Dentinal Tubule Occlusion and Dentin Permeability Efficacy of Silver Diamine Fluoride Solutions

AIM

This in vitro study compared the effect of two commercially available silver diamine fluoride (SDF) products on dentinal tubule (DT) occlusion and dentin permeability.

METHODS

Sixty-six dentin discs (1.0 mm thick) were divided equally into six groups: acid-etched with no treatment (negative control-NC), etched and sealed with nail varnish (positive control-PC), non-etched and treated with Advantage Arrest (AA), non-etched and treated with Topamine (TP), etched and treated with AA, and etched and treated with TP. Eight specimens from each group were tested for permeability using the dye percolation method. The remaining three samples from each group were assessed for dentinal tubule occlusion, depth of SDF penetration, and elemental analysis using a scanning electron microscope coupled with an energy-dispersive X-ray (SEM/EDX) system. One-way ANOVA and Tukey's post hoc test were used to analyze the results.

RESULTS

TP exhibited lower (p < 0.05) dye percolation compared to AA. While both SDF materials showed a statistically similar (p > 0.05) penetration depth in the DT, none of them had the ability to completely occlude all the DTs. AA exhibited more silver and fluoride ion deposition on etched dentin than TP, and both materials showed a similar increase in the deposition of Ca and P compared to NC.

CONCLUSIONS

Whereas the effectiveness of dentin tubule (DT) occlusion varies based on the material used, both tested SDF products exhibit the capability to seal dentinal tubules, decrease dentin permeability, and promote dentin remineralization. These findings suggest their potential advantage in managing dentin hypersensitivity.

Evaluation of the success of single-visit versus two-visit silver modified atraumatic restorative technique (SMART) in primary molars- a randomized controlled trial

OBJECTIVES

To compare the success of glass ionomer cement (GIC) restorations in carious primary molars using single-visit and two-visit silver modified atraumatic restorative technique (SMART).

METHODS

This was a parallel-group, two-arm randomized controlled trial conducted in a tertiary-care hospital. 150 children aged 4-9 years with asymptomatic carious lesions were recruited and randomized to one of the two interventions: single-visit and two-visit SMART. For each participant, a single tooth was selected to receive one of the interventions. Caries excavation was performed until firm dentin using hand instruments. In single-visit SMART, silver diamine fluoride (SDF) application, and GIC restoration were performed on the same visit while in the two-visit SMART, the GIC restoration was performed one week after the SDF application. Children were followed up at 6 and 12 months for the evaluation of restorations. The primary outcome was the success of the restoration at 12 months. Secondary outcomes were the proportions of failures (minor and major) in two groups. Fischer-exact test, logistic regression, and Kaplan-Meier curve were used for statistical analyses.

RESULTS

A total of 150 SMART restorations (single-visit=75, two-visit=75) were performed. At 12-months, 51 (68 %) restorations in the single-visit group and 62 (82.7 %) restorations in the two-visit group were evaluated as success (p = 0.051). Minor failures were observed in 21 teeth (28 %) in single-visit and 13 teeth (17.3 %) in two-visit SMART. Major failures were noted only in single-visit SMART in 3 teeth (4.0 %) (p = 0.052).

CONCLUSION

There was no statistically significant difference in the success rates of GIC restorations in single-visit and two-visit SMART groups.

CLINICAL SIGNIFICANCE

Both single-visit and two-visit SMART restorations showed comparable success rates, thus clinicians can choose either protocol based on the patient's needs and cooperation.

Diffusion of Silver Diamine Fluoride Solution in Dentine: An In Vitro Study

OBJECTIVES

The aim of this research was to assess the diffusion dynamics of silver and fluoride ions after 38% silver diamine fluoride (SDF) solution application on dentine of varying thicknesses over 24 weeks.

METHODS

Bovine dentine discs of 5.5 mm in diameter were prepared and separated into 3 groups with thicknesses of 0.5 mm (group 1), 1.0 mm (group 2), and 1.5 mm (group 3). The diameter and number of dentinal tubules of discs were assessed. Each disc received a topical application of 0.05 mL 38% SDF solution. The deionised water in the tube was collected weekly for 24 weeks. The silver and the fluoride ion concentrations in the collected deionised water were determined. Generalised estimating equations was used to explore the potential effects of the key factors on the silver/fluoride diffusion.

RESULTS

The amount of silver and fluoride ion diffusion through dentine almost levelled off after 4 weeks and showed a decline trend over 24 weeks. The mean (SD) 24-week cumulative ion diffusion through dentine in groups 1, 2, and 3 was as follows: 20 (4) μg, 10 (2) μg, and 5 (1) μg for silver (P < .05) and 18 (2) μg, 13 (2) μg, and 7 (1) μg for fluoride (P < .05), respectively.

CONCLUSIONS

Silver and fluoride ion diffusion through dentine showed a decline trend over 24 weeks. The diameter and the number of dentinal tubules on dentine with different thicknesses affects the ion diffusion dynamics. This study provides indications on the pattern of silver/fluoride ions diffusion through dentine to pulp after 38% SDF application. An increased amount of silver/fluoride diffuses through dentine into the pulp with decreased remaining dentine thickness.

Characteristics of phase 4 clinical trials on Dental Caries registered at Clinicaltrials.gov

BACKGROUND

Dental caries, a widespread chronic oral disease, is caused by multiple factors including microorganisms, genetic predisposition. Despite being preventable, it poses a significant global burden. This study reviews all phase 4 clinical trials on dental caries registered at ClinicalTrials.gov to provide a comprehensive overview of their characteristics.

METHODS

A search was conducted on the ClinicalTrials.gov database using keywords. The registration data for all relevant phase 4 studies concerning 'Dental Caries' were retrieved. This search was conducted on the 23rd of January, 2024.

RESULTS

The analysis included 58 phase 4 clinical trials, with most studies (67.2%) reporting complete data. The majority (63.8%) had fewer than 100 participants, and the predominant sponsors were medical institutions (77.6%). Geographically, the highest percentage of studies were conducted in South America (24.1%), with the lowest in North America (10.3%). Interventional trials primarily focused on treatment (51.7%) and prevention (41.4%), with a significant portion being randomized (93.1%). Blinding varied, with single and double blinding each used in 25.9% of studies. Drug interventions were the most common (60.6%), followed by other categories such as dietary supplements and procedures. Among drug interventions, agents containing fluoride were the largest category, accounting for 52.6% of the trials. Fluoride varnishes and silver diamine fluoride were the most frequently evaluated. Sedatives and pain relievers constituted 15.7% of the trials, with midazolam and ketamine being predominant. Other drugs accounted for 23.2% of the trials, featuring diverse substances such as inactivated poliovirus vaccine and xylitol. Dental materials and operative treatments made up 29.5% of the trials, with resin and fissure sealants being the most commonly evaluated.

CONCLUSION

This analysis of phase 4 clinical trials highlighted fluoride as the most studied intervention for dental caries prevention. The analysis also revealed a need for further research on non-fluoride interventions and emphasized the importance of using evidence-based practices in dental care for improved oral health outcomes.

CLINICAL TRIAL NUMBER

Not applicable.

Effects of glutathione and potassium iodide on silver diamine fluoride application on remineralisation and colour change in dentine caries of primary teeth: an in vitro study

PURPOSE

The aim of this study is to compare the effect of GSH (reduced glutathione) and KI (potassium iodide) on SDF (silver diamine fluoride) discolouration and dentine remineralisation.

METHODS

Sixteen primary molars were utilised, yielding 4 dentine specimens each. Three specimens per tooth were allocated: one as a control and the others to experimental groups. Initial microhardness measurements were taken from one remaining dentine specimen per tooth. Subsequently, all groups underwent exposure to a demineralisation solution. Colorimetry assessed specimen colour, and post-second microhardness measurements on demineralised specimens, treatments were administered as follows: group 1 (control, n = 16): 38% SDF, group 2 (n = 16): 38% SDF followed by KI, group 3 (n = 16): 38% SDF with 5% GSH added by weight. Following pH cycling across all groups, colorimetry reassessed 48 dentine specimens. Final microhardness measurements ensued, followed by statistical analysis. Normality was checked via Shapiro-Wilk, and homogeneity via Levene's test. Independent samples t test compared normally distributed groups; Mann-Whitney U compared non-normally distributed groups. ANOVA compared means of normally distributed groups, and Kruskal-Wallis for non-normally distributed ones. Repeated measures ANOVA compared dependent groups with normal distribution, and Friedman test for non-normal. Post hoc Bonferroni analyses identified significant differences. IBM SPSS 25 was used to conduct analyses.

RESULTS

The mean ΔE* values for SDF and SDF + GSH groups were significantly higher than those of the SDF + KI group (p < 0.05). Significant differences in L* values during final colour measurement were noted between the SDF + KI group and both SDF and SDF + GSH groups (p < 0.05). Although mean remineralisation microhardness measurements were higher than mean demineralisation microhardness measurements in all groups, statistical significance was observed only in the SDF and SDF + KI groups (p < 0.05).

CONCLUSION

The study found that the addition of 5% GSH by weight to SDF does not significantly affect discolouration. Moreover, the addition of 5% GSH to the SDF solution may have a minor impact on the remineralisation potential of SDF. The application of KI after SDF reduces discolouration and does not affect the expected remineralisation process.

Comparison of aesthetic perception and acceptability of silver diamine fluoride staining between Spanish and Italian parents

Assessing parental aesthetic acceptability of Silver Diamine Fluoride (SDF) staining is crucial for its potential implementation in paediatric dentistry in different regions. This study aimed to compare aesthetic perceptions and acceptance of SDF staining between Spanish and Italian parents, and assess weather acceptability is influenced by location, child's cooperation, or demographic background. A cross-sectional comparative study was conducted among Spanish and Italian parents at three university dental clinics, using a validated Italian version of the questionnaire "Parental perceptions of Silver Diamine Fluoride Dental Color Changes". 264 Spanish and 234 Italian parents participated in the survey. 41.8% of Spanish parents, compared to 65.4% of Italians, considered staining on posterior teeth acceptable (p < 0.001). 17.2% of Spaniards rated anterior teeth acceptable, versus 19.3% of Italians (p < 0.001). Italian parents showed increased acceptability as child's cooperation decreased. Acceptability levels in Spain remained more homogeneous, despite linear mixed model identifying a significant increase in acceptability scores from 'collaboration' to 'non-collaboration' scenario. Spanish and Italian parents found SDF staining on posterior teeth more acceptable than on anterior regions. Level of acceptance increased with child's uncooperative behavior. Spanish parents generally demonstrated a lower acceptance of SDF pigmentation compared to Italians.Trial registration: NCT, NCT06384326. Registered 21 April 2024, https://clinicaltrials.gov/study/NCT06384326.

Cariogenic Microbiota and Emerging Antibacterial Materials to Combat Dental Caries: A Literature Review

Dental caries is the most common oral disease in the world and a chronic infectious disease. The cariogenic microbiome plays an important role in the process of caries. The ecological imbalance of microbiota leads to low pH, which causes caries. Therefore, antibacterial materials have always been a hot topic. Traditional antibacterial materials such as cationic antibacterial agents, metal ion antibacterial agents, and some natural extract antibacterial agents have good antibacterial effects. However, they can cause bacterial resistance and have poor biological safety when used for long-term purposes. Intelligent antibacterial materials, such as pH-responsive materials, nanozymes, photoresponsive materials, piezoelectric materials, and living materials are emerging antibacterial nano-strategies that can respond to the caries microenvironment or other specific stimuli to exert antibacterial effects. Compared with traditional antibacterial materials, these materials are less prone to bacterial resistanceand have good biological safety. This review summarizes the characteristics of cariogenic microbiota and some traditional or emerging antibacterial materials. These emerging antibacterial materials can accurately act on the caries microenvironment, showing intelligent antibacterial effects and providing new ideas for caries management.

The Protective Effects of Silver Fluoride Solution and Fluoride Varnish on Dental Erosion-An In Vivo Study

Objectives: Dental erosion has evolved into a common condition with growing concern in the dental community. The aim of this study was to explore the protective effects of two highly fluoridated products, silver fluoride solution (silver diamine fluoride-potassium iodide solution, SDF-KI) and fluoride varnish, on dental erosion in mouse. Methods: Two groups of ten young CD-1 mouse were given a cola drink ad libitum over a 6-week period. A prophylactic treatment with a silver fluoride solution (38% SDF 48,000 ppm F with a silver concentration of 253,900 ppm) and a fluoride varnish (NaF, 22,600 ppm F) were applied on the mandibular molars, performed under sedation twice a week during the whole experiment. Furthermore, two control groups of ten mice were included, a positive (cola drink) and a negative (distilled water) control. A terminal procedure was followed by dissection of mandibular molars and analysis of them using scanning electron microscopy (SEM). The first molars were transversely ground, further analyzed by SEM, and measured for tooth height and tooth tissue loss. Results: Analyses of mandibular molars treated with a fluoride varnish indicated a 5% decreased tooth tissue loss, compared to the molars which served as a positive control. The best effect was achieved with the application of silver fluoride solution, displaying a 35% decreased tooth tissue loss compared to the positive control group. Conclusions: Preventive treatment with a solution of silver fluoride solution exhibits greater protection against dental erosion compared to a traditional fluoride varnish. This study indicates that silver fluoride solution is an effective fluoride compound and is highly beneficial in a clinical setting with the aim of preventing dental erosion.

Impact of Different Time Intervals on the Color Stability of Glass Ionomer Cement and Composite Materials Bonded to Silver Diamine Fluoride: An In Vitro Study

Objective This in vitro study evaluated the impact of different time intervals on the color stability of glass ionomer cement (GIC) and composite materials bonded to teeth treated with silver diamine fluoride (SDF). Specifically, the study sought to determine if immediate or delayed application of these restorative materials affects the degree of staining caused by SDF. Materials and methods Twenty-eight extracted primary molars with cavitated lesions were randomly divided into four groups, each comprising seven samples. SDF was applied to all samples, followed by either immediate or delayed restoration using GIC or composite materials. Group I received immediate composite restorations, Group II received immediate GIC restorations, Group III received composite restorations after a two-week delay, and Group IV received GIC restorations after a two-week delay. Color measurements were taken at various time points using a digital spectrophotometer, and the color difference (ΔE value) was calculated using the CIELAB color space system. Results Composite restorations exhibited better color stability than GIC. Immediate restorations had higher discoloration (ΔE: composite 4.25, GIC 26.95). Delaying restorations by two weeks reduced discoloration (composite 1.66, GIC 10.66), with composites showing minimal color change. Conclusion Composite restorations exhibited superior color stability compared to GIC, and delayed restoration reduced SDF-induced staining more effectively than immediate restoration.

Antibacterial and mineralising properties of copper tetraamine fluoride on dentine caries: A laboratory study

OBJECTIVE

To investigate the antibacterial, mineralising, and discolouring properties of copper tetraamine fluoride (CTF) on artificial dentine caries.

METHOD

Demineralised human dentine blocks were treated with CTF, silver diamine fluoride (SDF, positive control) and water (negative control) before they were subjected to cariogenic challenge with Streptococcus mutans biofilm. The morphology, viability, and growth kinetics of the biofilm were assessed by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and colony-forming unit (CFU) counting. The lesion depths, mineral loss, chemical structure, and crystal characteristics were measured using micro-computed tomography, Fourier transform infrared (FTIR), and X-ray diffraction (XRD). The discolouring property on demineralised dentine was assessed by spectrophotometry. One-way analysis of variance with the Bonferroni post hoc test was performed to assess and compare the data.

RESULTS

SEM revealed confluent bacterial growth covering the surface of dentine treated with Water but not CTF and SDF. CLSM showed the dead-to-live ratio of the biofilm treated with CTF, SDF and Water were 0.7 ± 0.1, 0.8 ± 0.1 and 0.5 ± 0.1 (p < 0.001, CTF, SDF>Water). The Log10 CFU values of the biofilm treated with CTF, SDF and Water were 7.8 ± 0.1, 7.8 ± 0.1 and 8.1 ± 0.2 (p < 0.001, CTF, SDF

CONCLUSION

CTF inhibited Streptococcus mutans. It mineralised but not discoloured artificial dentine caries.

CLINICAL SIGNIFICANCE

If CTF is successfully translated into clinical application, it may be a non-discolouring anti-caries agent for clinicians to arrest dentine caries.

Collapse

Key Words

• Antibacterial
• Caries
• Dentine
• Fluoride
• Remineralization

Collapse

MESH Headings

• Dentin/drug effects
• Humans
• Biofilms/drug effects
• Dental Caries/microbiology
• Anti-Bacterial Agents/pharmacology
• Streptococcus mutans/drug effects
• X-Ray Microtomography
• Spectroscopy, Fourier Transform Infrared
• Microscopy, Electron, Scanning
• Quaternary Ammonium Compounds/pharmacology
• Quaternary Ammonium Compounds/chemistry
• X-Ray Diffraction
• Silver Compounds/pharmacology
• Microscopy, Confocal
• Cariostatic Agents/pharmacology
• Cariostatic Agents/therapeutic use
• Cariostatic Agents/chemistry
• Fluorides, Topical/pharmacology

Collapse

Grants Collapse

Affiliation(s)

Veena Wenqing Xu Faculty of Dentistry, University of Hong Kong, Hong Kong, China
Iris Xiaoxue Yin Faculty of Dentistry, University of Hong Kong, Hong Kong, China
John Yun Niu Faculty of Dentistry, University of Hong Kong, Hong Kong, China
Ollie Yiru Yu Faculty of Dentistry, University of Hong Kong, Hong Kong, China
Mohammed Zahedul Islam Nizami Faculty of Dentistry, University of Hong Kong, Hong Kong, China; Department of Mineralized Tissue Biology and Bioengineering, The ADA Forsyth Institute, Cambridge, MA, USA.
Chun Hung Chu Faculty of Dentistry, University of Hong Kong, Hong Kong, China.

Collapse

Dentists' knowledge, attitude and practice towards silver diamine fluoride therapy in Hong Kong: a mixed-method study

This study explored the knowledge, attitude, and practice towards silver diamine fluoride (SDF) therapy among dentists in Hong Kong. The quantitative component was an online closed-ended questionnaire survey through the Society of Preventive Dentistry of Hong Kong. The qualitative component involved individual in-depth interviews with selected dentists. Descriptive analysis was performed on the quantitative data, whereas thematic analysis was performed on the qualitative data. The quantitative study invited 173 dentists, and 86 completed the questionnaire survey (86/173; 50%). All respondents were familiar with SDF and 73 (73/86; 85%) used SDF. They agreed that SDF therapy was simple (84/86; 98%), non-invasive (84/86; 98%), timesaving (82/86; 96%), effective (81/86; 94%), and painless (79/86; 92%). However, they expressed concerns about SDF's unaesthetic staining (81/86; 94%) and used it for primary teeth (77/86; 89%). The qualitative study conducted 12 individual interviews. Dentists asserted that SDF therapy is an evidence-based practice for arresting caries, including root caries. They acknowledged SDF therapy is straightforward and cost-effective. It is particularly useful for children or people with disabilities and can be used in community service. They considered the application skills, close monitoring and maintaining good oral hygiene to be vital for the success of SDF therapy. However, they noted that black staining of the carious lesions could cause patient dissatisfaction. They suggested that a guideline is warranted for SDF use. Hong Kong dentists are aware of the indications, merits and limitations of SDF therapy. They use SDF therapy for caries control, especially for children, elderly and those with disabilities, and consider it cost-effective for community dental care.

YouTube as a source of information for parents about silver diamine fluoride

PURPOSE

To depict and evaluate the characteristics, engagement, content, and quality of YouTube videos containing information about silver diamine fluoride (SDF).

METHODS

A total of 200 YouTube™ videos were selected and screened, and the video characteristics and engagement indicators were recorded. They were then reviewed for consistency with current professional guidelines on this topic. Two independent reviewers scored the videos using a customized 8-point scoring and 5-point Global Quality Scale (GQS) to assess the content information and the overall quality of each video. These videos were further classified into good, moderate, and poor videos. Kruskal-Wallis, Chi-squared, and Spearman's correlation tests were used for the statistical analysis.

RESULTS

110 videos met the inclusion criteria. The median total content score was 3 (IQR = 4) and the median GQS score was 2 (IQR = 2). Less than half (n = 49; 45.5%) of the videos were uploaded by healthcare professionals. The video content was classified as good (n = 26; 23.64%), moderate (n = 43; 39.09%), and poor (n = 41; 37.27%). Good-quality videos have a significantly higher information content score than the other groups (P = 0.001). A strong correlation was found between the total content score and GQS score (rho = 0.970, P = 0.001). Longer duration, higher interaction index, and recent upload are associated with higher content and quality scores.

CONCLUSION

A considerable number of videos are available on YouTube about SDF treatment and are attracting public interest. The content and quality of these videos vary widely and are related to several factors.

Tooth-Binding Graphene Quantum Dots Silver Nanocomposites for Prevention of Dental Caries

Objective

The objectives of this study were to develop a tooth-binding graphene quantum dots silver nanocomposites (ALN-GQDs-Ag) and evaluate their antibacterial, mineralising, and discolouring properties for the prevention of dental caries.

Methods

In this study, ALN-GQDs-Ag were developed by synthesising nano silver (Ag) with graphene quantum dots (GQDs) and functionalised GQDs with alendronate (ALN). ALN-GQDs-Ag were characterised by transmission electron microscopy (TEM), zeta potential analysis, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. The cytotoxicity of ALN-GQDs-Ag against human gingival fibroblasts (HGF-1) and stem cells from human exfoliated deciduous teeth (SHED) was examined using a colorimetric assay with reference to silver nitrate solution. The affinity of ALN-GQDs-Ag for hydroxyapatite particles was investigated using inductively coupled plasma spectroscopy (ICP). The antibacterial properties of ALN-GQDs-Ag against Streptococcus mutans were evaluated by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and colony-forming units counting (CFUs). The mineralisation properties of ALN-GQDs-Ag on human dentine were assessed using micro-computed tomography (micro-CT), scanning electron microscopy (SEM), and Fourier transform infrared in a biochemical cycling model. The discolouring properties of ALN-GQDs-Ag on artificial dentine caries were determined using spectrophotometry.

Results

TEM, Zeta potential, XPS, FTIR, and Raman spectroscopy confirmed the synthesis of stable spherical ALN-GQD-Ag nanocomposites with a 10.3 ± 5.5 nm diameter. The colorimetric assay demonstrated that ALN-GQDs-Ag were less cytotoxic than silver nitrate to HGF-1 and SHED (p<0.001). ICP showed that ALN-GQDs-Ag were bound to hydroxyapatite. SEM, CLSM, and CFUs showed that ALN-GQDs-Ag was bactericidal and inhibited biofilm growth of Streptococcus mutans. Micro-CT, SEM, and FTIR showed that ALN-GQDs-Ag repressed dentine demineralisation under a cariogenic challenge. Spectrophotometry revealed no significant discolouration of dentine caries in the ALN-GQDs-Ag.

Conclusion

This study developed a biocompatible and tooth-binding ALN-GQDs-Ag with promising antibacterial, mineralising, and non-discolouring properties. ALN-GQDs-Ag could be a novel anti-caries agent for preventing dentine caries if translated for clinical use.

Minimizing tooth discoloration caused by topical silver diamine fluoride application: A systematic review

OBJECTIVE

The objective of this systematic review is to examine the methods used to minimize discoloration of the carious lesions after topical silver diamine fluoride (SDF) application.

DATA/SOURCES

Two independent researchers conducted a search of English literature published up to 30th April 2024 in three databases (PubMed, Scopus, and Web of Science). They screened titles and abstracts, excluding conference proceedings, books, reviews and publications unrelated to SDF. They included only original research on methods to minimize SDF-induced discoloration. The publications lacking comparative color change data were excluded. Full texts of the included articles were then analyzed. The Cochrane guidelines for clinical trials and the guidelines for in-vitro studies on dental materials were used for the risk of bias assessment.

RESULTS

The systematic review included 33 publications from 1,283 identified publications (26 laboratory studies and 7 clinical studies). Thirteen laboratory studies and five clinical studies were rated as having 'low risk'. Three main methods to minimize discoloration were identified: masking with restoration, using chemicals, and substituting silver with nano-silver. Nine studies used resin composite or glass ionomer cement to mask the SDF-induced discoloration. Twenty-nine studies used chemicals to reduce SDF-induced discoloration. These chemicals included precipitating agents like potassium iodide, oxidizing agents like hydrogen peroxide, and chelating agents like glutathione. Seven publications used chemicals (potassium iodide or glutathione) before restoration and six of them found improved masking effect. Four studies substituted silver ions with silver nanoparticles which did not discolor carious lesion.

CONCLUSIONS

Masking with restoration, using chemicals, and substituting silver ions with nano-silver particles have been reported to address the discoloring effects of SDF therapy. However, most are laboratory studies, and more clinical trials are needed to confirm their effectiveness in reducing SDF-induced discoloration.

CLINICAL SIGNIFICANCE

SDF effectively arrests caries, but it discolors carious lesions. This review summarizes the methods and their outcomes for reducing SDF-induced discoloration. This study is supported by the General Research Fund of Research Grant Council No. 17,100,222.

Developing a novel antibacterial copper tetraamine fluoride

OBJECTIVE

To develop a novel and biocompatible copper tetraamine fluoride (CTF) with antibacterial and nondiscolouring properties.

METHOD

This study used copper fluoride and ammonia solution to develop CTF solution. The CTF was characterized by X-ray photoelectron spectroscopy (XPS). Cytotoxicity was evaluated by stem cells from human exfoliated deciduous teeth (SHED) and human gingival fibroblasts (HGF-1). The fluoride concentration was determined using ion-selective electrode. The alkalinity was measured by a pH electrode. The human dentine blocks were treated with CTF and then incubated with Streptococcus mutans to evaluate the antimicrobial and discolouring effects. The silver diamine fluoride (SDF) was employed as the positive control, and water was the negative control. The colony-forming units (CFUs) and confocal laser scanning microscopy (CLSM) were used to examine the kinetics and viability of the biofilm. The discolouring property on dentine was assessed by spectrophotometry. One-way analysis of variance with the Bonferroni post hoc test was performed to assess and compare the data.

RESULTS

XPS confirmed synthesis of CTF solution. The half-maximal inhibitory concentration of CTF on SHED and HGF-1 was 195±16 ppm and 137±11 ppm. The fluoride concentration was 121,000±5,000 ppm. The pH value was 9. Log10 CFU of the CTF, SDF and water group were 5.0 ± 0.2, 4.9 ± 0.1 and 7.4 ± 0.1 (p < 0.001, CTF, SDFWater). Spectrophotometry showed that the ΔE of the CTF, SDF and water group were 5 ± 2, 6 ± 3 and 45±2 (p < 0.001, CTF, Water

CONCLUSION

This study developed an alkaline 58% CTF solution, which is biocompatible, antibacterial and non-discolouring.

CLINICAL SIGNIFICANCE

If CTF is successfully translated into clinical care, CTF can be a simple and affordable anti-caries agent for clinicians to prevent dental caries.

Collapse

Key Words

• Antibacterial
• Caries
• Copper
• Dentine
• Fluoride

Collapse

MESH Headings

• Humans
• Anti-Bacterial Agents/pharmacology
• Streptococcus mutans/drug effects
• Fibroblasts/drug effects
• Tooth, Deciduous/drug effects
• Hydrogen-Ion Concentration
• Biofilms/drug effects
• Quaternary Ammonium Compounds/pharmacology
• Quaternary Ammonium Compounds/chemistry
• Copper/pharmacology
• Copper/chemistry
• Gingiva/drug effects
• Gingiva/cytology
• Dentin/drug effects
• Photoelectron Spectroscopy
• Stem Cells/drug effects
• Silver Compounds/pharmacology
• Microscopy, Confocal
• Biocompatible Materials/pharmacology
• Fluorides, Topical/pharmacology
• Fluorides/pharmacology
• Ion-Selective Electrodes
• Cariostatic Agents/pharmacology
• Cariostatic Agents/chemistry
• Materials Testing
• Microbial Sensitivity Tests
• Cell Survival/drug effects

Collapse

Grants Collapse

Affiliation(s)

Veena Wenqing Xu Faculty of Dentistry, University of Hong Kong, Hong Kong, China
Iris Xiaoxue Yin Faculty of Dentistry, University of Hong Kong, Hong Kong, China
John Yun Niu Faculty of Dentistry, University of Hong Kong, Hong Kong, China
Ollie Yiru Yu Faculty of Dentistry, University of Hong Kong, Hong Kong, China
Mohammed Zahedul Islam Nizami Faculty of Dentistry, University of Hong Kong, Hong Kong, China; Department of Mineralized Tissue Biology and Bioengineering, The Forsyth Institute, Cambridge, MA, USA.
Chun Hung Chu Faculty of Dentistry, University of Hong Kong, Hong Kong, China.

Collapse

An In-vitro Evaluation of Tooth Discoloration and Shear Bond Strength of Glass Ionomer Cement Bonded to Tooth Surface Pretreated with Silver Diamine Fluoride and Glutathione Biomolecule

BACKGROUND

Silver diamine fluoride (SDF) is employed in caries prevention and treatment; however, tooth discoloration post treatment is a significant disadvantage, which can be reduced using glutathione (GSH), a water soluble tripeptide.

AIM

To evaluate and compare the effect of glutathione biomolecule (GSH) and potassium iodide (KI) along with SDF on tooth discoloration and shear bond strength of glass ionomer cement (GIC) on the tooth surface.

METHODS

Artificial caries were created on 48 extracted unblemished premolars and divided into four groups (SDF, SDF + KI, SDF + GSH, and Water). The solutions were applied according to the manufacturer's instructions, and the samples were incubated for 24 hours. The color assessment was recorded on days 1, 7, and 14 by using a spectrophotometer. Following the color assessment, all the treated samples were bonded with GIC. The shear bond strength was evaluated using a universal testing machine.

RESULTS

Mixing SDF with GSH initially reduced tooth discoloration. Although there was an increase in the discoloration after 2 weeks, it was still less when compared to the SDF group. The application of GSH and KI post SDF application had no significant difference in the shear bond strength of GIC on the tooth surface.

CONCLUSIONS

The use of GSH along with SDF helps in reducing the discoloration without compromising the shear bond strength.

Silver nanoparticles versus chitosan nanoparticles effects on demineralized enamel

BACKGROUND

To compare the impacts of different remineralizing agents on demineralized enamel, we focused on chitosan nanoparticles (ChiNPs) and silver nanoparticles (AgNPs).

METHODS

This study was conducted on 40 extracted human premolars with artificially induced demineralization using demineralizing solution. Prior to the beginning of the experimental procedures, the samples were preserved in artificial saliva solution. The nanoparticles were characterized by transmission electron microscopy (TEM) and teeth were divided into four equal groups: Group A was utilized as a control group (no demineralization) and received no treatment. Group B was subjected to demineralization with no treatment. Group C was subjected to demineralization and then treated with ChiNPs. Group D was subjected to demineralization and then treated with AgNPs. The teeth were evaluated for microhardness. The enamel surfaces of all the samples were analysed by scanning electron microscopy (SEM) for morphological changes and energy dispersive X-ray analysis (EDX) for elemental analysis.

RESULTS

The third and fourth groups had the highest mean microhardness and calcium (Ca) and phosphorous (P) contents. SEM of these two groups revealed relative restoration of homogenous remineralized enamel surface architecture with minimal micropores.

CONCLUSION

Chitosan nanoparticles (NPs) and silver NPs help restore the enamel surface architecture and mineral content. Therefore, chitosan NPs and AgNPs would be beneficial for remineralizing enamel.

Evaluation of Fluoride and Silver Ion Concentrations in e-Silver Diamine Fluoride and Advantage Arrest: An Ion Chromatography and Atomic Absorption Spectrometer Study

Aims and background

Dentin hypersensitivity (DH) is characterized by sharp shooting pain due to exposed dentin, and the most common method for treating this pain is the occlusion of the dentinal tubules with the help of desensitizing agents. E-silver diamine fluoride (e-SDF) (Kids-e-Dental, Mumbai, India) is a commercially available 38% SDF solution in the Indian market. Despite the fact that its application for caries prevention has been proven, the fluoride (Fl) and silver (Ag) ion concentrations of e-SDF for use in treating DH have yet to be standardized. The aim of this study is to determine and compare the Fl and Ag ion concentrations released from two commercially available 38% silver diamine fluoride (SDF) solutions.

Materials and methods

The two most common commercially available 38% SDF solution brands, namely Advantage Arrest and e-SDF were used. Two drops of each of these solutions were taken in three beakers and diluted with distilled water. The Fl ion concentration was evaluated using a calibrated ion-specific electrode. The free Ag ion concentration was assessed using an atomic absorption spectrometry (AAS).

Results

Release of Ag ions shows that on days 1, 2, 5, 6, and 7, concentration (mg/L) was higher in the Advantage Arrest group but is statistically nonsignificant. On days 3 and 4, it is higher in an e-SDF group with a t-value of 1.085 and 0.243 and is statistically nonsignificant. Release of Fl ion showed that in comparison to the baseline, it was more with Advantage Arrest on days 2, 4, and 7 with a t-value of -3.766, -0.999, and 0.347 and on day 2 was statistically significant. On days 3, 5, and 6 Fl ion release from baseline was more with e-SDF in comparison with Advantage Arrest but statistically insignificant.

Conclusion

The AAS analysis as well as the ion chromatography showed that the Ag and Fl ion release respectively on days 1-7 from e-SDF was similar to the one seen in the case of Advantage Arrest.

Clinical significance

This helps dentists choose among different brands of the same commercially available 38% SDF solutions depending on the cost and availability of the product.

How to cite this article

Kamath P, Kamath P, P AN, et al. Evaluation of Fluoride and Silver Ion Concentrations in e-Silver Diamine Fluoride and Advantage Arrest: An Ion Chromatography and Atomic Absorption Spectrometer Study. Int J Clin Pediatr Dent 2024;17(10):1141-1145.

Efficacy of silver diamine fluoride (SDF) in arresting dentin caries against inter-kingdom biofilms of Streptococcus mutans and Candida albicans

OBJECTIVES

To compare, in vitro, the efficacy of three proprietary silver diamine fluoride (SDF) products in mitigating progression of dentinal caries induced by an inter-kingdom, dual-species, bacterial-yeast biofilm.

METHODS

Human dentin blocks were demineralized to create artificial caries lesions and randomized into three SDF test groups: Saforide, Topamine, T-SDF, and an aqueous control (n = 26 per group). After application of foregoing SDF variants, the blocks were incubated with Streptococcus mutans and Candida albicans for 24 h for biofilm development, and subsequently subjected to a microbe-induced, pH-cycling process for 7 days, to mimic the oral eco-system. The biofilm cell viability and surface topography were assessed by colony-forming units (CFUs) and scanning electron microscopy respectively. The lesion depth and mineral density were evaluated by micro-computer tomography. SDF precipitate and matrix-to-mineral ratio were evaluated by X-ray diffraction and Fourier transform infrared spectroscopy, respectively. Standard, accepted methodology was used for all these evaluations and procedures.

RESULTS

After pH cycling, the SDF groups demonstrated comparable inhibition of the biofilm relative to the control. the log CFU of S. mutans for Saforide, Topamine, T-SDF, and control were 6.69±0.73, 6.48±0.56, 6.63±0.66, and 8.01±0.45, respectively. For C. albicans, the log CFU were 4.86±0.44, 4.72±0.53, 4.92±0.29, and 5.60±0.27, respectively. The log CFU of S. mutans and C. albicans in the SDF groups were significantly lower than the control group (p<0.001). Further, the lesion depth decreased by approximately 14.79±7.00% in the SDF groups, while it increased by 11.07±8.61% in the control (p<0.001), and the mineral density increased by 16.36±4.58% in the SDF group, as opposed to a 5.59±2.64% reduction in the control (p<0.001) implying their caries mitigating effect. These findings were corroborated by SEM images of the lesions.

CONCLUSION

SDF significantly mitigated dentin caries due to an assault by a polymicrobial plaque biofilm whilst arresting mineral loss and lesion growth. There was no difference in the caries-arresting efficacy of the compared SDF variants.

Dental Applications of Ion-Substituted Hydroxyapatite: A Review of the Literature

Hydroxyapatite (HA) forms an essential constituent of human teeth and bone. Its distinctive characteristic features, such as bioactivity and osteoconductivity, make it an ideal candidate to be used as an implant coating in restorative dentistry and maxillofacial surgery for bone regeneration. However, low fracture toughness and brittleness are a few of the inherent features of HA, which limit its application in load-bearing areas. The potential of HA to engage its lattice structure with either partial or complete substitution with external ions has become an increasing area of research as this phenomenon has the potential to enhance the biological and functional properties of the material. Consequently, this review aimed to highlight the role of various substituted ions in dental applications. Data indicate that the newly formed HA-substituted biomaterials demonstrate enhanced remineralization and antimicrobial activity along with improved hardness. Ion-substituted HA offers a promising strategy for future clinical research as these materials may be incorporated into various dental products for therapeutic treatments.

Ion release of the glass ionomer restoration with silver diamine fluoride dentin pretreatment

OBJECTIVE

To assess the fluoride and silver ion release of glass ionomer cement (GIC) restorations, including conventional GIC (CGIC) and resin-modified GIC (RMGIC) restorations, with 38 % silver diamine fluoride (SDF) solution dentin pretreatment.

METHODS

Eighty dentin blocks were allocated into 4 groups and restored with SDF+CGIC, CGIC, SDF+RMGIC and RMGIC, respectively. Each block was stored in deionized water at 37 °C for 2 years. Fluoride and silver ion concentration in storage solution was measured using ion-selective electrode and inductively coupled plasma-optical emission spectrometry for up to 2 years. The cross-sectional surfaces of restored dentin blocks were assessed by X-Ray diffraction analysis (XRD), scanning electron microscope (SEM) with energy-dispersive X-ray spectroscopy (EDS) after 1 week and 2 years, respectively.

RESULTS

The mean ± standard deviation (SD) of accumulative fluoride releasing in SDF+CGIC, CGIC, SDF+RMGIC and RMGIC for 2 years were 0.13±0.005 mg, 0.09±0.006 mg, 0.15±0.008 mg and 0.05±0.003 mg, respectively (Groups SDF+RMGIC > SDF+CGIC > CGIC >RMGIC, p < 0.05). The mean ± SD of accumulative silver releasing in SDF+CGIC, CGIC, SDF+RMGIC and RMGIC for 2 years were 0.03±0.009 mg, 0.00±0.00 mg, 0.01±0.003 mg, and 0.00±0.00 mg, respectively (Groups SDF+CGIC > SDF+RMGIC > CGIC&RMGIC, p < 0.05). Groups SDF+CGIC and SDF+RMGIC showed sustainably higher fluoride and silver releasing compared to Groups CGIC and RMGIC (p < 0.05). XRD analysis indicated the fluorapatite and silver chloride were observed only in Groups SDF+CGIC and SDF+RMGIC, but not in Groups CGIC and RMGIC. SEM images of the cross-sectional view of the dentin blocks showed silver crystals within dentinal tubules 1 week and 2-year in Groups with SDF pretreatment.

CONCLUSION

The 38 % SDF dentin pretreatment sustainably increased the fluoride and silver release of GIC and RMGIC restorations for up to 2 years.

VMT/ACP/Dextran composite nanosheets against dental caries through promoting mineralization of dentin tubules, pH buffering, and antibacterial

Dental caries is a worldwide public healthcare concern, and is closely related to the acidic environment that caused by bacterial decomposition of food. In this study, a two-step ion exchange liquid-phase stripping method was applied to strip out vermiculite (VMT) nanosheets, then amorphous calcium phosphate (ACP) and dextran were inserted between the VMT nanosheets interlayer to obtain a composite two-dimension nanosheets (VMT/ACP/Dextran). VMT/ACP/Dextran composite nanosheets exhibited excellent biocompatibility and could provide exogenous Ca2+and PO43- from ACP, provide SiO44-, Mg2+, Fe2+ and obtain buffering pH and antibacterial properties from VMT, as well as improve suspension stability and targeting Streptococcus mutans through glucan. The in vitro study showed that the composite materials could promote the mineralization and sealing of dentin tubules by releasing active ions, buffer pH 4.5 (a value close to the pH in the dental plaque environment) to pH 6.6-7.1 (values close to the pH in human saliva) through ion exchange, and exert antibacterial effects by targeting Streptococcus mutans and exerting oxidase like and peroxidase like activities to produce reactive oxygen species (ROS). The in vivo animal study showed that daily cleaning teeth using VMT/ACP/Dextran composite nanosheets could effectively reduce the incidence rate and severity of dental caries in rats. Taking together, the developed VMT/ACP/Dextran composite nanosheets, which integrated the excellent properties of VMT, ACP and dextran, can effectively prevent dental caries through a combination of factors such as buffering acids, antibacterial properties, and promoting calcification, and may be used as an active ingredient for daily oral hygiene or filling materials to prevent and treat dental caries.

Effects of light curing on silver diamine fluoride-treated carious lesions: A systematic review

OBJECTIVE

This systematic review aims to evaluate the potential benefits and underlying mechanisms of combining SDF with light curing, based on available studies.

MATERIALS AND METHODS

A systematic search of publications was conducted with the keywords "silver diamine fluoride" or "silver fluoride" and "dental light curing," "LED curing," "dental laser," and "dental polymerization" in 4 databases: PubMed, EBSCO, Scopus, and Google Scholar to identify English-language articles published up to March 2023. Duplicate publications were deleted. Two reviewers screened the titles and abstracts and excluded irrelevant publications. The full text of the remaining publications was retrieved. Studies investigating the effect of light-curing on SDF-treated carious lesions were included.

RESULTS

The 175 publications initially found included 5 laboratory studies investigating the effects of light curing on 38% SDF-treated dentine carious lesions, but no clinical study was found. Four of these studies were conducted on extracted primary teeth, and one was on extracted permanent teeth. SDF with light curing increased microhardness (n = 3, p < .05) showed a higher mineral density (n = 1, p < .041) and had more silver ion precipitation in infected dentine (n = 1, p < .016) compared to SDF without light curing. Moreover, no significant differences in the antibacterial activity were observed between SDF with light curing and SDF alone (n = 1, p > .05).

CONCLUSION

Drawing from the limited number of laboratory studies, incorporating light curing subsequent to the SDF application yields potential favorable outcomes that include augmented microhardness, elevated mineral density, and heightened silver ion precipitation within infected dentine. Future clinical research is required to confirm or refute the benefit of light curing on SDF-treated carious lesions.

The effect of silver diammine fluoride on In Vitro Enamel caries lesion remineralization and staining as a function of lesion baseline mineral distribution

OBJECTIVES

to investigate whether baseline mineral distribution modulates the ability of silver diammine fluoride (SDF) to remineralize and stain enamel caries lesions.

METHODS

This laboratory study followed a 3 [treatment: SDF/fluoride varnish (FV)/deionized water (DIW)] ×3 [lesion protocol: methylcellulose (MeC)/hydroxyethylcellulose (HEC)/Carbopol 907 (C907)] factorial design. Lesions were created in bovine enamel specimens (n = 20). Treatments were applied and lesions remineralized in artificial saliva. Digital transverse microradiography (TMR-D) was used to analyze lesions. Lesion color was monitored spectrophotometrically. The effects of lesion protocol and treatment on changes in lesion depth (ΔLD), mineral loss (ΔΔZ), maximum mineral density at the surface zone (ΔSZmax), and color changes related to remineralization (ΔL*remin) were analyzed using two-way ANOVA.

RESULTS

The treatment×lesion protocol interaction was significant for ΔΔZ (p < 0.01) and ΔL*remin (p < 0.01), however not for ΔLD (p = 0.23) or ΔSZmax (p = 0.91). There were no differences in ΔΔZ between treatments in HEC and C907 lesions. However, DIW resulted in more remineralization than both SDF (p < 0.01) and FV (p = 0.01) in MeC lesions. Considering changes from lesion baseline after remineralization in MeC lesions, SDF treatment resulted in the highest mineral gain in the surface zone. However, DIW revealed the highest mineral gain after remineralization in the lesion body. SDF stained lesions with the intensity increasing after remineralization in C907 lesions, whereas staining decreased in MeC and HEC lesions.

CONCLUSION

High fluoride treatments can interfere with continuous remineralization of caries lesions due to partial arrest. Baseline lesion mineral distribution affects SDF's ability to enhance remineralization and the staining caused by SDF.

CLINICAL SIGNIFICANCE

SDF is being used to arrest active caries lesions extending into dentin and to treat dentin hypersensitivity. This study shed light on SDF's effect on an isolated process in dental caries only, remineralization. It achieved this by examining enamel caries lesions with differing mineral distributions and assessing their staining properties.

Effect of Curing Light with Different Intensities on the Penetration of Silver and Fluoride Ions and Dentin Hardness in Primary Carious Molars Following Silver Diamine Fluoride Application: A Comparative Microscopic Ex Vivo Study

Background

A paradigm shift from surgical to medical approach for caries management has popularized silver diamine fluoride (SDF) as a preventive and interim caries arrest medicament. Few studies conducted have explored the effect of curing light on SDF's microbial property, its penetration, and effect on dentin. However, there is a research gap regarding the effect of different intensities of curing light on SDF performance.

Aim

To determine the effect of different curing light intensities on SDF penetration depth and dentin hardness in carious lesions of primary molars.

Materials and methods

Silver diamine fluoride was applied on 30 extracted carious primary molars. Teeth were randomly allocated into three groups-(1) control group, no light curing after application of SDF; (2) light curing of SDF with low intensity (1000 mW/cm2); and (3) light curing of SDF with high intensity (2500 mW/cm2). A scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis was performed to check ion penetration after 1 week, and a Vickers hardness test was used to assess dentin hardness of both infected and affected dentin layers at 1-week and 1-month intervals. Based on the distribution of data, parametric and nonparametric tests were applied. Statistical Package for the Social Sciences (SPSS) version 26 was used for statistical analysis. The level of significance was set at 5%.

Results

Silver diamine fluoride penetrated beyond the carious lesion in all three groups. The mean silver ion precipitation in infected dentin in group III (16.90 ± 0.68) was maximum, whereas it was found to be minimum in group II (7.31 ± 0.63). The mean fluoride ion precipitation in affected dentin in group III (4.06 ± 0.41) was highest and least in group II (3.09 ± 0.58). A considerable increase in mean dentin hardness of infected dentin was observed in all three groups (214.00 ± 89.06, 218.00 ± 75.17, 231.00 ± 98.86, respectively; p < 0.001) after 1 month.

Conclusion

Applying SDF to carious lesions using a high-intensity dental curing light induced more silver ion precipitation in infected dentin and increased its hardness.

How to cite this article

Bhatt R, Patel M, Thakkar A, et al. Effect of Curing Light with Different Intensities on the Penetration of Silver and Fluoride Ions and Dentin Hardness in Primary Carious Molars Following Silver Diamine Fluoride Application: A Comparative Microscopic Ex Vivo Study. Int J Clin Pediatr Dent 2024;17(7):766-772.

Permanent and decidua dentition as chronological biomarkers of heavy metal contamination: A review of the forensic literature

STATEMENT OF PROBLEM

Contamination with heavy metals (HM) has great environmental consequences in the environment due to lack of biodegradation, in addition, accumulation in living beings causes defects in tissues and organs, deteriorating their function and inducing a wide spectrum of diseases. Human biomonitoring consists of the periodic measurement of a certain chemical substance or metabolite in a particular population, using matrices that can be acute or chronic. Teeth are chronic matrices that have great characteristics of resistance and chronological storage of information. This review aims to identify the mechanisms, spatial location, and affinity of HM within teeth, along with understanding its applicability as a chronological record matrix in the face of HM contamination.

MATERIAL AND METHODS

A systematic search review was performed using the PubMed/Medline, Web of Science, and Scopus metasearch engines, and the terms "teeth" OR "dental" OR "tooth" AND "heavy metals" were intersected. Complete articles are included in Spanish, English and Portuguese without time restrictions, involving studies in humans or in vitro; Letters to the editor, editorials and those that did not refer to information on the incorporation and relationship of HM with the teeth were excluded.

RESULTS

837 published articles were detected, 91 were adjusted to the search objective, and 6 were manually included. Teeth are structures with a great capacity for information retention in the face of HM contamination due to low physiological turnover and their long processes of marked formations by developmental biorhythm milestones such as the neonatal line (temporal reference indicator). The contamination mechanisms inside the tooth are linked to the affinity of hydroxyapatite for HM; this incorporation can be in the soft matrix during the apposition phase or as part of the chemical exchanges between hydroxyapatite and the elements of the environment.

CONCLUSION

The teeth present unique characteristics of great resistance and affinity for HM, as well as a chronological biomarker for human biomonitoring, so they can be used as means of expertise or evidence to confirm or rule out a fact of environmental characteristics in the legal field.

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

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

Chemical kinetics of silver diammine fluoride in demineralization and remineralization solutions-an in vitro study

Introduction

Silver Diammine Fluoride (SDF) is a clinical minimal intervention to manage dentin caries. Its chemistry in demineralization conditions has been investigated widely, but far less in remineralization conditions. The aim was to investigate and compare the chemical reactions when SDF is added to remineralization and demineralization solutions.

Methods

0.01 ml SDF (Riva Star) was added to deionized water (DW); demineralization (DS = pH4) and remineralization (RS = pH7.0) solutions. The time sequence of concentrations of NH4+, F-, and Ag+ were measured using ion selective electrodes (ISEs) every 2 min. The pH was also measured. Precipitates were characterized using x-ray Diffraction (XRD) and, 31P and 19F nuclear magnetic resonance spectroscopy (NMR).

Results

The concentrations of NH4+ and Ag+ showed decreasing trends in DW (-0.12 and -0.08 mM/h respectively), and in DS (-1.06 and -0.5 mM/h respectively); with corresponding increase in F- concentration (0.04 and 0.7 mM/h respectively). However, in RS, NH4+ concentration showed little change (0.001 mM/h), and Ag+ and F- concentrations were negligible. XRD results showed that precipitates (in RS only) contained AgCl, and metallic Ag. NMR showed that fluorapatite/carbonated fluorapatite (FAP/CFAP) were formed. The pH increased after SDF addition in all three solutions.

Discussion

SDF dissolved to release NH4+, F- and Ag + . In DW and DS, NH4+ combined with Ag+ to form diamminesilver, causing an increase of F- and pH. In RS, F- reacted with Ca2+ and (PO)43- to form FAP/CFAP, and Ag+ reacted with Cl- to form AgCl/Ag. These suggests why SDF is effective in managing dentin caries.

Efficacy of 38% silver diamine fluoride in reducing gingival inflammation and plaque accumulation in older adults living in retirement-homes: A randomized controlled pilot trial

OBJECTIVES

Emerging from earlier case reports the potential benefits of 38 % silver diamine fluoride (SDF) in addressing pathogenic biofilms and mitigating gingival inflammation and enlargement have sparked interest. Our study aimed to evaluate the efficacy of 38 % SDF in reducing gingival inflammation and plaque accumulation in older adults living in retirement-homes.

METHODS

This 7-week randomized, controlled, double-blinded pilot trial employed a parallel assignment design. The study enrolled older adults (aged ≥65) residing in retirement homes in Dallas County, ultimately comprising a cohort of 40 participants who were evenly divided into two arms. The experimental group received SDF treatment, whereas the comparator group received a placebo. Over three consecutive weeks, both groups had solutions applied to the facial surfaces of all their teeth once per week. The primary outcomes measured the change in Löe-Silness Gingival Index (GI) and Silness-Löe Plaque Index (PI) at 7 weeks following baseline treatment. Repeated measures ANOVA was utilized to assess changes over time within each group (n = 15 each). Post-hoc paired t-tests were conducted to compare changes between week 1 and each subsequent follow-up time point (weeks 3, 5, 7), supplemented with 95 % confidence intervals for change from week 1.

RESULTS

In the SDF group, within-group comparisons demonstrated significant reductions (adjusted p < .05) in GI scores within 3 weeks (-.93±.37), as opposed to week 1 (1.90±.39). Between-group comparisons unveiled reductions in both mean GI (p < .05) and PI (p < .05), indicating less gingival inflammation and plaque accumulation in the SDF group at all time points, commencing at week 3.

CONCLUSIONS

This study showed that 38 % SDF was effective in reducing gingival inflammation and plaque accumulation in older adults living in retirement-homes.

CLINICAL SIGNIFICANCE

Oral health in older adults is a public health concern, especially for the medically compromised or those without traditional care. Our findings offer hope for enhancing oral health quality of life by introducing a cost-effective, compliance-free, noninvasive, and accessible therapeutic.

TRIAL REGISTRATION

NCT03445286.(clinicaltrials.gov).

Silver Compounds for Caries Management

Silver metal and compounds have antibacterial properties, although their action's mechanisms are not fully understood. Scientists generally consider that silver disrupts the bacterial cell wall. It causes a structural change in the bacterial cell membrane and cytoplasm. It also stops deoxyribonucleic acid replication, resulting in inactivating enzymatic activity and cell death. The antimicrobial effect of silver-containing compounds relies on the release of bioactive silver ions. Hence, silver metal and compounds have been used in medicine to prevent infection for hundreds of years. Silver metal and compounds are also used as antibacterial agents in dentistry. Studies have shown that silver compounds are effective in the management of dental caries. Fluoride-containing silver compounds have been found in experiments to be beneficial at remineralising dental cavities. Silver diamine fluoride (SDF) can assist in preventing and arresting tooth cavities. The World Health Organization included SDF in its Model List of Essential Medicine for both adults and children in 2021. Clinicians also use SDF to manage dentine hypersensitivity as well as to inhibit growth of periodontal pathogens. However, traditional silver compounds cause tooth discolouration because of the silver-staining effect. These side effects of their applications depend on the amount applied and the frequency of application. Researchers are developing nanosilver fluoride and silver nanoparticles to overcome the staining. This review gives an overview of the antibacterial mechanism of silver compounds, namely silver nitrate, silver fluoride, SDF, silver nanoparticles, and nano silver fluoride for caries management. The outlook for the future development of silver compounds will be discussed.

Effect of light curing on the efficacy of silver diamine fluoride: A systematic review

Objective

This study was aimed at comparing the performance of light-cured (LC) silver diamine fluoride (SDF) to non-LC SDF in dental applications, in terms of various properties.

Methods

Articles published until April 2023 were retrieved from electronic databases (PubMed, Scopus and Science Direct) according to Boolean operators, and the reference lists of the included articles were manually searched. The included articles were all full-text, original studies in English that assessed the effects of LC SDF compared with SDF alone. The risk of bias in the in vitro studies on dental materials was evaluated with the modified Consolidated Standards of Reporting Trials (CONSORT) checklist.

Results

Six studies (five in vitro and one ex vivo) were included in qualitative analysis after a comprehensive manual search and electronic database search. Every study compared LC SDF versus non-LC SDF in terms of properties such as penetration depth, silver ion precipitation, dentine hardness, surface morphology and anti-bacterial characteristics. Four studies were categorised as low quality with a high risk of bias, whereas the remaining two studies were considered high quality with a low risk of bias.

Conclusion

In this investigation, LC SDF, compared with non-LC SDF, was found to be an efficacious approach for enhancing SDF properties. Future high-quality studies, particularly randomised clinical trials, remain necessary to verify these findings.

Clinical significance

The use of light curing with SDF can be a beneficial strategy that enhances SDF's clinical use. This review comparing various properties of LC SDF and non-LC SDF may help clinicians enhance clinical use and patient acceptance of LC SDF.

The Evolving Microbiome of Dental Caries

Dental caries is a significant oral and public health problem worldwide, especially in low-income populations. The risk of dental caries increases with frequent intake of dietary carbohydrates, including sugars, leading to increased acidity and disruption of the symbiotic diverse and complex microbial community of health. Excess acid production leads to a dysbiotic shift in the bacterial biofilm composition, demineralization of tooth structure, and cavities. Highly acidic and acid-tolerant species associated with caries include Streptococcus mutans, Lactobacillus, Actinomyces, Bifidobacterium, and Scardovia species. The differences in microbiotas depend on tooth site, extent of carious lesions, and rate of disease progression. Metagenomics and metatranscriptomics not only reveal the structure and genetic potential of the caries-associated microbiome, but, more importantly, capture the genetic makeup of the metabolically active microbiome in lesion sites. Due to its multifactorial nature, caries has been difficult to prevent. The use of topical fluoride has had a significant impact on reducing caries in clinical settings, but the approach is costly; the results are less sustainable for high-caries-risk individuals, especially children. Developing treatment regimens that specifically target S. mutans and other acidogenic bacteria, such as using nanoparticles, show promise in altering the cariogenic microbiome, thereby combatting the disease.

Penetration of SDF and AgF from the infected dentine towards the unaffected tooth structure

Background

The use of SEM-EDS line scan analysis to evaluate the movement of ions from dental materials towards the tooth structure and the concept of ion movement is well established. This analysis technique was used to determine the ion movement of two commercially available silver- and fluoride-containing products.

Methods

This study aimed to compare the elemental analysis of primary molar teeth treated with silver diamine fluoride (SDF) and water-based silver fluoride (AgF) and to analyse the penetration of SDF and AgF from the infected dentine towards the healthy dentine. The teeth were cleaned from debris and contaminants off the roots and stored until use. A total of 15 primary molars with large active cavitated lesions, not extending into the pulp (specimens), were divided into three test groups: silver diamine fluoride (SDF) (n = 5), water-based silver fluoride (AgF) (n = 5), and deionised water (W) (n = 5) as the control group. The teeth were sectioned, embedded, and received SEM-EDS line scans. The line scan had a total length of 82.65 μm. The visible end of the infected dentine and the start of the more affected dentine were chosen as the starting point to ensure that the infected caries' line distribution towards the affected dentine's transition area was as standardized as possible. Therefore, the infected dentine length of the scan was 22.80 μm (8 scan points of 2.85 μm apart), and the affected dentine, including the healthy dentine, was 59.8 μm (21 scan points). The SEM-EDS line scan from each specimen determined the average fluoride, iodide, and silver weight percentage for that specimen.

Results

The 15 sample SEM-EDS line scans were used to determine the average ion movement in wt%. The Kruskall-Wallis test and Tukey's HSD test were completed at a p < 0.05. SDF and AgF presented no significant fluoride movement in terms of the weight percentage. There was, however, significantly more fluoride movement from infected caries to the healthy dentine with SDF and AgF (p = 0.0010053) compared to the control specimens treated with deionised water. There was no significant difference between SDF and AgF for the movement of the iodide (p = 0.5953) and silver (p = 0.3708) from infected caries to the healthy dentine.

Conclusion

SDF and AgF easily penetrated through infected caries and affected tooth structure to the healthy dentine for the line scan of 82.65 μm. There was no significant difference between SDF and AgF for the movement of ions within the infected dentine nor in the affected/healthy dentine.

Pulp cell response to the application of silver diamine fluoride and potassium iodide on caries-like demineralized dentin

OBJECTIVES

To investigate the response of pulp cells to the application of silver diamine fluoride (SDF) and potassium iodide (KI) on demineralized dentin.

MATERIALS AND METHODS

The occlusal surfaces of human dentin discs (0.4 mm thick) with similar permeability were subjected to an artificial caries protocol, and then the discs were adapted into artificial pulp chambers. MDPC-23 cells were seeded on the healthy pulp dentin surface, while the demineralized surface was treated with SDF, KI, SDF + KI, or hydrogen peroxide (positive control-PC) (n = 8). The negative control (NC) received ultrapure water. After 24 h, cell viability (alamarBlue) and morphology (SEM) were evaluated. The extracts were then applied to new MDPC-23 cells seeded in culture plates to assess their viability and the formation of mineralized nodules (MN; Alizarin Red) after seven days. The data were analyzed using one-way analysis of variance/Tukey or Games-Howell tests (α = 5%).

RESULTS

SDF and PC significantly reduced the viability of cells seeded on discs (45.6% and 71.0%, respectively). Only cells treated with SDF or PC detached from the dentin substrate, while the remaining cells showed altered morphology. Cells in contact with extracts showed less reduction in viability, but it was still more toxic compared to NC. Only PC reduced MN deposition. SDF + KI or KI alone did not affect the cell response.

CONCLUSIONS

SDF applied alone showed a mild to moderate transdentinal cytotoxic effect on pulp cells. However, the combination of SDF + KI reduced the cytotoxic effects. Both materials used alone or in combination did not affect the mineralization ability of pulp cells.

CLINICAL RELEVANCE

Besides improving esthetic results, associating potassium iodide with silver diamine fluoride may reduce the transdentinal cytotoxic effects of this cariostatic agent on pulp cells.

Application of 20% silver nanoclusters in polymethacrylic acid on simulated dentin caries; its penetration depth and effect on surface hardness

The aims of this study were: To evaluate the surface hardness of simulated dentin caries lesions treated with either silver nanoclusters (AgNCls) synthesized in polymethacrylic acid (PMAA) or 38% silver diammine fluoride (SDF), as well as observe the penetration of the treatment solutions into the simulated caries lesions. Dentin blocks 4 mm thick obtained from caries-free third molars were sectioned and then simulated caries lesions on the occlusal dentin surfaces were created. Each specimen (n = 8) was divided into four sections: (A) treated with 20% AgNCls/PMAA; (B) treated with SDF 38% (FAgamin, Tedequim, Cordoba, Argentina); (C) sound tooth protected by nail-varnish during artificial caries generation (positive control); and (D) artificial caries lesion without surface treatment (negative control). AgNCls/PMAA or SDF were applied on the simulated lesions with a microbrush for 10 s, then excess removed. The surface hardness was measured by means of Vickers indentation test. To trace the depth of penetration, up to 400 μm, of silver ions, elemental composition of the samples was observed using EDX, coupled with SEM, and measured every 50 μm from the surface towards the pulp chamber. Laser Induced Breakdown Spectroscopy (LIBS) was also employed to trace silver ion penetration; the atomic silver line 328.06 nm was used with a 60 μm laser spot size to a depth of 240 μm. Student's-t test identified significant differences between treatment groups for each depth and the Bonferroni test was used for statistical analysis of all groups (p < 0.05). Mean surface hardness values obtained were 111.2 MPa, 72.3 MPa, 103.3 MPa and 50.5 MPa for groups A, B, C and D respectively. There was a significant difference between groups A and C compared with groups B and D, the group treated with AgNCls/PMAA achieved the highest surface hardness, similar or higher than the sound dentin control. A constant presence of silver was observed throughout the depth of the sample for group A, while group B showed a peak concentration of silver at the surface with a significant drop beyond 50 μm. The 20% AgNCls/PMAA solution applied to simulated dentin caries lesions achieved the recovery of surface hardness equivalent to sound dentin with the penetration of silver ions throughout the depth of the lesion.

Effects of silver diamine fluoride on demineralization protection after a secondary acid challenge

OBJECTIVE

This investigation describes the effects of 5% sodium fluoride varnish and 38% silver diamine fluoride on demineralization protection of human enamel lesions of three different severities after a secondary acid challenge.

STUDY DESIGN

Specimens underwent color and enamel surface microhardness change measurements after demineralization and treatment events. Transverse microradiography was conducted following the secondary demineralization.

RESULTS

After treatments, enamel surface microhardness change showed that 24-hour lesions treated with fluoride varnish had less rehardening than 24-hour lesions treated with silver diamine fluoride (p<0.05), whereas 144-hour lesions from both treatment groups showed a beneficial decrease in surface microhardness change that was markedly better in samples treated with silver diamine fluoride (p<0.05). After the secondary demineralization, 24- and 144-hour lesions treated with silver diamine fluoride showed a sustained beneficial decrease in enamel surface microhardness change when compared to fluoride varnish-treated samples of the corresponding lesion severity (p<0.05). Transverse microradiography showed no difference between fluoride varnish- and silver diamine fluoride-treated samples of any corresponding lesion severity, indicating that remineralization in both fluoride varnish- and silver diamine fluoride-treated samples was proportional to each other after a secondary acid challenge.

CONCLUSIONS

Using silver diamine fluoride may have comparable benefits to fluoride varnish in mineral loss prevention.

Effect of silver diamine fluoride activation on bond strength to root dentin

BACKGROUND

To investigate the effect of silver diamine fluoride (SDF) application and activation on the bond strength of gutta-percha to dentin and resin bonded post to dentin.

METHODS

Thirty-six human premolar teeth were used. The coronal part tooth was removed, and endodontic mechanical preparation was performed for all the teeth. The teeth were divided according to final rinse protocol (n = 9) as follows: Control group; no SDF application, SDF/NA; 38% SDF as a final rinse with no activation, SDF/MDA; 38% SDF as a final rinse with manual dynamic activation and SDF/US; 38% SDF as a final rinse with ultrasonic activation. Root canal obturation using lateral condensation technique followed by fiber post insertion after 48 h in the root canal after corresponding preparations. The roots were cut with a low-speed precision saw creating 2 mm thickness sections. A total of 4 sections were obtained from each tooth, 2 coronal specimens (with post) and 2 apical specimens (with Gutta percha). Each specimen was subjected to push-out bond strength test with a universal testing machine. Data were analyzed using two-way ANOVA.

RESULTS

The Push-out bond strength at the apical root section was significantly higher in SDF/MDA and SDF/US groups compared to control group. While for the coronal part, all SDF treated specimen showed reduced Push-out bond strength.

CONCLUSION

SDF application as final rinse may reduce the bonding performance between fiber post and dentine. Activation with manual and ultrasonic methods improved the bond strength at the apical root section.

Nano-CT characterization of dentinal tubule occlusion in SDF-treated dentin

Dentin hypersensitivity is an oral health concern affecting a large percentage of the world's adult population. Occlusion of the exposed dentinal tubules is among the treatment options available, and silver diammine fluoride (SDF) is an occluding agent used for interrupting or dampening the stimulus of the dental pulp nerves that produce pain. In addition to dentin permeability testing, the evaluation of desensitizing agents occluding dentinal tubules strongly relies on microscopic techniques, such as scanning electron microscopy (SEM). Limitations of SEM are that it provides only surface images that lack detailed information on the depth of penetration and amount of material present within the treated specimen, and it is prone to sample preparation artifacts. Here, we present high-resolution X-ray computed tomography (nano-CT) as a potential method for investigating dentin specimens with occluded tubules. We studied human dentin treated with SDF as an exemplary dentinal occlusion treatment option. We evaluated the silver deposits formed on the dentin surface region near the dentinal tubules and in the tubular regions using cross-section SEM, Energy Dispersive X-ray (EDX) analysis, and nano-CT. The resulting images obtained by SEM and nano-CT had comparable resolutions, and both techniques produced images of the tubules' occlusion. Nano-CT provided three-dimensional images adequate to quantitate tubule size and orientation in space. Moreover, it enabled clear visualization of dentinal tubules in any virtual plane and estimation of the amount and depth of occluding material. Thus, nano-CT has the potential to be a valuable technique for evaluating the occluding effects of virtually any material applied to dentinal tubules, supporting deciding between the best occluding treatment options.

Engineered Biomaterials Trigger Remineralization and Antimicrobial Effects for Dental Caries Restoration

Dental caries is the most prevalent chronic disease globally, significantly impacting individuals' quality of life. A key reason behind the failure of implanted restorations is their biological inactivity, meaning they are unable to form crosslinks with the surrounding tooth structures, thus making patients susceptible to implant loss and recurrent tooth decay. For the treatment of caries, antibacterial medicine and remineralization are effective means of treating the recurrence of caries. Owing to the rapid progression in the biomaterials field, several biomaterials have been reported to display antimicrobial properties and aid in dentin remineralization. Bioactive materials hold considerable potential in diminishing biofilm accumulation, inhibiting the process of demineralization, enabling dentin remineralization, and combating bacteria related to caries. Bioactive materials, such as fluoride, amorphous calcium phosphate, bioactive glass, collagen, and resin-based materials, have demonstrated their effectiveness in promoting dentin remineralization and exerting antibacterial effects on dental caries. However, the concentration of fluoride needs to be strictly controlled. Although amorphous calcium phosphate can provide the necessary calcium and phosphorus ions for remineralization, it falls short in delivering the mechanical strength required for oral mastication. Resin-based materials also offer different advantages due to the complexity of their design. In this review, we delve into the application of advanced bioactive materials for enhancing dentin remineralization and antibacterial properties. We eagerly anticipate future developments in bioactive materials for the treatment of dental caries.

Bonding performance of glass ionomer cement to carious dentin treated with different surface treatment protocols using silver diamine fluoride

This study investigated the influence of silver diamine fluoride (SDF) on the shear bond strength (SBS) to artificial carious dentin and GIC restorations with various SDF application protocols. Artificial caries were prepared on human dentin discs using bacteria model. These samples were randomly allocated to five groups (n = 10/group) according to the following treatment: (1) control group (CD): no treatment (2) CSR: dentin conditioner, SDF, and rinsing (3) CS: dentin conditioner and SDF (4) SRC: SDF, rinsing and dentin conditioner, and (5) SC: SDF and dentin conditioner. The treated-dentin surface was bonded with GIC and subjected to SBS test. Mean SBS was analyzed using one-way ANOVA. Surface morphology and elemental contents after surface treatment were examined (n = 3/group) by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX). There was no significant difference in the mean SBS among CD (2.45 ± 0.99 MPa), CSR (1.76 ± 0.65 MPa), and SRC (2.64 ± 0.95 MPa). Meanwhile, the mean SBS of CS (0.35 ± 0.21 MPa) was significantly lower than the control and SRC group. SEM/EDX demonstrated deeper silver penetration in CSR and CS groups when compared to SRC and SC groups. SDF-modified GIC restorations resulted in significantly lower bond strength in CS and SC groups. The findings suggested treating the carious dentin surface with CSR and SRC protocol. SDF-treated carious dentin should be rinsed off prior to restore with GIC.

Caries arrest using silver diamine fluoride: Knowledge, attitude, and perception of parents in Saudi Arabia

Objectives

The objective was to assess the current knowledge, attitudes, and perceptions of parents toward the use of Silver Diamine Fluoride in children's primary teeth and identify related factors.

Materials and Methods

In this cross-sectional study, data were collected from Parents of pediatric patients who had appointments at the King Saud University Pediatric Dentistry Clinic and several private clinics in Riyadh, Saudi Arabia from Jan to April 2021. A simple random sampling method was used. An electronic questionnaire was designed to collect data regarding participants' demographics and their knowledge, attitude, and perception toward the use of SDF for their children.

Results

A higher proportion of parents/relatives (87.3%) was strongly satisfied with the speed of treatment and its benefits. In terms of disadvantages, 23.8% and 30.4% of the parents/relatives were satisfied and dissatisfied, respectively (P < 0.05). Regarding attitudes, the majority of participants 22.8% responded as neutral to using SDF to treat their children's anterior primary teeth (P < 0.05), whereas 32.2% agreed to the use of SDF in their children's posterior primary teeth (P < 0.05). A higher proportion of parents/relatives who were in the age group of >50 years (27.8%) had responded as "satisfied" compared with the responses of other age groups (P < 0.05).

Conclusion

The present study demonstrates that SDF is acceptable among Saudi parents/relatives to arrest dental caries. However, pigmentation of anterior teeth is a major concern.

Comparative Evaluation of the Remineralizing Potential of Silver Diamine Fluoride, Casein Phosphopeptide-amorphous Calcium Phosphate, and Fluoride Varnish on the Enamel Surface of Primary and Permanent Teeth: An In Vitro Study

Introduction

With the paradigm shift in the management of dental caries, the focus is now laid on remineralization therapies that can arrest the progression of the disease and remineralize the subsurface lesions.

Objectives

The purpose of this study was to determine and compare the remineralizing potential of silver diamine fluoride (SDF), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), and fluoride varnish (FV) on enamel surfaces in primary and permanent teeth.

Materials and methods

A total of 120 primary anterior teeth and 120 premolars were used to prepare enamel blocks in acrylic resin. The mean baseline surface microhardness (SMH) for each sample was determined using a microvickers hardness testing machine. Thereafter, the samples were randomly and equally distributed into groups and subgroups based on the materials used, that is, SDF, CPP-ACP, FV, and distilled water (control). After subjecting the samples to a pH cycling regime, SMH was determined again and the percentage change in SMH was calculated.

Results

The data were tabulated and subjected to statistical analysis using an independent t-test and one-way analysis of variance (ANOVA). In primary teeth, the least mean percentage reduction in SMH was observed after the application of FV followed by SDF, CPP-ACP, and control. In permanent teeth, both SDF and FV showed the least percentage reduction of enamel SMH followed by CPP-ACP and control.

Conclusion

Silver diamine fluoride (SDF), FV, and CPP-ACP showed remineralizing potential in both primary and permanent teeth.

How to cite this article

Kaur S, Bhola M, Bajaj N, et al. Comparative Evaluation of the Remineralizing Potential of Silver Diamine Fluoride, Casein Phosphopeptide-amorphous Calcium Phosphate, and Fluoride Varnish on the Enamel Surface of Primary and Permanent Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(S-1):S91-S96.

Effect of silver diamine fluoride upon the microbial community of carious lesions: A scoping review

OBJECTIVES

To explore the effects of silver diamine fluoride (SDF) on the microbial community of carious lesions.

DATA

Original studies evaluating the effect of SDF treatment on the microbial community of human carious lesions were included.

SOURCES

A systematic search of English-language publications was performed in PubMed, EMBASE, Scopus, and Web of Science. Gray literature was searched in ClinicalTrials.gov and Google Scholar.

STUDY SELECTION/RESULTS

This review included seven publications reporting the effects of SDF on microbial community of dental plaque or carious dentin, including the microbial biodiversity, relative abundance of microbial taxa, and predicted functional pathways of the microbial community. The studies on microbial community of dental plaque reported that SDF did not have a significant effect on both the within-community species diversity (alpha-diversity) and inter-community microbial compositional dissimilarity (beta-diversity) of the plaque microbial communities. However, SDF changed the relative abundance of 29 bacterial species of plaque community, inhibited carbohydrate transportation and interfered with the metabolic functions of the plaque microbial community. A study on the microbial community in dentin carious lesions reported that SDF affected its beta-diversity and changed the relative abundance of 14 bacterial species.

CONCLUSION

SDF showed no significant effects on the biodiversity of the plaque microbial community but changed the beta-diversity of the carious dentin microbial community. SDF could change the relative abundance of certain bacterial species in the dental plaque and the carious dentin. SDF could also affect the predicted functional pathways of the microbial community.

CLINICAL SIGNIFICANCE

This review provided comprehensive evidence on the potential effect of SDF treatment on the microbial community of carious lesions.

Remineralization potential of phosphorylated chitosan and silver diamine fluoride in comparison to sodium fluoride varnish: invitro study

PURPOSE

The purpose of this study was to evaluate and compare the remineralization potential of phosphorylated chitosan nanoparticles (Pchi) and silver diamine fluoride (SDF) compared to sodium fluoride varnish (NaF) on microhardness of artificial carious lesions in a biomimetic minimally invasive approach that is being regarded as the future of preventive dentistry.

METHODS

The sample size included 40 intact extracted maxillary anterior human teeth. Baseline microhardness was recorded using Vickers hardness test and energy-dispersive X-ray spectroscopy (EDX). Artificial caries-like lesions were created on the exposed enamel by suspending all teeth in demineralizing solution for 10 days in a temperature of 37 °C and then the hardness and EDX were remeasured. Samples were then divided into four main groups: Group A (positive control group) n = 10, treated with NaF, Group B n = 10, treated with SDF, Group C n = 10, treated with Pchi and Group D (negative control group) n = 10 that received no treatment. After treatment, samples were incubated in artificial saliva solution at 37 °C in for 10 days and then reassessed. Data were then recorded, tabulated, and statistically analyzed using Kruskal-Wallis test and Wilcoxon signed test. Scanning electron microscope (SEM) was used to analyze the morphological changes of enamel surface after treatment.

RESULTS

Groups B and C showed the highest calcium (Ca) and phosphate (P) content as well as hardness values, while group B had the highest percentage of fluoride. SEM revealed a smooth layer of mineral formed on the surface of enamel for both groups.

CONCLUSION

Pchi and SDF showed the highest increase in enamel microhardness and remineralization potential.

CLINICAL RELEVANCE

The minimally invasive approach for remineralization could be enhanced using SDF and Pchi.

Novel bioactive dental restorations to inhibit secondary caries in enamel and dentin under oral biofilms

OBJECTIVE

To provide the first review on cutting-edge research on the development of new bioactive restorations to inhibit secondary caries in enamel and dentin under biofilms. State-of-the-art bioactive and therapeutic materials design, structure-property relationships, performance and efficacies in oral biofilm models.

DATA, SOURCES AND STUDY SELECTION

Researches on development and assessment new secondary caries inhibition restorations via in vitro and in vivo biofilm-based secondary caries models were included. The search of articles was carried out in Web of Science, PubMed, Medline and Scopus.

CONCLUSIONS

Based on the found articles, novel bioactive materials are divided into different categories according to their remineralization and antibacterial biofunctions. In vitro and in vivo biofilm-based secondary caries models are effective way of evaluating the materials efficacies. However, new intelligent and pH-responsive materials were still urgent need. And the materials evaluation should be performed via more clinical relevant biofilm-based secondary caries models.

CLINICAL SIGNIFICANCE

Secondary caries is a primary reason for dental restoration failures. Biofilms produce acids, causing demineralization and secondary caries. To inhibit dental caries and improve the health and quality of life for millions of people, it is necessary to summarize the present state of technologies and new advances in dental biomaterials for preventing secondary caries and protecting tooth structures against oral biofilm attacks. In addition, suggestions for future studies are provided.

Time-dependent structural changes and hypermineralisation of artificially demineralised dentine following treatment with silver diammine fluoride and glass ionomer cement

OBJECTIVES

This study aimed to evaluate the change of mineral content in dentine lesions over time and examine the effectiveness of the combined treatment with silver diammine fluoride (SDF) and glass ionomer cement (GIC).

METHODS

Sixty bovine dentine specimens were divided into 4 groups: cont, Fuji, Safo, and Safo+Fuji. The specimens were imaged and measured using microcomputed tomography (microCT) at 7 time points: pre-demineralisation, after demineralisation for two weeks, immediately after treatment, 1 week, 2 weeks, 1 month, and 3 months after treatment. The 3-month group was evaluated with a light microscope, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and scanning electron microscope (SEM)/energy-dispersive X-ray spectroscopy (EDS). Data were analysed by Dunn's test and Wilcoxon signed rank test with Bonferroni correction for microCT, and Kruskal-Wallis test and two-way analysis of variance for EDS characterisation.

RESULTS

MicroCT images showed high mineral density beneath dentine lesions in Safo+Fuji. The mineral density at 600 μm in Safo+Fuji increased significantly over time, while Safo showed an opposite trend (adjusted p<0.005). In Safo+Fuji, EDS revealed significantly high energy of fluorine (p<0.05, at 300 μm) and a tendency towards high energy of calcium (p>0.05). However, Safo+Fuji showed lower energy of silver compared to Safo (p<0.001). ATR-FTIR revealed that phosphate groups had the highest peak at a depth between 300 and 400 μm in Safo+Fuji.

CONCLUSIONS

Safo+Fuji was effective in remineralising the deep lesion in dentine after one and three months, and a hypermineralisation zone generated beneath the lesion demonstrated additional benefit in this study.

CLINICAL SIGNIFICANCE

This long-term in vitro study showed that SDF+GIC treatment could strengthen the structure of decayed teeth when applied in the treatment of patients with advanced rampant caries.

Enhanced effectiveness of silver diamine fluoride application with light curing on natural dentin carious lesions: an in vitro study

This study aimed to compare the mean mineral density difference (mMDD) and surface morphology of 10- and 60-s silver diamine fluoride (SDF)-applied dentin carious lesions and to study the effect of an additional 20-s light curing (LC) on SDF-treated teeth. Forty primary molar blocks with natural dentin carious lesions were measured for baseline lesion depth and mineral density using Image-Pro Plus software. The samples were randomly distributed into 4 groups; 38% SDF applied for 1) 10-s (10SDF), 2) 60-s (60SDF), 3) 10-s + LC (10SDF + LC), 4) 60-s + LC (60SDF + LC) and an additional control group to assess the outcome of pH-cycling only. Then all the groups underwent a 7-d bacterial pH-cycling. The dentin carious lesions' mMDD was determined by digital subtraction radiographic analysis. The surface morphology and elemental profile were assessed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The mMDD of the dentin lesions was analyzed using two-way ANOVA, generalized linear models analysis. Light curing was the only factor that affected the mMDD (p = 0.007). The mMDD in the 10SDF + LC and 60SDF + LC groups were significantly higher than those without light curing (p = 0.041 and 0.041, respectively). The 60SDF + LC group demonstrated a significantly higher mMDD than the 10SDF group (p = 0.010), while that in the 10SDF + LC group was similar to the 60SDF group (p = 1.00). Scanning electron microscopy revealed denser mineral content layers, which were likely silver and chloride, in the 10SDF + LC and 60SDF + LC groups than in the 10SDF and 60SDF groups, respectively. In conclusion, shortened application time with light curing enhanced SDF remineralization similarly to the conventional method.

Mussel-Inspired Caries Management Strategy: Constructing a Tribioactive Tooth Surface with Remineralization, Antibiofilm, and Anti-inflammation Activity

Dental caries is a common chronic oral disease in humans resulting from tooth demineralization caused by acid production of bacterial plaque, which leads to the destruction of enamel and dentin and oral inflammation. However, it is still a challenge that the function of natural active ingredients in currently available oral care products is not comprehensive, especially the lack of remineralization. Here, inspired by the strong biological adhesion ability of mussels and ancient oral disease plant therapy, a multifunctional strategy is proposed to construct a bioactive tooth surface to treat dental caries. It has been demonstrated that the Turkish gall extract (TGE) can inhibit adhesion of cariogenic bacteria Streptococcus mutans and Actinomyces viscosus and destroy biofilms on the tooth surface. Meanwhile, TGE can reduce the expression of inflammatory factors. Notably, the TGE coating can induce the growth of hydroxyapatite (HAP) crystals in vivo and in vitro, recovering the enamel mechanical properties under normal oral conditions. MD simulations interpreted the adsorption mechanism by which the hydroxyl groups in TGE bind to phosphate group (PO₄^3-) on the tooth surface, attracting calcium ions (Ca²⁺) as nucleation sites for remineralization. This work underlines the importance of TGE coating in remineralization, antibiofilm, and anti-inflammation activity as a promising strategy for dental caries.

Older patients' perception of treating root caries with silver diamine fluoride - a qualitative study based on the Theoretical Domains Framework

OBJECTIVES

Caries treatment with silver diamine fluoride (SDF) is effective, but often leads to irreversible tooth discoloration. This study aimed to investigate older patients' perceptions of root caries treatment with SDF and to identify factors that influence their decision process.

METHODS

Fifteen interviews were conducted in older patients (mean, min/max: 83, 71/92 years) with root caries experience, following a semi-structured interview-guide based on the domains of the Theoretical Domains Framework (TDF) including three case vignettes of SDF treatment. Transcripts of the interviews were used to perform deductive and inductive content analysis along the TDF and Capability-Opportunity-Motivation-Behavior model (COM-B) to assess influential factors.

RESULTS

All TDF domains and behavior determinants of the COM-B were covered, identifying twenty-two barriers, facilitators and conflicting themes. Main barriers for consenting to SDF treatment were patients' perceptions of permanent staining of visible root caries lesions, as well as preconceptions about those of others and lack of knowledge about root caries and SDF. Main facilitators were trust in advice given by dentists, especially regarding new treatment options, that aesthetics were less important in non-visible areas and the importance of tooth preservation and feasibility of treatments when immobile or in need of care.

CONCLUSION

Permanent discoloration is an important barrier to older patients' acceptance of SDF treatment for visible root caries. However, patients appear to accept SDF treatment under certain conditions, including less visible lesions or in comparison to more invasive treatment options.

CLINICAL SIGNIFICANCE

Our findings contribute to understanding both barriers and facilitators when treating root caries in older patients with SDF.

Bioactive Materials for Caries Management: A Literature Review

Researchers have developed novel bioactive materials for caries management. Many clinicians also favour these materials, which fit their contemporary practice philosophy of using the medical model of caries management and minimally invasive dentistry. Although there is no consensus on the definition of bioactive materials, bioactive materials in cariology are generally considered to be those that can form hydroxyapatite crystals on the tooth surface. Common bioactive materials include fluoride-based materials, calcium- and phosphate-based materials, graphene-based materials, metal and metal-oxide nanomaterials and peptide-based materials. Silver diamine fluoride (SDF) is a fluoride-based material containing silver; silver is antibacterial and fluoride promotes remineralisation. Casein phosphopeptide-amorphous calcium phosphate is a calcium- and phosphate-based material that can be added to toothpaste and chewing gum for caries prevention. Researchers use graphene-based materials and metal or metal-oxide nanomaterials as anticaries agents. Graphene-based materials, such as graphene oxide-silver, have antibacterial and mineralising properties. Metal and metal-oxide nanomaterials, such as silver and copper oxide, are antimicrobial. Incorporating mineralising materials could introduce remineralising properties to metallic nanoparticles. Researchers have also developed antimicrobial peptides with mineralising properties for caries prevention. The purpose of this literature review is to provide an overview of current bioactive materials for caries management.