Water fluoridation for the prevention of dental caries

A Scopus-Based Bibliometric Analysis of Global Research Contributions on Milk Fluoridation

Fluoridated-milk schemes have been developed and implemented in many countries to prevent dental caries. This study aimed to evaluate the impact/influence of scientific publications, researchers, and institutions conducting research on milk fluoridation; to explore the international and inter-institutional collaboration and illustrate scientific output trends; and to pinpoint research hotspots in milk fluoridation research. This bibliometric analysis of original research articles on milk fluoridation includes all of the original articles published in peer-reviewed journals systematically extracted from the SCOPUS database. In total, 108 articles were included in this study, with a total of 11,789 citations. A majority (67.6%) of these articles were in the subject area of ‘dentistry’, 22.2% externally funded, 14.8% published in the journal, Caries Research, 7.4% authored/co-authored by Twetman S, 6.5% by authors from Universidad de Chile, and the UK had the highest output (24.1%). The network visualizations showed that those countries with current/past histories of implemented milk fluoridation programs were interconnected on the network visualization map, and they were predominantly the hotspots for original research on milk fluoridation. This study also identified inequalities in research outputs on the topic. With the current enormous global burden of dental caries in children, particularly in low- and middle-income countries, there is an urgent need for greater and more equitable funding of milk fluoridation research globally.

The Correlation Between the DMFT of the 15-year-old Children and the Concentration of Fluoride in Drinking Water from the East Region of the Republic of Macedonia

AIM: The aim of this study is to determine the correlation between the DMFT index of 15-year-old children from the east region and the concentration of fluoride in drinking water from the populated areas where children live. METHODS: In the examination, 414 children were enrolled, out of seven central secondary schools from four bigger cities from east region, at which the DMFT index was determined. The children live in six different cities and 51 different villages. Fifty-seven water samples were taken from the examined area to determine the fluoride concentration using the electrochemical method using the pH/ISE meter-Thermo-Orion with a special F-electrode (Thermo Orion Ion Plus Fluoride Electrode) at the Institute for public health. Spearman’s method was used to determine the correlation between the specified variables. RESULTS: The total number of children in the examined sample was 414, out of which 226 (54.6%) were male and 188 (45.4%) were female. The prevalence of caries free children was 9.4%. SiC index was 10.22. The average DMFT index in this group of children was 5.77 with a standard deviation of ± 4.02. Maximum concentration of fluorine in drinking water of 0.99 ppmF was determined in the village Raslovci, and 0.87 ppmF in the village Star Karaorman, while the minimum (0.07 ppmF) in the village Dvorishte and (0.10 ppmF) in the village Grad. Correlation of the DMFT index in 15-year-old children from the east region and the concentration of fluorine in the drinking water has a negative, indirect correlation, with the value of the coefficient R = −0.27. CONCLUSION: The correlation between the DMFT index and the concentration of drinking water is a negative, indirect correlation, and statistically, this correlation is highly significant (p < 0.05).

Individual, Family, and Socioeconomic Contributors to Dental Caries in Children from Low- and Middle-Income Countries

Introduction: Collective evidence on risk factors for dental caries remains elusive in low- and middle-income countries (LMICs). The objective was to conduct a systematic review and meta-analysis on risk factors for dental caries in deciduous or permanent teeth in LMICs. Methods: Studies were identified electronically through databases, including Cochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials, PubMed/MEDLINE, and CINAHL, using “prevalence, dental caries, child, family, socioeconomic, and LMIC” as the keywords. A total of 11 studies fit the inclusion criteria. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale (NOS). The MedCalc software and Review Manager 5.4.1 were used. Results: From 11,115 participants, 38.7% (95% CI: 28.4−49.5%) had caries and 49.68% were female. Among those with caries, 69.74% consumed sugary drinks/sweets (95% CI: 47.84−87.73%) and 56.87% (95% CI: 35.39−77.08%) had good brushing habits. Sugary drinks had a two times higher likelihood of leading to caries (OR: 2.04, p < 0.001). Good oral hygiene reduced the risk of caries by 35% (OR: 0.65, p < 0.001). Concerning maternal education, only secondary education reduced the likelihood of caries (OR: 0.96), but primary education incurred 25% higher risks (OR: 1.25, p = 0.03). A 65% reduction was computed when caregivers helped children with tooth brushing (OR: 0.35, p = 0.04). Most families had a low socioeconomic status (SES) (35.9%, 95% CI: 16.73−57.79), which increased the odds of caries by 52% (OR: 1.52, p < 0.001); a high SES had a 3% higher chance of caries. In the entire sample, 44.44% (95% CI: 27.73−61.82%) of individuals had access to dental services or had visited a dental service provider. Conclusion: Our findings demonstrate that high sugar consumption, low maternal education, and low and high socioeconomic status (SES) increased the risk of dental caries in LMICs. Good brushing habits, higher maternal education, help with tooth brushing, and middle SES provided protection against caries across LMIC children. Limiting sugars, improving oral health education, incorporating national fluoride exposure programs, and accounting for sociodemographic limitations are essential for reducing the prevalence of dental caries in these settings.

Fluoride Metabolism in Pregnant Women: A Narrative Review of the Literature

Epidemiological studies use biomarkers of fluoride exposure in pregnant women as surrogate measures of fetal fluoride exposure; however, there is little understanding of how pregnancy affects fluoride metabolism and its biomarkers. This narrative review summarizes the changes of pregnancy that have the potential to impact fluoride’s absorption, distribution and excretion, and highlights the limited body of evidence on the topic. The physiologic systems that experience pregnancy-associated changes relevant to fluoride’s metabolism are the cardiovascular, renal, metabolic and gastrointestinal, as well bone and calcium metabolism and the body’s acid-base balance. The available evidence indicates that fluoride is found in the maternal plasma and urine, placenta, amniotic fluid and fetus. Although plasma and urinary fluoride vary across gestation, there is insufficient quality evidence to determine the direction or extent of such variation. Furthermore, there is no doubt that fluoride from maternal blood crosses the placenta and is absorbed and excreted by the fetus; however, the biological mechanisms behind this placental passage are unknown. Research on maternal and prenatal biomarkers of fluoride exposure would benefit from studies on how pregnancy-associated changes affect the metabolism of fluoride across gestation, the mechanisms for the intestinal absorption of fluoride in pregnant women, and the placental passage of fluoride.

PARTITIONING AROUND MEDOIDS CLUSTERING AND RANDOM FOREST CLASSIFICATION FOR GIS-INFORMED IMPUTATION OF FLUORIDE CONCENTRATION DATA

Community water fluoridation is an important component of oral health promotion, as fluoride exposure is a well-documented dental caries-preventive agent. Direct measurements of domestic water fluoride content provide valuable information regarding individuals' fluoride exposure and thus caries risk; however, they are logistically challenging to carry out at a large scale in oral health research. This article describes the development and evaluation of a novel method for the imputation of missing domestic water fluoride concentration data informed by spatial autocorrelation. The context is a state-wide epidemiologic study of pediatric oral health in North Carolina, where domestic water fluoride concentration information was missing for approximately 75% of study participants with clinical data on dental caries. A new machine-learning-based imputation method that combines partitioning around medoids clustering and random forest classification (PAMRF) is developed and implemented. Imputed values are filtered according to allowable error rates or target sample size, depending on the requirements of each application. In leave-one-out cross-validation and simulation studies, PAMRF outperforms four existing imputation approaches-two conventional spatial interpolation methods (i.e., inverse-distance weighting, IDW and universal kriging, UK) and two supervised learning methods (k-nearest neighbors, KNN and classification and regression trees, CART). The inclusion of multiply imputed values in the estimation of the association between fluoride concentration and dental caries prevalence resulted in essentially no change in PAMRF estimates but substantial gains in precision due to larger effective sample size. PAMRF is a powerful new method for the imputation of missing fluoride values where geographical information exists.

A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children

As a guide to establishing a safe exposure level for fluoride exposure in pregnancy, we applied benchmark dose modeling to data from two prospective birth cohort studies. We included mother-child pairs from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort in Mexico and the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort in Canada. Maternal urinary fluoride concentrations (U-F, in mg/L, creatinine-adjusted) were measured in urine samples obtained during pregnancy. Children were assessed for intelligence quotient (IQ) at age 4 (n = 211) and between six and 12 years (n = 287) in the ELEMENT cohort, and three to four years (n = 407) in the MIREC cohort. We calculated covariate-adjusted regression coefficients and their standard errors to assess the association of maternal U-F concentrations with children's IQ measures. Assuming a benchmark response of 1 IQ point, we derived benchmark concentrations (BMCs) and benchmark concentration levels (BMCLs). No deviation from linearity was detected in the dose-response relationships, but boys showed lower BMC values than girls. Using a linear slope for the joint cohort data, the BMC for maternal U-F associated with a 1-point decrease in IQ scores was 0.31 mg/L (BMCL, 0.19 mg/L) for the youngest boys and girls in the two cohorts, and 0.33 mg/L (BMCL, 0.20 mg/L) for the MIREC cohort and the older ELEMENT children. Thus, the joint data show a BMCL in terms of the adjusted U-F concentrations in the pregnant women of approximately 0.2 mg/L. These results can be used to guide decisions on preventing excess fluoride exposure in pregnant women.

Lithium in Drinking Water as a Public Policy for Suicide Prevention: Relevance and Considerations

Although suicide is considered a major preventable cause of mortality worldwide, we do not have effective strategies to prevent it. Lithium has been consistently associated with lowering risk of suicide. This effect could occur at very low concentrations, such as trace doses of lithium in tap water. Several ecological studies and recent meta-analysis have suggested an inverse association between lithium in water and suicide in the general population, with a lack of knowledge of clinically significant side effects. This paper is aimed as a proposal to discuss the addition of lithium to drinking water to decrease the suicide rate. For this, we review the evidence available, use previous experiences, such as water fluoridation to prevent dental caries, and discuss the complexity involved in such a public policy. Considering the limited data available and the controversies contained in this proposal, we suggest that a consensus on lithium concentration in water is needed, where the suicide rates start to reduce, as happened with water fluoridation. This measure will require to develop community-controlled trials with strict monitoring of any side effects, where democratic procedures would constitute one of the most appropriate ways to validate its implementation according to the reality of each community.

The Impact of Water Fluoridation on Medicaid-Eligible Children and Adolescents in Alaska

Juneau, Alaska, ceased community water fluoridation (CWF) in 2007, and previous research found a substantial increase in dental caries-related procedures and treatment costs for children from low-income families in Juneau between 2003 and 2012. We collected comparable dental caries-related procedures and treatment cost data for the same years for children in Anchorage, Alaska, where CWF has been continuously maintained. This retrospective study analyzed all Medicaid dental claims records in two separate years for caries-related procedures and associated costs among children (aged 0 to 18 years) residing in Anchorage's 99502 zip code and compared these records to data from Juneau. We obtained descriptive statistics and conducted bivariate analyses and binomial logistic regression. Between 2003 and 2012, children in Anchorage experienced a nonsignificant modest decrease in the mean number of caries-related procedures and only small, statistically nonsignificant changes to the mean inflation-adjusted service costs of caries-related restorative care. The lack of significant change in child dental caries-related procedures and treatment costs in Anchorage between 2003 and 2012 contrasted with the substantial increase in caries-related procedures and treatment costs over the same period in Juneau. Our results are consistent with previous research that has demonstrated a significant protective effect of CWF against dental caries.

Impact of water fortification with calcium on calcium intake in different countries: a simulation study

OBJECTIVE

To simulate the impact - effectiveness and safety - of water fortification with different concentrations of Ca using the Intake Modelling, Assessment and Planning Program.

DESIGN

This is a secondary analysis of national or sub-national dietary intake databases.

SETTING AND PARTICIPANTS

Uganda, Lao People's Democratic Republic (PDR), Bangladesh, Zambia, Argentina, USA and Italy.

RESULTS

We found that for dietary databases assessed from low- and middle-income countries (LMIC), the strategy of fortifying water with 500 mg of Ca/l would decrease the prevalence of low Ca intake in all age groups. We also found that this strategy would be safe as no group would present a percentage of individuals exceeding the upper limit in >2 %, except women aged 19-31 years in Lao PDR, where 6·6 % of women in this group would exceed the upper limit of Ca intake. The same strategy would lead to some groups exceeding the upper limit in USA and Italy.

CONCLUSIONS

We found that for most LMIC countries, water fortified with Ca could decrease the prevalence of Ca intake inadequacy without exceeding the upper levels of Ca intake.

NHS dental activity: a population marker for the effectiveness of community water fluoridation in children in England

Aim To understand the possible beneficiary effects of artificial and naturally occurring water fluoridation on dental health of children, using routinely collected NHS Dental Statistics.Method A secondary analysis of the NHS Dental Statistics for England 2018-2019 dataset. The proportion of Band 1 courses of treatments are compared with Band 2, Band 3 and urgent treatments collectively, for children attending dental practices in naturally and artificially fluoridated local authorities compared with non-fluoridated authorities who are their statistical peers. Proportions of dental treatments are described by the levels of Index of Multiple Deprivation for the area in which the practice is located.Results The dataset had, 2,001,921 banded paediatric courses of treatment; 1,227,282 provided by dental practices in fluoridated local authorities and 774,639 in non-fluoridated local authorities. Water fluoridation was associated with a significant reduction in dental interventions in the most deprived populations. The proportions of active interventional treatments in the 10% most deprived decile (decile 1) are 0.243 (Cl 0.239-0.247) and 0.188 (Cl 0.184-0.191), in non-fluoridated and fluoridated local authorities, respectively.Conclusion Analysis of routinely collected NHS dental statistics shows potential utility as a tool for demonstrating the effects of community water fluoridation schemes in reducing oral health inequalities among the most deprived socioeconomic populations. The pattern of dental need and intervention is not as expected and therefore, further research is required to control for systematic confounding factors.

Spectroscopic Determination of Fluoride Using Eriochrome Black T (EBT) as a Spectrophotometric Reagent from Groundwater

Fluoride health problem is a great concern worldwide, most often as a result of groundwater intake. Thus, determination of fluoride is vital to take appropriate measures upon fluoride contamination of water. Potentiometric method of analysis is reliable for the determination of fluoride in various samples. In addition, spectroscopic methods are found important to quantify fluoride levels from water; however, several factors hinder its easier determination. Among the bottlenecks, the use of toxic chemicals and tedious steps in preparing chemicals (e.g., SPADNS method) are to mention a few. In this study, a spectrophotometric method was developed for the determination of fluoride from groundwater using Eriochrome Black T (EBT) as a spectroscopic reagent. Experimental parameters that influence the determination of fluoride including ligand type, kinetics, pH, and ligand-to-metal ratio were assayed. Evaluation of fluoride levels showed that Beer–Lambert's law is obeyed in the range of 0.3–5.0 mg/L at 544 nm. The calibration curve, resulting in good linearity (R² = 0.9997), was considered during quantitative analysis of the samples and in the spiking analysis. The limits of detection (LOD) and quantification (LOQ) of the method were found to be 0.19 and 0.64 mg/L, respectively. The precision studied in terms of intraday and interday at three concentration levels showed less than 5.4% RSD. Applicability of the method was investigated by analyzing groundwater samples spiked with fluoride standards, and satisfactory recoveries in the range of 98.18–111.4 were demonstrated. The developed spectrophotometric method has been successfully applied for fluoride determinations in groundwater samples. Thus, it could be used as an attractive alternative for the determination of fluoride from groundwater.

Impact of water fluoridation on dental caries decline across racial and income subgroups of Brazilian adolescents

OBJECTIVES

The aim of this study was to assess the impact of community water fluoridation (CWF) on differences in dental caries decline across racial and socioeconomic subgroups of Brazilian adolescents.

METHODS

Two nationwide Brazilian population-based oral health surveys were used (Brazilian Oral Health Survey 2003 and 2010). In total, 7,198 adolescents from 15 years to 19 years old living in 50 cities investigated in both surveys were included. The mean numbers of untreated decayed teeth (DT) according to racial (Whites vs. Browns/Blacks) and socioeconomic subgroups (at or above the minimum wage per capita vs. under) were analysed. Difference-in-differences negative binomial regressions were adjusted by schooling, age, and sex. Decayed, missing, and filled teeth and DT prevalence, calculated as a categorical variable, were used in sensitivity analyses.

RESULTS

The adjusted difference of reduction in DT was similar across socioeconomic subgroups (β=-0.05; 95% confidence interval [CI], -0.45 to 0.35) and favoured, but not to a significant degree, Whites (β=-0.34; 95% CI, -0.74 to 0.04) compared to Brown/Blacks in fluoridated areas. In non-fluoridated areas, significant differences were observed in the mean number of DT, favouring the higher socioeconomic subgroup (β=-0.26; 95% CI, -0.53 to -0.01) and Whites (β=-0.40; 95% CI, -0.69 to -0.11) in relation to their counterparts. The sensitivity analyses confirmed the findings.

CONCLUSIONS

The similar reduction in DT across income subgroups suggests that CWF has had a beneficial effect on tackling income inequalities in dental caries within a 7-year timeframe.

Relationship between fluoride exposure and count of Streptococcus mutans in supragingival biofilm of mexican scholar children

Background/purpose

The use of fluoride is known to reduce the risk of dental caries. There is limited information on the relationship between Streptococcus mutans (S. mutans) and fluoride exposure. This study investigated the association between the count of S. mutans on supragingival biofilm and fluoride exposure of scholar children.

Materials and methods

In this cross-sectional study, 56 children from 9 to 11 years of age were selected. Fluoride concentration in drinking water, urine and saliva of each participant were assessed. The count of S. mutans was estimated by calculating the DNA copy number through a quantitative real time polymerase chain reaction (qPCR) assay. Also, sociodemographic data, oral and general health information and variables related to caries risk were evaluated. A stepwise multiple linear regression was performed in all caries related predictor variables with the count of S. mutans as the dependent variable.

Results

The multiple linear regression analysis showed that the concentration of fluoride in saliva (β = −3.029, p < 0.001) and urine (β = −2.057, p = 0.017), time of last visit to the dentist (β = 1.968, p = 0.001), plaque index (β = 1.637, p = 0.006) and number of surfaces with codes 3–6 (D_3-6MFS) of ICDAS II criteria (β = 0.283, p = 0.076) were significantly associated with the count of S. mutans (Adjusted R square = 0.427, p < 0.001).

Conclusion

Fluoride levels in urine and saliva were negatively associated with the count of S. mutans in supragingival biofilm. Plaque index, D_3-6MFS and time of last visit to the dentist showed a positive association.

Perspectives on Social and Environmental Determinants of Oral Health

Most oral conditions have a multifactorial etiology; that is, they are modulated by biological, social, economic, cultural, and environmental factors. A consistent body of evidence has demonstrated the great burden of dental caries and periodontal disease in individuals from low socioeconomic strata. Oral health habits and access to care are influenced by the social determinants of health. Hence, the delivery of health promotion strategies at the population level has shown a great impact on reducing the prevalence of oral diseases. More recently, a growing discussion about the relationship between the environment, climate change, and oral health has been set in place. Certainly, outlining plans to address oral health inequities is not an easy task. It will demand political will, comprehensive funding of health services, and initiatives to reduce inequalities. This paper sought to give a perspective about the role of social and physical environmental factors on oral health conditions while discussing how the manuscripts published in this Special Issue could increase our knowledge of the topic.

Serum exosome-derived biomarkers for the early detection of oral squamous cell carcinoma

Blood exosomes help regulate communication between tumour cells, moderating their behaviour. We sought to determine the protein content in serum exosomes (SEs), to characterise SEs, and to discover novel clinical biomarkers of oral squamous cell carcinoma (OSCC). Differentially expressed proteins (DEPs) of OSCC were identified using proteomics and then analysed using bioinformatics, before validation using ELISA, IHC, and RT-PCR. The influence of SEs on oral cancer cells was detected using CCK-8 and migration assays. Twelve DEPs were found in SEs from OSCC. Four proteins were targeted for further verification. New biomarkers exhibiting high sensitivity and specificity in diagnosing OSCC comprised C-reactive protein (CRP), von willebrand factor (VWF), and leucine-rich alpha-2-glycoprotein (LRG). Combined biomarkers outperformed any single protein. We also demonstrated that tumour-derived exosomes promoted tumour cell migration, but not proliferation and apoptosis. Our study indicates that CRP, VWF, and LRG are potential clinically relevant OSCC biomarkers. OSCC-related SEs may help promote migration of oral cells.

UK Dental Medicines Advisory Service: questions asked by dentists - part 4: prescribing of high-strength fluoride toothpastes and use of fluoride varnishes in dental practice

The UK Dental Medicines Advisory Service (UKDMAS) provides advice to dentists and other dental healthcare professionals concerning the use of medicines and medical devices in dental prescribing, administering, or dispensing. The commonly asked questions posed to the UKDMAS concerning the prescribing of high-strength fluoride toothpastes and use of fluoride varnishes in dental practice are discussed with answers, supplemented by relevant information from clinicians. These include: the prescribing of high-strength fluoride toothpastes and application of fluoride varnish in particular patient groups; issues concerning the amounts of fluoride toothpaste that can be prescribed; regulations related to the supply of fluoride toothpastes by dental hygienists and therapists; and the constituents and selection of fluoride varnishes.

Dental fluorosis prevalence in Saudi Arabia

Aim

In order to improve the understanding of dental fluorosis prevalence in Saudi Arabia and have a good idea of the quality of the studies that have been conducted, a systematic review was conducted to evaluate the prevalence of dental fluorosis among people who live in Saudi Arabia.

Methods

Online databases EMBASE and MEDLINE and the Cochrane Library were searched, without any restriction regarding age. In addition, there were no study design filters applied to the search engine. Study selection and data extraction were conducted in duplicate. Studies were included if they were conducted in Saudi Arabia on any population (adults and children) and collected dental fluorosis data. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the studies. A narrative synthesis was conducted.

Results

Seven cross-sectional studies were identified. Areas of weakness in study design/conduct were low response rates, and identification and handling of confounding factors. Statistical pooling of data was not appropriate due to substantial heterogeneity, due in part to variation in sample size, variation of water fluoridation concentration, index used, targeted population and age group. Seven studies present dental fluorosis at any level. The proportion of dental fluorosis prevalence at any level ranged from 0.00 to 0.91. Six studies explored the prevalence of dental fluorosis of aesthetic-only level of concern. The proportion of dental fluorosis in this category ranged from 0.07 to 0.76.

Conclusion

The proportion of dental fluorosis at any level ranged from 0.00 to 0.91 and fluorosis at aesthetics level ranged from 0.07 to 0.76. However, current data does not provide a complete assessment of dental fluorosis across Saudi Arabia. Existing studies are limited in terms of the population covered. The included studies had methodological flaws.

A systematic review and meta-analysis of the association between fluoride exposure and neurological disorders

Different studies have suggested that fluoride is related to neurological disorders in children and adolescents, but clinical evidences of which neurological parameters associated to fluoride exposure are, in fact, still controversial. In this way, this systematic review and meta-analysis aimed to show if there is an association between fluoride exposure from different sources, doses and neurological disorders. Terms related to "Humans"; "Central nervous system"; "Fluorides"; and "Neurologic manifestations" were searched in a systematic way on PubMed, Scopus, Web of Science, Lilacs, Cochrane and Google Scholar. All studies performed on humans exposed to fluoride were included on the final assessment. A meta-analysis was then performed and the quality level of evidence was performed using the GRADE approach. Our search retrieved 4,024 studies, among which 27 fulfilled the eligibility criteria. The main source of fluoride was naturally fluoridated water. Twenty-six studies showed alterations related to Intelligence Quotient (IQ) while only one has evaluated headache, insomnia, lethargy, polydipsia and polyuria. Ten studies were included on the meta-analysis, which showed IQ impairment only for individuals under high fluoride exposure considering the World Health Organization criteria, without evidences of association between low levels and any neurological disorder. However, the high heterogeneity observed compromise the final conclusions obtained by the quantitative analyses regarding such high levels. Furthermore, this association was classified as very low-level evidence. At this time, the current evidence does not allow us to state that fluoride is associated with neurological damage, indicating the need for new epidemiological studies that could provide further evidences regarding this possible association.

Development Strategy of Endodontic Filling Materials Based on Engineering and Medical Approaches

This article is a literature review aimed at presenting the general state of knowledge in manufacturing engineering and materials engineering to develop engineering materials applied for endodontic treatment as filling materials. Particular attention was paid to theoretical analyses concerning the selection of methods for developing and obturating root canals and discussing the results of experimental studies available in the literature. These activities aimed to compare the importance of the most commonly used endodontic filling materials based on gutta-percha or polymeric polyester materials, commonly known as resilon, respectively. The motivation to take up this complex, multi-faceted topic in this paper is the extent of caries, periodontal disease, and other oral diseases in 3 to 5 billion people, often affecting toothlessness and contributing to an increase in the index of disability-adjusted life years (number). Endodontics is an important element of the authors’ concept of Dentistry Sustainable Development (DSD) > 2020. The principles of qualifying patients for endodontic treatment are discussed. The introduction of rotary tools, especially manufactured from Nitinol alloy, to develop root canals and the latest thermohydraulic and condensation techniques for obturation guarantee progress in endodontics. The “Digital Twins” methodology was used, rooted in the idea of Industry 4.0 and the resulting idea of Dentistry 4.0, as well as knowledge management methods, to perform experimental research in virtual space, concerning methods of developing and obturating the root canal and assessing the tightness of fillings. Microscopic visualization methods were also used. Significant factors determining the effectiveness of endodontic obturation are the selection of the filling material and the appropriate obturation method. The generalized dendrological matrix of endodontic filling materials considers the criteria of mechanical strength influencing the potential root fracture and the quality of root canal filling. The results of the SWOT point analysis (strengths and weaknesses, opportunities, threats) were also compared. For both filling materials, the weaknesses are much less than the strengths, while the threats are slightly less than the opportunities for the gutta-percha-based material, while for resilon the opportunities are much smaller than the threats. It requires the application of an appropriate development strategy, i.e., MAXI-MAXI in the case of a filling material based on gutta-percha and MAXI-MINI in the case of resilon. Therefore, the analysis of these experimental data does not indicate the real competitiveness of resilon for the gutta-percha-based material. This material deservedly maintains its strong position as the “Gold Standard of Endodontics”.

Controversy: The evolving science of fluoride: when new evidence doesn't conform with existing beliefs

Over the past 75 years, health authorities have declared that community water fluoridation-a practice that reaches over 400 million worldwide-is safe. Yet, studies conducted in North America examining the safety of fluoride exposure in pregnancy were nonexistent. When a Canadian study reported that higher fluoride exposure in pregnant women was associated with lower IQ scores in young children, critics attacked the methodology of the study and discounted the significance of the results. Health authorities continued to conclude that fluoride is unequivocally safe, despite four well-conducted studies over the last 3 years consistently linking fluoride exposure in pregnancy with adverse neurodevelopmental effects in offspring. We describe the challenges of conducting fluoride research and the overt cognitive biases we have witnessed in the polarized fluoride debate. The tendency to ignore new evidence that does not conform to widespread beliefs impedes the response to early warnings about fluoride as a potential developmental neurotoxin. Evolving evidence should inspire scientists and health authorities to re-evaluate claims about the safety of fluoride, especially for the fetus and infant for whom there is no benefit.

Beyond oral hygiene, are capacity-altering, biologically based interventions within the moral domain of dentistry?

Oral diseases such as dental caries (DC) and periodontitis are widely prevalent, and existing approaches to managing these conditions have only a limited effect. Accordingly, there is growing interest in the development of novel biological interventions (including, among others, CRISPR-Cas9) that might, in the future, be used to prevent the development of or cure these conditions. However, in addition to familiar concerns about using biological interventions in children who cannot provide valid consent, it is not clear whether the provision of these interventions would fall within the proper domain of dentistry. In this opinion paper, we defend the view that the provision of reasonably safe and effective novel biological interventions aimed at preventing DC and periodontitis should be understood to fall within the proper domain of dentistry. To do so, we first argue that their use would be consistent with existing practice in dentistry. We then argue that: i) they may substantially increase the recipient's wellbeing and future autonomy; and ii) that their use could constitute a form of indirect preventative medicine by addressing a threat to systemic health.

Prophylaxis of caries with fluoride for children under five years

We looked at existing recommendations and supporting evidence on the effectiveness and potential harms of the different fluoride interventions in preventing dental caries in children under 5 years of age.

We conducted a literature search up to the 12th of September 2019 by using key terms and manual search in selected sources. We summarized the recommendations and the strength of the recommendation when and as reported by the authors. We summarized the main findings of systematic reviews with the certainty of the evidence as reported.

Water fluoridation has been widely implemented worldwide for several decades and evidence shows it reduces the prevalence of dental caries. Salt or milk fluoridation are other collective fluoride interventions that are also effective to prevent dental caries in children. The evidence of effects of oral fluoride supplements for caries prevention is limited and inconsistent. The use of fluoride toothpastes has consistently been proven to be effective in the prevention of dental caries. The evidence for the effects of the different levels of fluoride concentration in toothpastes is more limited. Topical fluorides (gels and varnishes) are effective in preventing dental caries and are mainly recommended to children with high risk of dental caries. Early childhood intake of fluoride supplements and fluoride level of 0.7 ppm (ppm) in drinking water are associated with the risk of dental fluorosis, ranging from minor forms to severe forms that are of aesthetic concerns.

Is Gutta-Percha Still the “Gold Standard” among Filling Materials in Endodontic Treatment?

The paper is an extensive monographic review of the literature, and also uses the results of the authors’ own experimental research illustrating the noticed developmental tendencies of the filling material based on gutta-percha. The whole body of literature proves the correctness of the research thesis that this material is the best currently that can be used in endodontics. Caries is one of the most common global infectious diseases. Since the dawn of humankind, the consequence of the disease has been the loss of dentition over time through dental extractions. Both tooth caries and tooth loss cause numerous complications and systemic diseases, which have a serious impact on insurance systems and on the well-being, quality, and length of human life. Endodontic treatment, which has been developing since 1836, is an alternative to tooth extraction. Based on an extensive literature review, the methodology of qualifying patients for endodontic treatment was analyzed. The importance of selecting filling material and techniques for the development and obturation of the root canal during endodontic treatment was described. Particular attention was paid to the materials science aspects and the sequence of phase transformations and precipitation processes, as well as the need to ensure the stoichiometric chemical composition of Ni–Ti alloys, and the vacuum metallurgical processes and material processing technologies for the effects of shape memory and superelasticity, which determine the suitability of tools made of this alloy for endodontic purposes. The phenomena accompanying the sterilization of such tools, limiting the relatively small number of times of their use, play an important role. The methods of root canal preparation and obturation methods through cold side condensation and thermoplastic methods, including the most modern of them, the thermo-hydraulic condensation (THC) technique, were analyzed. An important element of the research hypothesis was to prove the assumption that to optimize the technology of development and obturation of root canals, tests of filling effectiveness are identified by the density and size of the gaps between the root canal wall, and the filling methods used and devices appropriate for material research, using mainly microscopy such as light stereoscopic (LSM) and scanning electron (SEM). The most beneficial preparations were obtained by making a longitudinal breakthrough of 48 natural human teeth, extracted for medical reasons, different from caries, with compliance with all ethical principles in this field. The teeth were prepared using various methods and filled with multiple obturation techniques, using a virtual selection of experimental variants. The breakthroughs were made in liquid nitrogen after a one-sided incision with a narrow gap created by a diamond disc using a materialographic cutter. The best effectiveness of the root canal filling was ensured by the technology of preparing the root canals with K3 rotary nitinol tools and filling the teeth with the THC thermoplastic method using the System B and Obtura III devices with studs and pellets of filling material based on gutta-percha after covering the root canal walls with a thin layer of AH Plus sealant. In this way, the research thesis was confirmed.

External control of fluoridation in the public water supplies of Brazilian cities as a strategy against caries: a systematic review and meta-analysis

Background

Among the methods currently available to provide fluoride in population levels, fluoridated water is the most successful for presenting high efficacy, safety and good cost–benefit. However, recent studies on external control have shown great variability of fluoride concentrations in the water from treatment stations in Brazilian cities, which must present concentration between 0.6 and 0.8 mg/L to be considered acceptable in most cities. Thus, this study aimed to perform a systematic review of the literature to assess the adequacy of fluoride concentration in the water in Brazilian cities using external control.

Methods

The protocol was registered in PROSPERO. Six databases were used as primary search sources and three databases were used to partially capture the "gray literature". Only observational studies that assessed the fluoride concentration of artificially fluoridated water from the public supply network were included. The JBI Critical Appraisal Tools for Systematic Reviews was used to assess the risk of bias of the studies. A proportion meta-analyses using random-effect models were performed. The heterogeneity between studies was determined by I² statistic. Meta-regressions were conducted to identify relevant moderators to be used in stratified meta-analyses. Publication bias was investigated by Egger’s tests.

Results

The search provided 2038 results, from which 14 met the eligibility criteria and were included in the data extraction of the review. Overall, the water samples were collected from 449 different sources in three Brazilian regions. Thirteen studies presented a low risk of bias. The mean concentration of fluoride ranged from 0.17 to 0.89 ppmF. The meta-analyis demonstrated that more than half of the water samples analyzed had fluoride concentration levels outside the acceptable range (56.6%; 95% CI 45.5; 67.3), with high heterogeneity.

Conclusion

More than half of the public water supply analyzed in the studies selected had fluoride concentration levels outside the acceptable range, which may affect the risk of developing oral diseases in the Brazilian population, having an important impact on public health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01754-2.

Fluoridation cessation and children's dental caries: A 7-year follow-up evaluation of Grade 2 schoolchildren in Calgary and Edmonton, Canada

Objectives

We examined the effect of fluoridation cessation on children's dental caries experience in the Canadian cities of Calgary (cessation in 2011) and Edmonton (still fluoridated).

Methods

We used a pre‐post cross‐sectional design with comparison group. We studied Grade 2 schoolchildren (approximately 7 years old) 7‐8 years after fluoridation cessation in Calgary, thus capturing children born after cessation occurred. Data collection included a dental examination conducted in school by calibrated dental hygienists, a questionnaire completed by parents, and fingernail clippings for a small subsample. Our overall analytic approach was twofold. We first examined differences in dental caries experience (deft and DMFT, and smooth surface caries based on defs and DMFS) between Calgary and Edmonton and over time (comparing 2018/2019 data to pre‐cessation and early post‐cessation surveys in our setting). Second, we evaluated whether differences were likely to reflect fluoridation cessation in Calgary, rather than other factors.

Results

The prevalence of caries in the primary dentition was significantly higher (P < .05) in Calgary (fluoridation cessation) than in Edmonton (still fluoridated). For example, crude deft prevalence in 2018/2019 was 64.8% (95% CI 62.3‐67.3), n = 2649 in Calgary and 55.1% (95% CI 52.3‐57.8), n = 2600 in Edmonton. These differences were consistent and robust: they persisted with adjustment for potential confounders and in the subset of respondents who were lifelong residents and reported usually drinking tap water; they had widened over time since cessation; and they were corroborated by assessments of dental fluorosis and estimates of total fluoride intake from fingernail clippings. Findings for permanent teeth were less consistent, which likely reflects that 7‐year‐olds have not had the time to accumulate enough permanent dentition caries experience for differences to have become apparent.

Conclusions

Our findings are consistent with an adverse impact of fluoridation cessation on children's dental health in Calgary and point to the need for universal, publicly funded prevention activities—including but not limited to fluoridation.

Intestinal changes associated with fluoride exposure in rats: Integrative morphological, proteomic and microbiome analyses

Gastrointestinal signs and symptoms are the first signs of toxicity due to exposure to fluoride (F). This suggests the possibility that lower levels of subchronic F exposure may affect the gut. The aim of this study was to evaluate changes in the morphology, proteome and microbiome of the ileum of rats, after subchronic exposure to F. Male rats ingested water with 0, 10, or 50 mgF/L for thirty days. Treatment with F, regardless of the dose, significantly decreased the density of HuC/D-IR neurons, whereas CGRP-IR and SP-IR varicosities were significantly increased compared to the control group. Increased VIP-IR varicosities were significantly increased only in the group treated with 50 mgF/L. A significant increase in thickness of the tunica muscularis, as well as in the total thickness of the ileum wall was observed at both F doses when compared to controls. In proteomics analysis, myosin isoforms were increased, and Gastrotopin was decreased in F-exposed mice. In the microbiome metagenomics analysis, Class Clostridia was significantly reduced upon exposure to 10 mgF/L. At the higher F dose of 50 mg/L, genus Ureaplasma was significantly reduced in comparison with controls. Morphological and proteomics alterations induced by F were marked by changes associated with inflammation, and alterations in the gut microbiome. Further studies are needed to determine whether F exposure increases inflammation with secondary effects of the gut microbiome, and/or whether primary effects of F on the gut microbiome enhance changes associated with inflammation.

The Association of Social Determinants of Health with Somali Refugee Mother-Child Caries

Minnesota has the largest population of Somali refugees with the majority depending on public insurance for dental care. The social determinants of health (SDOH) framework is helpful to identify factors that may be related to oral health, and subsequently plan for public health initiatives. The purpose of this study was to measure the correlation between Somali refugee mother-child caries experience, and to identify associations between SDOH factors and child caries. The study was conducted in day care facilities where oral screenings and surveys identified SDOH factors at the individual, provider, community and environmental levels. A positive correlation was found between mother-child caries experience. Factors associated with child caries (p ≤ 0.05) were found at all SDOH levels except the provider level though only individual level factors for mothers and children yielded the expected results. SDOH affecting child caries were limited to individual demographic, behavioral and attitudinal factors.

Fluoride in the drinking water and dental caries experience by tooth surface susceptibility among adults

Background

Dental caries is the most prevalent non-communicable health condition globally. The surface-based susceptibility hierarchy indicates that surfaces in the same group have similar susceptibility to caries, where the most susceptible group consists of occlusal surfaces of first molars and buccal surfaces of lower first molars, and the least susceptible surfaces are smooth and proximal surfaces of first premolars, canines and incisors. Therefore, fluoride in the drinking water could impact one group more than the other group. The present study examined the association between fluoride levels in the drinking water and dental caries experience in adults in the context of varying tooth surface susceptibility.

Methods

Data from the cross-sectional National Lithuanian Oral Health Survey conducted in 2017–2019 included a stratified random sample of 1398 35–74-year-olds (52% response rate). Dental caries experience in dentine was measured at a surface level. The surfaces were grouped according to their caries susceptibility (group 1 being the most and group 4 the least susceptible), and dental caries experience was calculated separately for each susceptibility group, creating four outcomes. Information about explanatory variable, fluoride levels in the drinking water, was provided by the water suppliers. The questionnaire inquired about potential determinants: sociodemographic characteristics and oral health-related behaviors. Chi-square, Mann–Whitney U and Kruskal Wallis tests were used for descriptive statistics, and linear regression analyses to examine the association between fluoride levels and four outcomes.

Results

The proportions of median decayed, missing, filled surfaces decreased following the surface-based susceptibility hierarchy (group 1–33%, group 2–28%, group 3–24%, group 4–15%). When adjusted for potential determinants, higher-level fluoride (≥ 0.7 ppm vs < 0.7 ppm) in the drinking water associated with lower dental caries experience in all surface-based susceptibility hierarchy groups; Group 1: β = − 0.23 (95 %CI − 0.44; − 0.001), Group 2: β = − 0.44 (95 %CI − 0.82; − 0.07), Group 3: β = − 1.14 (95 %CI − 1.88; − 0.41) and Group 4: β = − 6.28 (95 %CI − 9.29; − 3.30).

Conclusions

The higher-level fluoride in the drinking water associated with lower dental caries experience in adults and this was observed in all surface-based susceptibility groups. However, there is a need to validate the surface-based susceptibility hierarchy in longitudinal adult studies.

Fluoride exposure and factors affecting dental caries in preschool children living in two areas with different natural levels of fluorides

BACKGROUND

Successful oral health interventions must be based on the specific needs of the population that they serve. Evaluation of habits related to dental caries development and estimation of fluoride exposure in a target group of young patients helps to plan effective and safe caries prevention strategies.

OBJECTIVES

The study aimed to evaluate factors affecting dental caries experience and sources of fluoride exposure in preschool children living in two areas: with optimal and low natural content of fluoride in drinking water.

MATERIALS AND METHODS

The study included a group of 73 children of both sexes aged 4-7 years attending two kindergartens in Środa Wielkopolska and Turek (Wielkopolska Voivodeship, Poland), where the content of fluoride in drinking water according to data obtained in the sanitary station ranged from 0.68 to 0.74 mg/L (optimal concentration of fluoride) and from 0.19 to 0.30 mg/L (low concentration of fluoride), respectively. Parents of patients completed a survey about diet, hygiene, and dental care, taking into account the child's fluoride exposure. The calibrated dentist assessed the oral health condition using a mirror, a CPI probe, and a headlamp. Oral hygiene was recorded using the Silness and Löe plaque index, caries experience by calculating the numbers of decayed, missing, and filled primary, and permanent teeth (dmf and DMF, respectively) while caries frequency by calculating the percentage of children with caries experience above 0. In order to assess the fluoride concentrations in urine and drinking water, parents were asked to provide a urine sample collected on fasting and a tap water sample. Fluoride concentrations were assessed using a 09-37 (MARAT) fluoride ion-selective electrode and a RAE 111 silver-chloride reference electrode. Statistical analysis was conducted using the data analysis software system Statistica (version 12, StatSoft, Inc. 2014), assuming a statistical significance level p < 0.05.

RESULTS

No statistically significant differences were found between caries indices of the examined children in each kindergarten (p > 0.05). Urinary fluoride levels were higher in children who tended to swallow toothpaste or used fluoride rinses and positively correlated with fluoride concentrations in the drinking water. Dental caries experience in the examined children depended on the effectiveness and frequency of oral hygiene procedures and dietary habits.

CONCLUSIONS

The strategy aimed at improving the oral health of the examined group of children should include accomplishing oral hygiene, promoting a non-cariogenic diet, and, finally, controlling fluoride exposure from at-home fluoride products. Caries prevention program ought to be adjusted to individual characteristics of each child, taking into consideration oral hygiene practices, dietary habits and total fluoride intake.

White enamel lesions in children: considering caries, chronological and congenital causes and their consequent care

White enamel lesions are a common presentation to the general dentist and aesthetic concerns are the most frequent presenting problem. Aetiology may be multifactorial and management of such lesions is heavily dependent on the cause. In the paediatric patient, differentiating white lesions caused by caries, fluorosis and genetic and developmental disorders is key to offering optimal long-term treatment outcomes. Early intervention allows for carefully planned management of less common disorders. Many of these disorders exist along a spectrum, and white lesions offer a useful clue to prompt intervention and referral to the relevant specialists. This article overviews common white lesions of the teeth and outlines the hierarchy of management options available.

Community Water Fluoridation: Caveats to Implement Justice in Public Oral Health

Community water fluoridation (CWF), a long-established public health intervention, has been studied for scientific evidence from both of yea and nay standpoints. To justify CWF with scientific evidence inevitably leads to ethical justification, which raises the question of whether oral health is of individual concern or social responsibility. As dental caries is a public health problem, public health ethics should be applied to the topic instead of generic clinical ethics. From both pro- and anti-fluoridationists’ perspectives, CWF is a public health policy requiring a significant level of intervention. Thus, there needs to take further considerations for justifying CWF beyond the simple aspect of utility. For further ethical considerations on CWF, three caveats were suggested: procedural justice, social contexts, and maintenance of trust. The process to justify CWF should also be justified, not simply by majority rule but participatory decision-making with transparency and pluralistic democracy. Social contexts are to be part of the process of resolving conflicting values in public health interventions. Public trust in the dental profession and the oral healthcare system should be maintained over the considerations. This article suggests accountability for reasonableness as a framework to consider infringement by CWF for public justification of its implementation.

How effective and cost-effective is water fluoridation for adults? Protocol for a 10-year retrospective cohort study

BACKGROUND

Tooth decay can cause pain, sleepless nights and loss of productive workdays. Fluoridation of drinking water was identified in the 1940s as a cost-effective method of prevention. In the mid-1970s, fluoride toothpastes became widely available. Since then, in high-income countries the prevalence of tooth decay in children has reduced whilst natural tooth retention in older age groups has increased. Most water fluoridation research was carried out before these dramatic changes in fluoride availability and oral health. Furthermore, there is a paucity of evidence in adults. The aim of this study is to assess the clinical and cost-effectiveness of water fluoridation in preventing invasive dental treatment in adults and adolescents aged over 12.

METHODS/DESIGN

Retrospective cohort study using 10 years of routinely available dental treatment data. Individuals exposed to water fluoridation will be identified by sampled water fluoride concentration linked to place of residence. Outcomes will be based on the number of invasive dental treatments received per participant (fillings, extractions, root canal treatments). A generalised linear model with clustering by local authority area will be used for analysis. The model will include area level propensity scores and individual-level covariates. The economic evaluation will focus on (1) cost-effectiveness as assessed by the water fluoridation mean cost per invasive treatment avoided and (2) a return on investment from the public sector perspective, capturing the change in cost of dental service utilisation resulting from investment in water fluoridation.

DISCUSSIONS

There is a well-recognised need for contemporary evidence regarding the effectiveness and cost-effectiveness of water fluoridation, particularly for adults. The absence of such evidence for all age groups may lead to an underestimation of the potential benefits of a population-wide, rather than targeted, fluoride delivery programme. This study will utilise a pragmatic design to address the information needs of policy makers in a timely manner.

The Antibacterial Effects of Resin-Based Dental Sealants: A Systematic Review of In Vitro Studies

This review aimed to assess the antimicrobial effects of different antibacterial agents/compounds incorporated in resin-based dental sealants. Four databases (PubMed, MEDLINE, Web of Science and Scopus) were searched. From the 8052 records retrieved, 275 records were considered eligible for full-text screening. Nineteen studies met the inclusion criteria. Data extraction and quality assessment was performed by two independent reviewers. Six of the nineteen included studies were judged to have low risk of bias, and the rest had medium risk of bias. Compounds and particles such as zinc, tin, Selenium, chitosan, chlorhexidine, fluoride and methyl methacrylate were found to be effective in reducing the colony-forming unit counts, producing inhibition zones, reducing the optical density, reducing the metabolic activities, reducing the lactic acid and polysaccharide production and neutralizing the pH when they are added to the resin-based dental sealants. In addition, some studies showed that the antibacterial effect was not significantly different after 2 weeks, 2 months and 6 months aging in distilled water or phosphate-buffered saline. In conclusion, studies have confirmed the effectiveness of adding antibacterial agents/compounds to dental sealants. However, we should consider that these results are based on laboratory studies with a high degree of heterogeneity.

Narrow band imaging observed oral mucosa microvasculature as a tool to detect early oral cancer: an Indian experience

BACKGROUND

Narrow band imaging (NBI) is a novel method with the potential to improve the diagnostic capability of white-light.

METHODS

A prospective observational study of 50 consecutive patients, with suspicious malignant/premalignant lesions. White-light images were assessed as suspicious for malignancy/negative for malignancy, whereas NBI images were classified based on the IPCL patterns. All lesions underwent biopsy and accuracy was compared with the histopathology (Fig. 1). Fig. 1 Representative images of the IPCL patterns from Types I-IV RESULTS: 25 lesions (49%) were positive for malignancy, 2 (3.9%) lesions showed severe dysplasia, and 24(47%) were considered negative on histopathology. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of white light and NBI in detecting invasive carcinoma was 74.07%, 79.17%, 80.00%, 73.08% and 76.47%, and 92.67%, 90.16%, 92.56%, 91.67% and 92.16% respectively. The NBI group had a significantly better sensitivity and specificity to white light. The interobserver concordance was κ = 0.881.

CONCLUSION

NBI is a highly effective tool to detect invasive carcinomas amongst suspicious lesions of the oral cavity.

The Concept of Sustainable Development of Modern Dentistry

This paper concerns the assessment of the current state of dentistry in the world and the prospects of its sustainable development. A traditional Chinese censer was adopted as the pattern, with a strong and stable support on three legs. The dominant diseases of the oral cavity are caries and periodontal diseases, with the inevitable consequence of toothlessness. From the caries 3.5–5 billion people suffer. Moreover, each of these diseases has a wide influence on the development of systemic complications. The territorial range of these diseases and their significant differentiation in severity in different countries and their impact on disability-adjusted life years index are presented (DALY). Edentulousness has a significant impact on the oral health-related quality of life (OHRQoL). The etiology of these diseases is presented, as well as the preventive and therapeutic strategies undertaken as a result of modifying the Deming circle through the fives’ rules idea. The state of development of Dentistry 4.0 is an element of the current stage of the industrial revolution Industry 4.0 and the great achievements of modern dental engineering. Dental treatment examples from the authors’ own clinical practice are given. The systemic safety of a huge number of dentists in the world is discussed, in place of the passive strategy of using more and more advanced personal protective equipment (PPE), introducing our own strategy for the active prevention of the spread of pathogenic microorganisms, including SARS-CoV-2. The ethical aspects of dentists’ activity towards their own patients and the ethical obligations of the dentist community towards society are discussed in detail. This paper is a polemic arguing against the view presented by a group of eminent specialists in the middle of last year in The Lancet. It is impossible to disagree with these views when it comes to waiting for egalitarianism in dental care, increasing the scope of prevention and eliminating discrimination in this area on the basis of scarcity and poverty. The views on the discrimination of dentistry in relation to other branches of medicine are far more debatable. Therefore, relevant world statistics for other branches of medicine are presented. The authors of this paper do not agree with the thesis that interventional dental treatment can be replaced with properly implemented prophylaxis. The final remarks, therefore, present a discussion of the prospects for the development of dentistry based on three pillars, analogous to the traditional Chinese censer obtaining a stable balance thanks to its three legs. The Dentistry Sustainable Development (DSD) > 2020 model, consisting of Global Dental Prevention (GDP), Advanced Interventionist Dentistry 4.0 (AID 4.0), and Dentistry Safety System (DSS), is presented.

The impact of stopping or reducing the level of fluoride in public water supplies on dental fluorosis: a systematic review

OBJECTIVE

The increased availability of fluoride and concern over the impact of fluorosis, have led to guidance suggesting a decrease or cease in the optimal concentration of fluoride in water fluoridation schemes. To date there have been no systematic reviews looking at both impact of fluoride reduction and total cessation. This review aimed to examine the impact of stopping or reducing the level of fluoride in public water supplies on dental fluorosis.

CONTENT

Multiple databases were searched (MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and the Web of Science). Two reviewers independently screened sources, extracted data and assessed study quality. Results were synthesised qualitatively and quantitatively. The main outcome measure was the prevalence of dental fluorosis.

SUMMARY

Six studies of cross-sectional design were included. Two studies were scored as evidence level B (moderate) and the remaining four publications were evidence level C (poor). Meta-analysis indicated fluorosis prevalence was significantly decreased following either a reduction in the concentration of fluoride or cessation of adding fluoride to the water supply (OR:6.68; 95% CI:2.48 to 18.00).

OUTLOOK

The evidence suggests a significant decrease in the prevalence of fluorosis post cessation or reduction in the concentration of fluoride added to the water supply. However, this work demonstrates that when studies are subject to current expectations of methodological and experimental rigour, there is limited evidence with low methodological quality to determine the effect of stopping or reducing the concentration of fluoride in the water supply on dental fluorosis.

Majority of New Onset of Dental Caries Occurred from Caries-Free Students: A Longitudinal Study in Primary School Students

We examined Rose's axiom that a large number of people exposed to a small risk may generate more cases than a small number exposed to a high risk, using data on caries incidence. This longitudinal study was based on the records of annual dental checks conducted in primary schools in Okinawa, Japan. Participants were students aged 6-11 years at baseline in 2014, and a follow-up survey was conducted after one-year. The outcome variable was the increased number of decayed, missing, and filled teeth (DMFT). The predictor variable was the baseline DMFT score. Gender, grade, and affiliated school variables were adjusted. A negative binomial regression model was used to obtain the estimated increase of DMFT score. Among 1542 students, 1138 (73.8%) were caries-free at baseline. A total of 317 (20.6%) developed new caries during the follow-up. The predicted number of new carious teeth in a caries-free students and students with DMFT = 1 at baseline were 0.26 (95% CI, 0.22-0.31) and 0.45 teeth (95% CI, 0.33-0.56), respectively. However, among the total of 502 newly onset of carious teeth, 300 teeth (59.7%) occurred from the caries-free students at baseline. Hence, prevention strategies should target the low-risk group because they comprise the majority of the population.

A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children

As a safe exposure level for fluoride in pregnancy has not been established, we used data from two prospective studies for benchmark dose modeling. We included mother-child pairs from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort in Mexico and the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort in Canada. Children were assessed for IQ at age 4 (n=211) and between 6 and 12 years (n=287) in the ELEMENT cohort and between ages 3 and 4 years (n=512) in the MIREC cohort. We calculated covariate-adjusted regression coefficients and their standard errors to explore the concentration-effect function for maternal urinary fluoride with children's IQ, including possible sex-dependence. Assuming a benchmark response of 1 IQ point, we derived benchmark concentrations (BMCs) of maternal urinary fluoride and benchmark concentration levels (BMCLs). No deviation from linearity was detected from the results of the two studies. Using a linear slope, the BMC for maternal urinary fluoride associated with a 1-point decrease in IQ scores of preschool-aged boys and girls was 0.29 mg/L (BMCL, 0.18 mg/L). The BMC was 0.30 mg/L (BMCL, 0.19 mg/L) when pooling the IQ scores from the older ELEMENT children and the MIREC cohort. Boys showed slightly lower BMC values compared with girls. Relying on two prospective studies, maternal urine-fluoride exposure at levels commonly occurring in the general population, the joint data showed BMCL results about 0.2 mg/L. These results can be used to guide decisions on preventing excess fluoride exposure in vulnerable populations.

Association Between Community Water Fluoridation and Severe Dental Caries Experience in 4-Year-Old New Zealand Children

IMPORTANCE

Robust contemporary epidemiologic evidence for the population-wide efficacy of reticulated community water fluoridation is required.

OBJECTIVE

To evaluate whether community water fluoridation is associated with the national rates of severe caries among 4-year-old children in New Zealand after accounting for key sociodemographic characteristics.

DESIGN, SETTING, AND PARTICIPANTS

This was a near whole population-level, natural, geospatial cross-sectional study of 4-year-old children who had a health and development assessment as part of the nationwide B4 School Check screening program conducted in New Zealand between July 1, 2010, and June 30, 2016. The extracted database included 391 677 children. However, geospatial information was missing for 18 558 children, another 32 939 children were unable to be geospatially matched, 5551 children resided in areas with changing fluoridation status, and 58 786 children had no oral health screen recorded, leaving 275 843 (70.4%) eligible children. Data were released in August 2019; statistical analysis was performed from September 2019 to December 2019.

EXPOSURES

Community water fluoridation status from 2011 through 2016.

MAIN OUTCOMES AND MEASURES

Severe caries experience derived from the "lift the lip" oral health screening. Analyses were adjusted for age, sex, ethnicity, area-level deprivation, and residential location differences. Multilevel mixed-effects logistic regression models were used. Sensitivity analyses based on multiple imputed data were undertaken to measure any differential influence of missing data.

RESULTS

In the eligible sample of 275 843 children, the median age was 4.3 years (interquartile range, 4.1-4.6 years), 141 451 children (51.3%) were boys, and 153 670 children (55.7%) resided within fluoridated areas. Severe caries were identified for 24 226 children (15.8%) in fluoridated and 17 135 children (14.0%) in unfluoridated areas, yielding an unadjusted odds ratio of 0.93 (95% CI, 0.90-0.95). However, in the adjusted analyses, children residing in areas without fluoridation had higher odds of severe caries compared with those within fluoridated areas (odds ratio, 1.21; 95% CI, 1.17-1.24). The population attributional fraction associated with unfluoridated community water was 5.6% (95% CI, 4.7%-6.6%) in a complete case analysis.

CONCLUSIONS AND RELEVANCE

This study finds that community water fluoridation continues to be associated with reduced prevalence of severe caries in the primary dentition of New Zealand's 4-year-old children.

Fluoride-Free Diet Stimulates Pineal Growth in Aged Male Rats

The pineal gland is a naturally calcifying endocrine organ which secretes the sleep-promoting hormone melatonin. Age-related changes of the pineal have been observed, including decreased pinealocyte numbers, increased calcification, and a reduction in melatonin production. Since fluoride is attracted to calcium within the pineal gland, this study sought to examine the effects of a fluoride-free diet on the morphology of the pineal gland of aged male rats (26 months old). All animals had previously been raised on standard fluoridated food and drinking water. These control animals were compared to other animals that were placed on a fluoride-free diet ("fluoride flush") for 4 or 8 weeks. At 4 weeks, pineal glands from fluoride-free animals showed a 96% increase in supporting cell numbers and at 8 weeks a 73% increase in the number of pinealocytes compared to control animals. In contrast, the number of pinealocytes and supporting cells in animals given an initial 4-week fluoride flush followed by a return to fluoridated drinking water (1.2 ppm NaF) for 4 weeks were not different from control animals. Our findings therefore demonstrate that a fluoride-free diet encouraged pinealocyte proliferation and pineal gland growth in aged animals and fluoride treatment inhibited gland growth. These findings suggest that dietary fluoride may be detrimental to the pineal gland.

The impact of a national caries strategy in Greenland 10 years after implementation. A failure or a success?

Aims 1) to describe the dental health goals and the single financial goal defined in 2008 with a new national caries strategy in Greenland (CSG) and the progress made during the subsequent 10-year period; 2) to describe the CSG initiatives; and 3) to report caries outcome data for 3-year-old children as well as 9-year-old children in 2012 and 2018; for 6-year-old children as well as 12-year-old children in 2015 and 2018 and for 15-year-old children in 2018, and to compare the data with the baseline data from 2008. Only 6 of the 20 dental health goals were close to being or were achieved over the 10-year period. The total cost of running PDHS-G increased by 4% from 2008 to 2018. The CSG strategy focused on predetermined visits/examinations, risk-related recalls, oral health promotion and predetermined fluoride and sealing policies. The percentage of children with a defs/DMFS = 0 increased by 8-18%, and the mean defs/DMFS decreased by 40-60% between 2008 and 2018 in all five age groups involved. To conclude, the goals defined in 2008 were generally not achieved (failure), but the caries status improved significantly from 2008 to 2018 in all age groups (success).

Use of public water supply fluoride concentration as an indicator of population exposure to fluoride in England 1995-2015

Public health monitoring of Community Water Fluoridation (CWF) schemes requires estimates of exposure to fluoride in public water supplies (PWS). We aimed to use routine data to estimate population exposure to PWS-fluoride in England and to determine whether PWS-fluoride exposure from 2005 to 2015 could be used as a proxy for exposure for 1995-2004, when fluoride concentration data that could be linked to population health data were unavailable. We calculated annual mean water supply zone PWS-fluoride concentrations from monitoring data for 1995-2015, stratified by fluoridation scheme-flagging. We allocated annual 2005-2015 mean PWS-fluoride concentrations to small area boundaries to describe population exposure within five concentration categories (< 0.1 to ≥ 0.7 mg/L). We compared zone-level 1995-2004 and 2005-2015 mean PWS-fluoride concentrations using Spearman correlation. Most (72%) of the population received PWS with < 0.2 mg/L fluoride and 10% with ≥ 0.7 mg/L. Fluoride concentrations in 1995-2004 and 2005-2015 were similar (median 0.11 mg/L (lower quartile-upper quartile (LQ-UQ) 0.06-0.17) and 0.11 mg/L (LQ-UQ 0.07-0.17), respectively) and highly correlated (coefficient 0.93) if un-fluoridated but differed (1995-2004 median 0.78 mg/L (LQ-UQ 0.59-0.92); 2005-2015 0.84 mg/L (LQ-UQ 0.72-0.95)) and correlated weakly (coefficient 0.31) if fluoridated. Fluoride concentrations in 2005-2015 approximate those in 1995-2004 but with a greater risk of misclassification in fluoridation schemes.

Prevalence and Correlation of Dental Caries with its Specific Risk Factors in 5-15-year-old School-going Children in Urban Population of Ghaziabad

Dental caries is a rapidly emerging oral health problem amid the children with differing prevalence rate in different states of India. The data available from Ghaziabad city regarding dental caries are scarce; therefore, the study was conducted in 5–15-year school-going children in urban population of Ghaziabad.

Did the extended coverage policy contribute to alleviating socioeconomic inequality in untreated dental caries of both children and adolescents in South Korea?

Background

Dental sealants have been covered by the National Health Insurance Service (NHIS) since December 2009 in South Korea. This study aims to determine whether the socioeconomic inequality in untreated dental caries decreased after implementing the extended coverage policy for dental sealant.

Methods

The data were derived from the fourth (2007–2009) and sixth (2013–2015) waves of the Korean National Health and Nutrition Examination Survey (KNHANES) conducted by the Korea Centers for Disease Control and Prevention (KCDC). Dental caries and sealant experience by income quartiles were tested using the Rao-Scott chi-squared test. In order to examine socioeconomic inequalities and their trends over time, the prevalence ratios (PRs), slope index of inequality (SII), and relative index of inequality (RII) were estimated for each wave and age group. All analyses were conducted using SAS version 9.3.

Results

The adjusted PRs of untreated dental caries and sealants in the poorest in the aged 6–11 group were significantly higher and lower, respectively, compared to the most affluent quartile group for the fourth wave; however, all significant differences disappeared for the sixth wave, after the sealant coverage. The gap between the lowest and the highest was similar for the aged 12–18 group but it widened in the untreated dental caries even after the sealant coverage. The statistical significance of the PRs was maintained at the sixth wave for both caries and sealants. Children showed decreases in both SII and RII over time so its significance disappeared. The SII among adolescents decreased over time but the RII of untreated dental caries increased.

Conclusions

This study found that the NHIS coverage expansion of dental care had a positive effect on overall status in dental health among children and adolescents. However, younger children benefited more in terms of inequalities. Our findings indicate that strategies to enhance access to preventive dental services should consider the differential effects for the vulnerable population in terms of socioeconomic status and age from the beginning stage of the policy.

Economic evaluations in water-fluoridation: a scoping review

BACKGROUND

Community water fluoridation (CWF) is considered one of the 10 greatest public health achievements of the twentieth century and has been a cornerstone strategies for the prevention and control of dental caries in many countries. However, for decision-makers the effectiveness and safety of any given intervention is not always sufficient to decide on the best option. Economic evaluations (EE) provide key information that managers weigh, alongside other evidence. This study reviews the relevant literature on EE in CWF.

METHODS

A systematic database search up to August 2019 was carried out using MEDLINE, EMBASE, Cochrane Library, LILACS, Paediatric Economic Database Evaluation and National Health Service Economic Evaluation Database. The review included full economic evaluations on CWF programs, written in English, Spanish or Portuguese. The selection process and data extraction were carried out by two researchers independently. A qualitative synthesis of the results was performed.

RESULTS

Of 498 identified articles, 24 studies met the inclusion criteria; 11 corresponded to cost-benefit analysis; nine were cost-effectiveness analyses; and four cost-utility studies. Two cost-utility studies used Disability-Adjusted Life Years,, one used Quality-Adjusted Tooth Years, and another Quality-Adjusted Life Years. EEs were conducted in eight countries. All studies concluded that water fluoridation was a cost-effective strategy when it was compared with non-fluoridated communities, independently of the perspective, time horizon or discount rate applied. Four studies adopted a lifetime time horizon. The outcome measures included caries averted (n = 14) and savings cost of dental treatment (n = 4). Most of the studies reported a caries reduction effects between 25 and 40%.

CONCLUSION

Findings indicated that CWF represents an appropriate use of communities' resources, using a range of economic evaluation methods and in different locations. These findings provide evidence to decision-makers which they could use as an aid to deciding on resource allocation.

A review of water fluoridation implementation strategy in England 2002-2005

Before 2002, there had been a long-term stalemate between private water companies and District Health Authorities across England. Between 2002 and 2005 the team in the Office of the Chief Dental Officer used leadership and advocacy skills to overcome political barriers, introducing the Water Act 2003 and a Statutory Instrument in 2005 providing indemnity for water companies. This legislation was key in removing obstacles towards the expansion water fluoridation across England.

Morpho-Chemical Observations of Human Deciduous Teeth Enamel in Response to Biomimetic Toothpastes Treatment

Today, biomaterial research on biomimetic mineralization strategies represents a new challenge in the prevention and cure of enamel mineral loss on delicate deciduous teeth. Distinctive assumptions about the origin, the growth, and the functionalization on the biomimetic materials have been recently proposed by scientific research studies in evaluating the different clinical aspects of treating the deciduous tooth. Therefore, appropriate morpho-chemical observations on delivering specific biomaterials to enamel teeth is the most important factor for controlling biomineralization processes. Detailed morpho-chemical investigations of the treated enamel layer using three commercial toothpastes (Biorepair, F1400, and F500) were performed through variable pressure scanning electron microscopy (VP-SEM) and energy dispersive X-ray spectroscopy (EDS) on deciduous teeth in their native state. A new microscopy methodology allowed us to determine the behaviors of silicate, phosphate, and calcium contents from the early stage, as commercially available toothpastes, to the final stage of delivered diffusion, occurring within the enamel layer together with their penetration depth properties. The reported results represent a valuable background towards full comprehension of the role of organic-inorganic biomaterials for developing a controlled biomimetic toothpaste in biofluid media.

How Fluoride Protects Dental Enamel from Demineralization

Introduction:

How fluoride (F^–) protects dental enamel from caries is here conveyed to dental health-care providers by making simplifying approximations that accurately convey the essential principles, without obscuring them in a myriad of qualifications.

Materials and Methods:

We approximate that dental enamel is composed of calcium hydroxyapatite (HAP), a sparingly soluble ionic solid with the chemical formula Ca₁₀(PO₄)₆(OH)₂.

Results:

The electrostatic forces binding ionic solids together are described by Coulomb’s law, which shows that attractions between opposite charges increase greatly as their separation decreases. Relatively large phosphate ions (PO₄^3–) dominate the structure of HAP, which approximates a hexagonal close-packed structure. The smaller Ca²⁺ and OH^– ions fit into the small spaces (interstices) between phosphates, slightly expanding the close-packed structure. F^– ions are smaller than OH^– ions, so substituting F^– for OH^– allows packing the same number of ions into a smaller volume, increasing their forces of attraction. Dental decay results from tipping the solubility equilibrium Ca₁₀(PO₄)₆(OH)₂ (s) ⇔ 10Ca²⁺ (aq) + 6PO₄^2– (aq) + 2OH^– (aq) toward dissolution. HAP dissolves when the product of its ion concentrations, [Ca²⁺]¹⁰×[PO₄^3–]⁶×[OH^–]², falls below the solubility product constant (Ksp) for HAP.

Conclusion:

Because of its more compact crystal structure, the Ksp for fluorapatite (FAP) is lower than the Ksp for HAP, so its ion product, [Ca²⁺]¹⁰×[PO₄^3–]⁶×[F^–]², must fall further before demineralization can occur. Lowering the pH of the fluid surrounding enamel greatly reduces [PO₄^3–] (lowering the ion products of HAP and FAP equally), but [OH^–] falls much more rapidly than [F^–], so FAP better resists acid attack.

Teeth: Small but Mighty and Mighty Important. A Comprehensive Review of Children's Dental Health for Primary Care Clinicians

Healthy teeth allow us to eat and stay well-nourished. Although primary care clinicians receive limited training about teeth, given the common nature of dental problems, it is important that they understand and recognize normal and abnormal dental conditions and can implement primary and secondary prevention of dental conditions in their practice. PubMed has been used to search the scientific literature for evidence on the following topics: normal dental development, dental abnormalities, malocclusion, teething, dental caries and related epidemiology and prevention, fluoride, dental injury and its management and prevention; and identification, prevention and treatment of gingivitis and periodontal disease. Literature review relied on randomized controlled trials, meta-analyses, systematic reviews, and Cochrane reviews when relevant and available. Other sources of evidence included cohort and case-control studies. Consensus statements and expert opinion were used when there was a paucity of high-quality research studies. The literature has been synthesized on these topics to make them relevant to pediatric primary care clinicians, and as available, the strength of evidence has been characterized when making clinical recommendations.