Comparative evaluation of four treatments for postorthodontic white spot lesions: a randomized controlled trial.

OBJECTIVES: To evaluate the treatment efficacy of fluoride toothpaste alone and those of adjunctive use of resin infiltration, sodium fluoride varnish, and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on white spot lesions (WSLs). MATERIALS AND METHODS: Seventy-nine patients (356 teeth) with WSLs after orthodontic treatment were randomly allocated into four groups. The WSLs of the participants received resin infiltration only at baseline, and the other groups received fluoride varnish, CPP-ACP mousse, and placebo treatment every 6 months, respectively. A toothpaste containing 1400 ppm fluoride and toothbrushes were distributed to all participants, and oral hygiene instructions were provided. Photos of the teeth with WSL were taken to compare the change between groups which was measured by ImageJ software. RESULTS: Twelve months later, different degrees of reduction in the area of WSLs were observed in all groups. The percentage of lesion area reduction in WSLs in the resin infiltration group was 46.6%, which was significantly higher than that in fluoride varnish group (26.6%), CPP-ACP group (28.6%), and control group (29.8%), and the differences were statistically significant (p < 0.001). CONCLUSIONS: This study shows that after 1-year follow-up, the use of fluoride toothpaste, with or without the use of fluoride varnish or CPP-ACP, can reduce the area of WSLs. While resin infiltration can immediately improve dental aesthetics and continuously improved in 12 months, resin infiltration group showed much better results than other groups. TRIAL REGISTRATION: Clinical Trials Registration Number: ChiCTR2000032516. CLINICAL SIGNIFICANCE: The use of fluoride toothpaste, with or without adjunctive use of fluoride varnish and CPP-ACP, can reduce the area of WSLs, while resin infiltration treatment has additional effect and can immediately improve dental aesthetics.

Effectiveness of Family-Centered Oral Health Promotion on Toddler Oral Health in Hong Kong.

Early childhood caries is common in Hong Kong, and parental practices on maintaining good oral health of their young children are far from satisfactory. This article reports on the effectiveness of a randomized controlled trial on family-centered oral health promotion to new parents in establishing proper feeding habits and oral hygiene practices and in reducing caries risk among 3-y-old toddlers. At baseline, pregnant mothers and their husbands were recruited and randomly allocated into 2 groups. The test group received individualized oral health education (OHE) via a behavioral and educational counseling approach while the control group received the OHE pamphlets only. Information related to the feeding habits, oral hygiene practices, and oral health of the toddlers was collected by parent-completed questionnaires and oral examination annually via home visits. A total of 580 families were recruited at baseline, and 436 toddlers were followed up when they reached 3 y old (test, n = 228; control, n = 208; follow-up rate, 75.2%). The proportions of toddlers who held food in the mouth, fell asleep when milk feeding, had prolonged use of the nursing bottle, ate before bed, and consumed a sweet snack daily were significantly lower in the test group than in the control group (all P < 0.05). Significantly higher proportions of toddlers brushed their own teeth twice daily, were brushed by their parents twice daily, and used fluoride toothpaste than in the control group (all P < 0.001). Toddlers in the test group had better oral health status with a lower level of visible plaque, Streptococcus mutans, white spot lesion, and cavitated lesion (all P < 0.05). Family-centered oral health promotion and individualized OHE for parents via a behavioral and educational counseling approach are more effective in establishing good feeding habits and parental toothbrushing practices and in decreasing the caries risk of their toddlers than the distribution of OHE pamphlets alone (ClinicalTrials.gov NCT02937194).

A Systematic Review and Meta-analysis of the Effect of Oral Exercises on Masticatory Function.

The aim of the current systematic review was to summarize and to evaluate the available information on the effectiveness of oral exercise in improving the masticatory function of people ≥18 y. Electronic databases (Medline, Embase, CENTRAL) and gray literatures were searched (up to December 2020) for relevant randomized and nonrandomized controlled clinical trials. Two reviewers independently conducted the study selection, data extraction, and quality assessments. Meta-analysis was conducted for the comparison of bite force and masticatory performance using mean difference (MD) and standardized mean difference (SMD), respectively. GRADE (Grading of Recommendations Assessment, Development, and Evaluation) assessment was adopted for collective grading of the overall body of evidence. Of the 1,576 records identified, 18 studies (21 articles) were included in the analysis. Results of meta-analysis indicated that oral exercise could significantly improve the mean bite force of the participants (parallel comparison: MD, 41.2; 95% CI, 11.6-70.7, P = 0.006; longitudinal comparison: MD, 126.5; 95% CI, 105.2-144.9, P < 0.001). However, the improvement in masticatory performance was not significant (parallel comparison: SMD, 0.11; 95% CI, -0.20 to 0.42, P = 0.48; longitudinal comparison: SMD, 0.4; 95% CI, -0.11 to 0.91, P = 0.13). Results of meta-regression showed that greater improvements in bite force can be achieved among younger adults and with more intensive exercise. Chewing exercise is the most effective oral exercise, followed by clenching exercise, while simple oral exercise may not have a significant effect. Based on the results of the meta-analysis and GRADE assessment, a weak recommendation for people with declined masticatory function to practice oral exercise is made.

Randomized Clinical Trial on Sodium Fluoride with Tricalcium Phosphate.

This 24-mo randomized controlled trial was based on a double-blind parallel design, and it compared the effectiveness of 2 fluoride application protocols in arresting dentine caries in primary teeth. Three-year-old children with active dentine caries were recruited and randomly allocated to 2 treatment groups. Children in group A received a semiannual application of a 25% silver nitrate (AgNO3) solution followed by a commercially available varnish with 5% sodium fluoride (NaF) on the carious tooth surfaces. Children in group B received a semiannual application of a 25% AgNO3 solution followed by another commercially available varnish with 5% NaF containing functionalized tricalcium phosphate (fTCP). Carious tooth surfaces that were hard when probing were classified as arrested. Intention-to-treat analysis and a hierarchical generalized linear model were undertaken. A total of 408 children with 1,831 tooth surfaces with active dentine caries were recruited at baseline, and 356 children (87%) with 1,607 tooth surfaces (88%) were assessed after 24 mo. At the 24-mo evaluation, the mean (SD) number of arrested carious tooth surfaces per child were 1.8 (2.2) and 2.6 (3.3) for group A (without fTCP) and group B (with fTCP), respectively (P = 0.003). The arrest rates at the tooth surface level were 42% for group A and 57% for group B (P < 0.001). Results of the hierarchical generalized linear model indicated that protocol B (with fTCP) had a higher predicted probability (PP = 0.656) in arresting dentine caries than protocol A (without fTCP; PP = 0.500) when the carious lesions were on buccal/lingual surfaces, were on anterior teeth, had dental plaque coverage, and were in children from low-income families (P = 0.046). In conclusion, protocol B, which applied a 25% AgNO3 solution followed by a commercially available 5% NaF varnish with fTCP semiannually, is more effective in arresting dentine caries in primary teeth as compared with protocol A, which applied a 25% AgNO3 solution followed by another commercially available 5% NaF varnish without fTCP semiannually (ClinicalTrials.gov NCT03423797).

Ethnic Disparities in Dental Caries among Adolescents in China.

Comprehensive research on ethnic disparities in dental caries in China is limited. The aims of this cross-sectional study were to compare the levels of dental caries in adolescents between the Han ethnic group and ethnic minority groups in China and to explore the risk indicators for dental caries within ethnic subgroups. Data from the Fourth National Oral Health Survey in 2015, which covered all 31 province-level administrative divisions in mainland China, were used. The dental caries status in the permanent dentition of adolescents aged 12, 13, 14, and 15 y was measured using the decayed, missing, and filled teeth (DFMT) score, and sociodemographic characteristics and oral health-related behaviors were also collected. A total of 118,601 adolescents were included, with ethnic minority groups accounting for 13.15%. Of the Han and minority groups, the standardized prevalence of dental caries experience was 40.58% and 47.67%, and the mean DMFT scores were 0.97 and 1.28, respectively. According to the multivariate zero-inflated negative binomial regression analysis, the caries status of minorities was more severe than Han adolescents (adjusted prevalence rate ratio [PRR], 1.14; 95% confidence interval [CI], 1.10-1.18). This disparity was greater among adolescents who lived in rural areas, had mid-level economic status, and frequently consumed sugary beverages. After propensity score matchings, Uygur (PRR, 1.44; 95% CI, 1.25-1.67), Tibetan (PRR, 1.39; 95% CI, 1.3-1.48), and Yi (PRR, 1.24; 95% CI, 1.04-1.48) adolescents were significantly more likely to have caries than Han adolescents. Subgroup analyses revealed that gender, age, location of residence, economic status, region, consumption of sweet snacks and sugary beverages, and dental visit pattern were significantly associated with dental caries within ethnic minorities.

Topical Fluoride to Prevent Root Caries: Systematic Review with Network Meta-analysis.

The aim of this systematic review and network meta-analysis was to summarize the direct and indirect clinical evidence on the effectiveness of professionally applied and self-applied topical fluorides in preventing dental root caries. Controlled clinical trials with any follow-up duration were included. MEDLINE, PubMed, Embase, Scopus, and Cochrane Library were searched. Two reviewers independently carried out the selection of studies, data extraction, risk-of-bias assessments, and assessment of the certainty in the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Fixed effects model and frequentist approach were used in the network meta-analyses. Nine clinical trials involving 4,030 participants were included. Five professionally applied and 7 self-applied topical fluoride agents or combinations were included in the meta-analyses. Compared to control group, 38% silver diamine fluoride solution, 5% sodium fluoride varnish, and 1.2% acidulated phosphate fluoride reduced root caries increment after 2 y (ranging from 0.59 to 0.85 mean decayed or filled root [DF-root]). Fluoride mouth rinse and fluoride toothpaste, used alone or in combination, reduced root caries increment after 1 y (ranging from 0.29 to 1.90 mean DF-root). Among the professionally applied topical fluorides reviewed, an annually applied 38% silver diamine fluoride (SDF) solution combined with oral health education is most likely to be the most effective in preventing dental root caries. Among the reviewed self-applied topical fluoride methods, daily use of a 0.2% sodium fluoride (NaF) mouth rinse is most likely to be the most effective, followed by 1100 ppm to 1500 ppm fluoride toothpaste plus 0.05% NaF mouth rinse, and 1100 ppm to 1500 ppm fluoride toothpaste.

Factors Associated with Dental Root Caries: A Systematic Review.

OBJECTIVES: The objectives of this review were to identify the factors associated with root caries and to describe their relationship with the presence and extent of root caries. METHODS: A search was carried out on the PubMed, Medline, Embase, and Scopus databases for articles published between January 1990 and October 2018. Information was extracted on the factors associated with the presence or extent of decayed or filled root surfaces and/or decayed root surfaces. Factors were sorted into 6 categories: social-demographic background, general health, health behaviors, fluoride exposure, oral health habits, and oral health condition. RESULTS: The quality of the 127 identified relevant papers was assessed, and those of low methodological quality were excluded. Finally, 44 articles reporting on 40 cross-sectional studies were included. The total sample size comprised 78,183 participants from different countries around the world. Positive correlations were detected between root caries and age, gingival recession, and use of tobacco, while negative correlations were found for social position, use of fluoride toothpaste, and oral hygiene status. Mixed findings were reported for association with the number of teeth and dental visit behaviors. CONCLUSION: This systematic review found a number of factors in different categories to be associated with root caries. People who are older, of lower socioeconomic status, or tobacco users and those with more gingival recession and poorer oral hygiene have higher risk of root caries. KNOWLEDGE TRANSFER STATEMENT: This systematic review found a number of factors associated with root caries, including age, social position, exposure to fluoride, and oral hygiene status. This information helps dental public health workers and clinicians identify the groups at high risk of caries and the factors to act on for more effective prevention and management of root caries (e.g., use fluoride toothpaste and improve oral hygiene).

A Century of Change towards Prevention and Minimal Intervention in Cariology.

Better understanding of dental caries and other oral conditions has guided new strategies to prevent disease and manage its consequences at individual and public health levels. This article discusses advances in prevention and minimal intervention dentistry over the last century by focusing on some milestones within scientific, clinical, and public health arenas, mainly in cariology but also beyond, highlighting current understanding and evidence with future prospects. Dentistry was initially established as a surgical specialty. Dental caries (similar to periodontitis) was considered to be an infectious disease 100 years ago. Its ubiquitous presence and rampant nature-coupled with limited diagnostic tools and therapeutic treatment options-meant that these dental diseases were managed mainly by excising affected tissue. The understanding of the diseases and a change in their prevalence, extent, and severity, with evolutions in operative techniques, technologies, and materials, have enabled a shift from surgical to preventive and minimal intervention dentistry approaches. Future challenges to embrace include continuing the dental profession's move toward a more patient-centered, evidence-based, less invasive management of these diseases, focused on promoting and maintaining oral health in partnership with patients. In parallel, public health needs to continue to, for example, tackle social inequalities in dental health, develop better preventive and management options for existing disease risk groups (e.g., the growing aging population), and the development of reimbursement and health outcome models that facilitate implementation of these evolving strategies. A century ago, almost every treatment involved injections, a drill or scalpel, or a pair of forceps. Today, dentists have more options than ever before available to them. These are supported by evidence, have a minimal intervention focus, and result in better outcomes for patients. The profession's greatest challenge is moving this evidence into practice.

EphrinB2/EphB4 Signaling Regulates DPSCs to Induce Sprouting Angiogenesis of Endothelial Cells.

Dental pulp stem cells (DPSCs) are capable of facilitating angiogenesis resembling pericytes when located adjacent to endothelial cells (ECs). Nevertheless, the precise mechanisms orchestrating their proangiogenic functions remain unclear. Using a 3-dimensional (3-D) fibrin gel model, we aimed to investigate whether EphrinB2/EphB4 signaling in DPSCs plays a role in supporting vascular morphogenesis mediated by ECs, together with the underlying mechanism involved. The EphrinB2/EphB4 signaling was inhibited either by a pharmacological inhibitor of EphB4 receptor or by knocking down the expressions of EphrinB2 and EphB4 using lentiviral small hairpin RNA (shRNA). DPSCs were either encapsulated in fibrin gel together with human umbilical vein endothelial cells (HUVECs) or cultured as a monolayer on top of HUVECs to investigate both paracrine and juxtacrine interactions simultaneously. Following 10 d of direct coculture, we found that pharmacological inhibition of EphrinB2/EphB4 signaling severely impaired vessel formation and laminin deposition. When directly cocultured with HUVECs, knockdown of EphrinB2 or EphB4 in DPSCs significantly inhibited endothelial sprouting, resulting in less capillary sprouts with reduced vessel length (P < 0.05). By contrast, when DPSCs were not in direct contact with HUVECs, attenuation of EphrinB2 or EphB4 expression levels in DPSCs did not exert any significant effects on capillary morphogenesis. Noticeably, exogenous stimulation with soluble EphrinB2-Fc or EphB4-Fc (1 µg/mL) enhanced vascular endothelial growth factor (VEGF) secretion from DPSCs, thereby moderately promoting angiogenic cascades in the fibrin matrix. This study, for the first time, reveals a crucial role of EphrinB2/EphB4 signaling in regulating the capacity of DPSCs to induce sprouting angiogenesis. These findings advance our understanding of postnatal angiogenesis and may have future regenerative medicine applications.

Randomized Trial of Silver Nitrate with Sodium Fluoride for Caries Arrest.

OBJECTIVES: The aim of this noninferiority double-blind randomized clinical trial was to compare the effectiveness of the topical semiannual application of a 25% silver nitrate (AgNO3) solution followed by a 5% sodium fluoride (NaF) varnish with that of a 38% silver diamine fluoride (SDF) solution in arresting caries among preschool children. METHODS: Healthy 3-y-old children with active dentine carious lesions were randomly allocated to 2 groups via computer-generated random numbers. Lesions in group A received applications of a 25% AgNO3 solution followed by a 5% NaF varnish semiannually (every 6 mo). Lesions in group B received semiannual applications of a 38% SDF solution followed by a placebo varnish. A trained examiner recorded the status of caries and oral hygiene at baseline and during follow-up examinations. The examiner, children, and their caretakers were blinded to the intervention allocation. This study adopted an intention-to-treat analysis. A noninferiority test was conducted for the data analysis. Group A's noninferiority was accepted if the lower limit of the 95% CI for the difference in the mean number of arrested surfaces was >-0.5. RESULTS: A total of 1,070 children were recruited at baseline, with 535 children in each group. After 18 mo, the mean ± SD number of arrested surfaces was 3.3 ± 3.4 in group A (n = 484) and 3.2 ± 3.5 in group B (n = 476; P = 0.664). The difference in the mean number of arrested surfaces between the groups was 0.092 (95% CI, -0.322 to 0.505). Apart from black staining on the arrested lesions, no other significant side effect was observed. CONCLUSION: A semiannual application of 25% AgNO3 followed by 5% NaF is no worse than a 38% SDF in arresting dentine caries among preschool children over 18 mo. The Hong Kong Research Grants Council (GRF 17107315) funded this trial, which was registered at ClinicalTrials.gov (NCT02019160). KNOWLEDGE TRANSFER STATEMENT: This randomized clinical trial found that silver nitrate solution followed by sodium fluoride varnish is effective in arresting dentine caries among preschool children. As silver nitrate followed by sodium fluoride is a noninvasive and simple protocol, it can be an alternative strategy to manage dental caries among young children, especially in countries where silver diamine fluoride is not available.

Arresting Dentine Caries with Silver Diamine Fluoride: What's Behind It?

Unlike other fluoride-based caries preventive agents, silver diamine fluoride (SDF) can simultaneously prevent and arrest coronal and root dentine caries. The profound clinical success of SDF has drawn many clinicians and researchers to study the mechanism of SDF in arresting dentine caries. This critical review discusses how silver and fluoride contribute to caries arrest, in terms of their effects on bacteria as well as on the mineral and organic content of dentine. Silver interacts with bacterial cell membrane and bacterial enzymes, which can inhibit bacterial growth. Silver can also dope into hydroxyapatite and have an antibacterial effect on silver-doped hydroxyapatite. Furthermore, silver is also a strong inhibitor of cathepsins and inhibits dentine collagen degradation. Early studies proposed that silver hardened caries lesions by forming silver phosphate. However, recent studies found that little silver phosphate remained on the arrested dentine lesion. The principal silver precipitate was silver chloride, which could not contribute to the significant hardening of the arrested lesions. On the other hand, fluoride enhances mineral formation by forming fluorohydroxyapatite with reduced solubility. A significant increase in microhardness occurs with an elevated level of calcium and phosphorus but not silver on the surface layer of the arrested dentine caries lesion following SDF treatment. Fluoride also inhibits matrix metalloproteinases activities and therefore inhibits dentine collagen degradation. The combination of silver and fluoride in an alkaline solution has a synergistic effect in arresting dentine caries. The alkaline property of SDF provides an unfavorable environment for collagen enzyme activation. Understanding the mechanisms of SDF in arresting dentine caries helps clinicians to develop appropriate protocols for the use of SDF in clinical care.

Caries arrest by topical fluorides in preschool children: 30-month results.

OBJECTIVE: To compare the effectiveness of three applications of silver diammine fluoride (SDF) solution at yearly interval and three applications of SDF solution or sodium fluoride (NaF) varnish at weekly interval at baseline in arresting active caries in the primary teeth of preschool children. METHODS: Children aged 3-4 years (n = 371) who had at least one active caries lesion (ICDAS codes 3-6) in their primary teeth were randomly allocated into three groups: Group 1 - annual application of 30% SDF solution; Group 2 - three applications of 30% SDF at weekly intervals; and Group 3 - three applications of 5% NaF varnish at weekly intervals. Follow-up examinations were performed every 6 mo nths by the same masked examiner. RESULTS: After 30 months, 309 (83%) children with 1877 caries lesions remained in the study. For cavitated lesions (ICDAS code 5 or 6), the caries arrest rate of Group 1 (48%) was significantly higher than those of Group 2 (33%) and Group 3 (34%), (p < 0.001). Results of multi-level survival analysis showed that the arrest times of cavitated lesions in both SDF groups (Groups 1 and 2) were significantly shorter than that of the NaF varnish group. For moderate caries lesions without visible dentine (ICDAS code 3 or 4), the caries arrest rates were 45%, 44% and 51% in Groups 1, 2 and 3, respectively (p > 0.05). Presence of plaque on caries lesion, tooth type and tooth surface type had an influence on caries arrest. CONCLUSION: Over a 30-month period, annual applications of SDF solution is more effective than three weekly applications of NaF varnish or SDF solution at baseline in arresting active cavitated dentine caries lesions in primary teeth. CLINICAL SIGNIFICANCE: As annual application of SDF solution was found to be more effective than 3 weekly applications of NaF varnish or SDF solution at baseline in arresting active cavitated dentine caries lesions, the former application protocol is preferred for young children who are available for regular caries arrest treatment.

Randomized Clinical Trial of 12% and 38% Silver Diamine Fluoride Treatment.

This 30-mo randomized clinical trial compared the effectiveness of 2 concentrations (12% or 38%) of silver diamine fluoride (SDF) and 2 periodicity of application (once or twice a year) in arresting cavitated dentin caries in primary teeth. Children aged 3 to 4 y who had at least 1 active cavitated caries lesion were enrolled and randomly allocated into 4 groups for intervention. Group 1 had 12% SDF applied annually (every 12 mo), group 2 had 12% SDF applied semiannually (every 6 mo), group 3 had 38% SDF applied annually, and group 4 had 38% SDF applied semiannually. Clinical examinations were performed semiannually in kindergarten by a single examiner to investigate whether the SDF-treated caries became arrested. A total of 888 children with 4,220 decayed tooth surfaces received SDF application at baseline, and 799 (90.0%) children with 3,790 surfaces (89.8%) were evaluated at the 30-mo examination. The caries arrest rates were 55.2%, 58.6%, 66.9%, and 75.7% for groups 1, 2, 3, and 4, respectively ( P < 0.001). Caries treated with 38% SDF had a higher chance of becoming arrested than those treated with 12% SDF (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.51-2.60, P < 0.001). The interaction between frequency of SDF application and visible plaque index (VPI) score was significant ( P = 0.017). Among those children who received annual SDF application, children with a higher VPI score had a lower chance to have their caries become arrested (OR, 0.59, 95% CI, 0.49-0.72). In conclusion, SDF at a concentration of 38% is more effective than that of 12% in arresting active caries in primary teeth. For children with poor oral hygiene, caries arrest rate of SDF treatment can be increased by increasing the frequency of application from annually to semiannually ( ClinicalTrials.gov NCT02385474).

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).

Formation of Fluorohydroxyapatite with Silver Diamine Fluoride.

Silver diamine fluoride (SDF) is found to promote remineralization and harden the carious lesion. Hydroxyapatite crystallization is a crucial process in remineralization; however, the role of SDF in crystal formation is unknown. We designed an in vitro experiment with calcium phosphate with different SDF concentrations (0.38, 1.52, 2.66, 3.80 mg/mL) to investigate the effect of this additive on the nucleation and growth of apatite crystals. Two control groups were also prepared-calcium phosphate (CaCl2·2H2O + K2HPO4 in buffer solution) and SDF (Ag[NH3]2F in buffer solution). After incubation at 37 oC for 24 h, the shape and organization of the crystals were examined by bright-field transmission electron microscopy and electron diffraction. Unit cell parameters of the obtained crystals were determined with powder X-ray diffraction. The vibrational and rotational modes of phosphate groups were analyzed with Raman microscopy. The transmission electron microscopy and selected-area electron diffraction confirmed that all solids precipitated within the SDF groups were crystalline and that there was a positive correlation between the increased percentage of crystal size and the concentration of SDF. The powder X-ray diffraction patterns indicated that fluorohydroxyapatite and silver chloride were formed in all the SDF groups. Compared with calcium phosphate control, a contraction of the unit cell in the a-direction but not the c-direction in SDF groups was revealed, which suggested that small localized fluoride anions substituted the hydroxyl anions in hydroxyapatite crystals. This was further evidenced by the Raman spectra, which displayed up-field shift of the phosphate band in all the SDF groups and confirmed that the chemical environment of the phosphate functionalities indeed changed. The results suggested that SDF reacted with calcium and phosphate ions and produced fluorohydroxyapatite. This preferential precipitation of fluorohydroxyapatite with reduced solubility could be one of the main factors for arrest of caries lesions treated with SDF.

Randomized Clinical Trial on Preventing Root Caries among Community-Dwelling Elders.

Dental root caries is a common disease among elders. More efforts on preventing this disease are needed. Silver diammine fluoride (SDF) is known to prevent dental caries in primary teeth. However, clinical evidence of its efficacy in preventing root surface caries is limited. This clinical trial aimed to compare the effectiveness of SDF in preventing root caries among elders in a water fluoridated area. A total of 323 elders who had at least 5 teeth with exposed root surfaces and who had self-care ability were randomly allocated into 3 intervention groups: group 1 (placebo control), annual application of tonic water; group 2, annual application of SDF solution; group 3, annual application of SDF solution, immediately followed by potassium iodide (KI) solution. Oral hygiene instructions and fluoride toothpaste were provided to all subjects. Status of dental root surface was assessed every 6 mo by the same independent examiner. After 30 mo, 257 (79.6%) elders were reviewed. The mean numbers of root surface with new caries experience in the control, SDF, and SDF/KI groups were 1.1, 0.4, and 0.5, respectively (analysis of variance, P < 0.001). Scheffe's multiple comparison showed that elders who received placebo developed more new root caries lesions ( P < 0.05), while the difference between the SDF and SDF/KI groups was not statistically significant ( P > 0.05). Moreover, elders who had higher visible plaque index scores at 30-mo examination (analysis of covariance, P < 0.001) and those who had higher baseline DMFT scores (analysis of covariance, P = 0.005) developed more new root caries. It is concluded that annual application of SDF or SDF/KI solution is effective in preventing root caries among community-dwelling elders in a fluoridated area ( ClinicalTrials.gov NCT02360124). Knowledge Transfer Statement: Annual topical application of silver diammine fluoride or silver diammine fluoride / potassium iodide solution is effective in preventing dental root surface caries among community-dwelling elders in a fluoridated area.

Restorative approaches to treat dentin caries in preschool children: systematic review.

AIM: Dental restorations have long been used for the management of early childhood caries, but there is a need to have an evidence based approach when selecting the most appropriate restorative intervention to treat dentin caries in preschool children. This systematic review aimed to assess the effectiveness of restorative treatments of dentin caries in primary teeth in preschool children. DESIGN: A systematic search of the main electronic databases (Pubmed, Cochrane Collaboration, EMBASE) was conducted to identify peer reviewed papers published in English in the years 1947-2014. Search keywords and MeSH headings were "dental caries", "primary dentition" and "dental restoration". The inclusion criteria were clinical studies conducted in children under 6 years old, and reported findings on the longevity or failure of restorations in primary teeth. Retrieved papers were read by two reviewers independently to assess suitability for inclusion, and the final decision was made by consensus. The quality of the included studies was assessed and data were extracted for analysis. RESULTS: The search identified 348 papers for screening. Among these, 218 papers did not satisfy the study inclusion criteria. Consequently, 130 full papers were retrieved and reviewed. Finally, 9 papers were included. Most of the trials were assessed as having high risk of bias. Five included studies that compared the success rates of restorations with different filling materials and liner materials. Two studies showed clinical advantages of using minimally invasive approaches in caries removal and cavity preparation. The other two trials showed low success rates of interim GI restorations done in a field setting, compared to the high caries arrest rates of silver diammine fluoride application. CONCLUSION: Within the limitation of this systematic review, there is insufficient evidence to make recommendations regarding which material and technique is the most appropriate for restorative treatment in young children. Minimally invasive approaches are advantageous in operative caries management in primary teeth in preschool children. More well-designed randomised controlled trials are required to confirm these findings.

Randomized clinical trial on arresting dental root caries through silver diammine fluoride applications in community-dwelling elders.

OBJECTIVES: To investigate the effectiveness of silver diammine fluoride (SDF) solution application in arresting dental root caries and to assess the color of arrested caries lesions. METHODS: This study was conducted in elderly centers in Hong Kong. A total of 83 elders with 157 root surfaces with active caries lesion were randomly allocated into 3 groups: Gp1 (placebo control)-annual application of soda water; Gp2-annual application of SDF solution; Gp3-annual application of SDF solution immediately followed by potassium iodide (KI) solution. Color of the arrested root caries lesion was assessed with reference to PANTONE color plates and classified into one of the followings: yellow (7401U); light brown (1245U); dark brown (4635U); and black (Black U). Status of root surfaces was assessed every 6 months by the same independent examiner. RESULTS: After 30 months, 100 (64%) of the included root caries lesions were reviewed. The arrest rates of root caries were 45%, 90%, and 93% in Gp1 (control), Gp2 (SDF) and Gp3 (SDF/KI), respectively (χ(2) test, p<0.001). Pairwise comparisons showed elders in the control group had a lower proportion of the active root caries changed to arrested (p<0.001) and the proportions of root caries being arrested in the SDF and SDF/KI groups were not significantly different (p>0.05). The distributions of arrested caries lesions by color were not significantly different between the SDF and SDF/KI groups (χ(2) test, p>0.05). CONCLUSIONS: Application of SDF solution, with or without application of KI afterwards, is effective in arresting root caries among elders in a water fluoridated area. In the long term, blackening of arrested root caries is not reduced by immediate application of KI after the application of SDF. CLINICAL SIGNIFICANCE: In a water fluoridated area, annual application of SDF solution or SDF/KI solution can arrest dental root caries in elders. In the long term, application of KI does not reduce the blackening of arrested caries lesions caused by SDF.

A randomized clinical trial on arresting dentine caries in preschool children by topical fluorides--18 month results.

OBJECTIVES: This study aimed to compare the effectiveness of three topical fluoride application protocols in arresting dentine caries in primary teeth of preschool children in a fluoridated area. METHODS: Children aged 3-4 years who had at least one active dentine caries lesion were randomly allocated into three intervention groups: Group 1-application of 30% silver diammine fluoride (SDF) solution every 12 months; Group 2-three applications of 30% SDF solution at weekly interval at baseline; and Group 3-three applications of 5% sodium fluoride (NaF) varnish at weekly interval at baseline. A masked examiner carried out follow-up examinations every 6 months to assess whether the treated lesions had become arrested. RESULTS: A total of 304 children with 1670 tooth surfaces with dentine caries received treatment at baseline. After 18 months, 275 children (91%) remained in the study. The caries arrest rates at tooth surface level were 40%, 35% and 27% for Groups 1, 2 and 3, respectively (p<0.001). Result of the multi-level survival analysis showed that the two SDF application protocols could shorten the time to arrest of dentine caries compared with the NaF application protocol. Presence of plaque on lesion surface, tooth type and tooth surface all had significant effects on caries arrest rates. CONCLUSIONS: Annual or three consecutive weekly applications of SDF solution is more effective in arresting dentine caries in primary teeth than three consecutive weekly applications of NaF varnish. CLINICAL SIGNIFICANCE: In a water fluoridated area, application of SDF solution, either three weekly applications at baseline or annually, can arrest active dentine caries lesions in primary teeth faster than three weekly applications of NaF varnish at baseline.

Arresting Dentine Caries with Different Concentration and Periodicity of Silver Diamine Fluoride.

Different regimens of silver diamine fluoride (SDF) have been used to manage early childhood caries. So far, there is limited information regarding the concentrations and frequency of applications for effective caries control in primary teeth. This study aimed to compare the efficacy of 2 commercially available SDF solutions at preprepared concentrations of 38% and 12% when applied annually or biannually over 18 mo in arresting dentine caries in primary teeth. This randomized double-blinded clinical trial recruited kindergarten children aged 3 to 4 y who had at least 1 tooth with dentine caries. The children were randomly allocated to receive 4 treatment protocols: group 1, annual application of 12% SDF; group 2, biannual application of 12% SDF; group 3, annual application of 38% SDF; and group 4, biannual application of 38% SDF. Clinical examinations at 6-mo intervals were conducted to assess whether active carious lesions became arrested. Information on the children's background and oral hygiene habits was collected through a parental questionnaire at baseline and follow-up examinations. A total of 888 children with 4,220 dentine carious tooth surfaces received treatment at baseline. After 18 mo, 831 children (94%) were examined. The caries arrest rates were 50%, 55%, 64%, and 74% for groups 1, 2, 3, and 4, respectively (P < 0.001). Lesions treated with SDF biannual application had a higher chance of becoming arrested compared with those receiving SDF annual application (odds ratio, 1.33; 95% confidence interval, 1.04-1.71; P = 0.025). The interaction between concentration and lesion site was statistically significant (P < 0.001). Compared with 12% SDF, the use of 38% SDF increased a chance of becoming arrested (P < 0.05), except lesions on occlusal surfaces. Based on the 18-mo results, SDF is more effective in arresting dentin caries in the primary teeth of preschool children at 38% concentration than 12% concentration and when applied biannually rather than annually. Knowledge Transfer Statement: The results of this study can be used by clinicians and dental public health professionals when deciding which concentrations and frequency of application of silver diamine fluoride solution should be adopted for arresting dentine caries. With consideration of caries arrest treatment with silver diamine fluoride, which is painless, simple, and low cost, this information could lead to more appropriate therapeutic decisions for caries control in young children or those who lack access to affordable conventional dental care.