A community-based caries control program for pre-school children using topical fluorides: 18-month results

Effect of silver diamine fluoride on the surface roughness of dental ceramics

STATEMENT OF PROBLEM

Application of silver diamine fluoride (SDF) can be a straightforward and efficient way to manage recurrent caries around the margins of crowns. However, its effect on ceramic surfaces is unknown.

PURPOSE

The purpose of this in vitro study was to evaluate and compare the effect of SDF, acidulated phosphate fluoride (APF), and distilled water on the surface roughness of dental ceramics.

MATERIAL AND METHODS

Forty-five rectangles (10×10×2 mm) each of 5% yttria-stabilized tetragonal zirconia polycrystal (5Y-TZP) zirconia (Zir), lithium disilicate (LDS), overglazed feldspathic porcelain (FO), and polished feldspathic porcelain (FP) were fabricated. The specimens were treated with 38% SDF, 1.23% APF, and distilled water to simulate 3 years of topical applications. The surface roughness (Ra) of each rectangle was measured with a profilometer before and after treatment with the solutions, and the change in Ra (△Ra) was calculated. Scanning electron microscope images were obtained of each treatment group. Multiple comparison of the means among the ceramics and testing solutions was done using 2-way ANOVA followed by the Tukey Honestly Significant test (α=.05).

RESULTS

ANOVA revealed significant differences in the 2 main factors, as well as their interaction (P<.001). The surface roughness of the treated rectangles was significantly dependent on the type of ceramic and the testing solution. The greatest surface roughness increase was seen in the interaction of LDS:APF (△Ramean=0.51 ±0.13 μm), closely followed by FO:APF (△Ramean=0.49 ±0.20 μm) and FP:APF (△Ramean=0.41 ±0.17 μm) (P<.001). SDF increased the surface roughness of LDS, FO, and FP; however, the increase was not significant (△Ramean LDS=0.25 ±0.11 μm; △Ramean FO=0.17 ±0.16 μm; △Ramean FP=.1 ±0.14 μm; P >.118). None of the solutions had any effect on zirconia (P>.977).

CONCLUSIONS

SDF is safe to use around zirconia restorations. Long-term and repeated application of SDF on lithium disilicate and feldspathic porcelain must be considered with caution.

Material of choice for non-invasive treatment of dentin caries: An in vitro study using natural carious lesions

INTRODUCTION

In community settings with limited dental personnel and equipment, and in an era when the aerosol transmission of infectious agents is on the rise, a non-invasive approach to caries management is critical. To provide information on non-invasive material selection, the aim of this study was to compare the remineralization effect of commonly used fluoride-containing materials, adjunctive to the everyday use of fluoride toothpaste (F-toothpaste), on primary tooth natural dentin caries.

METHODS

Fifty-five specimens were randomly divided into five groups: 38% silver diamine fluoride (SDF), 5% fluoride varnish (F-varnish), glass-ionomer cement (GIC), deionized water (DW) with F-toothpaste slurry, and DW as a control group (n = 11). The lesion depth and mineral density were measured before and after bacterial pH-cycling using micro-computed tomography. The percentage of mineral density change (%MDchange) was quantified. The dependent t-test, Wilcoxon-Signed-Rank Test, and one way ANOVA with Bonferroni correction were used to analyse the data.

RESULTS

SDF application reduced lesion depth from 844.6 to 759.1 μm (p < 0.045) while increasing mineral density from 551.4 to 763.0 mgHA/cm3 (p < 0.003). Only mineral density rose from 600.2 to 678.4 mgHA/cm3 (p < 0.013) when GIC was used. The other groups showed no difference. The highest %MDchange was also found after SDF treatment (49.7%, p < 0.05), whereas GIC (17.2%, p < 0.05) presented a higher percentage than the F-varnish (2.0%), F-toothpaste (-1.1%) and no-treatment groups (-1.4%).

CONCLUSION

In this in vitro study, where the pH of cycling was almost neutral, using SDF as an adjunct to F-toothpaste resulted in the highest remineralization compared with other remineralizing materials.

Using sequential applications of a novel silver diamine fluoride gel and sodium fluoride varnish to arrest severe early childhood caries lesions: A clinical trial with single group assignment

BACKGROUND

Silver diamine fluoride (SDF) gel was developed to overcome the clinical limitations of liquids with children. The authors conducted a clinical trial to determine caries lesion arrest in primary teeth at 1-year follow-up when 38% SDF gel and 2.5% sodium fluoride varnish were applied sequentially at the same appointment. Parent satisfaction was assessed.

METHODS

The study design was an open-label prospective, clinical trial with single group assignment. Participants were 237 children aged 3 through 4 years at enrollment and from 5 centros educativos iniciales (preschools). Eligible children had 1 or more d3 (cavitation into dentin) active caries lesions. Teeth with active caries lesions (cavitation confined to enamel [d2] or d3) were treated by applying 1 or 2 drops of viscous 38% SDF gel (Advantage Silver Dental Arrest Gel, Elevate Oral Care, LLC) dabbing the excess with cotton. Treated teeth were covered with 2.5% sodium fluoride varnish (Fluorimax, Elevate Oral Care, LLC) to mask the taste. Treatment was repeated at 5 months postexamination. The primary outcome was caries lesion (d2-d3) arrest at 1 year.

RESULTS

Two hundred nineteen children were available at the 1-year follow-up. There was a median of 21 (interquartile range [IQR], 13-34) active carious surfaces (d2-d3) at baseline. Median arrested carious surfaces was 92.6% (IQR, 81.1%-100.0%; 95% CI, 86.8% to 95.2%). When parents were asked whether they were bothered by the color change of teeth, the median response on a 10-point scale in which 1 equaled not bothered at all and 10 equaled very bothered was 1.0 (IQR, 1.0-2.0).

CONCLUSIONS

Two applications of 38% SDF gel and 2.5% sodium fluoride varnish arrested greater than 90% of carious surfaces at 1 year and with high levels of parental satisfaction.

PRACTICAL IMPLICATIONS

Combined treatment was highly efficacious in a population with many caries lesions. This clinical trial was registered at ClinicalTrials.gov. The registration number is NCT05395065.

Effectiveness of silver diamine fluoride in indirect pulp capping in primary molars: A systematic review and meta-analysis

Introduction

Recently, clinical trials have assessed the effectiveness of Silver Diamine Fluoride (SDF) as an indirect pulp capping material (IPC) in primary teeth. This systematic review aimed to assess the evidence presented in these trials.

Data sources

A comprehensive search identified relevant studies through five electronic databases (PubMed, Scopus, ClinicalTrials.gov, ScienceDirect, and Cochrane). Search strategies were designed using the PICO model to identify all studies that investigated SDF as an IPC compared to calcium hydroxide (CaOH) or mineral trioxide aggregate (MTA). Quality assessment and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) were used to assess the level of evidence.

Study selection

Four clinical trials were found to be suitable for inclusion in the qualitative synthesis and three studies were included in the quantitative analysis. Three studies compared SDF with CaOH and only one study compared SDF, CaOH, and MTA. Only one randomized controlled trial (RCT) had a low risk of bias, and the non-RCT study had a moderate risk of bias. The level of evidence based on the GRADE was low. Three out of four studies showed higher clinical and radiographic outcomes with SDF than with CaOH. One non-RCT study showed that SDF resulted in the least reparative dentin at the 6-months follow-up. The meta-analysis showed a non-significant difference between the SDF and CaOH groups (P = 0.36).

Conclusion

There is little evidence showing a higher clinical and radiographic outcome of SDF compared to CaOH as an IPC material in primary molars.

Clinical significance

This systematic review updates pediatric dentists regarding the effectiveness of using SDF as indirect pulp caping in primary teeth.

Silver Diamine Fluoride (SDF) Efficacy in Arresting Cavitated Caries Lesions in Primary Molars: A Systematic Review and Metanalysis

A systematic review and meta-analysis were carried out to evaluate the efficacy of silver diamine fluoride (SDF) in controlling caries progression in cavitated primary molars. A search for randomized and non-randomized trials with follow-up > 6 months was performed using PubMed, Scopus and Embase. The Cochrane risk of bias tools were used for the quality assessment. The success rate and odds ratios were chosen to calculate the effect size for the meta-analysis. A total of 792 papers were identified and 9 were selected. A high variability regarding SDF application protocol was found; otherwise, caries arrest was always recorded using visual/tactile methods. Two studies were judged at low risk of bias, six at moderate risk and one at high risk. Data from five studies were aggregated for meta-analysis. Heterogeneity was found moderate (I2 = 35.69%, p = 0.18). SDF application was found to be overall effective (fixed effect model) in arresting caries progression (ES = 0.35, p < 0.01). In a total of 622 arrested lesions, out of 1205 considered, the caries arrest rate was 51.62% ± 27.40% (Confidence = 1.55) using SDF ≥ 38% applied annually or biannually. In conclusion, when applied to active cavitated caries lesions in primary molars, SDF appears to be effective in arresting dental caries progression, especially if applied biannually.

Effect of Silver Diamine Fluoride and Potassium Iodide Solution on Enamel Remineralization and Discoloration in Artificial Caries

Silver diamine fluoride (SDF) is a strong fluoride agent for caries control, remineralization, and reducing the incidence of dental caries. This study used 38% SDF with potassium iodide (KI) on enamel remineralization and compared it with the currently used 38% SDF and 5% sodium fluoride (NaF) varnish to treat artificial caries. Bovine incisors were demineralized for 120 h and randomly distributed for treatment by the remineralization agents for 120 h as follows: control (n = 15), SDF/KI (n = 15), SDF (n = 15), and NaF (n = 15). Colorimetric analysis was performed using the ΔE value. The Vickers microhardness (VHN) was determined to evaluate the enamel remineralization of the specimens. Polarized light microscopy (PLM) and scanning electron microscopy (SEM) were performed to confirm the surfaces precisely and histologically. SDF/KI caused no significant difference in discoloration between the control and NaF groups. There was also no significant difference in the VHN after remineralization, but SDF/KI exhibited the highest mean microhardness. PLM revealed that SDF/KI had the greatest remineralization ability. In conclusion, SDF/KI is effective for dental enamel remineralization even with KI, which reduces discoloration.

The Effect of Loading Time on Color Stability of Various Restorative Materials Bonded to Silver Diamine Fluoride-Treated Demineralized Dentin

Aim

To investigate the effect of immediate versus one week later loading time on color stability of resin-based composite (RBC), resin-modified glass ionomer cement (RMGIC) and glass ionomer cement (GIC) restorative materials bonded to silver diamine fluoride (SDF)-treated demineralized dentin.

Materials and Methods

Ninety extracted premolars were randomly assigned to the following groups (n = 30 each): group-I (loaded with RBCs), group-II (loaded with RMGIC), and group-III (loaded with GIC). Each group was divided randomly into the following subgroups (n = 10): subgroup-A (control specimens) consisted of sound dentin and the restorative material was immediately loaded; subgroup-B consisted of demineralized dentin, underwent a SDF treatment and the restorative material was immediately loaded; subgroup-C consisted of demineralized dentin, underwent a SDF treatment and the restorative material was loaded 1 week later. The color difference (ΔE) and visual color changes (L*a*b*) of each specimen were calculated using a spectrophotometer. Data were analyzed using one-way ANOVA and post hoc Tukey's tests to compare the ΔE values and a paired t test to compare the mean of L* a* b* coordinates.

Results

The highest color stability was observed for GIC, followed by RMGIC, and the lowest color stability was observed for the RBC group. Significant differences within groups were noted in RBC and RMGIC (p < 0.001). Regarding the loading time of the restorative material, in RBCs, a significantly lower ΔE value was observed in the delayed loading group than in the immediate loading group (p = 0.035). In the RMGIC and GIC groups, there were no significant differences.

Conclusion

Delaying the loading time of the restorative material for 1 week following the application of SDF resulted in greater color stability than that of immediate loading. The caries arresting potential of SDF was revealed by the dark staining, which could be improved with the subsequent delayed restoration.

Minimally Invasive Therapies for the Management of Dental Caries—A Literature Review

In recent years, due to a better understanding of the caries pathology and advances in dental materials, the utilization of non-invasive and minimally invasive techniques that delay/obviate the need for traditional restorations has started gaining momentum. This literature review focuses on some of these approaches, including fluoride varnish, silver diamine fluoride, resin sealants, resin infiltration, chemomechanical caries removal and atraumatic restorative treatment, in the context of their chemistries, indications for use, clinical efficacy, factors determining efficacy and limitations. Additionally, we discuss strategies currently being explored to enhance the antimicrobial properties of these treatment modalities to expand the scope of their application.

Evidence-Based Bibliometric Analysis of Research on Silver Diamine Fluoride Use in Dentistry

Background

This bibliometric analysis is aimed at reviewing the research pattern on the use of silver diamine fluoride (SDF) in dentistry using various citation metrics.

Methods

A well-curated search was conducted on Elsevier's Scopus database for the relevant literature on SDF published between 1969 and 2021. Bibliographic information such as information related to citations, bibliographic data, abstracts, keywords, and other relevant information was extracted using different combinations of keywords (“silver diamine fluoride” OR “Silver Diamine Fluorides” OR “Diamine Fluoride” OR “Silver Fluoride”). Analysis and visualization of the selected documents and related data were performed using various tools and software including MS Excel, MS Access, Bibexcel, VOS viewer, Biblioshiny, and Gephi. VOS Viewer was utilized for the Graph Modeling Language (GML) to generate graphical representations of the data. Furthermore, network graphs were generated to assess the various associations between research themes, countries, organizations, authors, journals, and citations.

Results

The initial search yielded 662 documents, of which 410 were chosen for analysis. 252 records were deemed irrelevant. The chosen records consisted of journal articles (n = 351), conference papers (n = 14), book chapters (n = 1), and review articles (n = 44). The results showed that there was an upward trend in the research on SDF, and a substantial increase was observed in the citation index after 2014. Researchers from the United States of America, Hong Kong, and Japan were the top contributors, with organizations and authors from the Faculty of Dentistry, University of Hong Kong, leading the way in citations and productivity.

Conclusion

The bibliometric analysis provides valuable information regarding the total number of publications on SDF and their citation details. It also identifies the leading countries and organizations involved in the research on SDF and provides a comprehensive analysis of the research trends related to SDF.

Caries arrest effectiveness of silver diamine fluoride compared to alternative restorative technique: randomized clinical trial

OBJECTIVE

This RCT study assessed and compared the effect of a biannual application of 38% silver diamine fluoride (SDF) with alternative restorative technique (ART) on arresting caries in primary dentition.

METHODS

The RCT was conducted over a period of 12 months and included 79 healthy children (237 primary teeth), aged 3-8 years, selected from the University Pediatric Dentistry outpatient clinics, with at least one primary asymptomatic tooth with active dentinal occlusal/labial lesions. Children were randomly assigned to SDF application or ART treatment. Visual and tactile examinations were used after 6 and 12 months to assess the activity of the carious lesions using the ICDAS II.

RESULTS

At 6- and 12-month-evaluation periods, no statistically significant differences in lesions arrest were found between SDF and ART groups (P = 1.000). Considering the frequency of arrested caries between the test groups at 6 and 12 months, no significant differences were observed between anterior and posterior lesions, as well as between the maxillary and mandibular lesions. When comparing the working time for the two treatments, the median time for those treated with SDF was 3.3 min, compared to 14.4 min for ART and was statistically significant (P < 0.0001).

CONCLUSION

Both SDF and ART are, indeed, effective for arresting caries. However, the chair-time management required for SDF is significantly shorter compared to ART. Taking into consideration the present evidence, the best decision regarding disease management and application of SDF or ART is to be made by the dentist and the patient/parent, recognizing individuals' differences and preferences.

Time-Dependent Anti-Demineralization Effect of Silver Diamine Fluoride

This study compared the demineralization resistance of teeth treated with silver diamine fluoride (SDF) to that treated with fluoride varnish. A total of 105 healthy bovine incisors were divided into control, fluoride varnish, and SDF groups. The enamel surface density change was then measured by micro-computed tomography (micro-CT) at three depths. The demineralized zone volume was measured on 3D micro-CT images to evaluate the total demineralization rate. The enamel surface morphology was assessed by scanning electron microscope. The enamel density had continuously decreased while demineralization increased in the control and fluoride varnish groups. The enamel density had increased in the SDF group till the 7th day of demineralization treatment and decreased thereafter. However, the decrease in the SDF group was less severe than that in the other groups (p < 0.05). The demineralized enamel volume had increased through treatment and was the highest in the control group, followed by the fluoride varnish and SDF group. The enamel surface morphology was the roughest and most irregular in the control group, followed by the fluoride varnish group and SDF groups.

Effect of silver diamine fluoride on the prevention of erosive tooth wear in vitro

OBJECTIVES

To investigate the ability of silver diamine fluoride (SDF) to prevent erosive tooth wear in enamel and dentin.

METHODS

SDF (38 %) was compared to deionized water (DIW, negative control), potassium fluoride (KF, fluoride control), silver nitrate (AgNO₃, silver control), and fluoride varnish (FV, clinical reference) using erosion and erosion-abrasion cycling models. Bovine enamel and dentin slabs were embedded in resin blocks. Two resin blocks were glued to form study blocks (n=8, per treatment), one for erosion and the other for the erosion-abrasion model. The blocks were treated once and then subjected to a five-day cycling model, with five daily citric acid erosive challenges (0.3 % citric acid/pH 2.6). Abrasion was performed using a toothbrushing machine with a medium-abrasive silica as abrasive (erosion-abrasion model only). Artificial saliva was used to remineralize the specimens after erosion/abrasion and as storage media between cycles. Surface loss (SL) was determined by non-contact profilometry. Data were analyzed using ANOVA (α=0.05).

RESULTS

Both eroded-abraded enamel and dentin specimens exhibited significantly more SL in all treatment groups than the only eroded ones (p<0.001). For dentin, both AgNO₃ and DIW groups had significantly more SL than SDF, KF, and FV groups (p<0.001), for both models. For enamel, specimens had more SL in both AgNO₃ and DIW groups compared to SDF, KF, and FV groups, in the erosion model. When enamel specimens were subjected to erosion-abrasion, FV resulted in the least SL (p<0.001).

CONCLUSION

SDF was effective in reducing dental erosion on both substrates, but dental erosion-abrasion only on dentin.

CLINICAL SIGNIFICANCE

SDF may become a viable intervention for ETW prevention in dentin (e.g. exposed roots) once its efficacy has been confirmed under clinical conditions.

Does previous application of silver diammine fluoride influence the bond strength of glass ionomer cement and adhesive systems to dentin? Systematic review and meta-analysis

BACKGROUND

Silver diammine fluoride (SDF) applied before a restoration may prevent recurrent caries; therefore, its effect on the bonding of restorative materials is contradictory.

AIM

To assess through a systematic review and meta-analysis the influence of SDF on the bonding performance of adhesive materials to dentine.

DESIGN

A systematic search was carried out in PubMed, Web of Science, LILACS, and Scopus. Studies comparing bond strength of adhesive systems or glass ionomer cement to SDF-treated and -untreated (control) dentine were included. Global analysis comparing the bond strength data was performed, separately for adhesive systems and glass ionomer cement, using RevMan5.1, with a random-effect model, at a 5% significance level.

RESULTS

Eleven studies were included in the review and ten in the meta-analyses. Overall pooled effect for glass ionomer cement has shown no significant difference between the groups (Z = 0.47; P = .64). SDF treatment significantly impairs the bonding of adhesive systems to dentine (Z = 2.11; P = .03); this effect can be eliminated by the rinsing step (Z = 0.85; P = .40).

CONCLUSIONS

The previous application of SDF does not influence the dentine bond strength of glass ionomer cement, but compromises the bonding of adhesive systems.

Clinical and microbial oral health status in children and adolescents with type 1 diabetes mellitus

OBJECTIVES

To study the oral health of young individuals with controlled and uncontrolled type 1 diabetes mellitus (T1DM) and compare the results with those for healthy counterparts.

MATERIALS AND METHODS

One-hundred and forty-four youngsters (6-15 years of age) were assigned, according to glycaemic control, to three study groups: (i) diabetic patients with poor glycaemic control [glycated haemoglobin (HbA1c ≥7.5%)] (n = 35); (ii) diabetic patients with good glycaemic control (HbA1c <7.5%) (n = 39); and (iii) healthy individuals (n = 70). Plaque, gingival inflammation, calculus and decayed, missing and filled surfaces (DMFS) indices were recorded. Salivary parameters were determined, and stimulated saliva was collected to allow detection and determination of the levels of oral Candida albicans and Streptococcus mutans by real-time polymerase chain reaction (PCR).

RESULTS

Significantly different amounts of plaque were found among the study groups (P = 0.024): youngsters with poor glycaemic control had significantly more plaque than youngsters in the other two groups. The gingival, calculus and DMFS indices were not significantly different among groups (P > 0.05). Candida albicans levels were not statistically significant different among groups, but the group with poor glycemic control showed an elevated frequency of detection. Streptococcus mutans was isolated from the oral cavity of 96 of the 144 individuals. A statistically significant difference in the level of S. mutans was found between the group with poor glycaemic control and the healthy control group (P = 0.032).

CONCLUSIONS

The results imply that youngsters with T1DM have a lower level of oral hygiene and are potentially at a higher risk of future oral disease, particularly when their metabolic disorder is uncontrolled. However, factors outside the oral cavity may also have a considerable impact on the initiation and progression of oral diseases.

Assessment of the Silver Penetration and Distribution in Carious Lesions of Deciduous Teeth Treated with Silver Diamine Fluoride

The aim of this study was to determine the effects of 38% silver diamine fluoride (SDF) on carious lesions of human deciduous teeth. Ten extracted deciduous incisors with caries were collected and treated with SDF. After the treatment, the teeth were sectioned through the center of the carious lesion. The extent of sliver precipitation was examined using quantitative backscattered electron scanning electron microscopy (qBSE-SEM), energy-dispersive X-ray spectroscopy (EDX), and micro-computed tomography (micro-CT). The qBSE-SEM images revealed that the silver particles could penetrate through the pellicle complex, along with the rod sheaths into the demineralized enamel rods and the dentinal tubules, and form silver-enriched barriers surrounding the carious lesions at depths up to 2,490.2 μm (mean 744.7 ± 448.7 μm) within the dentinal tubules of the carious lesions, but less likely in the sound enamel. The EDX spectrum analysis revealed that carbon, oxygen, phosphorus, chlorine, silver, and calcium were the main elements detected in the lesions treated with SDF. Additionally, sodium, magnesium, aluminum, silicon, zinc, sulfur, and fluorine were detected as the minor elements within the SDF precipitation "zone." The micro-CT analysis further showed that in the deep cavitated lesions, the silver precipitation could be observed in the pulp chamber. These findings provide new evidence defining the SDF mode of action for arresting caries and suggest that the application of a highly concentrated SDF solution on deciduous teeth should be used with caution for various carious lesions.

Silver diamine fluoride versus sodium fluoride for arresting dentine caries in children: a systematic review and meta-analysis

Dental caries can compromise quality of life and is associated with demineralization of tooth structure by organic acids produced by microorganisms. This study systematically reviewed the dentine caries arrest capabilities of silver diamine fluoride (SDF) and sodium fluoride (NaF). A comprehensive search strategy was developed to identify the relevant publications in electronic databases and hand searched journals and reviews (to March 2018). By applying strict inclusion and exclusion criteria, only six papers (two randomized controlled trials, two follow-up articles and two secondary statistical analysis studies) were considered for full text qualitative and quantitative assessment. The included studies were critically appraised and statistically evaluated. Only four articles were considered for meta-analysis, as the other two were secondary analyses of included studies. When comparing the caries arrest lesions of SDF and NaF, SDF was found to be statistically more effective in dentine caries arrest of primary teeth during the 18 and 30 month clinical examinations. The weighted total effect size of the differences between SDF and NaF regarding arrested caries surfaces was calculated and showed nearly double the effectiveness of SDF to NaF at 30 months. Therefore, SDF is a more effective caries management reagent than NaF. Further clinical research is needed to consolidate the findings of this systematic review.

Comparative cariostatic efficacy of a novel Nano-silver fluoride varnish with 38% silver diamine fluoride varnish a double-blind randomized clinical trial

Background

To evaluate the clinical cariostatic efficacy of a concocted 5% Nano-silver incorporated Sodium fluoride (NSSF) dental varnish with 38% Silver diamine fluoride (SDF) in preventing the progression of dentinal caries of primary molars.

Material and Methods

A total of 159 active dentinal carious lesions in primary molars (from 50 children) were selected and randomly divided into two groups; NSSF and SDF. Varnish application was performed at the baseline visit and follow-up is carried out at 1, 3, 6 and 12 months. Parameters such as caries activity, depth, size, colour, and presence or absence of pain were noted at baseline and follow-up visits.

Results

The intergroup comparison of caries activity status did not reveal significant difference between the number of active and arrested caries lesions in NSSF and SDF groups at any visit (p >0.05) during the 12-month follow-up. There was no difference between overall failure and success rates between the two groups at any follow-up period (p-0.48).

Conclusions

Annual application of 5% NSSF is better than or equal to 38% SDF in preventing the progression of dentinal caries of primary molars. NSSF does not cause dark staining of dentinal tissue compared to the SDF and the use of NSSF can be recommended in children. Key words:Children, Nano-silver fluoride, Primary teeth, Silver diamine fluoride.

Antimicrobial Activity of a Colloidal AgNP Suspension Demonstrated In Vitro against Monoculture Biofilms: Toward a Novel Tooth Disinfectant for Treating Dental Caries

A novel silver nanoparticle (AgNP) formulation was developed as a targeted application for the disinfection of carious dentine. Silver nitrate (AgNO₃) was chemically reduced using sodium borohydrate (NaBH₄) in the presence of sodium dodecyl sulfate (SDS) to form micelle aggregate structures containing monodisperse 6.7- to 9.2-nm stabilized AgNPs. AgNPs were characterized by measurement of electrical conductivity and dynamic light scattering, scanning electron microscopy, transmission electron microscopy, and inductively coupled plasma mass spectrometry. Antimicrobial activity of AgNPs was tested against planktonic cultures of representative gram-positive and gram-negative oral bacteria using well diffusion assays on tryptic soy broth media and monoculture biofilms grown with brain heart infusion ± sucrose anaerobically at 37°C on microtiter plates. Biofilm mass was measured by crystal violet assay. Effects were compared to silver diamine fluoride and chlorhexidine (negative controls) and 70% isopropanol (positive control) exposed cultures. In the presence of AgNPs, triplicate testing against Streptococcus gordonii DL1, C219, G102, and ATCC10558 strains; Streptococcus mutans UA159; Streptococcus mitis I18; and Enterococcus faecalis JH22 for planktonic bacteria, the minimum inhibitory concentrations were as low as 7.6 µg mL^-1 and the minimum bacteriocidal concentrations as low as 19.2 µg mL^-1 silver concentration. Microplate readings detecting crystal violet light absorption at 590 nm showed statistically significant differences between AgNP-exposed biofilms and where no antimicrobial agents were used. The presence of sucrose did not influence the sensitivity of any of the bacteria. By preventing in vitro biofilm formation for several Streptococcus spp. and E. faecalis, this AgNP formulation demonstrates potential for clinical application inhibiting biofilms.

The Effect of Silver Diamine Fluoride in Preventing Caries in the Primary Dentition: A Systematic Review and Meta-Analysis

OBJECTIVES

To investigate whether silver diamine fluoride (SDF) is effective in preventing new caries lesions in primary teeth when compared to placebo or active treatments.

METHODS

Systematic review (CRD42016036963) of controlled clinical trials. Searches were performed in 9 electronic databases, 5 registers of ongoing trials, and reference lists of identified review articles. Two researchers carried out data extraction and quality appraisal independently. The primary outcome was the difference in caries increment (decayed, missing, and filled surfaces or teeth - dmfs or dmft) between SDF and control groups. These differences were pooled as weighted mean differences (WMD) and prevented fractions (PF).

RESULTS

Searches yielded 2,366 unique records; 6 reports of 4 trials that randomized 1,118 and analyzed 915 participants were included. Two trials compared SDF to no treatment, 1 compared SDF to placebo and sodium fluoride varnish (FV), and 1 compared SDF to high-viscosity glass ionomer cement (GIC). All studies had at least 1 domain with unclear or high risk of bias. After 24 months of follow-up, in comparison to placebo, no treatment, and FV, SDF applications significantly reduced the development of new dentin caries lesions (placebo or no treatment: WMD = -1.15, PF = 77.5%; FV: WMD = -0.43, PF = 54.0%). GIC was more effective than SDF after 12 months of follow-up but the difference between them was not statistically significant (WMD, dmft: 0.34, PF: -6.09%).

CONCLUSION

When applied to caries lesions in primary teeth, SDF compared to no treatment, placebo or FV appears to effectively prevent dental caries in the entire dentition. However, trials specifically designed to assess this outcome are needed.

Is Silver Diamine Fluoride Effective in Preventing and Arresting Caries in Elderly Adults? A Systematic Review

AIM

Silver diamine fluoride (SDF) has invoked interest in recent times due to its remineralization capacity and non-invasive application procedure. The aim of this systematic review was to report the findings concerning the effectiveness of SDF in managing caries in the elderly adults.

MATERIALS AND METHODS

A systematic search of publications was conducted using four databases: PubMed, MEDLINE, Embase, and CENTRAL. The key MeSH term combinations used were (silver diamine fluoride) AND (caries) AND (elderly).

RESULTS

The review found only three well-conducted randomized controlled trials evaluating the effectiveness of SDF on root caries in community-dwelling elders. None of the studies addressed coronal caries. The effectiveness improved when combined with structured oral health education.

CONCLUSION

The available limited evidence on SDF shows that it is effective in arresting and preventing root caries in the elderly. More high-quality studies need to be done to verify the effectiveness on coronal caries and long-term effects of SDF in the elderly with varying levels of dependency.

Silver Diamine Fluoride Has Efficacy in Controlling Caries Progression in Primary Teeth: A Systematic Review and Meta-Analysis

A systematic review was performed to evaluate the efficacy of silver diamine fluoride (SDF) in controlling caries progression in children when compared with active treatments or placebos. A search for randomized clinical trials that evaluate the effectiveness of SDF for caries control in children compared to active treatments or placebos with follow-ups longer than 6 months was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library, and grey literature. The risk of bias tool from the Cochrane Collaboration was used for quality assessment of the studies. The quality of the evidence was evaluated using the GRADE approach. Meta-analysis was performed on studies considered at low risk of bias. A total of 5,980 articles were identified. Eleven remained in the qualitative synthesis. Five studies were at "low," 2 at "unclear," and 4 studies at "high" risk of bias in the key domains. The studies from which the information could be extracted were included for meta-analysis. The arrestment of caries at 12 months promoted by SDF was 66% higher (95% CI 41-91%; p < 0.00001) than by other active material, but it was 154% higher (95% CI 67-85%; p < 0.00001) than by placebos. Overall, the caries arrestment was 89% higher (95% CI 49-138%; p < 0.00001) than using active materials/placebo. No heterogeneity was detected. The evidence was graded as high quality. The use of SDF is 89% more effective in controlling/arresting caries than other treatments or placebos. The quality of the evidence was graded as high.

Role of fluoride varnish in preventing early childhood caries: A systematic review

Background:

Early childhood caries is a public health problem that continues to affect babies and preschool children worldwide. This untreated caries process results in progressive destruction of the crowns of the teeth, often accompanied by severe pain and suffering, affecting the quality of life. Fluoride varnish which is one of the most important materials to prevent ECC is easy to apply and well tolerated by children. This study aimed to evaluate the scientific evidence regardingthe role of fluoride varnish in preventing early childhood caries.

Materials and Methods:

Records were searched from various databases such as PubMed/Medline, Cochrane, and EMBASE. Articles published over the past 36 years (1979-2015) were identified using the key search terms. A total of 190 records were identified by title/abstracts/full text articles and were retrieved. Potentially relevant reports identified from the reference lists of relevant studies, review articles and chapters were hand-searched, which yielded an additional 10 articles. The main outcome of our investigation was prevention of early childhood caries following application of fluoride varnish and unavoidable fluoride exposure. Out of 190 articles originally identified, 30 records were considered potentially eligible and sought for further assessment. 17 articles met the inclusion criteria and these studies were assessed independently for methodology and performance.

Results:

Analysis of literature revealed that basically two concentrations of fluoride varnishes have been used: 1% and 5%, with a caries preventive fraction ranges of 6.4-30% and 5-63%, respectively.

Conclusion:

The results showed that fluoride varnishes have been used at concentrations of 1% and 5% in the prevention of ECC. The preventive fraction was influenced by the frequency of application, the duration of study and sample size. The evidence level of the studies was of moderate to limited value.

Bayesian Analysis of Clustered Interval-censored Data

The recording of multiple interval-censored failure times is common in dental research. Modeling multilevel data has been a difficult task. This paper aims to use the Bayesian approach to analyze a set of multilevel clustered interval-censored data from a clinical study to investigate the effectiveness of silver diamine fluoride and sodium fluoride varnish in arresting active dentin caries in Chinese pre-school children. The time to arrest dentin caries on a surface was measured. A three-level random-effects Weibull regression model was used. Analysis was performed with WinBUGS. Results revealed a strong positive correlation (0.596) among the caries lesions’ arrest times on different surfaces from the same child. The software WinBUGS made the above complicated estimation simple. In conclusion, the annual application of silver diamine fluoride on caries lesions, and caries removal before the application, were found to shorten the arrest time.

Caries remineralisation and arresting effect in children by professionally applied fluoride treatment - a systematic review

BACKGROUND

As a low-cost and easily operated treatment, the use of professionally applied topical fluoride was approved for preventing dental caries and remineralising early enamel caries or white spot lesions. It is also used to arrest dentine caries. The aim of this study is to investigate the clinical efficacy of professional fluoride therapy in remineralising and arresting caries in children.

METHOD

A systematic search of publications from 1948 to 2014 was conducted using four databases: PubMed, Cochrane Library, ISI Web of Science and Embase. The key words used were (fluoride) AND (remineralisation OR remineralization OR arresting) AND (children caries OR early childhood caries). The title and abstract of initially identified publications were screened. Clinical trials about home-use fluorides, laboratory studies, case reports, reviews, non-English articles and irrelevant studies were excluded. The full texts of the remaining papers were retrieved. Manual screening was conducted on the bibliographies of the remaining papers to identify relevant articles.

RESULTS

A total of 2177 papers were found, and 17 randomised clinical trials were included in this review. Ten studies investigated the remineralising effect on early enamel caries using silicon tetrafluoride, fluoride gel, silver diamine fluoride or sodium fluoride. Seven studies reported an arresting effect on dentine caries using silver diamine fluoride or nano-silver fluoride. Meta-analysis was performed on four papers using 5 % sodium fluoride varnish to remineralise early enamel caries, and the overall percentage of remineralised enamel caries was 63.6 % (95 % CI: 36.0 % - 91.2 %; p < 0.001). Meta-analysis was also performed on five papers using 38 % silver diamine fluoride to arrest dentine caries and the overall proportion of arrested dentine caries was 65.9 % (95 % CI: 41.2 % - 90.7 %; p < 0.001).

CONCLUSION

Professionally applied 5 % sodium fluoride varnish can remineralise early enamel caries and 38 % silver diamine fluoride is effective in arresting dentine caries.

The effectiveness of the biannual application of silver nitrate solution followed by sodium fluoride varnish in arresting early childhood caries in preschool children: study protocol for a randomised controlled trial

Background

The application of 38 % silver diamine fluoride (SDF) has been shown to be effective in arresting early childhood caries (ECC). Since SDF is not available in certain countries, some dentists use adjunctive application of 25 % silver nitrate (AgNO₃) and 5 % sodium fluoride (NaF) to arrest ECC. This randomised controlled trial will systematically compare the efficacy of a 25 % AgNO₃ solution followed by 5 % NaF varnish with that of a 38 % SDF solution in arresting ECC when applied at half-yearly intervals over a 30-month period.

Methods/Design

This study is a randomised, double-blinded, non-inferiority clinical trial. The hypothesis tested is that adjunctive application of 25 % AgNO₃ followed by 5 % NaF is at least not appreciably worse than a 38 % SDF in arresting ECC. Approximately 3100 kindergarten children aged 3–4 years will be screened and at least 1070 children with caries will be recruited. This sample size is sufficient for an appropriate statistical analysis (power at 90 % (β = 0.10) with a 2-sided type-I error of α = 0.05), allowing for an overall 20 % drop-out rate. The children will be randomly allocated into 2 groups to treat their caries over a 30-month period:

Group A – biannual adjunctive application of a 25 % AgNO₃ solution and a 5 % NaF varnish, and

Group B – biannual adjunctive application of a 38 % SDF solution followed by a placebo varnish.

Clinical examinations will be conducted at 6-month intervals. Primary outcome measured is the number of active caries surfaces which are arrested. Information on confounding factors such as oral hygiene habits will be collected through a parental questionnaire.

Discussion

We expect that adjunctive application of 25 % AgNO₃ solution and 5 % NaF varnish and of 38 % SDF solution can both effectively arrest ECC. Lower concentrations of silver and fluoride are contained in 25 % AgNO₃ and 5 % NaF, respectively, than in 38 % SDF; therefore, AgNO₃/NaF are more favourable for use in young children. Because its use for caries management is painless, simple, low-cost, and approved in many countries, AgNO₃/NaF could be widely recommended and promoted as an alternative treatment to conventional invasive management of ECC.

Trial registration

ClinicalTrials.gov: NCT02019160. Date of registration: 11 December 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-0960-2) contains supplementary material, which is available to authorized users.

S. Approaches to Arresting Dental Caries: An Update

BACKGROUND

Dental caries is one of the most prevalent chronic oral diseases across the globe that can be both treated and prevented. Preventive management strategies can effectively arrest and even completely reverse the caries process. This article aimed to review the literature on different approaches explored towards arresting caries progression.

MATERIALS AND METHODS

Literature search of publications in Pubmed/Medline was carried out. Total 73 articles including clinical trials, invitro studies, case reports and review articles were reviewed.

RESULTS

Twenty-two clinical trials and invitro studies were selected for review. Most studies suggested use of Silver Diamine Fluoride (SDF) as simple and effective caries arresting approach. Fluoride varnish treatment effectively arrests caries by inhibiting demineralization, resulting in highly significant caries reductions. Arginine with an insoluble calcium compound enhances arresting and reversing buccal, coronal and root caries. A few clinical studies have shown that sealants placed in caries fissures can arrest the caries process.

CONCLUSION

Various fluoride containing agents are clinically effective in arresting progression of carious lesion. However, these materials should be used appropriately understanding their scope and limitations to arrest dental caries.

Non-surgical treatment of dentin caries in preschool children--systematic review

Background

Untreated dentin caries in primary teeth is commonly found in preschool children worldwide. Recently, the use of simple non-surgical approaches to manage the situation has been advocated.

The aim of the study was to systematically review and evaluate the literature on effectiveness of non-surgical methods in arresting or slowing down the progression of active dentin caries in primary teeth in preschool children.

Methods

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. Keywords and MeSH terms used in the search were “dental caries”, “primary dentition” and various non-surgical treatments (fluoride, sealant, resin infiltration, xylitol, chlorhexidine, CPP-ACP, ozone, etc.). The inclusion criteria were clinical studies conducted in children under 6 years old, and reported findings on caries arrest or caries progression in primary teeth. Retrieved papers were read by two reviewers independently to assess suitability for inclusion, and the final decision was made by consensus. Quality of the included studies was assessed and data were extracted for analysis.

Results

The search identified 323 papers for screening. Among these, 290 papers did not satisfy the study inclusion criteria. Consequently, 33 full papers were retrieved and reviewed. Finally, 4 studies were included. Three studies reported that topical applications of silver diammine fluoride (SDF) solution could arrest dentin caries in preschool children. One study supported that having a daily toothbrushing exercise in kindergarten using toothpaste with 1000 ppm fluoride could stabilize the caries situation in young children.

Conclusions

There is limited evidence to support the effectiveness of SDF applications or daily toothbrushing with fluoride toothpaste in arresting or slowing down the progression of active dentin caries in primary teeth in preschool children. More well-designed randomized controlled trials are required to confirm these findings.

New proposal of silver diamine fluoride use in arresting approximal caries: study protocol for a randomized controlled trial

BACKGROUND

Approximal surfaces are a challenge to caries lesions control. Silver diamine fluoride (SDF) is a simple,low-cost and promisor intervention for arresting caries lesions, but it has never been tested on approximal surfaces. Our aim is to evaluate the efficacy and cost-efficacy of SDF in arresting initial lesions compared to resin infiltration and exclusively flossing (control group). Our second aim is to assess discomfort and satisfaction regarding interventions.

METHODS/DESIGN

This is a randomized clinical trial, double-blinded, placebo-controlled study. Children/adolescents presenting at least one approximal initial caries lesion in primary molars/permanent premolars and molars will be included. Surfaces with advanced dentine lesions identified by radiography and participants who refuse to participate or present negative behaviors will be excluded. A minimum sample size of 504 surfaces will be required for each subgroup. Individuals will be randomly allocated in three groups of interventions: SDF, resin infiltration, and control group. Depending on the allocation, the patients will receive the active treatment and respective placebo therapies. All patients will be oriented to daily flossing the included surfaces. Our primary outcome will be caries progression by clinical and radiographic examinations. Appointments will be timed and costs of materials will be considered to calculate cost-efficacy. Patient discomfort will be assessed after interventions. Parent and patient satisfaction with the treatment will be collected after treatment and in the last follow-up visit. Individuals will be assessed at 1 and 3 months after treatment to evaluate dental biofilm and at 6, 12, and 24 months to assess caries progression by visual examination and/or radiography. Multilevel analyses will be used to verify if the type of treatment influenced on the tested outcomes. Costs will be compared and analyses of cost-efficacy will be performed. Poisson analysis will test the association between intervention and reported discomfort and satisfaction.

DISCUSSION

Our hypothesis is that SDF is the most cost-efficacious option from all tested interventions. If our hypothesis is confirmed, the use of SDF in private and public contexts could represent an easier and effective option in the treatment of enamel approximal caries in children/adolescents.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01477385), Initial release: 11/16/2011: last update: 06/02/2014.

Arresting rampant dental caries with silver diamine fluoride in a young teenager suffering from chronic oral graft versus host disease post-bone marrow transplantation: a case report

Background

Rampant caries is an advanced and severe dental disease that affects multiple teeth. This case describes the management of rampant caries in a young teenager suffering from chronic oral graft versus host disease after allogeneic bone marrow transplantation.

Case presentation

A 14-year-old Chinese boy suffering from β–thalassemia major was referred to the dental clinic for the management of rampant dental caries. An oral examination revealed pale conjunctiva, bruising of lips, and depapillation of tongue indicating an underlying condition of anemia. The poor oral condition due to topical and systemic immunosuppressants was seriously aggravated, and rampant caries developed rapidly, affecting all newly erupted, permanent teeth. The teeth were hypersensitive and halitosis was apparent. Strategies for oral health education and diet modification were given to the patient. Xylitol chewing gum was used to stimulate saliva flow to promote remineralization of teeth. Silver diamine fluoride was topically applied to arrest rampant caries and to relieve pain from hypersensitivity. Carious teeth with pulpal involvement were endodontically treated. Stainless steel crowns were provided on molars to restore chewing function, and polycarbonate crowns were placed on premolars, upper canines and incisors.

Conclusion

This case report demonstrates success in treating a young teenager with severe rampant dental decay by contemporary caries control and preventive strategy.

Effects of ammonium hexafluorosilicate application on demineralized enamel and dentin of primary teeth

Silver diamine fluoride (Ag(NH(3))(2)F) arrests caries but stains teeth black. To overcome this drawback, we applied ammonium hexafluorosilicate (AHF; (NH(4))(2)SiF(6)) and observed changes in the color and structure of demineralized enamel and dentin of extracted primary teeth. Enamel and dentin were demineralized in 10% EDTA solution for 90 s followed by 35% phosphoric acid gel for 60 s, then soaked in AHF solution for 60 s. Before analysis by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS), enamel and dentin were demineralized in 10% EDTA for 90 s. Teeth were divided into 4 groups according to AHF application and artificial saliva immersion status and then examined. The data were statistically analyzed using one-way ANOVA and Fisher's PLSD test at a significance level of P < 0.05. AHF treatment did not cause visible discoloration. Enamel prisms and dental tubules appeared by demineralization were covered with precipitates by AHF application. A sphere-filled membranous structure was observed in the saliva immersion groups. EDS analysis showed that AHF application had no effect on enamel; however, F% and Ca/P ratio were significantly higher on dentin surfaces after AHF application without artificial saliva immersion. Further study on arresting caries treatment is required.

Fluoride varnishes for preventing dental caries in children and adolescents

BACKGROUND

Topically-applied fluoride varnishes have been used extensively as an operator-applied caries-preventive intervention for over three decades. This review updates the first Cochrane review of fluoride varnishes for preventing dental caries in children and adolescents, which was first published in 2002.

OBJECTIVES

To determine the effectiveness and safety of fluoride varnishes in preventing dental caries in children and adolescents, and to examine factors potentially modifying their effect.

SEARCH METHODS

We searched the Cochrane Oral Health Group's Trials Register (to 13 May 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 4), MEDLINE via OVID (1946 to 13 May 2013), EMBASE via OVID (1980 to 13 May 2013), CINAHL via EBSCO (1980 to 13 May 2013), LILACS and BBO via the BIREME Virtual Health Library (1980 to 13 May 2013), ProQuest Dissertations and Theses (1861 to 13 May 2013), and Web of Science Conference Proceedings (1945 to 13 May 2013). A search for ongoing trials was undertaken on ClinicalTrials.gov on 13 May 2013. There were no restrictions on language or date of publication in the search of the electronic databases.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials with blind outcome assessment used or indicated, comparing topically-applied fluoride varnish with placebo or no treatment in children up to 16 years during at least one year. The main outcome was caries increment measured by the change in decayed, missing and filled tooth surfaces in both permanent (D(M)FS) and primary (d(e/m)fs) teeth.

DATA COLLECTION AND ANALYSIS

At least two review authors assessed all search results, extracted data and undertook risk of bias independently. Study authors were contacted for additional information. The primary measure of effect was the prevented fraction, that is the difference in mean caries increments between the treatment and control groups expressed as a percentage of the mean increment in the control group. The caries increments nearest to three years were used from each included study. Random-effects meta-analyses were performed where data could be pooled. Potential sources of heterogeneity were examined in random-effects meta-regression analyses. Adverse effects information was collected from the included trials.

MAIN RESULTS

Twenty-two trials with 12,455 participants randomised (9595 used in analyses) were included. For the 13 that contributed data for the permanent tooth surfaces meta-analysis, the pooled D(M)FS prevented fraction estimate comparing fluoride varnish with placebo or no treatment was 43% (95% confidence interval (CI) 30% to 57%; P < 0.0001). There was substantial heterogeneity, confirmed statistically (P < 0.0001; I(2) = 75%), however this body of evidence was assessed as of moderate quality. The pooled d(e/m)fs prevented fraction estimate was 37% (95% CI 24% to 51%; P < 0.0001) for the 10 trials that contributed data for the primary tooth surfaces meta-analysis, also with some heterogeneity (P = 0.009; I(2) = 59%). Once again this body of evidence was assessed as of moderate quality. No significant association between estimates of D(M)FS or d(e/m)fs prevented fractions and the pre-specified factors of baseline caries severity, background exposure to fluorides, application features such as prior prophylaxis, concentration of fluoride, frequency of application were found. There was also no significant association between estimates of D(M)FS or d(e/m)fs prevented fractions and the post hoc factors: whether a placebo or no treatment control was used, length of follow-up, or whether individual or cluster randomisation was used, in the meta-regression models. A funnel plot of the trials in the main meta-analyses indicated no clear relationship between prevented fraction and study precision. In both methods, power is limited when few trials are included. There was little information concerning possible adverse effects or acceptability of treatment.

AUTHORS' CONCLUSIONS

The conclusions of this updated review remain the same as those when it was first published. The review suggests a substantial caries-inhibiting effect of fluoride varnish in both permanent and primary teeth, however the quality of the evidence was assessed as moderate, as it included mainly high risk of bias studies, with considerable heterogeneity.

Effect of ammonium hexafluorosilicate application for arresting caries treatment on demineralized primary tooth enamel

Ammonium hexafluorosilicate (AHF) has been applied to arrest caries without discoloration. The purpose of this study was to observe structural and elemental changes of demineralized and AHF applied primary tooth enamel. Enamel from the labial surface of 20 primary canines was divided into an unground side and ground side at the center of the tooth, and demineralized with 35% phosphoric acid for 6 min. The teeth were divided into 4 groups according to a 3-min application of AHF and 1 week of soaking in artificial saliva, as follows: group A (neither AHF nor saliva), group B (only saliva), group C (only AHF), and group D (AHF and saliva), and then subdivided according to whether the enamel was ground or unground. Specimens were analyzed with scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The data were statistically analyzed using ANOVA and Fisher's PLSD test at α = 0.05. In groups A and B, prism structures were seen, however, in groups C and D, enamel surfaces were covered with spherical particles. Ca/P ratio was significantly higher in groups C and D than in groups A and B. There was no significant difference between ground and unground enamel in the content of any element. The values for F, Na, Mg and Si persents and Ca/P ratio were significantly higher for the enamel surface than for points 10-30 µm beneath the surface. Results of this study suggest the possibility that AHF treatment arrests caries, although further study will be required to confirm this result.

Silver diamine fluoride and education to prevent and arrest root caries among community-dwelling elders

BACKGROUND/AIMS

Root caries among elderly communities is of growing public health concern globally. This controlled clinical trial investigated the effectiveness of silver diamine fluoride and oral health education in preventing and arresting root caries.

METHODS

Two hundred sixty-six elderly subjects who had at least 5 teeth with exposed root surfaces and did not have serious life-threatening medical diseases were allocated to 3 groups according to a computer-generated random list: group 1 (the control group) received oral hygiene instructions (OHI) annually; group 2 received OHI and silver diamine fluoride (SDF) application annually, and group 3 was given OHI and SDF application annually, plus an oral health education (OHE) programme every 6 months.

RESULTS

Two hundred twenty-seven elderly subjects were followed for 24 months. The mean numbers of new root caries surfaces in groups 1, 2 and 3 were 1.33, 1.00 and 0.70, respectively (ANOVA, p < 0.05). Group 3 had fewer root surfaces with new caries than group 1 (Scheffé multiple-comparison test, p < 0.05). The mean numbers of arrested root caries surfaces in groups 1, 2 and 3 were 0.04, 0.28 and 0.33, respectively (ANOVA, p < 0.01). Group 3 and group 2 had a greater number of active root caries surfaces which became arrested than group 1 (Scheffé multiple-comparison test, p < 0.05).

CONCLUSION

Annual application of SDF together with biannual OHE was effective in preventing new root caries and arresting root caries among community-dwelling elderly subjects.

The inhibitory effects of silver diamine fluoride at different concentrations on matrix metalloproteinases

OBJECTIVE

To study the inhibitory effect of various commercially available concentrations of silver diamine fluoride (SDF) solutions on matrix metalloproteinases (MMPs).

METHODS

Three SDF solutions with concentrations at 38%, 30% and 12% were studied. Two sodium fluoride (NaF) solutions at 10% and 3% were prepared, and they had the same fluoride ion concentrations as 38% and 12% SDF, respectively. Two silver nitrate (AgNO(3)) solutions at 42% and 13% were also prepared, and they had the same silver ion concentrations as 38% and 12% SDF, respectively. Ten samples of each experimental solution were used to study their inhibitory effect on three MMPs, which were MMP-2 (gelatinase A), MMP-8 (neutrophil collagenase) and MMP-9 (gelatinase B) using MMP assay kits. Positive control containing assay buffer at pH 9 and MMPs dilution was used to calculate the percentage inhibition.

RESULTS

The percentage inhibition of 38%, 30% and 12% SDF on MMP-2 were 79%, 60% and 17%, respectively (p<0.001); on MMP-8 were 94%, 85% and 77%, respectively (p<0.001); on MMP-9 were 82%, 65% and 60%, respectively (p<0.001). The percentage inhibition on MMP-2, MMP-8 and MMP-9 by 38% SDF was significantly higher than the corresponding percentage inhibition by 10% NaF and 42% AgNO(3).

SIGNIFICANCE

Greater inhibitory effect on MMPs was found with higher concentration of SDF solution. SDF had more inhibition on MMPs than solutions of NaF and AgNO(3) containing equivalent concentration of fluoride and silver ions, respectively.

Analysis of multilevel grouped survival data with time-varying regression coefficients

Correlated or multilevel grouped survival data are common in medical and dental research. Two common approaches to analyze such data are the marginal and the random-effects approaches. Models and methods in the literature generally assume that the treatment effect is constant over time. A researcher may be interested in studying whether the treatment effects in a clinical trial vary over time, say fade out gradually. This is of particular clinical value when studying the long-term effect of a treatment. This paper proposed to extend the random effects grouped proportional hazards models by incorporating the possibly time-varying covariate effects into the model in terms of a state-space formulation. The proposed model is very flexible and the estimation can be performed using the MCMC approach with non-informative priors in the Bayesian framework. The method is applied to a data set from a prospective clinical trial investigating the effectiveness of silver diamine fluoride (SDF) and sodium fluoride (NaF) varnish in arresting active dentin caries in the Chinese preschool children. It is shown that the treatment groups with caries removal prior to the topical fluoride applications are most effective in shortening the arrest times in the first 6-month interval, but their effects fade out rapidly since then. The effects of treatment groups without caries removal prior to topical fluoride application drop at a very slow rate and can be considered as more or less constant over time. The applications of SDF solution is found to be more effective than the applications of NaF vanish.

Efficacy of silver diamine fluoride for Arresting Caries Treatment

Arresting Caries Treatment (ACT) has been proposed to manage untreated dental caries in children. This prospective randomized clinical trial investigated the caries-arresting effectiveness of a single spot application of: (1) 38% silver diamine fluoride (SDF) with tannic acid as a reducing agent; (2) 38% SDF alone; (3) 12% SDF alone; and (4) no SDF application in primary teeth of 976 Nepalese schoolchildren. The a priori null hypothesis was that the different treatments have no effect in arresting active cavitated caries. Only the single application of 38% SDF with or without tannic acid was effective in arresting caries after 6 months (4.5 and 4.2 mean number of arrested surfaces; p < 0.001), after 1 year (4.1 and 3.4; p < 0.001), and after 2 years (2.2 and 2.1; p < 0.01). Tannic acid conferred no additional benefit. ACT with 38% SDF provides an alternative when restorative treatment for primary teeth is not an option.

Silver diamine fluoride: a caries "silver-fluoride bullet"

The antimicrobial use of silver compounds pivots on the 100-year-old application of silver nitrate, silver foil, and silver sutures for the prevention and treatment of ocular, surgical, and dental infections. Ag(+) kills pathogenic organisms at concentrations of <50 ppm, and current/potential anti-infective applications include: acute burn coverings, catheter linings, water purification systems, hospital gowns, and caries prevention. To distill the current best evidence relative to caries, this systematic review asked: Will silver diamine fluoride (SDF) more effectively prevent caries than fluoride varnish? A five-database search, reference review, and hand search identified 99 human clinical trials in three languages published between 1966 and 2006. Dual review for controlled clinical trials with the patient as the unit of observation, and excluding cross-sectional, animal, in vitro studies, and opinions, identified 2 studies meeting the inclusion criteria. The trials indicated that SDF's lowest prevented fractions for caries arrest and caries prevention were 96.1% and 70.3%, respectively. In contrast, fluoride varnish's highest prevented fractions for caries arrest and caries prevention were 21.3% and 55.7%, respectively. Similarly, SDF's highest numbers needed to treat for caries arrest and caries prevention were 0.8 (95% CI=0.5-1.0) and 0.9 (95% CI=0.4-1.1), respectively. For fluoride varnish, the lowest numbers needed to treat for caries arrest and prevention were 3.7 (95% CI=3.4-3.9) and 1.1 (95% CI=0.7-1.4), respectively. Adverse events were monitored, with no significant differences between control and experimental groups. These promising results suggest that SDF is more effective than fluoride varnish, and may be a valuable caries-preventive intervention. As well, the availability of a safe, effective, efficient, and equitable caries-preventive agent appears to meet the criteria of both the WHO Millennium Goals and the US Institute of Medicine's criteria for 21st century medical care.

Ammonium hexafluorosilicate increased acid resistance of bovine enamel and dentine

Although diamine silver fluoride (AgF: (NH3)2AgF) stains teeth black, it is known as a very effective agent to prevent the dental caries progress. In order to find another fluoride that has a similar anticariogenic effect without changing tooth color, we prepared ammonium hexafluorosilicate (SiF: (NH4)2SiF6), in which the silver of AgF is replaced with silicon. In this study, the anticariogenic effect of SiF was evaluated using bovine teeth. Fluoride solutions, SiF, AgF, acidulated phosphate fluoride (APF), and sodium fluoride (NaF), were applied to bovine enamel and dentine blocks, and the depth of demineralization was measured after exposure to a demineralizing solution for 24 h. Also, fluoride was applied to a simulated dentine caries specimen to evaluate the caries progress-preventing ability. For the dentine specimens, mineral loss (Delta Z) was also measured with microradiography. We found that SiF treated enamel showed better acid resistance than specimens treated with NaF or APF. AgF treated enamel also showed similar acid resistance, but was stained black. SiF and AgF treated caries-affected dentine showed reduced demineralization when exposed to a demineralization solution for 24 h. Mineral loss (Delta Z) was reduced to 85% and 75%, respectively. Although the acid resistance of the SiF treated teeth was inferior to that of the AgF treated teeth, we consider that SiF has good potential as anticariogenic agent, since it increased acid resistance without changing tooth color.

Effect of fluoridated milk on caries in primary teeth: 21-month results

OBJECTIVES

Use of fluoridated milk has been shown to be a safe and effective method to prevent caries in permanent teeth in children. However, studies on its effectiveness on caries prevention in the primary teeth are scarce. The purpose of the present study was to evaluate the effect of milk fluoridation on caries development in young Chinese children.

METHODS

This was a community-based demonstration study carried out in Beijing, China. All children in three selected kindergartens were invited to participate. Each participant consumed 200 ml of fluoridated milk (concentration 2.5 mg F- per litre) per day from Monday to Friday in the kindergarten, and was given two packs of fluoridated milk (250 ml) for consumption at home on Saturday and Sunday every week. Children from a similar background, but without access to fluoridated milk, attending two other kindergartens, were used as the control.

RESULTS

There were 534 children (mean age 54 +/- 4 months) and 305 children (mean age 53 +/- 4 months) in the test and control groups, respectively, at baseline. After 21 months, 417 and 247 children in the test and control groups, respectively, remained in the study. There was no statistically significant difference in the baseline mean dmft scores between the two groups (3.2 vs. 3.5, P = 0.312). After 21 months, the mean net caries increment was 0.4 dmft for the test group and 1.3 dmft for the control group (t-test, P < 0.001).

CONCLUSION

The consumption of fluoridated milk by the kindergarten children in Beijing was an effective measure in preventing caries in the primary teeth.

Effectiveness of silver diamine fluoride and sodium fluoride varnish in arresting dentin caries in Chinese pre-school children

Untreated dental caries in Chinese pre-school children is common. This prospective controlled clinical trial investigated the effectiveness of topical fluoride applications in arresting dentin caries. Three hundred seventy-five children, aged 3-5 years, with carious upper anterior teeth were divided into five groups. Children in the first and second groups received annual applications of silver diamine fluoride solution (44,800 ppm F). Sodium fluoride varnish (22,600 ppm F) was applied every three months to the lesions of children in the third and fourth groups. For children in the first and third groups, soft carious tissues were removed prior to fluoride application. The fifth group was the control. Three hundred eight children were followed for 30 months. The respective mean numbers of arrested carious tooth surfaces in the five groups were 2.5, 2.8, 1.5, 1.5, and 1.3 (p < 0.001). Silver diamine fluoride was found to be effective in arresting dentin caries in primary anterior teeth in pre-school children.