A half-century of community water fluoridation in the United States: review and commentary

Dental caries in children in Ireland: A systematic review

BACKGROUND

Dental caries is the most common childhood disease worldwide. In the mid-1960s, mandatory Community Water Fluoridation (CWF) was introduced in the Republic of Ireland (RoI) aimed at reducing the prevalence and severity of dental caries in the population. In 2017, approximately, 71% of the Irish population was supplied with fluoridated drinking water.

OBJECTIVES

To review all children's dental health surveys at National, Regional and County-levels conducted in the Republic of Ireland from 1950 to 2021 and describe trends in dental caries prevalence. The secondary objective was to compare dental caries experience in children living in areas with and without CWF.

METHODS

Seven databases (Embase, Medline Ovid, PubMed, Cochrane, Web of Science, Scopus and Lenus Ireland) were systematically searched followed by lateral searches from reference lists. Studies reporting the caries experience of Irish children were eligible for inclusion. Two authors independently evaluated the quality of included studies using the Joanna Briggs Institute Critical Appraisal Checklist.

RESULTS

Thirty-one studies were included. Over the last 70 years, at National, Regional and County levels, mean dmft/DMFT (decayed, missing and filled teeth) scores have decreased and the percentage of caries-free children has increased in 5, 8, 12, and 15-year-olds. The decline in dental caries indices observed throughout the country was greater in children living in areas with CWF. Between the 1960s and 2002, the mean dmft scores for 5-year-olds living in the RoI were reduced by approximately 82% and 69% for the fluoridated and non-fluoridated groups respectively. Reduction in the mean DMFT scores for the 12-year-olds were 75% and 71%, respectively, for the fluoridated and non-fluoridated groups. Between 1961 and 2014, reductions in the mean dmft/DMFT scores among 5 and 12-years-olds living in County Dublin were approximately 88% and 90% respectively. These results should be interpreted in the context of widespread use of fluoridated toothpaste in the RoI.

CONCLUSIONS

Large reductions in the prevalence of dental caries in Irish children have been observed over the last seven decades. Greater dental caries reductions have been reported among children living in areas with CWF compared to those without CWF.

Shining light on fluoride detection: a comprehensive study exploring the potential of coumarin precursors as selective turn-on fluorescent chemosensors

In this study, we report a fluoride chemosensor based on the use of a non-fluorescent pre-coumarin, compound 1. This compound undergoes selective fluoride-triggered formation of coumarin 2, with a concomitant turn-on fluorescence signal. Although compound 1 exists as a mixture of alkene isomers (2 : 1 in favor of the E isomer), only the minor Z-isomer undergoes cyclization. Nonetheless, comprehensive computational and experimental studies provide evidence that in situ isomerization of E-1 to Z-1, followed by fluoride-triggered phenolate evolution and intramolecular cyclization, facilitates the generation of coumarin 2 in high yield. Moreover, this system is an effective turn-on fluorescence sensor for fluoride anions, which displays outstanding selectivity (limited response to other commonly occurring analytes), sensitivity (lowest reported limits of detection for this sensor class), and practicality (works in solution and on paper to generate both fluorometric and colorimetric responses). Ongoing efforts are focused on expanding this paradigm to other pre-coumarin scaffolds, which also undergo analyte-specific coumarin formation accompanied by turn-on fluorescence.

Diphenylpyrrole-Strapped Calix[4]pyrrole Extractant for the Fluoride and Chloride Anions

The anion binding features of diphenylpyrrole-strapped calix[4]pyrrole 1 have been investigated by means of 1 H NMR spectroscopy and ITC (isothermal titration calorimetry), as well as single crystal X-ray diffraction analyses. Receptor 1 bearing an auxiliary pyrrolic NH donor and solubilizing phenyl groups on the strap was found to bind F- , Cl- , and Br- as their tetrabutylammonium salts with high affinity in DMSO-d6 . In addition, receptor 1 was found to extract the fluoride anion (as both its tetraethylammonium (TEA+ ) and tetrabutylammonium (TBA+ ) salts), as well as the chloride anion into chloroform-d from an aqueous source phase. Cation metathesis using TBAI or the use of a dual host approach involving crown ethers enabled receptor 1 to extract simple alkali metal fluoride or chloride salts from water. Quantitative binding of NaF by receptor 1 was observed in 20 % D2 O-DMSO-d6 allowing for the direct determination of the NaF concentration in an unknown sample.

Exogenous Intake of Fluorides in Caries Prevention: Benefits and Risks

Caries incidence and prevalence have decreased significantly over the last few decades due to widespread use of fluoride. However, an increase in the prevalence of dental fluorosis has been reported in both fluoridated and non-fluoridated communities. Care must be taken to ensure that a balance between the optimal fluoride preventive effect at the individual and community level and minimal risk of dental fluorosis is maintained. This review describes the main sources of fluoride intake that have been identified: fluoridated drinking water, dietary fluoride supplement, and topical forms comprising toothpastes, rinses, gels and varnishes. The cited data were taken from meta-analytic studies and reports from Cochrane database systematic reviews up to December 2019. Efficiency, but safety, of topically applied fluorides in individual home care is dependent on the degree of compliance of individuals/parents and on the level of competence of providers of preventive counselling. The broad spectrum of these resources allows individualization of fluoride prevention based on risk analysis of caries attack and taking into consideration other preventive measures.

Capture and displacement-based release of the bicarbonate anion by calix[4]pyrroles with small rigid straps

Two-phenoxy walled calix[4]pyrroles 1 and 2 strapped with small rigid linkers containing pyridine and benzene, respectively, have been synthesized. 1H NMR spectroscopic analyses carried out in CDCl3 revealed that both of receptors 1 and 2 recognize only F- and HCO3 - among various test anions with high preference for HCO3 - (as the tetraethylammonium, TEA+ salt) relative to F- (as the TBA+ salt). The bound HCO3 - anion was completely released out of the receptors upon the addition of F- (as the tetrabutylammonium, TBA+ salt) as a result of significantly enhanced affinities and selectivities of the receptors for F- once converted to the TEAHCO3 complexes. Consequently, relatively stable TEAF complexes of receptors 1 and 2 were formed via anion metathesis occurring within the receptor cavities. By contrast, the direct addition of TEAF to receptors 1 and 2 produces different complexation products initially, although eventually the same TEAF complexes are produced as via sequential TEAHCO3 and TBAF addition. These findings are rationalized in terms of the formation of different ion pair complexes involving interactions both inside and outside of the core receptor framework.

Cohort differences among aging populations: An update

BACKGROUND

The US population is aging. Most older adults are retaining their natural teeth for longer, and fewer are becoming edentulous.

METHODS

Among people 65 years and older, there is greater heterogeneity than at any other time in the life cycle because these cohorts are influenced by historical experiences and the sociodental events during their life spans. These events and experiences have affected their health behaviors and, consequently, their systemic and oral health. This article is an update on 2 previous articles that described birth cohorts spanning from 1900 through 1945, whereas this article describes 5 specific cohorts born from 1920 through 1980.

RESULTS

The authors used data from the literature to describe the historical and socioeconomic influences, as well as the key events in the history of dentistry, that have affected each of these cohorts' attitudes and expectations toward the use of health care and dental care services.

CONCLUSIONS

The authors identified cohort differences regarding health behaviors, which included attitudes toward dentistry and dental care service use.

PRACTICAL IMPLICATIONS

Dentists should be aware of cohort differences in regard to dental care service use, in addition to modifiers that are specific to each patient, to offer the most customized and age-appropriate oral health care.

Small triiminopyrrolic molecular cage with high affinity and selectivity for fluoride

A small molecular cage (4) with high affinity and complete selectivity for fluoride to the limit of detection over other competing small anions was synthesized. Cage 4 was also found to retain the encapsulated fluoride anion within its cavity even after one or two pyrrolic NH protons were subject to deprotonation.

Community Water Fluoridation and Urinary Fluoride Concentrations in a National Sample of Pregnant Women in Canada

BACKGROUND

Fluoride exposures have not been established for pregnant women who live in regions with and without community water fluoridation.

OBJECTIVE

Our aim was to measure urinary fluoride levels during pregnancy. We also assessed the contribution of drinking-water and tea consumption habits to maternal urinary fluoride (MUF) concentrations and evaluated the impact of various dilution correction standards, including adjustment for urinary creatinine and specific gravity (SG).

METHODS

We measured MUF concentrations in spot samples collected in each trimester of pregnancy from 1,566 pregnant women in the Maternal-Infant Research on Environmental Chemicals cohort. We calculated intraclass correlation coefficients (ICCs) to assess variability in MUF concentrations across pregnancy. We used regression analyses to estimate associations between MUF levels, tea consumption, and water fluoride concentrations as measured by water treatment plants.

RESULTS

Creatinine-adjusted MUF values ([Formula: see text]; milligrams per liter) were almost two times higher for pregnant women living in fluoridated regions ([Formula: see text]) compared with nonfluoridated regions ([Formula: see text]; [Formula: see text]). MUF values tended to increase over the course of pregnancy using both unadjusted values and adjusted values. Reproducibility of the unadjusted and adjusted MUF values was modest ([Formula: see text]). The municipal water fluoride level was positively associated with creatinine-adjusted MUF ([Formula: see text], 95% CI: 0.46, 0.57), accounting for 24% of the variance after controlling for covariates. Higher MUF concentrations correlated with numbers of cups of black ([Formula: see text] but not green tea ([Formula: see text]). Urinary creatinine and SG correction methods were highly correlated ([Formula: see text]) and were interchangeable in models examining predictors of MUF.

CONCLUSION

Community water fluoridation is a major source of fluoride exposure for pregnant women living in Canada. Urinary dilution correction with creatinine and SG were shown to be interchangeable for our sample of pregnant women. https://doi.org/10.1289/EHP3546.

Survival analysis of caries incidence in African-American school-aged children

OBJECTIVES

To conduct an assessment of time-dependent covariates related to dental caries of the permanent dentition among a low socioeconomic status, understudied cohort of children, incorporating time-dependent covariates through the application of extended Cox proportional hazards modeling.

METHODS

This study modeled the time to first cavitated dental caries in permanent teeth among school-aged children and assessed factors associated with this event. A cohort of 98 low socioeconomic status African-American children with mean age of 5.85 years at baseline was recruited in Uniontown, Alabama and followed prospectively for 6 years. None of these children had dental caries on permanent teeth at baseline, and oral examinations were performed annually. Caries-free survival curves were generated to describe time to event (having first decayed, filled, or missing permanent surface). Bivariate and multivariable extended Cox hazards modeling was used to assess the relationships between time-dependent and time-independent covariates and time to event.

RESULTS

Twenty-eight children (28.6 percent) had their first permanent tooth caries event during the 6-year follow-up. Multivariable results showed that greater consumption of water was associated with lower dental caries hazard, while previous primary tooth caries experience was associated with greater dental caries hazard after adjustment for frequency of consumptions of milk, added-sugar beverages, and 100 percent juice.

CONCLUSIONS

There was a global/overall significant caries protective effect of water consumption during the school-age period of child development.

Milestones and controversies in maternal and child health: examining a brief history of micronutrient fortification in the US

Fortification of our food and drinking supply has decreased morbidity rates related to micronutrient deficiencies among mothers and their children, particularly during the perinatal and neonatal periods of development. The purpose of this historical review is to examine the impact of public policy changes related to micronutrient fortification. We provide a historical investigation of achievements and controversies related to iodine, vitamin D, fluoride and folic acid fortifications in our food and drinking supply. We also discuss the current status of fortification recommendations and their significance to maternal and child health.

Geochemistry and sources of fluoride and nitrate contamination of groundwater in Lar area, south Iran

Groundwater quality in bone-dry and semiarid areas of Iran is decreasing because of contaminants from natural origins and anthropogenic sources. Among many harmful contaminants, nitrate and fluoride ions are more common. This study was carried out with the aim of determining geochemical processes controlling chemistry of groundwater with special reference to nitrate and fluoride enrichment in groundwater in Lar plain aquifer, south of Iran. Groundwater samples were collected from 17 sites and analyzed for main constituents (Na, K, Ca, Mg, Cl, SO₄^2-, HCO₃^-, F^-, and NO₃^-). Composite diagram, saturation indices calculation, and multivariate analysis techniques including cluster and factor analyses were employed in evaluating groundwater quality. The EC ranges from 8793.87 to 13,345.00 μS/cm in wet season and from 9621.59 to 12,640.00 μS/cm in dry season. Fluoride amounts range between 0.59 and 3.92 mg/L. Nitrate concentrations range between 1.47 and 70.66 mg/L. Results indicate that dissolution-precipitation of carbonate and evaporate minerals, evaporation (in terms of agricultural water return), and opposite ion interchange are the main processes that determine groundwater chemistry. It seems that fluoride has a natural origin and the equilibrium reaction between fluorite and calcite is very significant to control fluoride concentration level in water. Vertical variation of nitrate concentration and distribution of agricultural areas have indicated that nitrate originated from nitrogenous inorganic fertilizers used during irrigation periods. The results also indicate that denitrification takes place in the aquifer and that nitrate decline is not only a function of dilution but also a process of denitrification.

Risk factors and prevalence of dental fluorosis and dental caries in school children of North India

The aim of the study was to assess the prevalence of dental fluorosis, dental caries, and associated risk factors in the school children of district Fatehgarh Sahib, Punjab, India, using a cross-sectional study design. Oral health status of children aged between 8 and 15 years was assessed using World Health Organization (WHO) 2013 criteria. Dental fluorosis was assessed using Dean's index, and dental caries were recorded using decayed, missing, filled/decayed, extracted, filled (DMF/def) indices. Four hundred school children were examined, of which 207 were in the 8-11-year-old group and 193 were in the 12-15-year-old group. The overall prevalence of dental fluorosis was 4.1%, which might be linked to a high concentration of fluoride in drinking water at certain locations of rural Punjab. The prevalence of dental caries was 36.5% with a mean DMF score of 0.3 and def score of 0.6. Risk factors for dental caries include oral hygiene behavior and sugar consumption patterns. The study highlights the need to increase awareness about the oral health and hygiene among the school children in India.

The Microbiome of the Built Environment and Human Behavior: Implications for Emotional Health and Well-Being in Postmodern Western Societies

It is increasingly evident that inflammation is an important determinant of cognitive function and emotional behaviors that are dysregulated in stress-related psychiatric disorders, such as anxiety and affective disorders. Inflammatory responses to physical or psychological stressors are dependent on immunoregulation, which is indicated by a balanced expansion of effector T-cell populations and regulatory T cells. This balance is in part driven by microbial signals. The hygiene or "old friends" hypothesis posits that exposure to immunoregulation-inducing microorganisms is reduced in modern urban societies, leading to an epidemic of inflammatory disease and increased vulnerability to stress-related psychiatric disorders. With the global trend toward urbanization, humans are progressively spending more time in built environments, thereby, experiencing limited exposures to these immunoregulatory "old friends." Here, we evaluate the implications of the global trend toward urbanization, and how this transition may affect human microbial exposures and human behavior.

Factors attributable for the prevalence of dental caries in Queensland children

BACKGROUND

Dental caries is a multifactorial condition, prevention of which requires comprehensive understanding of both contextual and compositional determinants and their population impact.

AIMS

To investigate contextual and compositional factors associated with the prevalence of dental caries in children and to estimate the population impact of those factors.

METHODS

Children in one Australian state were selected through stratified random sampling selection in 2010-2011. Oral epidemiological examinations provided individual-level outcomes: prevalence of dental caries in the primary (among 5- to 8-year-olds) and permanent dentitions (9- to 14-year-olds). Socioeconomic status, oral health behaviours and practices and dietary patterns were explanatory factors at the individual-level, school-level and area-level fluoridation status. Three-level multilevel multivariable models were sequentially specified for the prevalence of dental caries to estimate prevalence ratios (PR) associated with explanatory factors, adjusting for covariates and between- and within-group variances. Population attributable fraction (PAF) was estimated as the population impact of the statistically significant explanatory factors.

RESULTS

Data from 2214 5- to 8-year-olds and 3186 9- to 14-year-olds from 207 schools in 16 areas were analysed. The prevalence of dental caries in the primary and the permanent dentitions was 47.1% (43.9-50.4) and 38.8% (36.1-41.6), respectively. The highest prevalence of dental caries was observed in the nonfluoridated areas. In bivariate associations, factors at three levels were associated with prevalence of dental caries. In the full models, children in the nonfluoridated areas had significantly higher prevalence of dental caries [PR for the primary: 1.29 (1.11-1.50); PR for the permanent 1.49 (1.01-2.21)] compared with children in fluoridated areas, controlling for other factors. PAF estimates indicated that lack of water fluoridation attributed to 21% and 31% of primary and permanent dental caries, respectively in this child population.

CONCLUSION

A multitude of factors had significant population impact on the prevalence of dental caries in children. Water fluoridation has a significant population impact on dental caries experience in this child population.

A highly selective SBA-15 supported fluorescent “turn-on” sensor for the fluoride anion

TSBA (or ASBA) remained stable upon prolonged exposure to UV light (losing ∼0.12% of its fluorescence intensity), and was highly selective towards F⁻ over other common anions (Cl⁻, Br⁻, I⁻, HPO₄²⁻, ACO⁻, and NO₃⁻).

A critique of recent economic evaluations of community water fluoridation

BACKGROUND

Although community water fluoridation (CWF) results in a range of potential contaminant exposures, little attention has been given to many of the possible impacts. A central argument for CWF is its cost-effectiveness. The U.S. Government states that $1 spent on CWF saves $38 in dental treatment costs.

OBJECTIVE

To examine the reported cost-effectiveness of CWF.

METHODS

Methods and underlying data from the primary U.S. economic evaluation of CWF are analyzed and corrected calculations are described. Other recent economic evaluations are also examined.

RESULTS

Recent economic evaluations of CWF contain defective estimations of both costs and benefits. Incorrect handling of dental treatment costs and flawed estimates of effectiveness lead to overestimated benefits. The real-world costs to water treatment plants and communities are not reflected.

CONCLUSIONS

Minimal correction reduced the savings to $3 per person per year (PPPY) for a best-case scenario, but this savings is eliminated by the estimated cost of treating dental fluorosis.

Encapsulation of [X2(H2O)4]2- (X = F/Cl) clusters by pyridyl terminated tripodal amide receptor in aqueous medium: single crystal X-ray structural evidence

A new tris-amide receptor L based on 1,3,5-methyl substituted benzene platform and pyridyl as an attached unit is synthesized and explored towards anion recognition in aqueous environment. The presence of pyridyl terminal in L facilitates its aqueous solubility. The binding of halides and oxyanions towards L are examined by (1)H-NMR technique in solution and by single crystal X-ray crystallography in solid state studies. Crystallization of fluoride and chloride with L is carried out in acetone-water (1 : 1, v/v) binary solvent mixture that yields crystals for respective host-guest complexes, [L]2·[F2(H2O)4]·[TBA]2 (1) and [L]2·[Cl2(H2O)4]·[TBA]2 (2) suitable for single crystal X-ray diffraction studies. On the other hand, complexation of L with fluoride in dioxane-acetone (1 : 1, v/v) solvent mixture, results the formation of SiF6(2-) encapsulated complex, [L]2·[SiF6(H2O)2]·[TBA]2 (3). Crystallographic result shows the formation of [F2(H2O)4](2-) and [Cl2(H2O)4](2-) zipped 1D-polymeric tweezer-like assemblies of L in acetone-water (1 : 1, v/v) binary solvent mixture in complexes 1 and 2 respectively. Solution state (1)H-NMR studies in D2O-acetone-d6 (1 : 19, v/v) support 1 : 4 (host-guest) binding stoichiometry of F(-), Cl(-), Br(-), NO3(-), HSO4(-) and H2PO4(-) with L. Binding constants of these investigated anions with L by 1 : 1 binding model are calculated which show the following binding order: NO3(-) ≈ HSO4(-) > F(-) ≈ Cl(-) ≈ Br(-) > H2PO4(-). Further, solution state (19)F-NMR studies are also carried out to establish the F(-) binding with L in DMSO-d6.

A borane-bithiophene-BODIPY triad: intriguing tricolor emission and selective fluorescence response towards fluoride ions

The structure and photophysical properties of a new triad (borane–bithiophene–BODIPY) 1 have been investigated. Triad 1 exhibits unprecedented tricolour emission when excited at the borane centred high energy absorption band and also acts as a selective fluorescent and colorimetric sensor for fluoride ions with ratiometric response. The experimental results are supported by computational studies.

Highlights on contemporary recognition and sensing of fluoride anion in solution and in the solid state

The fluoride anion has recently gained well deserved attention among the scientific community for its importance in many fields of human activities, but also for concerns on its effect on health and the environment. Although surprisingly overlooked in systematic studies in the past, fluoride has nowadays become a topical target in the field of anion recognition. A multitude of scientific reports are published every year where the establishment of efficient and specific interaction with fluoride is sought in polar and aqueous media. Here, the emphasis is directed to a detailed description of the most interesting contemporary studies in the field, with a particular focus given to those published in the last few years.

Total knee arthroplasty in a patient with skeletal fluorosis

Published reports on patients with skeletal fluorosis undergoing total knee arthroplasty are rare. Skeletal fluorosis is a chronic condition that occurs secondary to the ingestion of food and water that contain high levels of fluoride. Although fluorosis may be described as osteosclerotic and marble-like in appearance, features may also include characteristics of osteomalacia and osteoporosis. This article describes the case of a 67-year-old man with skeletal fluorosis who underwent total knee arthroplasty complicated by fracture. An intramedullary guide was used for the proximal tibia and distal femoral bone cuts intraoperatively. Following the completion of the femoral bone cuts, it was noted that the drill used to open the femoral canal had breached the medial femoral cortex. Multiple fractures were seen in both femoral condyles. A revision femoral stem was chosen to complete the total knee arthroplasty but, after further manipulation of the femur, it appeared that the fracture had displaced. A LISS plate (Synthes, West Chester, Pennsylvania) was used to ensure fracture reduction and implant stability. The remainder of the procedure was completed without complication. One year postoperatively, functional knee range of motion was limited to 70° of flexion. Radiographs showed signs of healing and satisfactory implant position. This case highlights the importance of the preoperative examination and the need to fully appreciate the bone quality of patients prior to undertaking an orthopedic procedure. Variation from the use of intramedullary guides should be considered in patients with questionable bone quality undergoing total knee arthroplasty.

A model to determine the economic viability of water fluoridation

OBJECTIVES

In view of concerns expressed by South African local authorities the aim of this study was to develop a model to determine whether water fluoridation is economically viable to reduce dental caries in South Africa.

METHODS

Microsoft Excel software was used to develop a model to determine economic viability of water fluoridation for 17 water providers from all nine South African provinces. Input variables for this model relate to chemical cost, labor cost, maintenance cost of infrastructure, opportunity cost, and capital depreciation. The following output variables were calculated to evaluate the cost of water fluoridation: per capita cost per year, cost-effectiveness and cost-benefit. In this model it is assumed that the introduction of community water fluoridation can reduce caries prevalence by an additional 15 percent and that the savings in cost of treatment will be equal to the average fee for a two surface restoration.

RESULTS

Water providers included in the study serve 53.5 percent of the total population of South Africa. For all providers combined chemical cost contributes 64.5 percent to the total cost, per capita cost per year was $0.36, cost-effectiveness was calculated as $11.41 and cost-benefit of the implementation of water fluoridation was 0.34.

CONCLUSIONS

This model confirmed that water fluoridation is an economically viable option to prevent dental caries in South African communities, as well as conclusions over the last 10 years that water fluoridation leads to significant cost savings and remains a cost-effective measure for reducing dental caries, even when the caries-preventive effectiveness is modest.

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.

The challenge to delivering oral health services in rural America

OBJECTIVES

This review identifies the challenges to oral health in rural America and describes areas of innovation in prevention, delivery of dental services, and workforce development that may improve oral health for rural populations.

METHODS

This descriptive article is based on literature reviews and personal communications.

RESULTS

Rural populations have lower dental care utilization, higher rates of dental caries, lower rates of insurance, higher rates of poverty, less water fluoridation, fewer dentists per population, and greater distances to travel to access care than urban populations. Improving the oral health of rural populations requires practical and flexible approaches to expand and better distribute the rural oral health workforce, including approaches tailored to remote areas. Solutions that involve mass prevention/public health interventions include increasing water fluoridation, providing timely oral health education, caries risk assessment and referral, preventive services, and offering behavioral interventions such as smoking and tobacco cessation programs. Solutions that train more providers prepared to work in rural areas include recruiting students from rural areas, training students in rural locations, and providing loan repayment and scholarships. Increasing the flexibility and capacity of the oral health workforce for rural areas could be achieved by creating new roles for and new types of providers. Solutions that overcome distance barriers include mobile clinics and telehealth technology.

CONCLUSIONS

Rural areas need flexibility and resources to develop innovative solutions that meet their specific needs. Prevention needs to be at the front line of rural oral health care, with systematic approaches that cross health professions and health sectors.

The impact of changing dental needs on cost savings from fluoridation

BACKGROUND

Although community water fluoridation has been one of the cornerstone strategies for the prevention and control of dental caries, questions are still raised regarding its cost-effectiveness. This study assessed the impact of changing dental needs on the cost savings from community water fluoridation in Australia.

METHODS

Net costs were estimated as Costs((programme)) minus Costs((averted caries).) Averted costs were estimated as the product of caries increment in non-fluoridated community, effectiveness of fluoridation and the cost of a carious surface. Modelling considered four age-cohorts: 6-20, 21-45, 46-65 and 66+ years and three time points 1970s, 1980s, and 1990s. Cost of a carious surface was estimated by conventional and complex methods. Real discount rates (4, 7 (base) and 10%) were utilized.

RESULTS

With base-case assumptions, the average annual cost savings/person, using Australian dollars at the 2005 level, ranged from $56.41 (1970s) to $17.75 (1990s) (conventional method) and from $249.45 (1970s) to $69.86 (1990s) (complex method). Under worst-case assumptions fluoridation remained cost-effective with cost savings ranging from $24.15 (1970s) to $3.87 (1990s) (conventional method) and $107.85 (1970s) and $24.53 (1990s) (complex method). For 66+ years cohort (1990s) fluoridation did not show a cost saving, but costs/person were marginal.

CONCLUSIONS

Community water fluoridation remains a cost-effective preventive measure in Australia.

Natural fluoride levels from public water supplies in Piauí State, Brazil

The aim of this work was to determine the natural fluoride concentrations in public water supplies in Piauí State, Brazil, in order to identify cities in risk for high prevalence of dental fluorosis. For each city, two samples of drinking water were collected in the urban area: one from the main public water supply and another from a public or residential tap from the same source. Fluoride analyses were carried out in duplicate using a specific ion electrode and TISAB II. From a total of 222 cities in Piauí, 164 (73.8%) samples were analyzed. Urban population in these towns corresponds to 92.5% of the whole state with an estimated population of 1,654,563 inhabitants from the total urban population (1,788,590 inhabitants). A total of 151 cities showed low fluoride levels (<0.30 mg/L) and 13 were just below optimum fluoride concentration in the drinking water (0.31-0.59 mg/L). High natural fluoride concentration above 0.81 mg/L was not observed in any of the surveyed cities. As a conclusion, most of the cities in Piauí have low fluoride concentration in the drinking water. The risk for a high prevalence of dental fluorosis in these urban areas due to natural fluoride in the water supplies is very unlikely. Thus, surveys about the dental fluorosis prevalence in Piauí should be related with data about the consumption of fluoridated dentifrices and other fluoride sources.

Appraisal of salinity and fluoride in a semi-arid region of India using statistical and multivariate techniques

Various physico-chemical parameters, including fluoride (F(-)), were analyzed to understand the hydro-geochemistry of an aquifer in a semi-arid region of India. Furthermore, the quality of the shallow and deep aquifer (using tube well and hand pumps) was also investigated for their best ecological use including drinking, domestic, agricultural and other activities. Different multivariate techniques were applied to understand the groundwater chemistry of the aquifer. Findings of the correlation matrix were strengthened by the factor analysis, and this shows that salinity is mainly caused by magnesium salts as compared to calcium salts in the aquifer. The problem of salinization seems mainly compounded by the contamination of the shallow aquifers by the recharging water. High factor loading of total alkalinity and bicarbonates indicates that total alkalinity was mainly due to carbonates and bicarbonates of sodium. The concentration of F(-) was found more in the deep aquifer than the shallow aquifer. Further, only a few groundwater samples lie below the permissible limit of F(-), and this indicates a risk of dental caries in the populace of the study area. The present study indicates that regular monitoring of groundwater is an important step to avoid human health risks and to assess its quality for various ecological purposes.

Promoting social welfare through oral health: New Jersey's fluoridation experience

This study examines the contentious public health policy of treating community water with fluoride in the United States. The question for scholarly investigation is why water fluoridation has been unsuccessful in several parts of the United States relative to the rest. It addresses this question by looking into the processes of scientific discovery and information dissemination, benefits and risks of science-based health policy, related issues of provision and production, and spatial dimensions of policy development. The case method based on New Jersey's experience in public water fluoridation, was opted for this study. We find that policy debates, which are confined to single key issues, tend to breed binary choices and bipolar debates and result in policy stalemates. Consumer accessibility and desirability of merit goods thus become sharply conflicting social welfare values. They undermine the intent of science-based policies and often make alternative and second-best policies more practical to adopt.

Oral health status of Vietnamese children: findings from the National Oral Health Survey of Vietnam 1999

The National Oral Health Survey of Vietnam 1999 was conducted to inform policy development.

AIMS

The aims were to describe the oral health status, to analyze its socioeconomic distribution, and to evaluate change over time in the oral health of Vietnamese children.

METHODS

A multistaged stratified sampling process was employed. Children aged 6 to 17 years were examined by trained and calibrated dental examiners. A parental questionnaire was used. Drinking water was analyzed.

RESULTS

Preventive oral health behaviors and dental care utilization were infrequent. The decayed, missing, and filled surfaces referring to primary dentition (dmfs) and permanent dentition (DMFS) scores (SD) were 8.9 (11.3) and 2.5 (4.4), respectively. Primary caries experience was associated with fluoride level in drinking water, age, gender, residential status, and geographical location. Permanent caries was also associated with dental visiting and parental education. There was an increase in the prevalence of dental caries in the Vietnamese child population compared with 10 years earlier.

CONCLUSION

The oral health of Vietnamese children was characterized by high level of dental caries with variation among socioeconomic groups. It suggests the need for a population oral health program that includes measures to target high-need children.

Fluorides in dental public health programs

The use of fluorides in dental public health programs has a long history. With the availability of fluoridation and other forms of fluorides, dental caries have declined dramatically in the United States. This article reviews some of the ways fluorides are used in public health programs and discusses issues related to their effectiveness, cost, and policy.

A comparison of dental treatment utilization and costs by HMO members living in fluoridated and nonfluoridated areas

OBJECTIVES

To compare dental treatment experiences and costs in members of a health maintenance organization (HMO) in areas with and without community water fluoridation.

METHODS

HMO members with continuous dental eligibility (January 1, 1990 to December 31, 1995) who resided in Oregon and Washington were identified using administrative databases. Fluoridation status was determined by geocoding subscriber address. Measures were utilization of dental procedures, fluoride dispensings, and associated costs. Costs were based on nonmember fees, adjusted to 1995 dollar values. Data were analyzed using analysis of covariance, controlling for age and interactions.

RESULTS

About 85 percent of eligible members (n = 51,683) were classified as residing either in a fluoridated (n = 12,194) or nonfluoridated (n = 39,489) area. Mean age was 40.0 years; 52.3 percent were women. More than 92 percent of members had one or more dental visits. Community water fluoridation was associated with reduced total and restorative costs among members with one or more visits, but the magnitude and direction of the effect varied with locale and age and the effects were generally small. In two locales, the cost of restorations was higher in nonfluoridated areas in young people (<age 18) and older adults (>age 58). In younger adults, the opposite effect was observed. The impact of fluoridation may be attenuated by higher use of preventive procedures, in particular supplemental fluorides, in the nonfluoridated areas.

CONCLUSIONS

These results are particularly relevant to insured populations with established access to dental care. Differences in treatment costs (savings) associated with water fluoridation should be estimated and included in future cost-effectiveness analyses of community water fluoridation.

A systematic review of the efficacy and safety of fluoridation

SCOPE AND PURPOSE

The systematic review was commissioned by the Australian National Health and Medical Research Council (NHMRC) to evaluate the scientific literature relating to the health effects of fluoride and fluoridation. The systematic review's research questions relate to the caries-reducing benefits and associated potential health risks of providing fluoride systemically (via addition to water, milk and salt) and the use of topical fluoride agents, such as toothpaste, gel, varnish and mouthrinse. Although the review summarises the recent evidence, it does not constitute health policy or clinical practice recommendations.

DATA SOURCES

A literature search was undertaken using the Medline and Embase databases (via www.embase.com). In addition, the Cochrane Systematic Review and Clinical Trial databases were searched to help identify additional systematic reviews and original studies. Because of the availability of recent systematic reviews, searches were limited to publications from 1996 onwards . The search was conducted in December 2006 and limited to English-language publications.

STUDY SELECTION

Based on types of intervention (individual or population) and the outcomes assessed (efficacy or safety), the hierarchy of study types considered most relevant for answering each of the clinical questions defined in this review was chosen (Table 1). The levels of evidence used by NHMRC for intervention and aetiological studies are summarised in Table 2.

DATA EXTRACTION AND SYNTHESIS

Screening of eligible studies was conducted by three reviewers. Data were extracted for all of the included systematic reviews and individual studies using standardised data-extraction forms. This included information about the study design, NHMRC level of evidence, population, intervention, comparator, outcome definitions and results. Information relating to potential biases and study quality were also extracted. Where appropriate, study results were pooled using standard meta-analysis techniques.

RESULTS

In total, 5418 nonduplicate citations were identified. After applying the inclusion and exclusion criteria, 408 citations were considered potentially eligible for inclusion in the review. After the review of the full papers of potentially eligible articles, 77 citations were included in the review. The summary of findings was presented in the context of the research questions (Table 3).

RECOMMENDATIONS

Fluoridation of drinking water remains the most effective and socially equitable means of achieving community-wide exposure to the caries prevention effects of fluoride. It is recommended (see also www.nhmrc.gov.au/news/media/rel07/_files/fluoride_flyer.pdf) that water be fluoridated in the target range of 0.6-1.1 mg/l, depending on the climate, to balance reduction of dental caries and occurrence of dental fluorosis.n particular with reference to care in hospital for those following stroke.

Optical fluoride sensor based on monomer-dimer equilibrium of scandium(III)-octaethylporphyrin in a plasticized polymeric film

A fluoride-selective optical sensor based on scandium(III)-octaethylporphyrin (Sc(III)OEP) as an ionophore within a plasticized PVC film is described. The presence of fluoride ion in the aqueous sample phase increases the formation of a difluoro-bridged Sc(III)OEP dimer species in the polymer film. The ability of the Sc(III) porphyrin to form the dimeric structure in the presence of fluoride is confirmed by UV-vis spectroscopy and X-ray crystallography. For more practical sensing applications, a pH chromoionophore (ETH 7075) is added to the plasticized PVC film along with Sc(III)OEP and the observed optical response is based on coextraction of protons with sample phase fluoride to create the dimeric porphyrin and a protonated chromoionophore species. The selectivity pattern observed is F- >> ClO4(-), SCN-, NO3(-) > Br-, Cl-. Only organic salicylate is a significant interferent. Fast and reversible fluoride response is observed over the range of 10(-4) to 10(-2) M fluoride, allowing use of the sensing film in a waveguide configuration for flow-injection measurements.

Heterocontrole da fluoretação das águas em três cidades no Piauí, Brasil

O objetivo deste trabalho foi monitorar as concentrações de flúor na água de abastecimento público de Teresina, Floriano e Parnaíba, municípios do Piauí, Brasil. A coleta das amostras foi mensal por um período de um ano entre 2004 e 2005. Selecionaram-se aleatoriamente seis pontos de coleta de amostras de água em cada um dos três municípios, totalizando 576 amostras, sendo 192 por cidade. As análises de flúor foram realizadas em duplicata, utilizando-se um eletrodo específico. Os resultados demonstraram que a maioria da amostras ficou abaixo da concentração de flúor ideal e apenas 4,3% (n = 25) das amostras coletadas apresentaram valores aceitáveis de flúor (0,60 a 0,80ppm). Por cidade, o percentual de amostras aceitáveis foi de 7,8% (n = 15), 4,7% (n = 9) e 0,5% (n = 1) para Teresina, Floriano e Parnaíba, respectivamente. Conclui-se que as concentrações de flúor na água de abastecimento público das cidades avaliadas estão abaixo do ideal e que existe a necessidade de implantar medidas de controle e heterocontrole permanentes para garantir a eficácia da fluoretação de águas no Estado do Piauí.

Custo da fluoretação das águas de abastecimento público, estudo de caso Município de São Paulo, Brasil, período de 1985-2003

O objetivo do artigo é estimar o custo da fluoretação das águas de abastecimento público no Município de São Paulo no período de 1985-2003. Para o cálculo da composição de custos da fluoretação das águas levou-se em conta os seguintes custos: (a) capital inicial de instalação; (b) produto químico (ácido fluorsilícico); (c) operacionalização do sistema (manutenção do sistema, energia elétrica e recursos humanos); e (d) controle dos teores de flúor. A ação do flúor mostrou-se efetiva, pois para a idade de 12 anos observou-se redução de 73% na experiência de cárie dentária, sendo que em 1986 a média do índice CPO-D era de 6,47 (6,12-6,82) e em 2002 foi de 1,75 (1,48-2,92). Nesta idade-índice 40% das crianças apresentaram CPO-D = 0 em 2002. O custo médio per capita/ano na Cidade de São Paulo foi de R$ 0,08 (US$ 0,03) em 2003. O custo acumulado em 18 anos de implantação do sistema de fluoretação foi de R$ 1,44 (US$ 0,97) per capita.

Assessment of teeth as biomarkers for skeletal fluoride exposure

Skeletal fluorosis and dental fluorosis are diseases related to fluoride (F) ingestion. Bone is the largest storage site of F in our body. Therefore, bone F concentrations are considered biomarkers for total F body burden (exposure). However, difficult accessibility limits its use as a biomarker. Thus, a more accessible tissue should be considered and analyzed as a biomarker for total F body burden. The objective of this study, which was divided into two parts, was to evaluate teeth as a biomarker for skeletal F exposure. In part 1 of the study, 70 mice of three different strains (SWR/J, A/J and 129P3/J) were exposed to different levels of water fluoridation (0, 25, 50 and 100 ppm). Bone (femora and vertebrae) and teeth from these mice were then analyzed for F concentration using Instrumental Neutron Activation Analysis (INAA). In part 2 of the study, human teeth (enamel and dentin) and bone from 30 study subjects were collected and analyzed for F concentration using INAA. Study subjects lived in areas with optimum levels of water fluoridation (0.7 and 1 ppm) and underwent therapeutic extraction of their unerupted third molars. The values of bone and teeth F concentration were correlated for parts 1 and 2 of this study. The results showed that in the animal model, where animals were exposed to a wide range of F in their drinking water, tooth [F] correlated with bone [F]. However, no correlation was seen between bone and enamel F concentrations or between bone and dentin F concentrations in the human samples. Therefore, teeth are not good biomarkers for skeletal F exposure in humans when exposure is confined to optimum levels of F in the drinking water.

Relative effects of pre- and post-eruption water fluoride on caries experience by surface type of permanent first molars

OBJECTIVES

To determine the relative pre- and post-eruption exposure effects of fluoridated water on the caries experience of different surface types of first permanent molars.

METHODS

Parental questionnaires covering residential history of participants were linked to the oral examinations of 6-15-year-old Australian children conducted in 1992 by the School Dental Services of South Australia and Queensland. Percentage of lifetime exposed to optimally fluoridated water pre- (PRE) and post-eruption (POST) was calculated with respect to tooth eruption age. Combined pre- and post-eruption categories were created to test PRE against POST exposure: PRE and POST = 0, PRE < POST, PRE = POST and in the range 0-90% of lifetime exposure, PRE > POST and, PRE and POST >or= 90% lifetime exposure. These categories were used as indicator variables in linear regression models with PRE and POST = 0 as reference in an analysis of first permanent molar DMFS scores overall and by surface type.

RESULTS

Participation rates were 69.7% in South Australia (n = 9690) and 55.6% in Queensland (n = 10 195). Compared with the reference, the categories PRE > POST (beta = -0.033), PRE = POST (beta = -0.028) in the range 0-90% and, PRE and POST >or= 90% (beta = -0.055) showed significantly lower caries overall (P < 0.01), with a similar pattern for pit and fissure surface caries (beta = -0.035, -0.031 and -0.052, respectively). Only a high PRE and POST exposure decreased caries levels significantly in the approximal (beta = -0.038; P < 0.01) and free smooth surfaces (beta = -0.023; P = 0.03).

CONCLUSIONS

Pre-eruption exposure was important for a caries preventive effect on first permanent molars in children 6-15 years old since post-eruption exposure alone could not lower caries levels significantly. For pit and fissure surfaces, a high pre-eruption exposure could decrease caries levels significantly. However, for other surface types, only a high pre- and post-eruption exposure produced a caries preventive effect.