Rapid Intrafibrillar Mineralization Strategy Enhances Adhesive-Dentin Interface.

Biomimetic mineralization of dentin collagen appears to be a promising strategy to optimize dentin bonding durability. However, traditional postbonding mineralization strategies based on Ca/P ion release still have some drawbacks, such as being time-consuming, having a spatiotemporal mismatch, and having limited intrafibrillar minerals. To tackle these problems, a prebonding rapid intrafibrillar mineralization strategy was developed in the present study. Specifically, polyacrylic acid-stabilized amorphous calcium fluoride (PAA-ACF) was found to induce rapid intrafibrillar mineralization of the single-layer collagen model and dentin collagen at just 1 min and 10 min, as identified by transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. This strategy has also been identified to strengthen the mechanical properties of demineralized dentin within a clinically acceptable timeframe. Significantly, the bonding strength of the PAA-ACF-treated groups outperformed the control group irrespective of aging modes. In addition, the endogenous matrix metalloproteinases as well as exogenous bacterial erosion were inhibited, thus reducing the degradation of dentin collagen. High-quality integration of the hybrid layer and the underlying dentin was also demonstrated. On the basis of the present results, the concept of "prebonding rapid intrafibrillar mineralization" was proposed. This user-friendly scheme introduced PAA-ACF-based intrafibrillar mineralization into dentin bonding for the first time. As multifunctional primers, PAA-ACF precursors have the potential to shed new light on prolonging the service life of adhesive restorations, with promising significance.

Generalized permanent dentition fluorosis severity becomes less evident over time among a birth cohort.

Objectives: There are relatively few cohort studies which have examined changes in fluorosis appearance over time, and none of these have assessed changes in generalized fluorosis. In this analysis, we quantified and assessed changes in multiple measures of generalized fluorosis severity through childhood, adolescence, and young adulthood. Methods: Participants were from the Iowa Fluoride Study, a birth cohort recruited from 1992 to 1995. Permanent dentition fluorosis exams were carried out at ages 9, 13, 17, and 23 years using the Fluorosis Risk Index (FRI). Generalized fluorosis was assessed using mean FRI scores at the tooth- and person-level as well as a five-category measure of generalized fluorosis. Generalized fluorosis prevalence and severity was summarized at each time point and differences in adjacent time points were assessed using gamma statistics, signed-rank tests, and plotting changes in generalized fluorosis between adjacent time points. Results: We observed a statistically significant decline in the percentage of non-zero mean FRI scores at later exam ages at both the person- and tooth-levels. Based on our five-category generalized fluorosis measure, there were 34.0%-54.1% of participants with generalized fluorosis at baseline for each tooth group, and these percentages declined to 8.9%-27.2% at the age 23-year exam. Conclusions: We observed a statistically significant decline in generalized fluorosis severity scores and overall prevalence at later exam ages across all three measures of generalized fluorosis severity. This trend should be accounted for when estimating the prevalence of fluorosis in a population using fluorosis severity data collected in children and adolescents.

F0F1-ATPase Contributes to the Fluoride Tolerance and Cariogenicity of Streptococcus mutans.

The phenotypic traits of Streptococcus mutans, such as fluoride tolerance, are usually associated with genotypic alterations. The aim of this study was to identify adaptive mutations of S. mutans to gradient fluoride concentrations and possible relationships between the mutations and fluoride tolerance. We identified a highly resistant S. mutans strain (FR1000) with a novel single nucleotide polymorphism (SNP, -36G→T) in the promoter region of F0F1-ATPase gene cluster (SMU_1527-SMU_1534) resistant to 1,000 ppm fluoride using the whole-genome Illumina PE250 sequencing. Thus, a -36G→T F0F1-ATPase promoter mutation from the parental strain S. mutans UA159 was constructed and named UA159-T. qRT-PCR showed that the F0F1-ATPase gene expression of both FR1000 and UA159-T was up-regulated, and fluoride tolerance of UA159-T was significantly improved. Complementation of Dicyclohexylcarbodiimide (DCCD), a specific inhibitor of F0F1-ATPase, increased fluoride susceptibility of FR1000 and UA159-T. Intracellular fluoride concentrations of fluoride tolerance strains were higher compared to UA159 strain as demonstrated by 18F analysis. Further validation with rat caries models showed that UA159-T caused more severe caries lesions under fluoride exposure compared with its parental UA159 strain. Overall, the identified -36G→T mutation in the promoter region of F0F1-ATPase gene drastically contributed to the fluoride tolerance and enhanced cariogenicity of S. mutans. These findings provided new insights into the mechanism of microbial fluoride tolerance, and suggested F0F1-ATPase as a potential target for suppressing fluoride resistant strains.

Substituted Nano-Hydroxyapatite Toothpastes Reduce Biofilm Formation on Enamel and Resin-Based Composite Surfaces.

Background: Toothpastes containing nano-hydroxyapatite (n-HAp) substituted with metal ions provide calcium and phosphate ions to dental hard tissues, reducing demineralization, and promoting remineralization. Few data are available about the effect of these bioactive compounds on oral microbiota. Methods: This in vitro study evaluated the influence of two commercially-available substituted n-HAp-based toothpastes (α: Zn-carbonate substituted n-HAp; ß: F, Mg, Sr-carbonate substituted n-HAp) on early colonization (EC, 12 h) and biofilm formation (BF, 24 h) by oral microbiota. Controls were brushed with distilled water. Artificial oral microcosm and Streptococcus mutans biofilms were developed using human enamel and a resin-based composite (RBC) as adherence surfaces. Two test setups, a shaking multiwell plate and a modified drip-flow reactor (MDFR), were used to simulate clinical conditions during the night (low salivary flow and clearance) and daytime, respectively. Energy-dispersive X-ray spectrometry (EDS) was used to evaluate specimens' surfaces after toothpaste treatment. Fluoride release from ß toothpaste was evaluated. Viable adherent biomass was quantified by MTT assay, and biofilms' morphology was highlighted using confocal microscopy. Results: EDS showed the presence of remnants from the tested toothpastes on both adherence surfaces. ß toothpaste showed significantly lower EC and BF compared to control using the artificial oral microcosm model, while α toothpaste showed lower EC and BF compared to control, but higher EC and BF compared to ß toothpaste. The effect shown by ß toothpaste was, to a minimal extent, due to fluoride release. Interestingly, this result was seen on both adherence surfaces, meaning that the tested toothpastes significantly influenced EC and BF even on RBC surfaces. Furthermore, the effect of toothpaste treatments was higher after 12 h than 24 h, suggesting that toothbrushing twice a day is more effective than brushing once. Conclusions: The efficacy of these treatments in reducing microbial colonization of RBC surfaces may represent a promising possibility in the prevention of secondary caries.

Decline in Dental Fluorosis Severity during Adolescence: A Cohort Study.

Dental fluorosis occurs from overingestion of fluoride during tooth formation. However, there is little evidence in the literature on whether or how fluorosis prevalence and severity change over time after tooth eruption. Permanent dentition dental examinations were conducted at ages 9, 13, 17, and 23 as part of the Iowa Fluoride Study, which has followed a cohort from birth. Fluorosis was assessed using the Fluorosis Risk Index (FRI) and Russell's criteria for differential diagnosis. Measures of fluorosis severity at the person and tooth level were calculated: second highest FRI score at the person level (the maximum FRI score for each tooth was determined and the tooth with the second highest maximum FRI score was used) and highest FRI score at the tooth level. At both the person and tooth levels, a decline in mild to moderate fluorosis severity was observed across adolescence and young adulthood. Across each pair of adjacent examinations at the person level, for participants with a baseline second highest FRI of 0, most participants stayed at 0 (82% to 91%). Many participants with a baseline second highest FRI of 1 had a follow-up score of 0 (47% to 54%), while about a third had a follow-up score of 1 (34% to 38%), and a lower percentage had an increase to a score of 2 (9% to 15%). For participants with baseline second highest FRI score of 2, between 25% and 44% of participants had follow-up FRI scores each of 0, 1, and 2. Similar patterns were observed at the tooth level. These results were consistent with most of the existing, limited literature. Overall, fluorosis severity, which was initially mild to moderate, tended to decline during adolescence and young adulthood. Additional study of how this trend affects esthetic perceptions of fluorosis is warranted.

Fluoride Revolution and Dental Caries: Evolution of Policies for Global Use.

Epidemiological studies over 70 y ago provided the basis for the use of fluoride in caries prevention. They revealed the clear relation between water fluoride concentration, and therefore fluoride exposure, and prevalence and severity of dental fluorosis and dental caries. After successful trials, programs for water fluoridation were introduced, and industry developed effective fluoride-containing toothpastes and other fluoride vehicles. Reductions in caries experience were recorded in many countries, attributable to the widespread use of fluoride. This is a considerable success story; oral health for many was radically improved. While previously, water had been the only significant source of fluoride, now there are many, and this led to an increase in the occurrence of dental fluorosis. Risks identified for dental fluorosis were ingestion of fluoride-containing toothpaste, water fluoridation, fluoride tablets (which were sometimes ingested in areas with water fluoridation), and infant formula feeds. Policies were introduced to reduce excessive fluoride exposure during the period of tooth development, and these were successful in reducing dental fluorosis without compromising caries prevention. There is now a much better understanding of the public perception of dental fluorosis, with mild fluorosis being of no aesthetic concern. The advantages of water fluoridation are that it provides substantial lifelong caries prevention, is economic, and reduces health inequalities: it reaches a substantial number of people worldwide. Fluoride-containing toothpastes are by far the most important way of delivering the beneficial effect of fluoride worldwide. The preventive effects of conjoint exposure (e.g., use of fluoride toothpaste in a fluoridated area) are additive. The World Health Organization has informed member states of the benefits of the appropriate use of fluoride. Many countries have policies to maximize the benefits of fluoride, but many have yet to do so.

Prevention Program Including Fluoride Varnish and 1450-ppm Fluoride Toothpaste Targeting Young Children in Clinical Setting in UK did not Stop Sental Caries From Developing but Slowed Lesion Progression.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: A randomized controlled trial of caries prevention in dental practice. Tickle M, O'Neill C, Donaldson M, Birch S, Noble S, Killough S, Murphy L, Greer M, Brodison J, Verghis R, Worthington HV. J Dent Res 2017; 96:741-46. SOURCE OF FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme in UK. TYPE OF STUDY/DESIGN: Randomized clinical trial with a parallel design.

Dental Fluorosis Trends in US Oral Health Surveys: 1986 to 2012.

INTRODUCTION: Dental fluorosis has been assessed only 3 times in nationally representative oral health surveys in the United States. The first survey was conducted by the National Institute of Dental Research from 1986 to 1987. Subsequently, the National Health and Nutrition Examination Survey (NHANES) conducted fluorosis assessments from 1999 to 2004 and more recently from 2011 to 2012. A large increase in prevalence and severity of fluorosis occurred between the 1986-1987 and 1999-2004 surveys. OBJECTIVES: To determine whether the trend of increasing fluorosis continued in the 2011-2012 survey. METHODS: We analyzed publicly available data from the 2011-2012 NHANES, calculating fluorosis prevalence and severity using 3 measures: person-level Dean's Index score, total prevalence of those with Dean's Index of very mild degree and greater, and Dean's Community Fluorosis Index. We examined these fluorosis measures by several sociodemographic factors and compared results with the 2 previous surveys. Analyses accounted for the complex design of the surveys to provide nationally representative estimates. RESULTS: Large increases in severity and prevalence were found in the 2011-2012 NHANES as compared with the previous surveys, for all sociodemographic categories. For ages 12 to 15 y-an age range displaying fluorosis most clearly-total prevalence increased from 22% to 41% to 65% in the 1986-1987, 1999-2004, and 2011-2012 surveys, respectively. The rate of combined moderate and severe degrees increased the most, from 1.2% to 3.7% to 30.4%. The Community Fluorosis Index increased from 0.44 to 0.67 to 1.47. No clear differences were found in fluorosis rates among categories for most of the sociodemographic variables in the 2011-2012 survey. CONCLUSION: Large increases in fluorosis prevalence and severity occurred. We considered several possible spurious explanations for these increases but largely ruled them out based on counterevidence. We suggest several possible real explanations for the increases. KNOWLEDGE TRANSFER STATEMENT: The results of this study greatly increase the evidence base indicating that objectionable dental fluorosis has increased in the United States. Dental fluorosis is an undesirable side effect of too much fluoride ingestion during the early years of life. Policy makers and professionals can use the presented evidence to weigh the risks and benefits of water fluoridation and early exposure to fluoridated toothpaste.

Biological and Mechanical Evaluation of Novel Prototype Dental Composites.

The breakdown of the polymeric component of contemporary composite dental restorative materials compromises their longevity, while leachable compounds from these materials have cellular consequences. Thus, a new generation of composite materials needed to be designed to have a longer service life and ensure that any leachable compounds are not harmful to appropriate cell lines. To accomplish this, we have developed concurrent thiol-ene-based polymerization and allyl sulfide-based addition-fragmentation chain transfer chemistries to afford cross-linked polymeric resins that demonstrate low shrinkage and low shrinkage stress. In the past, the filler used in dental composites mainly consisted of glass, which is biologically inert. In several of our prototype composites, we introduced fluorapatite (FA) crystals, which resemble enamel crystals and are bioactive. These novel prototype composites were benchmarked against similarly filled methacrylate-based bisphenol A diglycidyl ether dimethacrylate / triethylene glycol dimethacrylate (bisGMA/TEGDMA) composite for their cytotoxicity, mechanical properties, biofilm formation, and fluoride release. The leachables at pH 7 from all the composites were nontoxic to dental pulp stem cells. There was a trend toward an increase in total toughness of the glass-only-filled prototype composites as compared with the similarly filled bisGMA/TEGDMA composite. Other mechanical properties of the glass-only-filled prototype composites were comparable to the similarly filled bisGMA/TEGDMA composite. Incorporation of the FA reduced the mechanical properties of the prototype and bisGMA/TEGDMA composite. Biofilm mass and colony-forming units per milliliter were reduced on the glass-only-filled prototype composites as compared with the glass-only-filled bisGMA/TEGDMA composite and were significantly reduced by the addition of FA to all composites. Fluoride release at pH 7 was greatest after 24 h for the bisGMA/TEGDMA glass + FA composite as compared with the similarly filled prototypes, but overall the F- release was marginal and not at a concentration to affect bacterial metabolism.

Reducing Potentially Preventable Dental Hospitalizations of Young Children: A Community-Level Analysis.

An increasing number of Australians are being admitted to hospitals and day procedure centers to have dental treatment under a dental general anesthetic (DGA). Children younger than 2 y are having DGAs. These operations are costly and, although there have been improvements in safety, are not without risk. Most DGAs in children are to treat dental caries and have been defined as potentially preventable dental hospitalizations (PPDHs). This article reports on an analysis of the impact of access to community water fluoridation (CWF), availability of oral health professionals (OHPs), and socioeconomic status (SES) on PPDHs of 0- to 4-y-olds in 2012-2013 in Victoria, Australia. Data on these variables were obtained at the community (postcode) level. From the negative binomial multivariate analysis, each of the 3 independent variables was independently significantly associated with PPDHs at the postcode level. Children residing in postcodes without CWF on average had 59% higher rates than those with access (incident rate ratio [IRR], 1.59; P < 0.0001), children in postcodes with the lowest level of availability of OHPs had 65% higher rates than those with the highest access (IRR, 1.65; P < 0.0001), and children living in the most disadvantaged SES quintiles had 57% higher rates than children in the most advantaged quintiles (IRR, 1.57; P < 0.0001). There was a stepwise social gradient by SES quintile. In analysis of access to CWF and SES status, children without access to CWF had 86% higher PPDH rates than children with access (IRR, 1.86; P < 0.0001). In summary, no access to CWF, poor availability of OHPs, and lower SES status were independently associated with higher PPDH rates among 0- to 4-y-olds in Victoria at the postcode level. The study highlights the importance of considering 3 interacting factors-access to CWF, access to OHPs, and SES-in efforts to reduce PPDH rates in young children. Knowledge Transfer Statement: Extending access to water fluoridation, increasing the availability of dental services, and raising disadvantaged families' socioeconomic status are each likely to decrease the rate of dental general anesthetics in young children.

Adverse Effects of Silver Diamine Fluoride Treatment among Preschool Children.

This randomized clinical trial aimed to compare the adverse effects and parental satisfaction following the different regimes of silver diamine fluoride (SDF) treatment among preschool children. A total of 888 preschool children who had active dentin caries received different SDF application regimes: group 1, 12% SDF applied annually; group 2, 12% SDF applied semiannually; group 3, 38% SDF applied annually; and group 4, 38% SDF applied semiannually. Information on adverse effects-including tooth or gum pain, gum swelling, gum bleaching, and systemic toxicity-was collected through a parent-reported questionnaire within 1 wk after every SDF or placebo application. Information of parental satisfaction on children's dental appearance was collected at baseline and 30-mo examination. At the 30 mo, 799 children (90%) remained in the study. No acute systemic illness or major adverse effect was reported. No differences of all minor adverse effects among the 4 groups were found ( P > 0.05). Overall, prevalence of tooth and gum pain as perceived by patients and reported by parents was 6.6%, while gum swelling and gum bleaching were 2.8% and 4.7%, respectively. Blackening of carious lesions was common among all groups, with 36.7%, 49.5%, 65.6% and 76.3% in groups 1 to 4, respectively (χ2 test, P < 0.001). The proportion of parents who were satisfied with their children's dental appearance in groups 1 to 4 was as follows: 67.6%, 61.5%, 70.8%, and 62.3%, respectively (χ2 test, P > 0.05). Based on parental reporting, SDF does not cause acute systemic illness. Tooth or gum pain, gum swelling, and gum bleaching were uncommon and not significantly different among the study groups. Parental satisfaction with children's dental appearance was similar among all groups. The use of SDF following the study protocol for caries arrest is safe for preschool children. Collecting information on parental satisfaction and adverse effects is beneficial for dental professionals when deciding to adopt SDF treatment for preschool children (ClinicalTrials.gov NCT02385474).

Oral health behaviours of parents and young children in a practice-based caries prevention trial in Northern Ireland.

OBJECTIVES: The NICPIP trial evaluated the costs and effects of a caries prevention intervention delivered to 2- to 3-year-old children attending dental practices in Northern Ireland. This supplementary study explored the oral health behaviours of children and their parents to help understand the reasons for the trial's findings. METHODS: A mixed methods study that included a questionnaire completed by all parents (n = 1058) at the time they brought their child for the NICPIP final clinical assessment. The questionnaire collected data on frequency of toothbrushing and sugar consumption. Questionnaire data were analysed by trial group and caries status. Parents of trial participants (n = 42) were invited to take part in telephone interviews. Parents were purposively sampled according to trial group and whether or not their child developed caries. The interviews explored how and why oral health behaviours happened. Interview data were audio-recorded, transcribed verbatim and analysed thematically. RESULTS: The questionnaire data indicated that toothbrushing and between-meal sugar snacking were common in the majority of children. The children of parents who automatically reminded their child to brush their teeth were more likely to remain caries-free (Odds Ratio 1.24; 95% CI 1.08, 1.41; P = .002). Frequency of sweet drink consumption was associated with the child developing caries (Odds Ratio 0.88; 95% CI 0.79, 0.98; P = .021). The interview data showed that parents had positive attitudes towards brushing both in terms of perceived importance and expected outcomes. Attitudes towards sugar snacking were more complex, with parents reporting difficulties in controlling this behaviour. Sugar was described as being something that was "ever present" in children's lives. CONCLUSIONS: Toothbrushing was widely adopted from a young age, but between-meal sugar consumption was highly prevalent. The results suggest that effective family-level and population-level interventions are needed to reduce sugar consumption if substantial improvements in caries prevention are to be achieved.

Managing Early Childhood Caries with Atraumatic Restorative Treatment and Topical Silver and Fluoride Agents.

Early childhood caries (ECC) is a significant global health problem affecting millions of preschool children worldwide. In general, preschool children from families with 20% of the lowest family incomes suffered about 80% of the ECC. Most, if not all, surveys indicated that the great majority of ECC was left untreated. Untreated caries progresses into the dental pulp, causing pain and infection. It can spread systemically, affecting a child's growth, development and general health. Fundamental caries management is based on the conventional restorative approach. Because preschool children are too young to cope with lengthy dental treatment, they often receive dental treatment under general anaesthesia from a specialist dentist. However, treatment under general anaesthesia poses a life-threatening risk to young children. Moreover, there are few dentists in rural areas, where ECC is prevalent. Hence, conventional dental care is unaffordable, inaccessible or unavailable in many communities. However, studies showed that the atraumatic restorative treatment had a very good success rate in treating dentine caries in young children. Silver diamine fluoride is considered safe and effective in arresting dentine caries in primary teeth. The aim of this paper is to review and discuss updated evidence of these alternative approaches in order to manage cavitated ECC.

Effect of application sequence of fluoride and CPP-ACP on remineralization of white spot lesions in primary teeth: An in-vitro study.

OBJECTIVE: To explore how application sequence of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and fluoride influences remineralization of enamel white spot lesions (WSL) in primary teeth. DESIGN: In this in-vitro study, artificial WSLs were created in 130 primary teeth. Teeth were divided into 4 groups (n=27) and a control group (n=22) and exposed to one of the following remineralization regimens for 10 weeks: Group-1; 500ppm fluoride dentifrice; Group-2; 10% w/v CPP-ACP; Group-3; fluoride applied first, then CPP-ACP; Group-4; CPP-ACP applied first, then fluoride, and Group-5 was control. All groups were kept in a remineralizing solution. Mineral changes (ΔF) were quantified weekly using quantitative light-induced fluorescence. Statistical analysis was done using Statistical Package for the Social Sciences (SPSS version 20.0). RESULTS: Remineralization occurred in all groups to different degrees; changes from baseline were significant in groups 1-4 (P≤0.05). Group-4 showed the earliest significant remineralization (after 2 weeks) among groups, (P<0.001). Group-4 showed maximum changes in ΔF among groups; however, only differences with Groups 1 and 5 were significant (P<0.05 and P<0.01, respectively). Group-3 showed better remineralization than Groups 1, 2 and 5; however, the difference was only significant with Group-5 (P<0.001). There were no significant differences between Group 1and 2, however, only Group 2 showed better remineralization than Group 5, (P<0.01). CONCLUSION: Combined treatment with CPP-ACP followed by fluoride exhibited the best remineralization of white spot lesions in primary teeth in this study. Combined treatment with fluoride followed by CPP-ACP showed a tendency towards better remineralization than fluoride or CPP-ACP alone.

Cost-Effectiveness of Caries Prevention in Practice: A Randomized Controlled Trial.

A 2-arm parallel-group randomized controlled trial measured the cost-effectiveness of caries prevention in caries-free children aged 2 to 3 y attending general practice. The setting was 22 dental practices in Northern Ireland. Participants were centrally randomized into intervention (22,600 ppm fluoride varnish, toothbrush, a 50-mL tube of 1,450 ppm fluoride toothpaste, and standardized prevention advice) and control (advice only), both provided at 6-monthly intervals during a 3-y follow-up. The primary outcome measure was conversion from caries-free to caries-active states assessed by calibrated and blinded examiners; secondary outcome measures included decayed, missing, or filled teeth surfaces (dmfs); pain; and extraction. Cumulative costs were related to each of the trial's outcomes in a series of incremental cost effectiveness ratios (ICERs). Sensitivity analyses examined the impact of using dentist's time as measured by observation rather than that reported by the dentist. The costs of applying topical fluoride were also estimated assuming the work was undertaken by dental nurses or hygienists rather than dentists. A total of 1,248 children (624 randomized to each group) were recruited, and 1,096 (549 in the intervention group and 547 in the control group) were included in the final analyses. The mean difference in direct health care costs between groups was £107.53 (£155.74 intervention, £48.21 control, P < 0.05) per child. When all health care costs were compared, the intervention group's mean cost was £212.56 more than the control group (£987.53 intervention, £774.97 control, P < 0.05). Statistically significant differences in outcomes were only detected with respect to carious surfaces. The mean cost per carious surface avoided was estimated at £251 (95% confidence interval, £454.39-£79.52). Sensitivity analyses did not materially affect the study's findings. This trial raises concerns about the cost-effectiveness of a fluoride-based intervention delivered at the practice level in the context of a state-funded dental service (EudraCT No: 2009-010725-39; ISRCTN: ISRCTN36180119).

A Randomized Controlled Trial of Caries Prevention in Dental Practice.

We conducted a parallel group randomized controlled trial of children initially aged 2 to 3 y who were caries free, to prevent the children becoming caries active over the subsequent 36 mo. The setting was 22 dental practices in Northern Ireland, and children were randomly assigned by a clinical trials unit (CTU) (using computer-generated random numbers, with allocation concealed from the dental practice until each child was recruited) to the intervention (22,600-ppm fluoride varnish, toothbrush, 50-mL tube of 1,450 ppm fluoride toothpaste, and standardized, evidence-based prevention advice) or advice-only control at 6-monthly intervals. The primary outcome measure was conversion from caries-free to caries-active states. Secondary outcome measures were number of decayed, missing, or filled teeth (dmfs) in caries-active children, number of episodes of pain, and number of extracted teeth. Adverse reactions were recorded. Calibrated external examiners, blinded to the child's study group, assessed the status of the children at baseline and after 3 y. In total, 1,248 children (624 randomized to each group) were recruited, and 1,096 (549 intervention, 547 control) were included in the final analyses. Eighty-seven percent of intervention and 86% of control children attended every 6-mo visit ( P = 0.77). A total of 187 (34%) in the intervention group converted to caries active compared to 213 (39%) in the control group (odds ratio, 0.81; 95% confidence interval, 0.64-1.04; P = 0.11). Mean dmfs of those with caries in the intervention group was 7.2 compared to 9.6 in the control group ( P = 0.007). There was no significant difference in the number of episodes of pain between groups ( P = 0.81) or in the number of teeth extracted in caries-active children ( P = 0.95). Ten children in the intervention group had adverse reactions of a minor nature. This well-conducted trial failed to demonstrate that the intervention kept children caries free, but there was evidence that once children get caries, it slowed down its progression (EudraCT No: 2009-010725-39; ISRCTN: ISRCTN36180119).

Dental Prophylaxis and Osteoradionecrosis: A Population-Based Study.

The aim of this study was to investigate the association of different dental prophylactic modalities and osteoradionecrosis (ORN) and determine the risk of ORN under different timing periods of scaling, with the use chlorhexidine mouth rinse after surgery and with different strategies of fluoride gel application in head and neck cancer (HNC) participants. A cohort of 18,231 HNC participants, including 941 ORN patients and 17,290 matched control cases, were enrolled from a Longitudinal Health Insurance Database for Catastrophic Illness Patients (LHID-CIP) in Taiwan. Based on different dental prophylactic modalities before radiotherapy, including chlorhexidine mouth rinse, scaling, and fluoride gel, all HNC subjects were stratified into different groups. The Cox proportional hazard regression was used to compare ORN incidences under different dental prophylactic modalities. The results revealed that scaling and chlorhexidine mouth rinse were significantly related to ORN risk ( P = 0.004 and P < 0.0001). Chlorhexidine mouth rinse was highly correlated to ORN occurrence (hazard ratio [HR], 1.83-2.66), as exposure increased the risk by 2.43-fold among oral cancer patients, regardless of whether they had received major oral surgery or not. Oral cancer patients receiving scaling within 2 wk before radiotherapy increased their incidence of ORN by 1.28-fold compared with patients who had not undergone scaling within 6 mo. There is no significance of fluoride application for dental prophylaxis in increasing ORN occurrence. In conclusion, dental prophylaxis before radiotherapy is strongly correlated to ORN in HNC patients. Chlorhexidine exposure and dental scaling within 2 wk before radiotherapy is significantly related to ORN risk, especially in oral cancer patients. The use of 1.1% NaF topical application did not significantly increase the risk of ORN in HNC patients. An optimal dental prophylaxis protocol to reduce ORN should concern cancer location, cautious prescription of chlorhexidine mouth rinse, and proper timing of scaling.