Penetration of Silver Diamine Fluoride in Deep Carious Lesions of Human Permanent Teeth: An In Vitro Study

Clinical, Microbiological, and Microcomputed Tomography Evaluation of Silver Diamine Fluoride in Controlling Root Carious Lesions: An in Vivo Study

Background

Silver diamine fluoride (SDF) application without removing necrotic tissue is an applicable non-invasive measure to primary care practice and may reduce the burden of untreated root caries. This study aims to examine clinical feature change, root caries-related bacteria, and silver penetration of SDF in arresting root caries.

Material and Methods

Ten study participants with 16 root carious teeth were included in this study. The clinical characteristics of root caries lesions (plaque deposit, color, hardness, and sensitivity symptom) were recorded. Then root caries samples were collected using a spoon excavator before and 2 weeks after treated with 38% SDF. The amounts of Streptococcus mutans (S.mutans), Actinomyces naeslundii (A. naeslundii), and Lactobacillus casei (L. casei) were determined using real-time PCR. Any tooth sample scheduled for extraction was further analyzed using micro-CT, stereoscopic microscope, and FE-SEM/ EDX to determine the silver penetration.

Results

Most treated samples were darker in color, predominantly turning black (n =15, 93.8%), had increased surface hardness (n =11, 68.8%), were non-sensitive teeth (n=14, 87.5%), and were negative to air blowing (n =12, 75%). Only S.mutans had a significantly lower number of bacteria after 2 weeks (p-value = 0.041). The micro-CT analysis revealed that the silver increased the root carious lesion's density in proportion to its depth. According to a stereoscopic microscope study, silver penetration caused dark bands, appearing along the dentinal tubule toward the dental pulp. An FE-SEM analysis showed that silver was found to be densely deposited on the surface of the lesions and penetrated through the dentinal tubule into the dental pulp direction. EDX mapping confirmed that the increased density was related to silver.

Conclusions

Based on clinical and microbiological profiles, this investigation indicated that SDF is beneficial for controlling root caries, particularly S.mutans reduction. Silver can also penetrate deep into the lesion. Key words:Microbiology, Root caries, Silver diamine fluoride, Silver ion, Streptococcus mutans, Actinomyces naeslundii, Lactobacillus casei.

Silver Diamine Fluoride in Pediatric Dentistry: Effectiveness in Preventing and Arresting Dental Caries-A Systematic Review

BACKGROUND

Tooth decay is considered a global scourge by the World Health Organization (WHO) starting at an early age. In recent years, silver diamine fluoride (SDF) has regained interest, particularly in pediatric dentistry, used to prevent the development of carious lesions or arrest their progression.

OBJECTIVE

The aim of this study was to assess, through a systematic review of the literature, the effectiveness of SDF, used in pedodontics, in temporary teeth, in preventing or arresting dental caries.

MATERIAL AND METHODS

An electronic search was conducted on PubMed, Web of Science and Scopus. The effect of SDF on both temporary and permanent teeth has been considered.

RESULTS

The inclusion criteria identified 16 randomized controlled trials involving patients aged 18 months to 13 years and followed over a period of 12-30 months.

CONCLUSIONS

SDF is a practical, accessible and effective non-invasive way to prevent and arrest caries in temporary and permanent teeth. Its application requires regular monitoring. The resulting black spot is diminished by immediate application of potassium iodide but this may affect its effectiveness.

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.

The Caries-Arrest Effectiveness of Silver Diamine Fluoride Treatment with Different Post-Treatment Instructions in Preschool Children: A Study Protocol for a Randomized Controlled Trial

In this 12-month randomized active-controlled clinical trial, we compare two post-treatment instructions for silver diamine fluoride (SDF) therapy in arresting dentine caries. The trial will include at least 254 kindergarten children with active dentine caries. The children will be randomized into two groups and receive a 38% SDF solution applied topically to their carious lesions. Children in Group A will rinse immediately, whereas those in Group B will refrain from rinsing, eating, and drinking for 30 min. One trained examiner will perform the dental examination at baseline and every six months. The primary outcome measurement will be the proportion of caries lesions that become arrested at the 12-month examination. Potential confounding factors and parents' satisfaction with SDF therapy at baseline and after 12 months will be collected using parental questionnaires. This trial will provide evidence-based information for clinical practitioners to give post-treatment instructions for SDF therapy. This study is registered at ClinicalTrial.gov (USA) (registration number: NCT05655286).

Radiographic Changes to Silver Diamine Fluoride Treated Carious Lesions after a Rinsing Step

Silver diamine fluoride (SDF) is radiopaque. This in vitro study compares the changes in the radiopacity of carious lesions after SDF application, potassium iodide (PI) application, and water rinse. Ten recently extracted human teeth were sectioned and divided into two groups (n = 10 in each group): Group 1 = SDF, Group 2 = SDF + PI. Teeth in Group 1 received SDF for 1 min and rinsed with 15 mL water. Group 2 received the same protocol with the addition of PI application for 1 min after SDF application. All samples were scanned with micro-computed tomography before SDF application, after SDF application, after PI application (group 2) and after water rinse. The radiopacity of the carious lesions increased significantly after SDF application in Group 1 and 2 (p < 0.017, p < 0.008, respectively). A significant increase in radiopacity after PI application was also observed in Group 2 (p < 0.008). Water rinsing significantly decreased the radiopacity in Group 1 and 2 (p < 0.017, p < 0.008, respectively), but the radiopacity remained significantly higher than the preoperative values (Group 1 p < 0.017, Group 2 p < 0.008). The radiopacity of carious lesions increases after SDF and SDF + PI applications. Water rinsing could reduce the radiopacity of SDF and SDF + PI treated carious lesions, and might reduce the content of SDF in carious lesions.