Skip to main content
NCBI home page
The Saudi Dental Journal logoLink to The Saudi Dental Journal
. 2025 May 19;37(4-6):8. doi: 10.1007/s44445-025-00012-3

Silver diamine fluoride versus sodium fluoride varnish in the treatment of proximal caries in primary molars: A randomized clinical trial

Afsoon Motallebi 1, Ali Karimi 2, Fatemeh Mazhari 3, Melika Hoseinzadeh 4,✉
PMCID: PMC12089539  PMID: 40397187

Abstract

The present randomized clinical trial with a split-mouth design investigated the effectiveness of 30% silver diamine fluoride (SDF) compared to 5% sodium flouride varnish (NaD) in arresting proximal caries in the primary molars of preschool-aged children. Forty-three children with contralateral initial proximal carious lesions on primary molars were included. Caries status at the baseline was recorded using clinical and radiographic indices. Lesions restricted to the enamel or the exterior third of dentin were included. A sufficient space was created between the contacts using elastic separators. Then, 5% NaF varnish and 30% SDF were randomly applied to either side of the mouth. Six months later, bitewing radiographs were obtained, and the post-intervention caries scores were compared with the baseline radiographs. Children's oral hygiene was recorded via a questionnaire. The findings indicated that the baseline and post-intervention caries status were comparable between the groups. The success rate of the SDF treatment (74.4%) and the NaF varnish (67.5%) was comparable. Baseline radiographic caries status was significantly related to the treatment result in the NaF group (p = 0.047). Dental flossing was significantly associated with the treatment result when SDF was used (p = 0.027). In conclusion, both fluoride-containing materials exhibited comparable efficacy in arresting early proximal caries lesions in primary molars. SDF 30% showed a higher but insignificant success rate in arresting initial proximal lesions of the primary molar compared to NaF 5% varnish.

Trial registration: IRCT, IRCT20220425054647N1. Registered on 24 September 2022, https://en.irct.ir/trial/63168.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44445-025-00012-3.

Keywords: Fluoride varnish, Interproximal caries, Silver diamine fluoride, Primary teeth

Introduction

Managing caries in the interproximal areas of primary molars presents unique challenges. Factors such as the broad contact surfaces between teeth, the thin layers of enamel and dentine, restricted access for saliva, and the difficulty children face in using dental floss contribute to this complexity (Kirthiga et al. 2018; Banihani et al. 2022). Timely intervention for early carious lesions in primary teeth is crucial for arresting caries progression, reducing the risk of developing new carious lesions later in life, and avoiding higher treatment costs (Zou et al. 2022). Professional topical products can impede or remineralize carious lesions. Sodium Fluoride (NaF) varnish is a concentrated fluoride solution containing 5% NaF applied to the teeth to enhance fluoride uptake and strengthen enamel (Hassan et al. 2024). NaF varnish reduces the likelihood of caries in primary teeth by 37% (Rijkom et al. 1998). According to a meta-analysis, applying 5% NaF varnish caused 63.6% enamel remineralization (Gao et al. 2016). Some research indicates that NaF varnish may not be as effective as silver diamine fluoride (SDF) in halting caries, particularly in dentine caries in primary teeth (Duangthip et al. 2018).

SDF contains silver and fluoride, which acts by killing bacteria, promoting remineralization of the tooth surface by providing a high concentration of calcium and phosphate (Mei et al. 2014) and preventing the breakdown of the organic matrix in dentin (Mei et al. 2013). SDF is able to arrest dentin caries in primary teeth with success rates between 65 and 91% (Gao et al. 2016; Seifo et al. 2019). Possible side effects of SDF include staining of the decayed tooth structure; however, parents might tolerate the discoloration in less noticeable areas (Timms et al. 2020). According to Jain et al. (Jain et al. 2023), SDF therapy is more cost-effective than other topical fluorides. Moreover, SDF +NaF varnish have shown comparable anticaries effects with glass ionomer sealants/atraumatic restorations (ART) + NaF varnish (Ruff et al. 2023).

Numerous investigations that have explored the effectiveness of SDF and NaF varnish in preventing caries in children demonstrated that SDF is either more effective or equally effective (Jain et al. 2023; Yassin et al. 2023a; Abdellatif et al. 2023; Chu et al. 2002; Phonghanyudh et al. 2022). However, most of them applied the agents to the occlusal, buccal, and lingual surfaces rather than proximal surfaces. Hammersmith et al. (Hammersmith et al. 2020) delivered SDF to the interproximal areas using woven floss; however, they did not compare SDF efficacy with an alternative treatment or control group. Moreover, SDF was not fully applied to the interproximal surfaces because there was no separation between the teeth to allow access for the applicators. A potential solution to achieve direct visual access to the proximal surfaces of the teeth is to temporarily place orthodontic elastic separators between them. This method has been used to assess preventive or conservative restorative treatments for proximal caries (Treeratweerapong et al. 2023). Therefore, the current randomized clinical trial (RCT) aimed to investigate the efficacy of SDF compared to NaF varnish in arresting or remineralizing interproximal lesions by straight application of the materials in the temporarily spaced primary molars.

Methods and materials

Sample size calculation

The present RCT was conducted from January to August 2023 and reported according to the CONSORT guidelines. Figure 1 illustrated the CONSORT diagram of the study. The CONSORT checklist was provided a supplementary material. According to the findings of an earlier study (Santos et al. 2012) and considering an α = 0.05 and β = 0.2, the required sample size was determined to be 43 teeth per group. According to the study's split-mouth design, 50 children were selected.

Fig. 1.

Fig. 1

Open in a new tab

CONSORT flow diagram of study recruitment

Participants

A total of 135 patients referred to the 3 private pediatric dentistry clinics at Bojnurd, North Khorasan, Iran, for routine dental exams were examined by a pediatric dentistry specialist (A.M.). Out of these patients, fifty children, aged between 3 and 6 years, were included if they had the following inclusion criteria:

  • Complete physical and mental health, with no history of systemic diseases (classified as American Society of Anesthesiologists (ASA) classification I) and taking local or systemic medications.

  • Having at least two contralateral untreated proximal carious lesions of primary molars with radiographic and clinical characteristics described later in the manuscript

  • Absence of gingival or peri-oral ulcers, signs or symptoms indicating pulp involvement, use of any tooth desensitizer in the past month, receiving NaF in the last month, and known allergy to silver or other heavy metal ions or receiving a NaF varnish treatment within the preceding month, or known allergy to silver or other heavy-metal ions

Children were excluded from the study if:

  • The carious lesion treated with SDF or NaF varnish did not have a neighboring proximal contact.

  • Either they or their parents refused to cooperate.

The benefits and risks of the research and the treatments were communicated to the parents, and written informed consent was acquired.

Initial assessments

The study included 50 primary molars on each side with untreated proximal caries. The initial radiographic examination was performed using bitewing radiographs, prepared with a phosphor imaging plate (PSP) device (Kavo, Biberach, Germany) and a pediatric film holder (Kerr, Karlsruhe, Germany) under the following conditions: 7 milliamperes, 60 KVP, and 0.3 s. Professional technicians obtained the images with a pediatric film holder under the supervision of a radiologist. Therefore, radiographic errors and the number of radiographs obtained from the patient were minimized.

Caries severity was classified according to the International Caries Classification and Management System (ICCMS™) criteria by an expert radiologist. Teeth were included in the study whose proximal decay was at the initial stages. The radiolucency was restricted to either the outer and inner halves of the enamel, which could involve the enamel-dentin junction (categories RA1 and RA2), or it affected the outer third of the dentin (RA3). Additionally, the count of the patient's decayed, missing, and filled primary teeth (dmft) was noted.

Three days before the intervention, elastic separators were inserted between the contacting surfaces to create a space about the size of an ultrafine microbrush tip so that the operator could observe the carious lesions and apply the varnish and SDF directly. On the day of the intervention, the caries advancement was monitored using the International Caries Detection and Assessment System (ICDAS).

Intervention

On the intervention day, the elastic separators were removed, the bacterial plaque was cleaned with a rubber cap, and the teeth were rinsed and dried. Then, the proximal areas were examined with an explorer. The lesions corresponding to ICDAS 1–3 scores were included in the study. A pediatric dentistry specialist (A.M.) performed a clinical caries status assessment.

The teeth which needed treatment were randomly selected. Parents were requested to select from the sealed, opaque envelopes that held the names of SDF and NaF varnish. Teeth allocation was conducted by a blinded person who was unaware of the investigation objectives. The material in the selected envelope was applied to the caries of the first or second molar teeth on the left side of the child's mouth. The lesions on the right side were treated with the other material. The treatments were carried out as follows.

  1. Applying SDF: The proximal area was air-dried and isolated using a cotton roll. Then, a drop of 30% SDF (Cariostop, Biodinamica, Paraná, Brazil) was placed over the area using an ultra-fine microbrush and left in place for 3 min. The excess material was removed using a micro brush.

  2. Applying NaF varnish: After establishing isolation in the other quadrant with a cotton roll and air-drying the surfaces, a drop of 5% NaF varnish (Fluorodose, Centrix Dental, Connecticut, United States) was applied to the tooth and remained for 1 min. The patient was advised to keep their mouth closed to allow the varnish to set while saliva is present and was instructed not to rinse or suction immediately after application. Children and their parents were told to refrain from eating hard or sticky foods and drinking hot drinks for the next two hours, to follow a soft diet, and to avoid brushing and flossing for the remainder of the day.

Additionally, both the child and parents received guidance on how to perform daily supervised tooth brushing using fluoridated toothpaste and the proper technique for using dental floss. SDF and NaF varnish were applied by a single operator (A.K.).

Follow-up examination

Six months later, the participants were recruited for a follow-up examination. The post-intervention bitewing radiographs were obtained in the same Oral and Maxillofacial Radiology Clinic where the pre-intervention radiographs using a film holder were obtained to ensure the comparable quality and the consistency of the radiographs’ angle. The ICCMS criteria was used to assess the caries severity of the post-intervention images. The lesion was graded as no radiolucency (R0), RA1, RA2, RA3, and radiolucency reaching the middle third of dentin (RB). The treatment was successful if the caries regression or arrest was observed in the follow-up radiographs according to ICCMS criteria. However, if the caries progressed, the treatment failure was recorded, and the patient was referred for tooth restoration.

For clinical examination, elastic separators were inserted between the contacts for 3 days. After removing the separators, the proximal surfaces were examined. The black color change of the earlier caries site and the lack of progression to the adjacent pits and fissures were considered criteria for treatment success. On the contrary, the spread of decay to susceptible areas and the white and chalky color indicated an active lesion and the need for restoration. Also, the parents were given a questionnaire to evaluate the child's behaviors for oral hygiene maintenance (Shah and Jeevanandan 2020; Fernandes et al. 2021).

Blinding

The operator (A.K.) could not be blinded because of the differences in the materials used. However, patients and the statisticians were unaware of the interventions. Also, the radiologist who performed radiographic assessments and the pediatric dentistry specialist who performed the follow-up clinical assessments were blinded. ‘

Statistical analysis

Data were analyzed using SPSS 20.0 (IBM Inc., New York, USA). The Chi-squared test was used to evaluate the baseline caries grades (according to ICDAS and ICCMS indices) and treatment success, compare the treatment success and color change between the intervention groups and determine the relationship between the variables on child's behaviors for oral hygiene maintenance and treatment success. Values less than 0.05 were considered as statistically significant. ‘

Results

A total number of 50 children were included; however, four patients received NaF varnish before the follow-up examination, and three patients refused to take the follow-up radiographs. Therefore, 43 patients (25 boys (58.13%)- 18 girls (41.86%)) were included in the final analysis. On the right side, 23 first molars (53.5%) and 20 s molars (46.5%) were included, and on the left side, 25 first molars (58.1%) and 18 s molars (41.9%) were studied. The patients'mean age was 4.98 ± 0.91 years. The average dmft index of the participants was 6.79 ± 2.37. Also, the mean baseline total ICCMS index of the examined teeth was 2.19 ± 0.82. On the SDF and NaF varnish sides of the mouth, the ICCMS index of teeth was 2.20 ± 0.80 and 2.18 ± 0.85, respectively (p = 0.897). Baseline ICCMS (p = 0.753) and ICDAS indices (p = 0.396) were comparable between the groups.

Post-intervention ICCMS values were comparable among the groups (p = 0.563). According to Table 1, most of the caries lesions in the SDF (74.4%) and NaF varnish groups (67.5%) either arrested or showed regression in the radiographic examination and the treatment was considered to be successful. The success rate of the groups was comparable (p = 0.744).

Table 1.

Comparing the treatment success/failure rate between the groups

Treatment result Caries status SDF
N (%)		 Fluoride varnish
N (%)		 P value
Success Regression 11 (25.6) 11 (25.6) 0.744
Arrested 21 (48.8) 18 (41.9)
Total 32 (74.4) 29 (67.5)
Failure Progression 11 (25.6) 14 (32.6)
Open in a new tab

As described in Table 2, in the SDF group, 90%, 71.4%, and 68.4% of samples in the RA1, RA2, and RA3 subgroups, respectively, based on the initial ICCMS classification, were treated successfully. Also, 100%, 66.7%, and 66.6% of teeth initially divided into subgroups I, II, and III based on ICDAS were successfully treated after receiving SDF. The Chi-square test indicated that the initial clinical and radiographic status of the lesions was not related to SDF treatment success.

Table 2.

The relationship between baseline clinical and radiographic caries status based on ICCMS and ICDAS indices and treatment success or failure among the groups

Treatment result Caries status SDF
N (%)		 Fluoride varnish
N (%)
Baseline ICCMS Baseline ICDAS Baseline ICCMS Baseline ICDAS
RA1
N (%)		 RA2
N(%)		 RA3 N(%) P value I
N(%)		 II
N(%)		 III
N(%)		 P value RA1
N (%)		 RA2
N(%)		 RA3 N(%) P value I
N(%)		 II
N(%)		 III
N(%)		 P value
Success Regression 2(20) 6(42.8) 3(15.8) 0.427 3 (30) 4 (26.7) 4 (22.2) 0.106 3(25) 5(45.4) 3(15) 0.047* 3(25) 6(31.6) 2(16.7) 0.081
Arrested 7(70) 4(28.6) 10(52.6) 7 (70) 6 (40) 8 (44.4) 8(66.7) 3(27.3) 7(35) 8(66.7) 6(31.6) 4(33.3)
Total 9(90) 10(71.4) 13(68.4) 10 (100) 10 (66.7) 12(66.6) 11(91.7) 8(72.7) 10(50) 11(91.7) 12(63.2) 6(50)
Failure Progression 1(10) 4(28.6) 6(31.6) 0 (0) 5 (33.3) 6 (33.3) 1(8.3) 3(27.3) 10(50) 1(8.3) 7(36.8) 6(50)
Open in a new tab

*Values less than 0.05 represent a significant difference between the intervention groups according to the Chi-squared test

Regarding NaF varnish, the treatment success rate was noticed in 91.7%, 72.7%, and 50% of samples in RA1, RA2, and RA3 subgroups. Also, in ICDAS subgroups I, II, and III, treatment success was observed in 91.7%, 63.2%, and 50% of the samples, respectively. The Chi-square test indicated that, unlike the initial clinical conditions of the lesion, the radiographic classification of the lesion was significantly related to the success or failure of the treatment with NaF varnish (p = 0.047).

Table 3 represents the relationship between the variables on child's behaviors for oral hygiene maintenance and caries status following intervention. Unlike the NaF varnish group, in the SDF group, dental floss daily usage was significantly related to the treatment result (p = 0.027). Among the samples that did not or did floss their teeth, 46.7% and 14.3% showed caries progression, respectively. However, daily toothbrushing, using toothpaste, and parental participation in oral hygiene care were unrelated to the treatment results in neither group.

Table 3.

The relationship between caries status and child's behavior for maintaining oral hygiene among the groups

Variables SDF Fluoride varnish
Caries regression
N (%)		 Arrested caries
N (%)		 Caries progression
N (%)		 P-value Caries regression N (%) Arrested caries
N (%)		 Caries progression
N (%)		 P value
Daily brushing No 0 (0) 1 (100) 0 (0) 0.585 0 (0) 0 (0) 1 (100) 0.346
Yes 11 (26.2) 20 (47.6) 11 (26.2) 11 (26.2) 18 (42.9) 13 (31)
Parents cooperation in tooth brushing No 5 (21.7) 10 (43.5) 8 (34.8) 0.331 4 (17.4) 9 (39.1) 10 (43.5) 0.202
Yes 6 (30) 11 (55) 3 (15) 7 (35) 9 (45) 4 (20)
Using toothpaste No 0 (0) 2 (66.7) 1 (33.3) 0.574 0 (0) 1 (33.3) 2 (66.7) 0.362
Yes 11 (27.5) 19 (47.5) 10 (25) 11 (27.5) 17 (42.5) 12 (30)
Using dental floss No 1 (6.7) 7 (46.7) 7 (46.7) 0.027* 2 (13.3) 5 (33.3) 8 (53.3) 0.091
Yes 10 (35.7) 14 (50) 4 (14.3) 9 (32.1) 13 (46.4) 8 (21.4)
Open in a new tab

*Values less than 0.05 represent a significant difference between the intervention groups according to the Chi-squared test

Discussion

In the present study, most teeth treated with SDF (74.4%) and NaF varnish (67.5%) demonstrated radiographic signs of caries arrest or regression after six months. Notably, there was no significant difference in caries arrest rates between the two treatment groups. The effectiveness of both treatments was not affected by the carious lesions’ initial clinical state or most of the variables on child's behaviors for oral hygiene maintenance. Nevertheless, radiographic baseline values were significantly related to the treatment success with NaF vanish. On the other hand, daily dental flossing was significantly related to treatment success only in the SDF group.

Children under the age of five are particularly vulnerable to dental caries, as they often lack awareness of proper brushing techniques (Jain et al. 2023). The second peak of caries susceptibility occurs around age six with the eruption of the first permanent molars. Therefore, the current research focuses on children aged three to six (Jain et al. 2023). Additionally, a split-mouth design was chosen to subject the carious lesions to the same salivary, nutritional, hard tissue structure, and hygiene conditions.

This study utilized visual and radiographic measures to assess the dental caries. The ICDAS clinical scoring system is recognized as one of the most dependable and consistent methods for visual detection of caries (Neuhaus et al. 2009; Honkala et al. 2011). It reflects the exact relation of clinical hard tissues with lesion histology (Dikmen 2015). Scoring the lesions via the ICDAS system and applying the materials directly became possible due to temporary separation with orthodontic plastic separators. Notably, this is the first study that used SDF directly on incipient proximal caries. Furthermore, the caries status was evaluated by a blinded pediatric dentistry specialist according to the ICCMS™ radiographic scoring system, which provides an accurate assessment of the depth of interproximal dental caries. This index has a high reproducibility and accuracy with histologic lesion depth (Ekstrand et al. 2022).

Various percentages of SDF are available globally; however, this study used 30% SDF as it is the only concentration available in the Iranian market. According to the study by Punhagui et al. (Punhagui et al. 2021), 30% SDF and 38% SDF showed no difference in enamel remineralization. In addition, the findings from micro-CT analysis in the mentioned study revealed that the internal porosity of demineralized enamel resembled that of enamel subjected to 38% SDF. In comparison, enamel treated with 30% SDF had a comparable to intact enamel.

The overall caries arrest rate of 74.4% was higher than a recent meta-analysis result, which found a caries arrest rate of 51.62% using SDF with a concentration of 38% or more, applied annually or biannually (Zaffarano et al. 2022). However, the reviewed studies used a higher percentage of SDF than the present study. Moreover, in those studies, SDF was applied to the outer surfaces of the teeth rather than the interproximal surfaces. Also, its effectiveness was assessed using visual and tactile examinations. Additionally, the studies included children within a wider age range who had active dentin lesions, and they conducted follow-ups lasting more than six months (Tirupathi et al. 2019; Mabangkhru et al. 2020; Abdellatif et al. 2021; Vollú et al. 2019; Fung et al. 2018). In the current study, caries status was accurately evaluated using digital bite-wing radiographs. More importantly, SDF was applied directly to the interproximal area that could explain the higher caries arrest rate. On the other hand, the current results were lower than the findings of Hammersmith et al. (Hammersmith et al. 2020), who reported an overall caries arrest rate of 84% after 12 months. Variations in the findings from the two studies could be due to differences in their methodologies and the characteristics of the participants involved. Hammersmith et al. (Hammersmith et al. 2020) applied NaF varnish over the SDF. Moreover, some patients were treated for multiple lesions that increase the total dose. Additionally, certain patients received treatment for multiple lesions, which resulted in an increased overall dose. Furthermore, both anterior and posterior teeth, with varying numbers of surfaces were included, highlighting the need for careful interpretation. Furthermore, the mean ICCMS™ of the participants was approximately 1.5, which was lower than the current study (2.20). Although the baseline ICCMS values were not related to the treatment result of SDF, the proportion of treatment success decreased by increasing the caries severity. In the current study, NaF varnish was not applied over the SDF because it was intended to evaluate the SDF treatment alone. Our findings were comparable with Zhi et al. (Zhi et al. 2012), who found a caries arrest rate of 79% on 24 months follow-up. However, they examined children 3–4 years old and both anterior and posterior dentition.

According to the latest American Academy of Pediatric Dentistry (AAPD) and American Dental Association (AAD) guidelines for fluoride therapy, topical fluoride therapy should be performed every six months for children with a high risk of caries (Clark et al. 2020). Despite recommendations for multiple applications of topical fluoride agents (Khehra 2018), adherence to these guidelines is often lacking in lower-and-middle-income countries (LMICs). Systemic barriers, including limited access, lack of awareness, and socioeconomic challenges, significantly hinder regular dental visits. Research shows that the uptake of fluoride treatments tends to be restricted to infrequent dental appointments, primarily due to issues like cost and the availability of dental services (Osadolor and Osadolor 2024). In resource-constrained settings, parents might deprioritize multiple fluoride visits because of financial limitations or misunderstandings about the necessity and advantages of such treatments (Osadolor and Osadolor 2024). Consequently, this study explored whether a single application of SDF and NaF varnish could effectively protect against proximal caries. The promising findings suggest that while encouraging parents to make regular visits to dental clinics is ideal, even a single application of fluoride agents can still offer significant protective benefits after 6 months. Remineralization effects can be observed as early as 60 min post-application, with significant changes noted at three and six months (Nehme et al. 2019; Shaalan et al. 2024). Thus, in this trial, we assessed the impact of over a period of six months, consistent with the methodology used in prior studies (Abdellatif et al. 2023).

Unlike with SDF, the baseline radiographic caries depth was significantly associated with the treatment result of the NaF varnish. This could be attributed to NaF's lower efficacy on penetrating into deeper lesions (Mashhour et al. 2023). Our results align partially with the study conducted by Phonghanyudh et al. (Phonghanyudh et al. 2022), which revealed that the treatment impact on ICDAS-2 lesions exceeded that on ICDAS-3 lesions for both the 38% SDF and 5% NaF varnish groups. This underscores the importance of early intervention in effectively managing enamel caries using NaF varnish.

The findings indicated that the success rate of SDF and NaF varnish was comparable. As expected, black staining was observed more in the SDF group. However, since stains were out of sight, they were not concerning for the parents. Numerous studies have examined the effectiveness of SDF and NaF varnish in preventing or halting caries in primary dentition (Jain et al. 2023; Yassin et al. 2023a; Abdellatif et al. 2023; Chu et al. 2002; Phonghanyudh et al. 2022). Similar to our findings, Duangthip et al. (Duangthip et al. 2018) reported 30% SDF and 5% NaF arrest ICDAS-3 or ICDAS-4 lesions to a comparable extent. Yassin et al. (Yassin et al. 2023b) and Phonghanyudh et al. (Phonghanyudh et al. 2022) also declared that after 6 and 18 months, respectively, the impact of 38% SDF and NaF varnish were comparable in moderate lesions and enamel lesion.

However, some studies have indicated a superior effect of 38% SDF over NaF varnishes in arresting caries lesions, especially moderate or advanced lesions in primary teeth (Jain et al. 2023; Chu et al. 2002; Phonghanyudh et al. 2022). Duangthip et al. (Duangthip et al. 2015) indicated that applying SDF solution annually or over three consecutive weeks is more effective in halting dentin carious lesions in primary dentition than using NaF varnish three weeks in a row. The difference between the findings might be attributed to several factors. According to the manufacturer's declaration, Cariestop 30% contains 35,400 ppm of F. However, Soares-Yoshikawa et al. (Soares-Yoshikawa et al. 2020) informed that the fluoride concentration found in the Cariestop 30% was 11,858 ppm, which disagrees with the manufacturer's declaration. On the other hand, FluoroDose contains 22,600 ppm of fluoride, according to the manufacturer. Therefore, the fluoride concentration of 30% SDF was lower than NaF varnish. Moreover, we have focused on initial caries arrest, while other studies have investigated dentin lesions arrest (Chu et al. 2002) and caries prevention (Jain et al. 2023). Furthermore, in the current study, radiographic examination was performed by a blinded examiner. The split-mouth design also decreased patient-related confounding factors (Mohammadipour et al. 2024), and only proximal caries between primary molars were investigated. These considerations have enhanced the reliability of our findings.

It must be noted that despite the advantages of split-mouth designs, this methodology's limitations include the crossover effects of the intervention. SDF also retains fluoride 2 to 3 times more effectively than other types of topical agents, inhibits biofilm growth, and decreases bacterial load more strongly than NaF (Chhattani, et al. 2021; Yu et al. 2018). SDF could be the sole treatment alternative for specific groups with limited resources (Vollú et al. 2019). It is also more cost-effective than NaF varnish (Jain et al. 2023). However, parents must be encouraged to maintain the oral hygiene of their children, as the findings indicated that dental flossing was significantly related to the SDF group treatment success.

The present RCT had some limitations. No positive control group was included due to ethical concerns. Other teeth in the child's mouth could not be used as a control group due to the existing fluoride. Second, only initial caries lesions were investigated. Further RCTs are warranted to assess the efficacy of SDF on moderate and advanced caries and in a longer follow-up period. Moreover, parents may have filled out the questionnaire inaccurately regarding their child's oral hygiene due to social desirability bias or inaccurate memory. However, it is challenging to assess children's oral hygiene habits using objective measures, such as plaque index scoring, because plaque can accumulate quickly, often within hours. This makes a single measurement inadequate for reflecting long-term oral hygiene practices (Buskin 1977). Nevertheless, future studies should incorporate both objective measures and self-reported oral hygiene practices to enhance the accuracy of the findings.

Conclusion

The present study concluded that applying 5% NaF varnish and 30% SDF on proximal initial lesions led to a comparable overall caries arrest rate in primary molars during the study duration. However, the success of NaF varnish treatment, unlike SDF therapy, was associated with initial caries depth. Further studies are warranted to investigate more advanced proximal lesions.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOC 219 KB) (219KB, doc)

Acknowledgements

The current study was extracted from a master thesis and authors wish to thank the research deputy of North Khorasan University of Medical Sciences for providing support to do this work (No.: 990198).

Author contributions

A.M., F.M, and M.H. made a substantial contribution to the concept and design of the study, supervised the study, participated in analysis, and interpretation of data. A.K. and A.M. collected and analyzed the data. M.H. prepared the first draft of the manuscript. A.M., F.M., and A.K. revised the manuscript. Finally, all authors have read and approved the final manuscript.

Funding

This study was funded by the North Khorasan University of Medical Sciences, Bojnurd, Iran.

Data availability

The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

All methods were carried out in accordance with relevant guidelines and regulations. The protocol of this RCT was approved by the Ethics Committee of the North Khorasan University of Medical Sciences (Code: IR.NKUMS.REC.1401.040) and was registered at the Iranian Registry of Clinical Trials (IRCT) (identifier: IRCT20220425054647 N1, https://en.irct.ir/trial/63168). Participants’ parents were informed about the study purpose, risks, and benefits, and the written informed consent was obtained from them.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Footnotes

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

  1. Abdellatif HM, Ali AM, Baghdady SI, Elkateb MA (2021) Caries arrest effectiveness of silver diamine fluoride compared to alternative restorative technique: randomized clinical trial. Eur Arch Paediatr Dent 22:575–585 [DOI] [PubMed] [Google Scholar]
  2. Abdellatif EB, El Kashlan MK, El Tantawi M (2023) Silver diamine fluoride with sodium fluoride varnish versus silver diamine fluoride in arresting early childhood caries: a 6-months follow up of a randomized field trial. BMC Oral Health 23:875 [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Banihani A, Santamaría RM, Hu S, Maden M, Albadri S (2022) Minimal intervention dentistry for managing carious lesions into dentine in primary teeth: an umbrella review. Eur Arch Paediatr Dent 23:667–693 [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Buskin S (1977) The plaque control index: A practical method of assessing the effectiveness of oral hygiene procedures.
  5. Chhattani B et al (2021) Comparative evaluation of antimicrobial efficacy of silver diamine fluoride, chlorhexidine varnish with conventional fluoride varnish as a caries arresting agent. An in vivo sodium dodecyl sulfate-polyacrylamide gel electrophoresis study. J Indian Soc Pedod Prev Dent 39:398–402 [DOI] [PubMed] [Google Scholar]
  6. Chu CH, Lo EC, Lin HC (2002) Effectiveness of silver diamine fluoride and sodium fluoride varnish in arresting dentin caries in Chinese pre-school children. J Dent Res 81:767–770 [DOI] [PubMed] [Google Scholar]
  7. Clark MB, Keels MA, Slayton RL (2020) Fluoride Use in Caries Prevention in the Primary Care Setting. Pediatrics 146 [DOI] [PubMed]
  8. Dikmen B (2015) Icdas II criteria (international caries detection and assessment system). J Istanb Univ Fac Dent 49:63–72 [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Dos Jr Santos VE, De Vasconcelos FM, Ribeiro AG, Rosenblatt A (2012) Paradigm shift in the effective treatment of caries in schoolchildren at risk. Int Dent J. 62:47–51 [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Duangthip D, Jiang M, Chu CH, Lo EC (2015) Non-surgical treatment of dentin caries in preschool children–systematic review. BMC Oral Health 15:44 [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Duangthip D, Wong MCM, Chu CH, Lo ECM (2018) Caries arrest by topical fluorides in preschool children: 30-month results. J Dent 70:74–79 [DOI] [PubMed] [Google Scholar]
  12. Ekstrand KR, Cordeschi T, Abreu-Placeres N (2022) ICCMS™ root caries lesions stages and their underlying depth towards the pulp: an in vitro study with histologic evaluation. Clin Oral Investig 26:2597–2605 [DOI] [PubMed] [Google Scholar]
  13. Fernandes SC, Louceiro A, Lopes LB, Esteves F, Arriaga P (2021) Children’s Attitudes and Behaviors about Oral Health and Dental Practices. Healthcare (Basel) 9:416 [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Fung MHT, Duangthip D, Wong MCM, Lo ECM, Chu CH (2018) Randomized Clinical Trial of 12% and 38% Silver Diamine Fluoride Treatment. J Dent Res 97:171–178 [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Gao SS, Zhang S, Mei ML, Lo EC, Chu CH (2016) Caries remineralisation and arresting effect in children by professionally applied fluoride treatment - a systematic review. BMC Oral Health 16:12 [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Hammersmith KJ, Depalo JR, Casamassimo PS, Maclean JK, Peng J (2020) Silver Diamine Fluoride and Fluoride Varnish May Halt Interproximal Caries Progression in the Primary Dentition. J Clin Pediatr Dent 44:79–83 [DOI] [PubMed] [Google Scholar]
  17. Hassan M, Mohamed Ismai AADA, Abbas AN, Ibrahim HF (2024) Evaluation of Antibacterial Effect of Silver Diamine Fluoride and Sodium Fluoride Varnish on Bacterial Biofilm (An In Vitro Study). Al-Azhar J Dental Sci 27:261–267 [Google Scholar]
  18. Honkala E et al (2011) Measuring Dental Caries in the Mixed Dentition by ICDAS. Int J Dent 2011:150424 [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Jain A, Deshpande AN, Shah YS, Jaiswal V, Tailor B (2023) Effectiveness of Silver Diamine Fluoride and Sodium Fluoride Varnish in Preventing New Carious Lesion in Preschoolers: A Randomized Clinical Trial. Int J Clin Pediatr Dent 16:1–8 [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Khehra R (2018) Fluoride varnish application. British Dental J 224:124 [DOI] [PubMed] [Google Scholar]
  21. Kirthiga M, Muthu MS, Kayalvizhi G, Krithika C (2018) Proposed classification for interproximal contacts of primary molars using CBCT: a pilot study. Wellcome Open Res 3:98 [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Mabangkhru S, Duangthip D, Chu CH, Phonghanyudh A, Jirarattanasopha V (2020) A randomized clinical trial to arrest dentin caries in young children using silver diamine fluoride. J Dent 99:103375 [DOI] [PubMed] [Google Scholar]
  23. Mashhour A, Allam G, Wassel M (2023) Comparative evaluation of prevention of demineralization of artificial enamel caries treated with two fluoride varnishes and 38% SDF in primary teeth: an in vitro study. BMC Oral Health 23:110 [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Mei ML et al (2013) Inhibitory effect of silver diamine fluoride on dentine demineralisation and collagen degradation. J Dent 41:809–817 [DOI] [PubMed] [Google Scholar]
  25. Mei ML et al (2014) An ex vivo study of arrested primary teeth caries with silver diamine fluoride therapy. J Dent 42:395–402 [DOI] [PubMed] [Google Scholar]
  26. Mohammadipour HS et al (2024) Evaluation and comparison of the effects of a new paste containing 8% L-Arginine and CaCO3 plus KNO3 on dentinal tubules occlusion and dental sensitivity: a randomized, triple blinded clinical trial study. BMC Oral Health 24:507 [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Nehme M, Parkinson CR, Zero DT, Hara AT (2019) Randomised study of the effects of fluoride and time on in situ remineralisation of acid-softened enamel. Clin Oral Investig 23:4455–4463 [DOI] [PubMed] [Google Scholar]
  28. Neuhaus KW, Longbottom C, Ellwood R, Lussi A (2009) Novel lesion detection aids. Monogr Oral Sci 21:52–62 [DOI] [PubMed] [Google Scholar]
  29. Osadolor OO, Osadolor AJ (2024) Fluoride Varnish Intervention for Caries Prevention in Resource-Limited African Settings-A Review. Update Dental College J 14:28–30 [Google Scholar]
  30. Phonghanyudh A, Duangthip D, Mabangkhru S, Jirarattanasopha V (2022) Is Silver Diamine Fluoride Effective in Arresting Enamel Caries? A Randomized Clinical Trial. Int J Environ Res Public Health 19 [DOI] [PMC free article] [PubMed]
  31. Punhagui MF et al (2021) Effect of application time and concentration of silver diamine fluoride on the enamel remineralization. J Clin Exp Dent 13:e653–e658 [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Ruff RR, Barry-Godín T, Niederman R (2023) Effect of Silver Diamine Fluoride on Caries Arrest and Prevention: The CariedAway School-Based Randomized Clinical Trial. JAMA Netw Open 6:e2255458 [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Seifo N, Cassie H, Radford JR, Innes NP (2019) Silver diamine fluoride for managing carious lesions: an umbrella review. BMC Oral Health 19:1–10 [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Shaalan O, Fawzy El-Sayed K, Abouauf E (2024) Evaluation of the remineralization potential of self-assembling peptide P11–4 with fluoride compared to fluoride varnish in the management of incipient carious lesions: a randomized controlled clinical trial. Clin Oral Invest 28:438 [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Shah P, Jeevanandan G (2020) Oral Hygiene Maintenance In Children -A Survey On Parental Awareness. Int J Pharm Res 12:1965–1973 [Google Scholar]
  36. Soares-Yoshikawa AL, Cury JA, Tabchoury CPM (2020) Fluoride Concentration in SDF Commercial Products and Their Bioavailability with Demineralized Dentine. Braz Dent J 31:257–263 [DOI] [PubMed] [Google Scholar]
  37. Timms L, Sumner O, Deery C, Rogers HJ (2020) Everyone else is using it, so why isn’t the UK? Silver diamine fluoride for children and young people. Community Dent Health 37:143–149 [DOI] [PubMed] [Google Scholar]
  38. Tirupathi S, Svsg N, Rajasekhar S, Nuvvula S (2019) Comparative cariostatic efficacy of a novel Nano-silver fluoride varnish with 38% silver diamine fluoride varnish a double-blind randomized clinical trial. J Clin Exp Dent 11:e105–e112 [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Treeratweerapong Y, Nakornchai S, Jirarattanasopha V (2023) Effectiveness of applying proximal enamel caries with fluoride-releasing sealant and fluoride varnish on caries progression in permanent teeth: A 12-month split-mouth randomized clinical trial. Int J Paediatr Dent 33:30–39 [DOI] [PubMed] [Google Scholar]
  40. Van Rijkom HM, Truin GJ, Van T’Hof MA (1998) A meta-analysis of clinical studies on the caries-inhibiting effect of fluoride gel treatment. Caries Res 32:83–92 [DOI] [PubMed] [Google Scholar]
  41. Vollú AL et al (2019) Efficacy of 30% silver diamine fluoride compared to atraumatic restorative treatment on dentine caries arrestment in primary molars of preschool children: A 12-months parallel randomized controlled clinical trial. J Dent 88:103165 [DOI] [PubMed] [Google Scholar]
  42. Yassin R, Amer H, Tantawi ME (2023a) Effectiveness of silver diamine fluoride versus sodium fluoride varnish combined with mother’s motivational interviewing for arresting early childhood caries: a randomized clinical trial. BMC Oral Health 23:710 [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Yu OY, Zhao IS, Mei ML, Lo ECM, Chu CH (2018) Caries-arresting effects of silver diamine fluoride and sodium fluoride on dentine caries lesions. J Dent 78:65–71 [DOI] [PubMed] [Google Scholar]
  44. Zaffarano L et al (2022) Silver Diamine Fluoride (SDF) Efficacy in Arresting Cavitated Caries Lesions in Primary Molars: A Systematic Review and Metanalysis. Int J Environ Res Public Health 19:12917 [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Zhi QH, Lo EC, Lin HC (2012) Randomized clinical trial on effectiveness of silver diamine fluoride and glass ionomer in arresting dentine caries in preschool children. J Dent 40:962–967 [DOI] [PubMed] [Google Scholar]
  46. Zou J et al (2022) Expert consensus on early childhood caries management. Int J Oral Sci 14:35 [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Supplementary file1 (DOC 219 KB) (219KB, doc)

Data Availability Statement

The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request.

Articles from The Saudi Dental Journal are provided here courtesy of Springer

RESOURCES