value fluoride varnish application compared to Childsmile Core. METHODS/DESIGN: The Protecting Teeth@3 Study is an ongoing 2 year parallel group randomised treatment as usual controlled trial. Three-year-old children attending the ante pre-school year are randomised (1:1) to the intervention arm (fluoride varnish & treatment as usual) or the control arm (treatment as usual). Children in the intervention arm will have Duraphat® fluoride varnish painted on the primary tooth surfaces and will continue to receive treatment as usual: the core Childsmile Nursery intervention. Children in the treatment as usual arm will receive the same series of contacts, without the application of varnish and will also continue with the Childsmile Core intervention. Interventions are undertaken by Childsmile trained extended duty dental nurses at six-monthly intervals. Participants receive a baseline dental inspection in nursery and an endpoint inspection in Primary 1 at the age of 5 years old. We will use primary and secondary outcome measures to compare the effectiveness of Duraphat® fluoride varnish plus treatment as usual with treatment as usual only in preventing any further dental decay. We will also undertake a full economic evaluation of the trial. TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov. Number: NCT01674933 (24 August 2012).

Changes in Caries Experience, Untreated Caries, Sealant Prevalence, and Preventive Behavior Among Third-Graders in New York State, 2002-2004 and 2009-2012.

OBJECTIVE: This study assessed changes in caries experience, untreated caries, sealant prevalence, and preventive behavior among third-grade children in New York State to monitor progress toward state health objectives. METHODS: We analyzed children's data from the 2002-2004 (n=10,865) and 2009-2012 (n=6,758) New York State Oral Health Survey. We calculated differences in weighted percentages and 95% confidence intervals for caries experience, untreated caries, sealant prevalence, and preventive behavior. We used logistic regression procedures to assess the independent effects and interaction terms on dental caries experience. RESULTS: The percentage of children with dental caries and untreated caries decreased from 54.1% and 33.0% in 2002-2004 to 45.2% and 23.6% in 2009-2012, respectively. While this decrease was not uniform across income subgroups, the prevalence of sealants, a key measure of the use of preventive services, increased significantly from 16.7% to 36.0% among lower-income children. CONCLUSIONS: Measurable improvement in reducing dental caries prevalence among third-grade children has been made in New York State, but this improvement was not uniform across subgroups. Specifically, disease prevalence among lower-income children remained high, underscoring the need to strengthen existing programs and identify additional policy and programmatic interventions.

[Extension study and evaluation of the therapeutic response in a patient with metastatic lung adenocarcinoma using sequential study with ¹8F-FDG PET-CT and ¹8F-fluoride PET-CT]. / Estudio de extensión y valoración de la respuesta terapéutica en un paciente con adenocarcinoma pulmonar metastásico mediante estudio secuencial con (18)F-FDG PET-TC y (18)F-fluoruro PET-TC.

We report a case of a patient with lung adenocarcinoma and bone and extraosseus metastases studied with (18)F-FDG PET-CT, (99m)Tc-HMDP and (18)F-fluoride PET-CT. It assesses the usefulness of (18)F-FDG PET-CT for initial staging of the disease and monitoring response to therapy. For the study of the sclerotic bone metastases it shows the superiority of 99mTc-HMDP bone scintigraphy and (18)F-fluoride PET-CT over (18)F-FDG PET-CT, and (18)F-fluoride PET-CT over bone scintigraphy. It also shows the usefulness of (18)F-fluoride PET-CT for monitoring the bone metastases.

In situ assessment of effects of the bromide- and fluoride-incorporating adhesive systems on biofilm and secondary caries.

AIM: This in situ study assessed the effects of adhesive systems containing or not fluoride and/or the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) on the microbiological composition of dental biofilm and enamel demineralization. MATERIALS AND METHODS: During two phases of 14 days, ten volunteers wore intraoral palatal appliances containing two slabs of human enamel according to a double-blind, crossover design. The slabs were randomly restored using a composite resin and one of the following adhesive systems: All-Bond SE(TM) (self-etch, fluoride/MDPB free adhesive, AB) and Clearfl Protect Bond (self-etch containing fluoride and MDPB adhesive, CB). The biofilm formed on the slabs was analyzed with regard to total and mutans streptococci and lactobacilli counts. Demineralization represented by integrated area of hardness × lesion depth Delta S ( ΔS) was determined on enamel by analysis of cross-sectional microhardness, at 20 and 70 µm from the restoration margin. Data were analyzed by ANOVA. RESULTS: No statistically significant difference was found either in enamel demineralization or in the microbiological composition of dental biofilm. CONCLUSION: All adhesive systems containing or not fluoride and/or MDPB tested were unable to inhibit secondary caries in the in situ model used in the present research.

Trends and costs of high concentration fluoride toothpaste prescribing in Scotland.

Within Scotland there has been a significant increase in the prescription of 2,800 ppm and 5,000 ppm fluoride toothpaste. The objective of this paper was to analyse the trends in high concentration fluoride toothpaste (HCFT) in the five Scottish South East and Tayside (SEAT) health boards and consider the options for future national management of this prescribing. A retrospective analysis of routine prescribing data for the years 2006-2012 was carried out in primary care dental practices in Scotland. The cost of HCFT prescribing in the five Scottish health boards has increased from £15,243 (4,147 items) in 2006/07 to £206,529 (24,113 items), in 2011/12. Out of 2,430 dental list numbers, 100 list numbers (4.1%) accounted for 70% of the total prescribing costs (£144,367). The public dental service employs 153 (6%) of dentists working in Scotland, who in turn prescribe 11.6% HCFT. There is a need to ensure that the prescription of HCFT is both encouraged as best practice care but also managed appropriately to ensure that its delivery is targeted at those who are most in need.

Impact of socio-demographic, socioeconomic, and water variables on dental fluorosis in adolescents growing up during the implementation of a fluoridated domestic salt program.

The objective of this study is to determine the impact of socio-demographic, socioeconomic, and other risk indicators on dental fluorosis (DF) among Mexican adolescents. A cross-sectional study was carried out in 1,538 adolescents 12 and 15 years of age in semi-rural communities located at high altitude (>2,000 m) and with high concentration of fluoride in water (1.38-3.07 ppm) in Hidalgo, Mexico. DF was determined by means of Dean's Index and all teeth were examined. Remaining variables were collected using a questionnaire. The adjusted final model was performed using ordered logistic regression. After adjusting for sex, the variables associated with DF were (p < 0.05): being 12 years old (OR = 1.10) versus 15 years old; having lived the first 6 years of life in El Llano (3.07 F ppm) (OR = 3.19) or San Marcos (1.38 F ppm) (OR = 1.63) versus Tula (1.42 F ppm); having public (OR = 1.35) or private health insurance (OR = 1.36) versus those without insurance; belonging to the lower quartiles of socioeconomic position (SEP) [1st quartile (OR = 2.48), 2nd quartile (OR = 1.81), 3rd quartile (OR = 1.49)] versus the highest quartile; having drunk tap water (OR = 1.83) or from a well or spring (OR = 2.30) versus those who drank water purchased in large containers or bottles. Demographic and socioeconomic variables were associated with DF. While better SEP appeared to play an important role in DF, a pattern of water intake associated with water purchased in large containers or bottles (which have different connotations to the use of bottled water in industrialized Western countries) did reduce DF risk in these high fluoride content, high altitude communities.