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.

The aim of this article was to quantify socioeconomic inequalities in dental caries experience among Australian children and to identify factors that explain area-level socioeconomic inequalities in children’s dental caries. We used data from the National Child Oral Health Survey conducted in Australia between 2012 and 2014 ( n = 24,664). Absolute and relative indices of socioeconomic inequalities in the dental caries experience in primary and permanent dentition (decayed, missing, and filled surfaces [dmfs] and DMFS, respectively) were estimated. In the first stage, we conducted multilevel negative binomial regressions to test the association between area-level Index of Relative Socioeconomic Advantage and Disadvantage (IRSAD) and dental caries experience (dmfs for 5- to 8-y-olds and DMFS for 9- to 14-y-olds) after adjustment for water fluoridation status, sociodemographics, oral health behaviors, pattern of dental visits, and sugar consumption. In the second stage, we performed Blinder-Oaxaca and Neumark decomposition analyses to identify factors that explain most of the area-level socioeconomic inequalities in dental caries. Children had a mean dmfs of 3.14 and a mean DMFS of 0.98 surfaces. Children living in the most disadvantaged and intermediately disadvantaged areas had 1.96 (95% confidence interval, 1.69–2.27) and 1.45 (1.26–1.68) times higher mean dmfs and 1.53 (1.36–1.72) and 1.43 (1.27–1.60) times higher mean DMFS than those living in the most advantaged areas, respectively. Water fluoridation status (33.6%), sugar consumption (22.1%), parental educational level (14.2%), and dental visit patterns (12.7%) were the main factors explaining area-level socioeconomic inequalities in dental caries in permanent dentition. Among all the factors considered, the factors that contributed most in explaining inequalities in primary dental caries were dental visits (30.3%), sugar consumption (20.7%), household income (20.0%), and water fluoridation status (15.9%). The inverse area-level socioeconomic inequality in dental caries was mainly explained by modifiable risk factors, such as lack of fluoridated water, high sugar consumption, and an unfavorable pattern of dental visits.

Breastfeeding is important for health and development. Yet, the interaction between breastfeeding duration and usage of fluoridated water on caries experience has not been investigated. This study examined exposure to fluoridation as an effect modifier of the association between breastfeeding duration and caries. The 2012 to 2014 national population-based study of Australian children involved parental questionnaires and oral epidemiological assessment. Children were grouped by parent-reported breastfeeding duration into minimal (none or <1 mo), breastfed for 1 to <6 mo, breastfed for 6 to 24 mo, and sustained (>24 mo). Residential history and main water source used for the first 2 y of life were collected to group children into exposed (WF) and nonexposed (NF) to fluoridation. Socioeconomic status, infant formula feeding, and sugar-sweetened beverage (SSB) consumption data were collected. The prevalence and severity of caries in children aged 5 to 6 y were primary outcomes. Multivariable regression models with robust error estimation were generated to compute prevalence ratios (PRs) and mean ratios (MRs) for 3 breastfeeding groups against the reference (breastfed for 6–24 mo). Of the 5- to 6-y-old children, 2,721 were in the WF and 1,737 were in the NF groups. The groups had comparable distributions of socioeconomic factors, infant formula feeding, and SSB consumption. There were U-shape distributions of caries experience among breastfeeding groups, being more pronounced among NF children. Among NF children, the minimal and sustained breastfeeding groups had significantly higher PR (1.4 [1.1–1.9] and 1.8 [1.4–2.4]) and MR (2.1 [1.4–3.3] and 2.4 [1.4–4.1]) than the reference group. However, among the WF children, this association between breastfeeding duration and caries attenuated after adjustment for other factors. The study contributes evidence of a nonlinear (U-shape) association between breastfeeding duration and dental caries. Early life exposure to fluoridated drinking water attenuated the potential cariogenic effect of both lack of and sustained breastfeeding.

Inequality in child oral health exists by race and income. Water fluoridation (WF) is effective in caries prevention, but evidence for WF reducing inequality in caries experience is equivocal. This study tested the hypothesis that WF reduces race-and income-related inequality in child caries experience. A crosssectional national population-based study of child oral health was conducted across 2012 to 2014 for Australian children aged 5 to 14 y, involving a parental questionnaire and an oral epidemiological examination. Children were stratified by fluoridated (F) and nonfluoridated (NF) area of residence, equivalized household income quartiles, and Indigenous and non-Indigenous status. Directly standardized caries experience (measured by the decayed, missing, or filled tooth surfaces [dmfs/DMFS] in both primary [age 5-10] and permanent dentitions [age 9-14]) was estimated for each stratum accounting for the complex sampling design. Differences in caries experience by Indigenous status and equivalized income quartiles were examined between F and NF strata. Socioeconomic inequality in caries experience was examined using the Absolute Concentration Index

Policy on fluoride intake involves balancing caries against dental fluorosis in populations. The origin of this balance lies with Dean's research on fluoride concentration in water supplies, caries, and fluorosis. Dean identified cut points in the Index of Dental Fluorosis of 0.4 and 0.6 as critical. These equate to 1.3 and 1.6 mg fluoride (F)/L. However, 1.0 mg F/L, initially called a permissible level, was adopted for fluoridation programs. McClure, in 1943, derived an "optimum" fluoride intake based on this permissible concentration. It was not until 1944 that Dean referred to this concentration as the "optimal" concentration. These were critical steps that have informed health authorities through to today. Several countries have derived toxicological estimates of an adequate and an upper level of intake of fluoride as an important nutrient. The US Institute of Medicine (IOM) in 1997 estimated an Adequate Intake (AI) of 0.05 mg F/kg bodyweight (bw)/d and a Tolerable Upper Intake Level (UL) of 0.10 mg F/kg bw/d. These have been widely promulgated. However, a conundrum has existed with estimates of actual fluoride intake that exceed the UL without the expected adverse fluorosis effects being observed. Both the AI and UL need review. Fluoride intake at an individual level should be interpreted to inform more nuanced guidelines for individual behavior. An "optimum" intake should be based on community perceptions of caries and fluorosis, while the ultimate test for fluoride intake is monitoring caries and fluorosis in populations.

The rural population had a high prevalence of periodontitis. Sociodemographic factors, poor oral hygiene, tobacco and alcohol were the main risk indicators attributable to periodontitis.

Introduction: Many studies have investigated associations between demographic, socioeconomic status (SES), behavioral, and clinical factors and parental ratings of child oral health. Caries experience, pain, missing teeth, malocclusions, and conditions and treatments likely to negatively affect the child or family in the future have been consistently associated with poorer parental ratings. In contrast, effect sizes for associations between demographic and SES indicators (race/ethnicity, country of birth, family structure, household income, employment status, and parental education levels) and parental ratings vary greatly. Objectives: The primary objectives of this study were to estimate effect sizes for associations between demographic and SES variables and parental ratings of child oral health and then to consider possible causal implications. Methods: This article uses a nationally representative data set from 24,664 Australian children aged 5 to 14 y, regression analyses guided by a directed acyclic graph causal model, and sensitivity analyses to investigate effects of demographic and SES factors on parental ratings of oral health. Results: One in 8 children had oral health rated as fair or poor by a parent. Indigenous children, older boys, young children with a migrant parent, children from single-parent families, low-income households and families where no parent worked full-time, and children whose parents had lower education levels were much more likely to receive a fair or poor parental oral health rating in crude and adjusted models. Conclusion: This cross-sectional study helps to clarify inconsistent findings from previous research and shows many demographic and SES variables to be strong determinants of parental ratings of child oral health, consistent with the effects of these variables on other health outcomes. Sensitivity analyses and consideration of the potential for chance and bias to have affected these findings suggest that many of these associations may be causal. Knowledge Transfer Statement: Based on regression analyses driven by a directed acyclic graph causal model, this research shows a strong impact of demographic and socioeconomic determinants on parental ratings of child oral health, consistent with associations between these variables and other oral and general health outcomes. Many of these associations may be causal. We demonstrate the value of causal models and causal thinking when analyzing complex multilevel observational data.

Introduction: Oral health affects quality of life. Many studies have investigated the factors associated with oral health–related quality of life (OHRQoL). Little is known about OHRQoL of adults living in rural and remote areas of India, where many have lower levels of education and limited availability of oral health care services. Objectives: To determine the prevalence, extent, and severity of OHRQoL impacts associated with psychosocial factors, functional dentition, and patterns of dental visits among rural Indian adults between the ages of 35 and 54 y. Methods: A cross-sectional study was conducted with a multistage stratified sampling strategy targeting 35- to 54-year-olds. Interviews and oral examinations were performed to collect data on sociodemographic variables, Oral Health Impact Profile-14 (OHIP-14), patterns of dental visits, stress, tobacco and alcohol use, and dentition status. Univariate, bivariate, and multivariable analyses were done to determine the factors associated with prevalence, extent, and severity of OHIP-14 using SAS version 9.3. Results: There were 873 participants. Prevalence, extent, and severity of OHIP-14 were 13.4%, 0.5 (0.4-0.7), and 11.8 (11.2-12.5), respectively. The OHIP-14 impacts reported were not severe and mostly affected physical functioning. Levels of education, income, and number of functional teeth (FT) were inversely associated and last dental visit within the previous year was positively associated with prevalence, extent, and severity of OHIP-14. The prevalence of 1 or more oral health impacts was nearly 13% among rural middle-aged adults in India. Conclusions: Low socioeconomic conditions, dental visits, and FT ≤19 were positively associated with prevalence, extent, and severity of oral health impacts. Knowledge Transfer Statement: This article provides data regarding OHRQoL of people in rural areas of a developing country. The study was intended to determine the factors associated with OHRQoL in rural people who are less educated and living in areas with minimal oral health care facilities. The findings of this study could potentially facilitate further research and health promotional activities for rural people of developing countries.