Effectiveness of risk-based caries management among Chinese preschool children: a randomized controlled single-blind trial.

BACKGROUND: Early childhood caries (ECC) remain a serious oral health problem on a global scale. Risk-based caries management (RBCM) implemented in some parts of the world has been effective in preventing ECC. However, there is a lack of prospective research on the application of RBCM among Chinese children, and little is known about its effectiveness. The purpose of this study was to evaluate the effectiveness of RBCM in preventing caries among children aged 3-5 years in Wanzhou District, Chongqing Municipality, China. METHODS: Three- to five-year-old children from four kindergartens in Wanzhou were randomly selected for baseline dental examination and caries risk assessment (CRA) and randomly assigned to the experimental group (EG) or the control group (CG) according to the kindergarten. The EG received caries prevention measures of different intensities based on the child's caries risk level. The CG received full-mouth fluoride twice a year according to standard prevention, regardless of their caries risk. One year later, another dental examination and CRA were conducted, to observe changes in the decayed, missing, and filled teeth (dmft) index and caries risk, and to analyze potential factors that may affect the incidence of new caries. RESULTS: Complete data were collected from 291 children (EG, N = 140, 84.8%; CG, N = 181, 83.4%). A total of 25.7% of the EG and 50.3% of the CG children developed new caries, with newly added dmft scores of 0.54 ± 1.12 and 1.32 ± 1.72, respectively (P < 0.05). Multivariate logistic regression indicated that children living in rural areas, assigned to the CG, and rated as high-risk at baseline were more likely to develop new caries (P < 0.05). The proportion of children with an increased caries risk in the EG was significantly lower than that in the CG (P < 0.05). CONCLUSIONS: RBCM effectively prevented new caries in 3- to 5-year-old Wanzhou children and reduced the proportion of children at increased risk of caries. It is an effective approach for preventing ECC. CLINICAL TRIAL REGISTRATION: This trial was registered in the Chinese Clinical Trials Register. The registration number was ChiCTR230067551 (11/01/2023).

Knowledge of the health personnel involved in the fluoride varnish therapy programs of primary schools in Tehran, Iran.

INTRODUCTION: The World Health Organization (WHO) places great importance on oral health promotion programs in schools, given that approximately one billion people worldwide are students. This demographic not only includes the students themselves, but also extends to school staff, their families, and the broader community, all of whom are interconnected. The objectives of this study were firstly to assess the knowledge of health personnel conducting fluoride varnish treatment (FVT) in schools, and secondly to solicit their views on the effectiveness of their training methods. METHODS: Data was collected from health personnel involved in FVT in schools, supervised by medical universities in Tehran province, using a questionnaire. The questionnaire was divided into four sections: demographic information, methods of receiving FVT training, respondents' knowledge regarding FVT, and opinions about the effectiveness of FVT training methods. The questionnaire was distributed via social media, phone conversations, and email. The collected data was analyzed using Mann-Whitney in SPSS Version 26. A regression model was also fitted to the data. RESULTS: The present study included 403 participants. Among various educational methods, it was found that participation in previous workshops (P = 0.001) and FVT workshops (P = 0.013) was significantly correlated with a higher FVT knowledge score. Additionally, participation in previous oral health promotion programs was significantly associated with a higher knowledge score (P < 0.05). Therefore, a history of participating in previous health promotion programs significantly contributed to the participants' knowledge. CONCLUSION: Participation in previous oral health programs was found to be significantly correlated with a higher knowledge score. The effectiveness of training programs can be attributed to participation in previous workshops and FVT workshops. This study provided insights into potential strategies for enhancing personnel training in national oral health programs.

Microleakage of Silver-Modified Atraumatic Restorative Technique (SMART) Restorations Using Silver Diammine Fluoride and High-Viscosity Glass Ionomer.

Purpose: The purpose of this study was to investigate the microleakage of atraumatic glass ionomer restorations with and without silver diammine fluoride (SDF) application. Restorations with SDF are termed silver-modified atraumatic restorations (SMART). Methods: Sixty carious extracted permanent teeth were randomly allocated to two SMART groups and two control groups (n equals 15 per group) for a total of four groups. After selective caries removal, test specimens were treated with 38 percent SDF and polyacrylic acid conditioner was applied and rinsed; teeth were restored with Fuji IX GP® glass ionomer (n equals 15) or with SMART Advantage™ glass ionomer (SAGI; n equals 15). For control groups, specimens were restored with their respective GI material after selective caries removal, both without SDF. Restored teeth were placed in Dulbecco's Phosphate-Buffered Saline solution at 37 degrees Celsius for 24 hours. Teeth were thermocycled between five and 55 degrees Celsius for 1,000 cycles, stained with two percent basic fuchsin, sectioned, and visually inspected for microleakage utilizing stereomicroscopy on a four-point scale. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance on ranks using Dunn's method (P<0.05). Results: Microleakage between the two SMART restoration groups was insignificant. SAGI alone demonstrated significantly more microleakage than all other groups. There was no statistical significance between the Fuji IX GP® control group and the two SMART restoration groups. Conclusions: This in vitro study indicated that silver diammine fluoride placed before glass ionomer restoration does not increase microleakage. Polyacrylic acid may be used after SDF placement without increasing microleakage.

Longitudinal Follow-up Comparing Future Care of Primary Teeth Treated with Silver Diammine Fluoride: A Private Dental Claims Review.

Purpose: The purpose of this study was to longitudinally evaluate follow-up treatment on primary teeth initially treated with silver diammine fluoride (SDF). Methods: This retrospective cohort evaluated private insurance (not Medicaid) claims data from 2018 to 2019 for children no older than 12 years with at least one primary tooth initially treated with SDF. Additional treatment per tooth was recorded over a follow-up of at least 24 months. Results: The mean and standard deviation (±SD) age of 46,884 patients was 5.7±2.3 and for SDF-treated teeth per patient was 2.6±2.1. Forty percent (95 percent confidence interval [95% CI] equals 39 to 40.7 percent) of teeth initially treated with SDF received additional treatment. The odds of SDF-treated teeth receiving future treatment significantly decreased with patient age by 22 percent per year (odds ratio equals 0.78; 95% CI equals 0.077 to 0.79; P<0.001). Pediatric dentists had only slightly lower odds than general dentists for providing additional treatment (0.91, P<0.001). Posterior teeth and teeth expected to exfoliate in two or more years had significantly higher odds of receiving additional treatment (2.47 and 1.27, respectively, P<0.001). Conclusions: Beginning at age four, patient age at placement of silver diammine fluoride was inversely proportional to future treatment provided. Posterior teeth and teeth expected to exfoliate in two or more years were more likely to receive additional treatment.

Evaluation of staining potential of Silver Diamine Fluoride, Potassium Iodide, Nanosilver Fluoride: an in vitro study.

BACKGROUND: The black staining effect of silver-containing solutions for use to arrest caries can have a negative aesthetic impact on children and parents. This study aims to assess the staining effects of Silver Diamine Fluoride/Potassium Iodide (SDF/KI), SDF and Nanosilver Fluoride (NSF). MATERIALS AND METHODS: Forty-four extracted carious primary molars were collected and randomly divided into four groups (n = 11). The carious tissue in all teeth was removed using a chemo-mechanical caries removal agent with an excavator. After caries removal in all groups, SDF, SDF/KI, and NSF were applied to the different groups, while no solution was applied to the control group. Subsequently, the teeth in all groups were restored with compomer. Color values L*, a* and b* were measured using a spectrophotometer at three time points: immediately after compomer restoration (T0), one week later (T1), and four week later (T2). Changes in brightness (ΔL) and color (ΔE) over time were calculated and comparisons among groups were made. RESULTS: The SDF solution induced statistically significant black staining (p = 0.013) and a decrease in L* value (p < 0.001) on the compomer material compared to the other groups over time. CONCLUSIONS: It was observed that SDF/KI has the potential to reduce the black staining effect of SDF, though not entirely. Novel experimental solutions like NSF may offer an alternative to counteract the staining effect of SDF.

Oral Irrigation Devices: A Scoping Review.

OBJECTIVES: Self-performed oral hygiene is essential for preventing dental caries, periodontal, and peri-implant diseases. Oral irrigators are adjunctive oral home care aids that may benefit oral health. However, the effects of oral irrigation on oral health, its role in oral home care, and its mechanism of action are not fully understood. A comprehensive search of the literature revealed no existing broad scoping reviews on oral irrigators. Therefore, this study aimed to provide a comprehensive systematic review of the literature on oral irrigation devices and identify evidence gaps. METHODS: The Joanna Briggs Institute and Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines were utilized to prepare the review. Four databases and eight gray literature sources were searched for English publications across any geographical location or setting. RESULTS: Two hundred and seventy-five sources were included, predominantly from scientific journals and academic settings. Most studies originated from North America. Research primarily involved adults, with limited studies in children and adolescents. Oral irrigation was safe and well-accepted when used appropriately. It reduced periodontal inflammation, potentially by modulating the oral microbiota, but further research needs to clarify its mechanism of action. Promising results were reported in populations with dental implants and special needs. Patient acceptance appeared high, but standardized patient-reported outcome measures were rarely used. Anti-inflammatory benefits occurred consistently across populations and irrigant solutions. Plaque reduction findings were mixed, potentially reflecting differences in study designs and devices. CONCLUSIONS: Oral irrigators reduce periodontal inflammation, but their impact on plaque removal remains unclear. Well-designed, sufficiently powered trials of appropriate duration need to assess the clinical, microbiological, and inflammatory responses of the periodontium to oral irrigation, particularly those with periodontitis, dental implants, and special needs. Patient-reported outcome measures, costs, caries prevention, and environmental impact of oral irrigation need to be compared to other oral hygiene aids.

Longitudinal study of the role of salivary proteins on radiation-related caries onset in head and neck cancer patients using 5000 ppm fluoride dentifrice up to one-year post-intensity modulated radiotherapy.

OBJECTIVES: Longitudinal assessment of the role of specific proteins on radiotherapy caries (RC) onset in head and neck cancer patients(HNC) up to one-year post-IMRT using a 5000ppm fluoride paste daily. MATERIALS AND METHODS: Dental status/salivary protein data were obtained from 40 HNC patients pre-IMRT, six months (T1) and 12 months (T2) post-IMRT (ethical approval/consent). DMFT/salivary parameters were quantified, including flow rate, mucin 5B/7, Immunoglobulin A (IgA), cystatin S and α-amylase. RESULTS: 45% patients had at least one carious lesion at T2, a significant reduction in the number of remaining teeth (65% <21), salivary flow rate (< 50%) and, protein secretion (< 0.05) post-IMRT. T1 IgA concentration/secretion rate was associated with RC (p < 0.05). Finally, IgA and total protein concentration obtained at T1 could provide a predictive pattern (AUC 82.3%) for the patients more predisposed to developing RC at T2. CONCLUSIONS: This study demonstrated the significant association of RC with salivary proteins in HNC patients treated with IMRT, revealing the potential role of salivary proteins in the early diagnosis of RC. CLINICAL RELEVANCE: This research contributes to revealing salivary proteins association with RC, and its role in early diagnosis. Therefore, this could be the first step towards personalized medicine approaches to improve this group quality-of-life.

Silver modified atraumatic restorative treatment: a paradigm shift in dental caries management.

Silver diamine fluoride (SDF) and atraumatic restorative treatment (ART) are treatment modalities that are minimally invasive and used for the prevention and control of dental caries. The amalgamation of these two techniques has led to the development of silver modified atraumatic restorative treatment (SMART). In this approach the carious lesion is restored with glass-ionomer cement (GIC) after SDF application. SMART effectively arrests caries without removing additional tooth structure, making it a promising option for caries management in children who lack cooperative ability.This article reviews the literature on SMART, the evidence regarding its applications in dental practice, its advantages, drawbacks, the scope for research, and clinical use.

Effectiveness of nanosilver fluoride and silver diamine fluoride in arresting early childhood caries: a randomized controlled clinical trial.

BACKGROUND: One of the most prevalent health problems affecting children worldwide is untreated caries in primary teeth. Agents to arrest caries are used to manage untreated decay in children in disadvantaged communities. Nano Silver Fluoride (NSF) overcomes the staining problems of Silver Diamine Fluoride (SDF). This study compared the clinical cariostatic effect of NSF to 38% SDF for arresting caries lesions. METHODS: The study included 360 children younger than 4 years, with at least one active lesion, ICDAS score ≥ 3, recruited from nurseries in a rural area in Alexandria, Egypt, in 2022. They were randomly assigned to receive a single application of NSF at baseline, or two applications of SDF at baseline and after 6 months. The arrest of active carious lesions was assessed after 6 and 12 months using ICDAS criteria, and parents' satisfaction with child appearance was also assessed. Chi-Square test was used to compare the groups and multi-level multiple logistic regression was used to assess the effect of the intervention on caries arrest at lesion level and binary logistic regression was used to assess the effect at patient level. RESULTS: 1853 active lesions were included in children whose mean (SD) age was 42.3 (8.2) months. The arrest rate was significantly higher in the NSF than the SDF group at lesion level (78.4% and 65.0% at 6 months and 71.3% and 56.3% at 12 months, p < 0.001). In regression analysis, NSF had significantly higher odds of caries arrest than SDF at lesion level (at 6 months, AOR = 2.57, 95% CI: 1.55, 4.26 and at 12 month, AOR = 3.27, 95% CI: 1.89, 5.67). Parents of children receiving NSF had significantly greater satisfaction with their children's dental appearance than those receiving SDF: (97.2% and 76.1%, respectively, p < 0.001). CONCLUSION: NSF demonstrated greater effectiveness in arresting caries in preschool children without inducing black staining of teeth and with greater parental satisfaction than SDF. NSF can be an alternative to SDF in arresting caries especially in underprivileged communities. TRIAL REGISTRATION: The trial was registered in the clinicaltrials.gov registry (#NCT05255913)-16/02/2022.

Parental acceptance of Silver Diamine Fluoride in two lower-middle-income countries: Iran and Tajikistan.

BACKGROUND: Using Silver Diamine Fluoride (SDF) may be an effective public health approach for managing dental caries in children. Parental acceptance of SDF has rarely been investigated in low-income and middle-income countries (LMICs). The aim of this study was to evaluate parental acceptance of SDF to manage dental caries in children aged 2-12 in Iran and Tajikistan. METHODS: This cross-sectional study was conducted in the Kurdistan province of Iran and Khatlon region of Tajikistan, 2022-2023. Parents watched a video about SDF and its weaknesses and strengths as compared to conventional approaches before completing the questionnaire. We also reported Prevalence Ratios with 95% confidence intervals for the relationship between parental acceptance and associated demographic factors as well as dental attitude and experience. RESULTS: Participants were 245 and 160 parents in Iran and Tajikistan, respectively. In both countries, a majority (Iran: 61.6%, Tajikistan: 77.9%) accepted SDF over conventional treatments for all primary teeth. The majority also accepted SDF only for posterior permanent teeth (Iran: 73.5%, Tajikistan: 78.7%). Black discoloration was the main reason for rejecting SDF. Overall, demographic factors and dental experience and attitude were not significantly associated with SDF acceptance. CONCLUSIONS: SDF was widely accepted by Iranian and Tajik parents. Establishing parental acceptance of SDF is an important step toward its application in LMICs where inexpensive solutions are needed.

A review of oral health promotion programmes in Eastern Mediterranean Region.

Background: Oral health conditions, such as dental caries, periodontal disease, tooth loss, dental fluorosis, dental trauma, and oral cancer, are prevalent in the WHO Eastern Mediterranean Region. However, there has been no systematic review of oral health promotion interventions in the region. Aims: To review existing literature on oral health promotion programmes in the Eastern Mediterranean Region and recommend improvements for the future. Method: We reviewed on PubMed and Google Scholar 61 articles published in the Eastern Mediterranean Region between 2010 and 2023. Quality assessment of included studies was performed using established criteria. We used the content analysis approach to create appropriate themes from the studies and to document meaningful conclusions about oral health promotion. Results: Majority of the studies were cross-sectional, a few were randomized controlled, quasi-experimental, longitudinal studies, or reviews. Oral health problems identified included poor oral health knowledge, dental caries, periodontal disease, tooth loss, dental fluorosis, and oral cancer. Although oral disorders were common in most of the countries, very few have implemented oral health promotion programmes. Conclusion: We recommend prioritization of oral health promotion programmes in the Eastern Mediterranean Region to tackle the diverse oral health challenges. To be effective, such programmes should be region- and context-specific. More studies on oral health promotion are needed in the region.

The Influence of Vitamin D Levels on Dental Caries: A Retrospective Study of the United States Population.

(1) Background: This study examines vitamin D's impact on dental caries to inform prevention strategies, given its critical role in bone and calcium regulation, vital for dental health. (2) Methods: Data from 18,683 participants of the National Health and Nutrition Examination Survey (NHANES) 2011-2016 were analyzed. NHANES collects U.S. population data through interviews, physical exams, and tests, including vitamin D levels and dental health assessed using both the decayed, missing, and filled teeth (DMFT) index and the presence of untreated dental caries. Vitamin D levels were measured according to serum 25(OH)D concentrations, and the analyses adjusted for confounders such as body mass index (BMI) and socioeconomic status (SES) using Chi-square, Mann-Whitney U, Kruskal-Wallis tests, as well as logistic and Poisson regression. (3) Results: This study found a mean DMFT score of 7.36 and a 33.2% prevalence of untreated dental caries. A higher caries prevalence was correlated with a lower SES (p < 0.001), the male gender (p < 0.001), and a higher BMI (p < 0.001). Severe vitamin D deficiency (<25 nmol/L) doubled the risk of dental caries, with odds ratios of 2.261 and 1.953 after adjusting for demographic factors and BMI. (4) Conclusions: Our study confirms a significant relationship between low vitamin D levels and an increased risk of dental caries nationwide, even after accounting for sociodemographic factors, emphasizing the importance of maintaining sufficient vitamin D levels for preventing caries.

The Assessment of Resin-Based Composite Sealants' Effectiveness in Arresting Non-Cavitated Dentin Carious Lesions (ICDAS 3)-A 12 Month Follow-Up Preliminary Study.

Background and Objectives: The therapeutic management of carious lesions remains a significant focus for researchers, given their persistently high prevalence despite being largely preventable. This study aimed to compare the effectiveness of a composite resin-based sealant material in halting extended non-cavitated dentin carious lesions when used therapeutically versus preventively on caries-free teeth over a period of twelve months. Materials and Methods: out of the 236 children examined, 45 were excluded from the study due to non-compliance with the inclusion criteria. Thus, the study included 191 children aged 10-12 years, and 764 molars in total. Results: among these molars, 171 were caries-free (ICDAS II code 0), forming the Control group, while 180 molars were classified with an ICDAS II score of 3, forming the Study group. All molars were sealed and evaluated at 6- and 12-month follow-up intervals. Both intervals revealed statistically significant differences (p < 0.05) in sealant retention and carious lesion development between sound (ICDAS code 0) and decayed (ICDAS code 3) teeth. Conclusions: the findings did not support the effectiveness of sealants in halting non-cavitated dentin carious lesions classified as ICDAS II with code 3 compared to their preventive application in sound teeth classified as ICDAS II with code 0.

Survival Analysis of Glass Ionomer Cement and Resin-Based Sealant Retention: A 10-Year Follow-Up Study.

Background and Objective: Sealant application is a proven method to prevent occlusal caries; however, long-term studies on this topic are scarce. This study aimed to assess the survival rate and clinical effectiveness of glass ionomer cement (GIC) and resin-based sealants (RBSs) on second permanent molars over a long-term follow-up period. Materials and methods: Sixteen patients aged 11-13 years with all four completely erupted permanent second molars were enrolled in the study. All patients attended 1-year and 3-year follow-ups; however, one participant did not respond after 10 years and was excluded from the final analyses. The oral health status evaluation was based on WHO criteria. A total of 32 teeth received an RBS (Clinpro), and a further 32 teeth were sealed with GIC (Fuji IX). The sealant retention was determined according to the Kilpatrick criteria after 1 year, 3 years, and 10 years, respectively. Statistical analysis included a chi-square test, the Kaplan-Meier method, and the Cox proportional hazard model. Results: At baseline, seven boys and eight girls participated in the study, with a mean age of 12.3 ± 0.9 years. The 1-year follow-up results revealed that 90% of the RBSs and 43.3% of the GIC sealants were completely retained, and no caries lesions were recorded (p = 0.01). The 3-year follow-up results showed that 23.3% of the RBSs and 0% of the GIC sealants demonstrated complete retention (p = 0.034). Moreover, 10.0% of the occlusal surfaces in the RBS group and 13.3% of the occlusal surfaces in the GIC group were filled (p > 0.05). A total of 6.7% of the RBSs showed complete retention. One-third of the sealed teeth (30.0% of the teeth sealed with RBSs and 36.7% of teeth applied with GIC) were filled after 10 years. The Kaplan-Meier analysis demonstrated a higher survival rate in the RBS group when compared with the GIC over the entire follow-up period (p = 0.001). Conclusions: Although the survival rate of RBSs was higher than GIC sealants, their effectiveness in preventing fissure caries in permanent second molars did not differ significantly over a 10-year follow-up.

Enamel Matrix Derivative, 58S5 Bioactive Glass, and Fluoride Varnish for Enamel Remineralization: A Multi-analysis Approach.

PURPOSE: This study aimed to evaluate the enamel remineralization efficacy of enamel matrix derivative (EMD), experimental bioactive glass (BAG), and fluoride varnish in vitro. METHODS AND MATERIALS: Artificial initial caries lesions were developed on fifty human enamel specimens using demineralization solution (pH 4.5, 37°C, 96 hours). Specimens were randomly assigned to five groups (n=10): I-5% NaF varnish (Enamelast), II-experimental 58S5 BAG+37% phosphoric acid (PA), III-EMD (Emdogain) + Ethylenediaminetetraacetic Acid (EDTA), IV-EMD+37% PA, V-Control (untreated). All remineralization agents were applied with pH cycling for seven days. The specimens were scanned by spectral domain optical coherence tomography (SD-OCT) at baseline, at demineralization, and after pH cycling. Lesion depths were measured using image analysis software (ImageJ). Lesions were evaluated using surface microhardness (SMH) and two fluorescence methods (FluoreCam and DIAGNOdent Pen [DDPen]). The data were statistically analyzed by Kruskal Wallis, Friedman, and Wilcoxon tests (α=0.05). RESULTS: According to SD-OCT results, fluoride varnish was found to be the most effective agent in reducing lesion depth (p=0.005). All agents increased the SMH values after pH cycling. No significant difference was found among fluoride varnish, BAG, and EMD+PA groups. These SMH values were significantly higher than EMD+EDTA and control groups (p<0.001). All groups showed lower DDPen scores compared with the control group (p<0.001), however, no significant difference was found among the remineralization agents. In FluoreCam assessment, size and intensity values of all treated groups showed improvement. However, there was no significant difference between the treatment groups in terms of FluoreCam size measurements (p=0.186). CONCLUSION: 58S5 BAG and EMD+PA have remineralization capacity as effective as fluoride varnish. EMD+PA showed better SMH and lesion intensity results than EMD+EDTA.

Interplay Between Minerals in Bottled Water and Fluoride Toothpaste and Caries Lesion Remineralization.

OBJECTIVES: he aim of this in vitro study was to evaluate the effects of some bottled waters on fluoride toothpaste efficacy in enhancing caries lesion remineralization. METHODS: Early caries lesions were created in bovine enamel specimens and stratified into treatment groups based on Vickers surface microhardness (VHN). The present study followed a two (fluoride and fluoride-free toothpaste) by five (four bottled waters and tap water) factorial design. The treatment groups were bottled water with the following attributes: (a) 309.9 ppm Ca/1.20 ppm F; (b) 118.4 ppm Ca/0.16 ppm F; (c) 1.00 ppm Ca/1.01 ppm F; and (d) 0.1 ppm Ca/0.04 ppm F and tap water (48.7 ppm Ca/0.7 ppm F). The five water groups were paired either with 1100 ppm fluoride or fluoride-free toothpaste, yielding 10 groups. Specimens were pH-cycled for 10 days with the daily regimen comprised of twice daily toothpaste slurry, with four exposures to water in between. VHN was measured again and the difference was calculated (ΔVHN). Data were analyzed using two-way ANOVA at a 5% significance level. RESULTS: The two-way interaction between water and toothpaste was significant (p<0.001). All groups except fluoride-free toothpaste/bottled water with 0.1 ppm Ca/0.04 ppm F (p=0.411) had significant increases in VHN after pH cycling (p≤0.023). Fluoridated toothpaste resulted in a higher rate of remineralization compared to fluoride-free toothpaste (all p<0.001). Bottled water with 1.20 ppm F/309.9 ppm Ca exhibited the greatest extent of remineralization within fluoride toothpaste groups (p<0.001) and higher remineralization than lower fluoride water in fluoride-free toothpaste groups (p≤0.006). Within the fluoridated toothpaste group, tap water exhibited significantly less remineralization than all bottled waters (all p<0.001). CONCLUSION: Within the limitation of this study, bottled water with higher fluoride and calcium concentrations might improve fluoridated toothpaste efficacy by enhancing remineralization of early enamel caries-like lesions.

Effect of fluoridated water on invasive NHS dental treatments for adults: the LOTUS retrospective cohort study and economic evaluation.

Background: Most water fluoridation studies were conducted on children before the widespread introduction of fluoride toothpastes. There is a lack of evidence that can be applied to contemporary populations, particularly adolescents and adults. Objective: To pragmatically assess the clinical and cost effectiveness of water fluoridation for preventing dental treatment and improving oral health in a contemporary population of adults, using a natural experiment design. Design: Retrospective cohort study using routinely collected National Health Service dental claims (FP17) data. Setting: National Health Service primary dental care: general dental practices, prisons, community dental services, domiciliary settings, urgent/out-of-hours and specialised referral-only services. Participants: Dental patients aged 12 years and over living in England (n = 6,370,280). Intervention and comparison: Individuals exposed to drinking water with a fluoride concentration ≥ 0.7 mg F/l between 2010 and 2020 were matched to non-exposed individuals on key characteristics using propensity scores. Outcome measures: Primary: number of National Health Service invasive dental treatments (restorations/'fillings' and extractions) received per person between 2010 and 2020. Secondary: decayed, missing and filled teeth, missing teeth, inequalities, cost effectiveness and return on investment. Data sources: National Health Service Business Services Authority dental claims data. Water quality monitoring data. Primary outcome: Predicted mean number of invasive dental treatments was 3% lower in the optimally fluoridated group than in the sub/non-optimally fluoridated group (incidence rate ratio 0.969, 95% CI 0.967 to 0.971), a difference of -0.173 invasive dental treatments (95% CI -0.185 to -0.161). This magnitude of effect is smaller than what most stakeholders we engaged with (n = 50/54) considered meaningful. Secondary outcomes: Mean decayed, missing and filled teeth were 2% lower in the optimally fluoridated group, with a difference of -0.212 decayed, missing and filled teeth (95% CI -0.229 to -0.194). There was no statistically significant difference in the mean number of missing teeth per person (0.006, 95% CI -0.008 to 0.021). There was no compelling evidence that water fluoridation reduced social inequalities in treatments received or missing teeth; however, decayed, missing and filled teeth data did not demonstrate a typical inequalities gradient. Optimal water fluoridation in England in 2010-20 was estimated to cost £10.30 per person (excluding original setup costs). Mean National Health Service treatment costs for fluoridated patients 2010-20 were 5.5% lower per person, by £22.26 (95% CI -£23.09 to -£21.43), and patients paid £7.64 less in National Health Service dental charges per person (2020 prices). Limitations: Pragmatic, observational study with potential for non-differential errors of misclassification in fluoridation assignment and outcome measurement and residual and/or unmeasured confounding. Decayed, missing and filled teeth data have not been validated. Water fluoridation cost estimates are based on existing programmes between 2010 and 2020, and therefore do not include the potentially significant capital investment required for new programmes. Conclusions: Receipt of optimal water fluoridation between 2010 and 2020 resulted in very small health effects, which may not be meaningful for individuals, and we could find no evidence of a reduction in social inequalities. Existing water fluoridation programmes in England produced a positive return on investment between 2010 and 2020 due to slightly lower National Health Service treatment costs. These relatively small savings should be evaluated against the projected costs and lifespan of any proposed capital investment in water fluoridation, including new programmes. Future work: National Health Service dental data are a valuable resource for research. Further validation and measures to improve quality and completeness are warranted. Trial registrations: This trial is registered as ISRCTN96479279, CAG: 20/CAG/0072, IRAS: 20/NE/0144. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (NIHR award ref: NIHR128533) and is published in full in Public Health Research; Vol. 12, No. 5. See the NIHR Funding and Awards website for further award information.

Fluoride is a natural mineral that prevents tooth decay. It is added to some drinking water and toothpastes to improve dental health. Water with fluoride added is known as 'optimally fluoridated'. Most research on water fluoridation was carried out before fluoride was added to toothpastes in the 1970s and only included children. We wanted to know if water fluoridation still produced large reductions in tooth decay, now that decay levels are much lower because of fluoride in toothpaste. We also wanted to look at its effect on adults and teenagers. Dental patients we spoke to told us they worried about needing treatment with the 'drill', or 'injection', losing their teeth and paying for their dental care. To see if water fluoridation helped with these concerns, we compared the National Health Service dental records of 6.4 million adults and teenagers who received optimally fluoridated or non-optimally fluoridated water in England between 2010 and 2020. We found water fluoridation made a very small difference to each person. Between 2010 and 2020, the number of NHS fillings and extractions was 3% lower per person for those who received optimally fluoridated water. We found no difference in the number of teeth lost per person and no strong sign that fluoridation reduced differences in dental health between rich and poor areas. Between 2010 and 2020, the cost of optimal water fluoridation was £10.30 per person (not including setup costs). National Health Service dental patients who received optimally fluoridated water cost the National Health Service £22.26 (5.5%) less and paid £7.64 (2%) less per person in National Health Service dental charges over the 10 years. The benefits we found are much smaller than in the past, when toothpastes did not contain fluoride. The cost to set up a new water fluoridation programme can be high. Communities may need to consider if these smaller benefits would still outweigh the costs.

An optimized caries model of Streptococcus mutans in rats and its application for evaluating prophylactic vaccines.

Dental caries is a prevalent oral disease that mainly results from Streptococcus mutans. Susceptibility to S. mutans decreased rapidly after weaning in a well-known rat model. However, owing to the lack of time to establish protective immunity ahead of challenge, the weaning rat model is suboptimal for assessing prophylactic vaccines against S. mutans infection. In this study, we found that, in adult rats, S. mutans cultured under air-restricted conditions showed dramatically increased colonization efficacy and accelerated development of dental caries compared with those cultured under air-unrestricted conditions. We propose that S. mutans cultured under air-restricted conditions can be used to develop an optimal caries model, especially for the evaluation of prophylactic efficacy against S. mutans. Therefore, we used the anti-caries vaccine, KFD2-rPAc, to reevaluate the protection against the challenge of S. mutans. In immunized rats, rPAc-specific protective antibodies were robustly elicited by KFD2-rPAc before the challenge. In addition to inhibiting the initial and long-term colonization of S. mutans in vivo, KFD2-rPAc immunization showed an 83% inhibitory efficacy against the development of caries, similar to that previously evaluated in a weaning rat model. These results demonstrate that culturing under air-restricted conditions can promote S. mutans infection in adult rats, thereby helping establish a rat infection model to evaluate the prophylactic efficacy of vaccines and anti-caries drugs.