Antimicrobial efficacy of 3.8% silver diamine fluoride and its effect on root dentin

Effect of Silver Diamine Fluoride on Bonding Performance and Ultra-morphological Characteristics to Sound Dentin

OBJECTIVES

This study aimed to evaluate microtensile bond strength (µTBS) and ultra-morphological characteristic changes in sound dentin resulting from silver diamine fluoride (SDF) when using adhesives.

METHODS

Ninety-six extracted human third molars were divided into the SDF-contaminated dentin group and the sound dentin group. In the SDF-contaminated dentin group, 38% SDF was agitated for 1 min, left undisturbed for 2 min, and rinsed with distilled water for 30 s. Then, each group was further subdivided into six subgroups (n = 8 / group) according to application modes: self-etch mode (SE) and etch-and-rinse mode (ER) followed by three adhesives: (1) Scothbond Universal Plus Adhesive (SUP); (2) G2-Bond Universal Adhesive (G2B); and (3) Clearfil Mega Bond 2 (MB2). All specimens were restored with resin composite and were stored in distilled water for 24 h before μTBS testing. Data from the μTBS test were analyzed using Three-way ANOVA and Duncan test (p < 0.05). The morphology of fractured surface and adhesive-dentin interfaces were evaluated by SEM, TEM, and STEM. Further elemental analysis was done by EDX.

RESULTS

All SDF-contaminated dentin groups demonstrated significantly lower μTBS than sound dentin groups. All ER groups had higher μTBS than SE groups, except for G2B in the sound dentin group. STEM/EDX revealed an SDF-dentin-reacted layer in the SDF-contaminated dentin group.

SIGNIFICANCE

SDF had an adverse effect on adhesives. Additionally, ER mode is preferable when bonded to SDF-contaminated dentin. A calcium and fluoride-contained layer was observed in all SDF-contaminated dentin.

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.

Evaluation of cytotoxicity of 3.8 % SDF and BioAKT solutions on the viability of dental pulp stem cells

Introduction

Nonsurgical endodontic therapies have evolved from classic endodontic therapies to regenerative endodontic treatments (RETs) in recent years. In context of the cytotoxic activity of the most commonly used endodontic irrigant, NaOCl, newer endodontic irrigating solutions should be tested for its effective use in RETs. The aim of this trial was to examine and assess the cytotoxic response of 3.8 % SDF and BioAKT irrigating solutions on the viability of DPSCs.

Methods

The viability of DPSCs cultivated in 5.25 % NaOCl, 3.8 % SDF & BioAKT at dilutions of 1:100,1:20 &1:10 were evaluated through MTT assay after 10 min, 60 min and 24 h incubation, detection of apoptosis and ALP activity after 7,14 & 21-days incubation. A two-way analysis of variance (ANOVA) with post hoc Turkey HSD was performed to determine significant differences between the specimens tested.

Results

When compared to the control at all time periods, all test specimens at varied dilutions (1:100, 1:20, and 1:10) caused no cytotoxic effects. The maximum number of live cells and ALP activity was observed with DPSCs cultivated in BioAKT followed by 3.8 % SDF and 5.25 % NaOCl at all time intervals.

Conclusion

Different doses of 3.8 % SDF and BioAKT solution revealed encouraging outcomes when compared to 5.25 % NaOCl in terms of viability, proliferation and long-term ALP functioning potential when cultivated in DPSCs.

Nanoparticles and Their Antibacterial Application in Endodontics

Root canal treatment represents a significant challenge as current cleaning and disinfection methodologies fail to remove persistent bacterial biofilms within the intricate anatomical structures. Recently, the field of nanotechnology has emerged as a promising frontier with numerous biomedical applications. Among the most notable contributions of nanotechnology are nanoparticles, which possess antimicrobial, antifungal, and antiviral properties. Nanoparticles cause the destructuring of bacterial walls, increasing the permeability of the cell membrane, stimulating the generation of reactive oxygen species, and interrupting the replication of deoxyribonucleic acid through the controlled release of ions. Thus, they could revolutionize endodontics, obtaining superior results and guaranteeing a promising short- and long-term prognosis. Therefore, chitosan, silver, graphene, poly(lactic) co-glycolic acid, bioactive glass, mesoporous calcium silicate, hydroxyapatite, zirconia, glucose oxidase magnetic, copper, and zinc oxide nanoparticles in endodontic therapy have been investigated in the present review. The diversified antimicrobial mechanisms of action, the numerous applications, and the high degree of clinical safety could encourage the scientific community to adopt nanoparticles as potential drugs for the treatment of endodontic diseases, overcoming the limitations related to antibiotic resistance and eradication of the biofilm.

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.

Antimicrobial Efficacy of Silver Diamine Fluoride against Enterococcus faecalis: A Systematic Review of In Vitro Studies

Introduction/Objectives. Enterococcus faecalis has been implicated in infections of treated root canals. Current irrigants and intracanal medicaments cannot eliminate E. faecalis completely from the root canal. Silver diamine fluoride (SDF) prevents caries by promoting remineralization and exerting an antibacterial effect. Studies suggest that SDF may possess antibacterial properties against E. faecalis. The purpose of this review is to systematically and critically analyze the literature, focusing on the use of SDF as an intracanal medicament or irrigant, when compared to other antibacterial agents. Data/Sources. The focused question was "Is the antibacterial effect of SDF against E. faecalis better than other intracanal medicaments and irrigants?" Using the keywords ((silver diamine fluoride) AND (Enterococcus faecalis)) AND ((sodium hypochlorite) OR (NaOCl) OR (chlorhexidine) OR (calcium hydroxide) OR (Ca(OH)₂)), an electronic search was conducted on the following databases: PubMed/MEDLINE, ISI Web of Science, Scopus, EMBASE, and Google Scholar. The clinical trial registers ClinicalTrials.gov and CONTROL were also searched using the same keywords. General characteristics and outcomes were extracted, and quality of the studies was assessed using the Preferred Reporting Items for Laboratory studies in Endodontology (PRILE) guidelines. Study Selection. Six articles (five in vitro studies and one ex vivo study) were included in this systematic review. In the majority of the studies, SDF had equal or better antibacterial efficacy against E. faecalis compared to calcium hydroxide, sodium hypochlorite, and chlorhexidine. However, the majority of the studies did not fulfill several items in the PRILE criteria and had numerous sources of bias. Conclusions. Within the limitations of the systematic review and the studies reviewed, SDF may be effective against E. faecalis and therefore could be used as an intracanal medicament and/or irrigant to prevent reinfections of the root canals and improve the outcomes of endodontic treatment. However, animal and clinical studies should be carried out to determine the efficacy of SDF in endodontics. Trial Registration. The protocol for this review was registered on PROSPERO. Registration number: CRD42021224741.

Silver diamine fluoride therapy for dental care

Silver diamine fluoride (SDF) was developed in Japan in the 1960s. It is used to control early childhood caries, arrest root caries, prevent fissure caries and secondary caries, desensitise hypersensitive teeth, remineralise hypomineralised teeth, prevent dental erosion, detect carious tissue during excavation and manage infected root canals. SDF is commonly available as a 38% solution containing 255,000 ppm silver and 44,800 ppm fluoride ions. Silver is an antimicrobial and inhibits cariogenic biofilm. Fluoride promotes remineralisation and inhibits the demineralisation of teeth. SDF also inactivates proteolytic peptidases and inhibits dentine collagen degradation. It arrests caries without affecting dental pulp or causing dental fluorosis. Indirect pulp capping with SDF causes no or mild inflammatory pulpal response. However, direct application of SDF to dental pulp causes pulp necrosis. Furthermore, SDF stains carious lesions black. Patients must be well informed before SDF treatment. SDF therapy is simple, painless, non-invasive, inexpensive, and requires a simple armamentarium and minimal support. Both clinicians and patients generally accept it well. In 2021, the World Health Organization included SDF as an essential medicine that is effective and safe for patients. Moreover, it can be used for caries control during the COVID-19 pandemic because it is non-aerosol-generating and has a low risk of cross-infection.

Surface characteristics and bacterial adhesion of endodontic cements

OBJECTIVES

To investigate the effect of inclusion of silver nano-particles (SNP) or bioactive glass (BG) on the surface characteristics and bacterial adhesion of prototype tricalcium silicate (TCS)-based cements alongside two commercial cements, under different aging periods and exposure conditions.

MATERIALS AND METHODS

A basic formulation of radio-opacified TCS without (TZ-base) and with additions of SNP (0.5, 1, or 2 mg/ml) or BG (10 or 20%) was used. Biodentine and intermediate restorative material (IRM) served as reference materials. Material disks were immersed in ultrapure water or fetal bovine serum (FBS) for 1, 7, or 28 days. Surface roughness (n = 3), microhardness (n = 9), and wettability (n = 6) were analyzed by standard procedures. Adhesion of Enterococcus faecalis was assessed by fluorescence microscopy (n = 5). Data from these assays were evaluated for normality and comparisons among groups were conducted with statistical procedures (p < 0.05 for significance).

RESULTS

The surface morphology of SNP- and BG-containing cements had higher roughness values than TZ-base after 28 days (p < 0.05). No differences in microhardness were observed among prototype cements (p > 0.05). Biodentine presented smooth surface characteristics and the highest hardness values (p < 0.05). The FBS-immersion resulted in surface reactions in prototype materials and Biodentine, depicted with scanning electron microscopy. All 1- and 7-day prototype cements showed negligible bacterial adhesion, while in Biodentine and IRM, noticeable E. faecalis adherence was observed from day 1 (p < 0.05).

CONCLUSIONS

Incorporation of SNP or BG did not improve the antibacterial effect of the experimental cement; all 28-day aged materials failed to inhibit bacterial adherence. The measured physical parameters did not appear to be related to the degree of bacterial adhesion. Exposure of TCS-based cements in FBS resulted in surface reactions, which did not affect bacterial adhesion.

CLINICAL RELEVANCE

Changes in the surface characteristics of prototype TCS-based cements by inclusion of SNP and BG or exposure to different environments did not affect bacterial adhesion. All experimental materials showed inferior physical properties and higher antibacterial effect than Biodentine.

Effect of Preirradiation Fluoride Treatment on the Physical Properties of Dentin

Objective. To determine the effects of preirradiation fluoride treatments on the Knoop hardness of dentin. Materials and Methods. Human posterior teeth mounted into acrylic resin molds were polished with silicon carbide (SiC) abrasives and 3-micron diamond paste. The Knoop hardness of dentin was measured with a Leco hardness instrument. The teeth were divided into groups of ten teeth per group as follows: no treatment (control), treatment with silver diamine fluoride (SDF), MI varnish (MI), and cavity shield (CS). The teeth were exposed to 2 Gy of daily radiation for six weeks using an X-Rad 320ix biological irradiator. Hardness was measured weekly, before, during, and after irradiation. The teeth were stored in artificial saliva at 37oC between radiation treatments. Results. In preirradiation dentin, a Knoop hardness value of 58.8 (14.1) KHN was obtained. Treatment with SDF significantly increased KHN before irradiation. Immediately after radiation treatment, hardness was significantly reduced in all experimental groups. Postirradiation fluoride treatments increased the hardness of dentin to varying degrees. Conclusions. Preirradiation fluoride treatment does not provide protection from decreases in the hardness of dentin. Treatment of teeth with fluoride formulations after radiation progressively restores the hardness of dentin to different degrees.

Quantification of Bacterial DNA from Infected Human Root Canals Using qPCR and DAPI after Disinfection with Established and Novel Irrigation Protocols

The removal of bacterial infections within the root canal system is still a challenge. Therefore, the cleansing effect of established and new irrigation-protocols (IP) containing silver diamine fluoride (SDF) 3.8% on the whole root canal system was analyzed using quantitative PCR (qPCR) and 4′,6-diamidino-phenylindole-(DAPI)-staining. Extracted human premolars were instrumented up to F2 (ProTaper Gold) under NaCl 0.9% irrigation and incubated with Enterococcus faecalis for 42 days. Subsequently, different ultrasonically agitated IP were applied to the roots: control (no irrigation), 1. NaOCl 3%, EDTA 20%, CHX 2%, 2. NaOCl 3%, EDTA 20%, 3. NaOCl 3%, EDTA 20%, SDF 3.8%, 4. SDF 3.8%, and 5. NaCl 0.9%. One half of the root was investigated fluorescent-microscopically with DAPI. The other half was grinded in a cryogenic mill and the bacterial DNA was quantified with qPCR. The qPCR results showed a statistically significant reduction of bacteria after the application of IP 1, 2, and 3 compared to the control group. While IP 4 lead to a bacterial reduction which was not significant, IP 5 showed no reduction. These data corresponded with DAPI staining. With qPCR a new molecular-biological method for the investigation of the complete root canal system was implemented. The novel IP 3 had an equally good cleansing effect as the already established IP.

Assessment of Bacterial Load Using 3.8% SDF as an Irrigant in Pulpectomized Primary Molars: A Randomized Controlled Trial

Aim and objective

The aim of the present study was to evaluate the reduction in bacterial loading using 3.8% as an irrigating solution in pulpectomized primary molars.

Study design

A randomized, controlled clinical trial was performed that included primary molars with pulp necrosis. Sixty necrotic canals were included, 30 irrigated with 3.8% SDF (experimental group) and 30 with 1% NaOCl solution (control group); in all cases, two microbiological samples from within the canals were taken with sterile paper points, the first after the canal opening and before the first irrigation, and the second after instrumentation and final irrigation, before obturation. All samples were evaluated by Agar plate method.

Results

The results were statistically analyzed by student “t“ test. After analyzing samples before and after irrigation in the control group (NaOCl), we found a strong significant decrease of bacterial load (p = < 0.001). The same occurred in the 3.8% SDF group samples (p = < 0.001). When both groups were compared post irrigation, a statistically significant difference was observed in favor of 3.8 % SDF.

Conclusion

3.8% SDF can be suggested as an alternative irrigant for pulpectomy of necrotic teeth.

How to cite this article

Maru V, Padawe D, Naik S, et al. Assessment of Bacterial Load Using 3.8% SDF as an Irrigant in Pulpectomized Primary Molars: A Randomized Controlled Trial. Int J Clin Pediatr Dent 2022;15(S-1):S47-S51.

Caries effected dentin disinfection using Ozone, methylthioninium chloride and turmeric activated by photodynamic therapy on bond integrity of resin-modified glass ionomer cement

AIM

To evaluate the shear bond strength (SBS) of caries effected dentin (CAD) bonded to resin-modified glass ionomer cement (RMGIC) after being disinfected with different methods their effect on microleakage scores.

MATERIAL AND METHODS

Based on criteria of ICDAS seventy-five teeth were selected and disinfected. All samples were grounded and a cavity prepared followed by random allocation of samples into different disinfection groups i.e., methylene blue photosensitizer (MBP), Silver diamine fluoride (SDF), Ozone (O₃); curcumin photosensitizer (CP) and chlorhexidine (CHX) (n = 15). All samples were restored with resin modified glass ionomer (RMGIC) incrementally. Ten specimens from each group were placed in universal testing machine (UTM) to calculate bond failure and failure type. Five samples from each group were evaluated for microleakage scores. SBS and microleakage scores was examined using analysis of variance (ANOVA) with a Post-hoc test. For all tests p-value, less than 0.5 was considered statistically significant.

RESULTS

The highest SBS was observed in CAD disinfected with CP bonded to RMGIC (16.42 ± 1.10 MPa). Similarly, the lowest bond values were demonstrated by CAD disinfected with MBP (9.21 ± 0.22 MPa) bonded to RMGIC respectively. CAD disinfected with CHX (Control) bonded to RMGIC demonstrated the lowest microleakage scores and showed a significant difference compared to other experimental groups (p< 0.05).

CONCLUSION

Curcumin along with O₃ has the potential to be used as a disinfectant in CAD as it improves SBS to RMGIC. CHX demonstrates low microleakage scores with decrease of bond integrity.

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

Background

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

Methods

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

Results

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

Conclusion

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

Effect of different activations of silver nanoparticle irrigants on the elimination of Enterococcus faecalis

OBJECTIVES

This study aimed to compare the efficacy of silver nanoparticles (AgNPs) irrigating solution alone and following activation with photon-induced photoacoustic streaming (PIPS), photodynamic therapy (PDT) with indocyanine green (ICG), passive ultrasonic irrigation (PUI), and manual dynamic activation (MDA) method for elimination of Enterococcus faecalis (E. faecalis) from the root canal system.

MATERIALS AND METHODS

A total of 59 extracted human single-rooted teeth were collected and prepared. E. faecalis was inoculated into the root canals and incubated for 4 weeks. The teeth were then randomly divided into five experimental groups (n = 10): the AN group, irrigation with AgNPs alone; the AN/ICG/DL group, irrigation with AgNPs and ICG, then activation with diode laser; the AN/PIPS group, irrigation with AgNPs and activation with 0.3 W Er: YAG laser; the AN/MDA group, irrigation with AgNPs and activation with tapered gutta-percha; and the AN/PUI group, irrigation with AgNPs and activation with ultrasonic. Also, two control groups of irrigation with 2.5% sodium hypochlorite (n = 5) and no intervention (n = 4) were also used. Samples were collected from the dentinal chips before and after the intervention, and the percentage of reduction in colony count was calculated.

RESULTS

A significant reduction in E. faecalis colony count was noted in all groups (P < 0.05). Maximum reduction in colony count was noted in AN/PIPS and AN/PUI groups by 91.03 and 91.29%, respectively. Minimum reduction was noted in the AN group alone.

CONCLUSION

Activation with PUI and PIPS enhanced the efficacy of AgNPs irrigating solution for elimination of E. faecalis from the root canal system.

CLINICAL RELEVANCE

AgNPs activated by ultrasound or PIPS can be used as an adjunct for disinfection of the root canal system in endodontic treatment.

En-face optical coherence tomography analysis of gold and silver nanoparticles in endodontic irrigating solutions: An in vitro study

Optical coherence tomography (OCT) is a non-invasive, non-radioactive optical diagnostic method based on low-coherence interferometry, which achieves images with different orientation. In dentistry, its major advantage is represented by the localization and characterization of the smallest defects in hard dental tissues, dental materials and of the smallest details in dental anatomy (supplementary canals, recesses, isthmuses, or intra-radicular connections). The aim of the present in vitro study was to evaluate using c-scan en-face optical coherence tomography, the optical opacity, and the distribution inside the root canal lumen of several extracted human teeth of silver and gold nanoparticles from special irrigating solutions used in endodontic treatment. Twelve root canals from 5 human teeth were instrumented using the ProTaper Universal system after initial negotiation with hand K-files ISO no. 10 and rotary nickel-titanium PathFile instruments. An initial c-scan OCT analysis was performed for each sample to confirm that the root canal lumen was empty from radiopaque materials (Group 1). Teeth were first irrigated with NanoCare Plus (Group 2) and then with NanoCare Gold (Group 3) and C-scans were repeated after each irrigation method. The OCT investigation started at the tooth apex, at a depth of 1 mm from its tip. Subsequently, 100 slices of 10 microns were obtained from each root canal. Images were captured and then analyzed with ImageJ software to calculate the level of grey inside the root canal lumen. The highest values of grey were obtained in the samples irrigated with NanoCare Gold after NanoCare Plus (Group 3). The present study proved that both nanoparticles inserted in root canal irrigants were evidenced through OCT imagistic analysis due to their optical opacity, which allowed their highlighting in an empty root canal lumen, after the endodontic treatment was performed and the root canal was cleaned and shaped using specific protocols.

Silver nanoparticles in endodontics: recent developments and applications

The elimination of endodontic biofilms and the maintenance of a leak-proof canal filling are key aspects of successful root canal treatment. Several materials have been introduced to treat endodontic disease, although treatment success is limited by the features of the biomaterials used. Silver nanoparticles (AgNPs) have been increasingly considered in dental applications, especially endodontics, due to their high antimicrobial activity. For the present study, an electronic search was conducted using MEDLINE (PubMed), the Cochrane Central Register of Controlled Trials (CENTRAL), Google Scholar, and EMBASE. This review provides insights into the unique characteristics of AgNPs, including their chemical, physical, and antimicrobial properties; limitations; and potential uses. Various studies involving different application methods of AgNPs were carefully examined. Based on previous clinical studies, the synthesis, means of obtaining, usage conditions, and potential cytotoxicity of AgNPs were evaluated. The findings indicate that AgNPs are effective antimicrobial agents for the elimination of endodontic biofilms.

Effect of silver diamine fluoride on hyperplastic gingivitis in an adult with intellectual disability-A case report

Silver diamine fluoride 38% (SDF) may possess therapeutic effects beyond desensitization, caries prevention and arresting. We report the case of a 41-year-old male with intellectual disability. He had generalized gingivitis on a reduced periodontium and presented with enlarged gingiva with mobile teeth, particularly on the upper anterior and upper left. The inflammation could not be fully resolved despite multiple debridement treatments. Due to prevalent demineralization and hypersensitive teeth on the upper left area, SDF was applied. This not only reduced the perceived hypersensitivity, but significantly improved his periodontal condition and tooth mobility over the applied areas. We discuss the potential of SDF beyond its current use.

Efficacy of MTA Modified by Nanosilver for the Prevention of Coronal Leakage

Background:

Numerous materials have been introduced as coronal barriers, however, they have shown various degrees of microleakage. Therefore, attempts are undertaken to introduce more reliable materials with the potential to provide a long-term coronal seal.

Introduction:

This in vitro study aimed to assess the efficacy of gray ProRoot Mineral Trioxide Aggregate (MTA) modified by a suspension of silver nanoparticles (AgNPs) as an orifice plug using a bacterial leakage method.

Methods:

40 extracted human teeth were prepared and filled (except for the negative control group) using the lateral compaction technique. The coronal 2 mm of the root filling was removed in the experimental groups. The teeth were randomly divided into two experimental (n = 15) and two control (n = 5) groups. In the experimental group 1 (MTA group) and the experimental group 2 (Ag-MTA group), MTA modified by a suspension of AgNPs was used as an orifice plug. In the negative control group, the entire root surfaces were covered with two layers of nail varnish. In the positive control group, the root canals were filled with a single gutta-percha cone without a sealer and no orifice plug. Bacterial leakage was assessed using a two-chamber system. The teeth were incubated at 37°C and 100% humidity for 120 days, and human saliva was added to the samples every 3 days. Bacterial microleakage was assessed by daily monitoring and observating the turbidity of the Brain Heart Infusion (BHI) broth. The data were analyzed using the log-rank test.

Results:

All positive controls showed contamination after 5 days. None of the negative controls were contaminated during the experiment. The Ag-MTA group demonstrated a significantly better coronal seal than the MTA group (p = 0.031).

Conclusion:

Gray ProRoot MTA modified by AgNPs has the potential for being used as an orifice plug in endodontically treated teeth.

The effect of calcium hydroxide on dentine composition and root fracture resistance of human teeth: An in vitro study

The purpose of this study was to evaluate the effect of calcium hydroxide [Ca(OH)₂ ] on dentine composition and root fracture resistance. Root canals of fifty extracted mandibular premolars were prepared and divided into five groups (N = 10). Canals were filled with non-setting Ca(OH)₂ or left empty and were subsequently stored in phosphate buffered saline for 7, 14, 30, or 90 days, respectively. Ca(OH)₂ was then washed out, and roots were separated from the crowns and subjected to fracture strength test. Fractured fragments were examined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results showed a significant and progressive reduction in fracture resistance the longer the duration of exposure to Ca(OH)₂ , and the fracture resistance in teeth exposed for 90 days was significantly lower than in any other group. SEM revealed cracks in the dentine surfaces that had been exposed to Ca(OH)₂ . FTIR showed a significantly lower mineral to matrix ratio in roots exposed to Ca(OH)₂ for 30 and 90 days than seen in roots exposed for a shorter duration. XRD analysis revealed a reduction in dentine crystallinity. It was concluded that Ca(OH)₂ significantly reduced the fracture resistance of the roots overtime. Exposure to Ca(OH)₂ reduced the mineral to matrix ratio and crystallinity of the dentine.

Antibacterial effect of silver diamine fluoride and potassium iodide against E. faecalis, A. naeslundii and P. micra

Background

The aim of this study was to determine in vitro the bactericidal potential of 38% silver diamine fluoride (SDF) alone, potassium iodide (PI) alone, and the two in combination (SDF + PI) against three bacterial species commonly found in root canal samples (Enterococcus faecalis, Actinomyces naeslundii and Parvimonas micra).

Methods

The potential bactericidal rates for SDF, PI and SDF + PI against E. faecalis, A. naeslundii and P. micra were calculated as reduction of bacteria colony forming units.

Results

The bactericidal potential of SDF was at 99.97–100% against E. faecalis and 100% against A. naeslundii and P. micra. SDF + PI showed a 100% bactericidal effect against P. micra, 99.89–99.98% against E. faecalis and 99.98–100% against A. naeslundii. The bactericidal effect of PI was 99.51–99.98% against E. faecalis, 99.27–99.95% against A. naeslundii and 99.93–100% against P. micra. The differences between controls and bacteria exposed to the antibacterial agents were statistically significant (p < 0.05).

Conclusions

SDF had an effective bactericidal effect against the examined bacteria. However, the limitations of this in vitro study do not allow a recommendation of the employment of these solutions as root canal irrigants. Additional investigations are necessary to assess their endodontic clinical applicability.

Micro-CT assessment of the effect of silver diammine fluoride on inhibition of root dentin demineralization

This study evaluated the ability of different types of silver diammine fluoride (SDF) to inhibit dentin demineralization using micro-focused X-ray computed-tomography (µCT). Dentin specimens were divided into five groups (n=10); no-treatment (control), 3.8% SDF (RC), 38% SDF, 38% SDF with potassium iodide (SDF/KI), and potassium fluoride (KF). The treated-dentin surfaces were subjected to demineralization for 7-days and assessed using µCT to determine mineral loss (ML) values. Specimens were also analyzed with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The ML values of the SDF and KF groups were significantly lower than those of the RC and SDF/KI groups. EDS detected fluoride ions in the SDF and KF groups but not in the RC and SDF/KI groups. It was concluded that 38% SDF demonstrated a high ability to inhibit dentin demineralization while additional application of KI may diminish the inhibitory effect of SDF. The amount of dentin demineralization with SDF treatments was material dependent.

Effects of silver diamine fluoride preparations on biofilm formation of Streptococcus mutans

Effects of silver diamine fluoride preparations (SDFs) on cariogenic biofilm formation on root dentin (RD) were investigated. Streptococcus mutans (S. mutans) biofilms were formed on bovine RD blocks coated with one of three the SDFs (38%-SDF, 3.8%-SDF and 35%-SDF+potassium-iodide; SDF+KI) and a non-coated Control which were quantified (spectrometric-measurement) and thickness measured (optical coherence tomography) after 20 h. Bacterial viability test (BacLight) and biofilm-morphometry (SEM) of 2 h biofilms were also performed. The amounts of biofilms (bacteria and water insoluble glucan) and the thickness of biofilm were minimum on 38%-SDF specimen; 3.8%-SDF and SDF+KI had significantly more than that, but had significantly less than Control (p<0.05). Most S. mutans cells found dead and morphology damaged by 38%-SDF. Some dead bacteria and remarkably damaged biofilms were observed in case of 3.8%-SDF and SDF+KI. Inhibition potential of 3.8%-SDF and SDF+KI on S. mutans biofilm formation is almost similar, although not equivalent to 38%-SDF.

Impact of graphene oxide and silver diamine fluoride in comparison to photodynamic therapy on bond integrity and microleakage scores of resin modified glass ionomer cement to demineralized dentin

AIM

To evaluate the impact of graphene oxide (GO) and silver diammine fluoride (SDF) in comparison to photodynamic therapy (PDT) on adhesive bond integrity and microleakage scores of resin-modified glass ionomer cement (RMGIC) to demineralized dentin.

METHODS

80 non-carious and atraumatic third molars were mounted inside the segments of polyvinyl pipes. Exposure, homogenization, and polishing of dentinal tubules was performed. 20 specimens were left unconditioned and classified a group 4. Exposure of acetic acid was done to 60 specimens and randomly allocated into 3 groups. Group 1 specimens were treated with 0.25 % GO; group 2 specimens were treated with 3.8 % SDF; and group 3 specimens were exposed to PDT. The bonding of all samples to RMGIC was performed by light curing and universal testing machine was utilized for testing shear bond strength (SBS). For failure modes, an optical microscope at 40x magnification was used to observe the debonded interfaces. For microleakage, all the specimens were submerged in 2% methylene blue for 1 day and observed under a digital microscope. The post hoc Tukey and analysis of variance (ANOVA) were used to examine SBS. A p-value of ≤0.05 was considered statistically significant.

RESULTS

Group 2 showed the highest bond strength (3.8 % SDF + RMGIC + DD - 15.27 ± 2.19 MPa). Groups 1 (0.25 % GO + RMGIC + DD - 14.11 ± 3.82) and 2 showed comparable results of SBS, which was significantly higher when compared with other research groups (p < 0.05). According to the post hoc Tukey test, the SBS scores of treatment groups exhibited statistically significant values as compared to the control group (p < 0.05). Group 2 samples showed the least microleakage mean score (0.8 ± 0.42), followed by group 1 specimens (1.02 ± 0.88). The comparable microleakage mean scores were demonstrated by the samples in group 1 and 2 (p < 0.01). According to one-way ANOVA, a significant difference was observed in microleakage scores among experimental groups (p < 0.01).

CONCLUSION

Improved bond strength and marginal microleakage scores were demonstrated by the demineralized dentin treated with 0.25 % graphene oxide and 3.8 % silver diamine fluoride when bonded to resin-modified glass ionomer cement. The application of methylene blue photosensitizer for photodynamic therapy undermined the adhesive bond strength applied on demineralized dentin.

Evaluating the substantivity of silver diamine fluoride in a dentin model

Objectives

The goal of endodontic therapy is to prevent apical periodontitis. This is achieved by biomechanical preparation, microbial control using endodontic irrigants, and complete obturation of the canal space. In order to prevent possible post‐obturation complications and for an added antimicrobial effect, substantivity is a desired characteristic of endodontic irrigants. Currently the most commonly used endodontic irrigant that produces an antibacterial substantivity effect is chlorohexidine (CHX). Silver diamine fluoride (SDF) is a topically applied agent for managing dental caries and has shown to stop caries lesion progression. The objective of this study was to compare the antimicrobial substantivity effect of 3.8% SDF against other commonly used endodontic irrigants such as 2% CHX and 6.25% Sodium hypochlorite (NaOCl).

Material and methods

Using a diffusion disc assay we determined the antimicrobial activities of 38%, 3.8%, 0.38%, and 0.038% of SDF against the bacterium Enterococcus faecalis OG1RF. Subsequently, we compared the levels of colonization of E. faecalis by scanning electron microscopy (SEM) at 1.5‐ and 3‐week time intervals on dentin pretreated with 3.8% SDF, 6.25% NaOCl, 2% CHX or sterile phosphate buffered saline (PBS).

Results

The diffusion disc assay demonstrated that 38% and 3.8% of SDF inhibited the growth of E. faecalis. Moreover, the substantivity of 3.8% SDF (p < 0.01) was comparable to 2% CHX (p < 0.01) and it is significantly greater than 6.25% of NaOCl compared to the PBS treated samples after 1.5 and 3 weeks of incubation.

Conclusions

In this study, we demonstrate that SDF possesses antimicrobial properties against the opportunistic pathogen E. faecalis. Moreover, using a dentin model we show the substantivity of 3.8% SDF is significantly greater than 6.25% NaOCl, but is comparable to 2% CHX.

Effect of Silver Antibacterial Agents on Bond Strength of Fiber Posts to Root Dentin

This study was conducted to evaluate whether antibacterial pretreatment irrigation with silver nanoparticles (SNPs) and silver diamine fluoride (SDF) has any effect on bond strength of fiber posts cemented with three types of resin cements in root canal space. Fifty-four endodontically treated maxillary central incisor roots were prepared for fiber post (FRC Postec Plus NO.3, Ivoclar Vivadent) cementation and divided into nine groups in terms of three cement types and two pretreatments with silver antibacterial agents. The cements were as follows: an etch-and-rinse cement (ER, Excite DSC/Variolink N), a self-etch cement (SE, ED Primer/Panavia F2.0), and a self-adhesive cement (SA, Panavia SA Luting Plus). For each cement, the control group was with no treatment and two experimental groups were with SNPs and SDF treatments that were used after acid-etching for ER cement and after EDTA treatment for SE and SA cements. After fiber post cementation, each bonded root was horizontally sectioned into 1-mm thickness microslices to create two slices for each root region (apical, middle and coronal) and underwent push-out bond strength (PBS) test. Data in MPa were analyzed with two-way ANOVA and Tukey test (p=0.05). The interaction of the pretreatment type and cement type was significant (p<0.001). SNPs and SDF significantly increased PBS with ER cement (p≤0.04). This positive effect was also marginally significant for SDF with SE cement (p=0.049). For SA cement, SNPs showed a significant positive effect, but SDF had a significant adverse effect on PBS (p<0.001). The effect of pretreatment with silver antibacterial agents prior to adhesive cementation of fiber posts depends on the resin cement used. Contrary to SNPs with beneficial or no significant effect on bonding for all cements, SDF exhibited a deleterious effect with self-adhesive cement.

Assessment of knowledge and perception about silver diamine fluoride (SDF) for treating older adults among graduating dental students

PURPOSE/OBJECTIVES

Silver diamine fluoride (SDF) is a promising therapy for arresting and preventing caries in difficult to treat, high-risk populations, including institutionalized older adults. This study investigates the knowledge and perceptions about SDF of graduating dental students in multiple U.S. dental schools, as well as their willingness to use SDF in their practices.

METHODS

A survey was designed consisting of 21 total questions: 6 questions regarding students' demographic information and their SDF content exposure contextualization, 8 questions tailored to investigate 2 domains regarding students' knowledge about SDF (properties and indication), and 7 questions aiming to investigate 3 domains regarding students' perceptions about SDF (SDF usefulness, appropriateness of using SDF, and willingness to use SDF when in private practice). The survey was then distributed to graduating dental students at 7 U.S. dental schools.

RESULTS

A total of 386 surveys (response rate of 55%) was collected from 7 schools in the Spring of 2019. The median score resulting from the SDF content exposure questions was 3 (SD = 1.43) from a range of 0-5. The median score from knowledge about SDF properties was 4 (SD = 1.18) from a range of 0 to 6. In the multivariate analysis, a linear model found that the covariates "SDF Usefulness", "SDF Appropriateness" and "SDF Patient Willingness to Use" were significantly associated with higher student willingness to use SDF (R²  = 0.395).

CONCLUSION

The results indicated that the graduating students have a positive perception of SDF regarding its usefulness and appropriateness. Graduating students appear inclined to utilize SDF upon entering private practice.

Antibacterial efficacy of silver diamine fluoride as a root canal irrigant

Objectives

Conventional disinfectants and medicaments have not been able to achieve and maintain sterilization of root canals. The purpose of the study was to evaluate the antibacterial efficacy of 3.8% silver diamine fluoride (SDF) in comparison with 2% chlorhexidine (CHX) against Enterococcus faecalis biofilm.

Materials and methods

Extracted human teeth were used to make 70 dentin discs that were then inoculated with E. faecalis to generate a 3‐week‐old biofilm model. The discs were subjected to treatment with 3.8% SDF, 2% CHX, sodium hypochlorite (NaOCl), or saline for 10 min. After exposure, the dentin discs were examined with a confocal laser scanning microscope to verify the percentage of live versus dead cells within the biofilm. Univariate one‐way analysis of variance and Tukey‐honestly significant difference post hoc analysis (p < .05) were performed to detect significant differences.

Results and conclusion

The NaOCl group showed the greatest percentage of dead cells (62.26%) among all groups (p < .05). The SDF group showed a significantly higher percentage of dead cells (57.39%) than the 2% CHX and saline groups (p < .05). SDF possessed higher antimicrobial activity than 2% CHX against E. faecalis biofilms.

Oroactive dental biomaterials and their use in endodontic therapy

Dental biomaterials have revolutionized modern therapies. Untreated dental caries remains the major etiological factor for endodontic treatment, and together with a decreasing rate of tooth loss escalates the importance of continuously improving the materials used for endodontic therapies. Endodontic biomaterials are used for vital pulp therapies, irrigation, intracanal medicaments, obturation and regenerative procedures. These materials offer several functions including: antimicrobial activity, mechanical reinforcement, aesthetics, and therapeutic effects. Vital pulp therapies have seen an improvement in clinical results with an incremental approach to build on the strengths of past materials such as calcium hydroxide and calcium silicates. While sodium hypochlorite remains the gold standard for canal irrigation, numerous nanoparticle formulations have been developed to promote sustained antimicrobial action. Gutta-percha based bulk fillers remain the most common materials for root filling. However, while multiple studies focus on the development of novel formulations containing drugs, glass derivatives or ionic-, polymeric-, or drug- loaded nanoparticles, a lack of reliable and long-term clinical evidence obligates further study as experienced clinicians prefer to use what has worked for decades. This review delves in to the biochemistry of the materials to scrutinize their shortcomings, and where opportunity lies to further enhance their efficacy in endodontic practice. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:201-212, 2020.

Silver deposition on demineralized dentine surface dosed by silver diammine fluoride with different saliva

AIM

Silver diammine fluoride (SDF) is an anticaries agent that binds to tooth tissue. The aim of the present study was investigate the dose-response effect of SDF on demineralized dentine in basal medium mucin (BMM) saliva substitute and human saliva.

METHODS

Dentine discs stored in saliva substitute, BMM, and human unstimulated whole saliva (UWS) were chemically demineralized, and 10 μL of 10 wt%, 24 wt%, or 38 wt% SDF was applied and then stored in its respective saliva (BMM or UWS) for 5 days. Dentine disc samples were digested in 70% HNO₃ , and silver was quantitatively detected by inductively coupled plasma mass spectroscopy.

RESULTS

For both the BMM and UWS groups, the presence of silver increased proportionally with increasing concentrations of SDF (P < 0.05). For the 38 wt% SDF application, the mean absorption percentage of silver in dentine was 3.90% for the UWS group and 6.61% for the BMM group. The BMM group was found to yield a significantly higher amount of silver compared to UWS at 10 wt% and 38 wt% SDF application (α = 0.05); 38 wt% SDF interacts more with BMM with higher silver deposition than UWS.

CONCLUSION

The amount of silver found in dentine was in proportion to the concentration of SDF. Extrapolation of in vitro investigations using artificial saliva for SDF tooth interactions should be interpreted with caution.

Arrest of Root Carious Lesions via Sodium Fluoride, Chlorhexidine and Silver Diamine Fluoride In Vitro

OBJECTIVE

To compare the root carious lesion arrest of chlorhexidine (CHX) and silver diamine fluoride (SDF) varnishes and/or sodium fluoride rinses (NaF) in vitro.

BACKGROUND

Effective and easily applicable interventions for treating root carious lesions are needed, as these lesions are highly prevalent amongst elderly individuals.

METHODS

In 100 bovine dentin samples, artificial root carious lesions were induced using acetic acid and a continuous-culture Lactobacillus rhamnosus biofilm model. One quarter of each induced lesion was excavated and baseline dentinal bacterial counts assessed as Colony-Forming-Units (CFU) per mg. Samples were allocated to one of four treatments (n = 25/group): (1) untreated control; (2) 38% SDF or (3) 35% CHX varnish, each applied once, plus 500 ppm daily NaF rinse in the subsequent lesion progression phase; and (4) daily NaF rinses only. Samples were re-transferred to the biofilm model and submitted to a cariogenic challenge. After six days, another quarter of each lesion was used to assess bacterial counts and the remaining sample was used to assess integrated mineral loss (ΔZ) using microradiography.

RESULTS

ΔZ did not differ significantly between control (median (25th/75th percentiles): 9082 (7859/9782) vol % × µm), NaF (6704 (4507/9574) and SDF 7206 (5389/8082)) (p < 0.05/Kruskal-Wallis test). CHX significantly reduced ΔZ (3385 (2447/4496)) compared with all other groups (p < 0.05). Bacterial numbers did not differ significantly between control (1451 (875/2644) CFU/µg) and NaF (750 (260/1401)) (p > 0.05). SDF reduced bacterial counts (360 (136/1166)) significantly compared with control (p < 0.05). CHX reduced bacterial counts (190 (73/517)) significantly compared with NaF and control (p < 0.05).

CONCLUSION

CHX varnish plus regular NaF rinses arrested root carious lesions most successfully.

Anti-microbial efficiency of silver diamine fluoride as an endodontic medicament - An ex vivo study

CONTEXT

Antisepsis achieved through appropriate use of irrigants is essential for endodontic success. Identification of newer anti-bacterial agents gives alternatives to clean the canal as eradication of the infection prior to obturation does affect prognosis.

OBJECTIVE

Comparison of the anti-bacterial action of 3.8% silver diamine fluoride and 2% chlorhexidine gluconate against Enterococcus faecalis in root canals.

MATERIALS AND METHODS

Forty-four single-rooted teeth were decoronated, and the root section was enlarged with peeso-reamer (No: 3) to standardize length and diameter. The samples were then autoclaved and divided into two study groups and two control groups. Enterococcus faecalis ATCC 29212 was inoculated into all test samples for 72 hours. The samples were enlarged with peeso-reamer (No: 5) after placement of respective medicament for 24 hours. Shavings were collected and inoculated on Brain Heart Infusion agar for 24 hrs to measure the colony forming units.

RESULTS

Both 3.8% silver diamine fluoride and 2% chlorhexidine showed a superior capacity to sterilize the root canals than control groups.

CONCLUSION

The use of silver diamine fluoride as an endodontic irrigant is feasible as it can effectively remove the microbes present in the canal and circumpulpal dentin.

Root canal irrigants

Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ‘root canal irrigants’ and ‘endodontic irrigants.’ The reference lists of each article were manually checked for additional articles of relevance.