Key messages
- We can't tell if silver diamine fluoride (SDF) is better than no treatment at preventing or treating tooth decay.
- We can't tell if SDF is better or worse than other treatments at preventing or treating tooth decay.
- New studies could help to find out about the unwanted effects of SDF, whether people are bothered by the staining on the teeth caused by SDF, and the best treatment approach.
What is tooth decay?
Tooth decay happens when bacteria in your mouth break down sugars from food, producing acids that damage tooth enamel (hard surfaces). This can lead to holes, or cavities, in the teeth. Tooth decay affects the crown of the tooth (the part above the gum) of baby teeth, and the crown and root of permanent teeth. If it is not prevented or treated it can cause toothache, infections and tooth loss.
How is tooth decay treated?
Treatments for tooth decay include liquids, gels (varnishes) and sealants. These treatments are painted onto the tooth to protect against bacteria. Treatment may also include fillings in larger cavities. Silver diamine fluoride (SDF) is a low-cost liquid that can be painted on a tooth by a dentist or another trained person. It is suitable for people of all ages, including people with special health needs. However, SDF can permanently stain the treated tooth surface black or dark brown.
What did we want to find out?
We wanted to find out:
- if SDF was better than no treatment or other treatments at preventing new tooth decay, stopping existing tooth decay or preventing tooth decay from progressing;
- if there were benefits to applying SDF for different numbers of times, strengths of solution, or durations;
- if SDF caused unwanted effects, toothache, or if people were bothered by staining.
What did we do?
We searched for studies that compared SDF with no treatment or placebo (a dummy treatment), other treatments, or different application approaches. We compared and summarised the results of the studies and rated our confidence in the evidence, based on factors such as study methods and sizes.
What did we find?
We found 29 studies, with 12,020 children and 1016 older adults.
Main results
Compared with no treatment or placebo, we can't tell if SDF prevents new tooth decay in baby teeth or crown surfaces of permanent teeth. SDF is likely to prevent new tooth decay on root surfaces of permanent teeth. It may also completely stop existing tooth decay in baby teeth. However, we are unsure if it completely stops existing tooth decay on crown and root surfaces of permanent teeth, prevents existing tooth decay from progressing in any types of teeth, increases the risk of unwanted effects, or if people are bothered by the appearance of staining.
Studies used different combinations of treatment approaches (number of times SDF is applied and how often, the strength of solution, and duration of treatment). We can't tell if one approach is better than another at stopping or preventing further decay, unwanted effects, or bother with appearance of staining.
When SDF is compared with fluoride varnish, neither treatment may be better than the other at preventing new tooth decay in baby teeth. We are unsure about the effect on crown and root surfaces of permanent teeth. We also can't tell if either treatment is better than the other at stopping existing tooth decay or preventing further decay in baby teeth, or if there are any differences in unwanted effects, toothache, or bother with appearance of staining.
When SDF is compared with sealants, we can't tell if there are any differences between treatments in preventing new tooth decay on the crown surfaces of permanent teeth, or whether there are any differences between these treatments in unwanted effects.
When SDF is compared with fillings (with tooth decay first removed using only hand tools), we can't tell if there were any differences between treatments in stopping existing decay in baby teeth, unwanted effects, toothache, or bother with appearance of staining.
What are the limitations of the evidence?
Often we were very unsure of the evidence for the following reasons.
- SDF stains the teeth. Everyone in the studies would have known what treatment they were given. This might affect their usual teeth-brushing routine. In most studies, the person checking teeth for new or existing decay would also have known this information.
- When we compared different approaches to SDF, the studies were too different from one another to allow us to compare them.
- Although we found 29 studies, most evidence was from individual (or few) studies, which were very small.
How current is this evidence?
The evidence is current to June 2023.
In the primary dentition, evidence remains uncertain whether SDF prevents new caries or progression of existing caries compared to placebo or no treatment, but it may offer benefit over placebo or no treatment in caries arrest. Compared to placebo or no treatment, SDF probably also helps prevent new root caries. However, the evidence is uncertain for other caries outcome measures in this dentition and in all caries outcomes for coronal surfaces of permanent dentition.
Compared to flouride varnish, SDF may offer little or no benefit in preventing new caries in the primary dentition, but the evidence is very uncertain for other caries outcome measures in the primary dentition and for preventing new caries in the permanent dentition.
We were unable to establish whether one SDF treatment approach was better than another, or how SDF compared to other treatments, because of very low-certainty evidence.
The impact of SDF staining of teeth was poorly reported and the evidence for adverse effects is very uncertain. Additional well-conducted studies are needed. These should measure the impact of staining and be analysed to take account of clustering issues within participants.
Dental caries is the world's most prevalent disease. Untreated caries can cause pain and negatively impact psychosocial health, functioning, and nutrition. It is important to identify cost-effective, easy-to-use agents, which can prevent or arrest caries. This review evaluates silver diamine fluoride (SDF).
To assess the effects of silver diamine fluoride for preventing and managing caries in primary and permanent teeth (coronal and root caries) compared to any other intervention including placebo or no treatment.
We searched CENTRAL, MEDLINE, Embase, Cochrane Oral Health's Trial Register and two clinical trials registers in June 2023.
We included randomised controlled trials (RCTs), with parallel-group or split-mouth design, in children and adults (with or without carious lesions) that compared SDF with placebo or no treatment; different frequencies, concentrations or duration of SDF; or any other intervention.
We used standard methodological procedures expected by Cochrane, and GRADE to assess the certainty of the evidence. We collected data for primary caries prevention (change in caries increment), arrest of carious lesions, secondary prevention of caries (lesions do not progress from initial classification), adverse effects, dental pain or sensitivity, and aesthetics at the end of study follow-up.
We included 29 RCTs (13,036 participants; 12,020 children, 1016 older adults).
We summarise outcome data for the five most clinically relevant comparisons. All studies included high risks of bias, and some findings were imprecise (e.g. because of small sample sizes).
SDF versus placebo or no treatment (14 studies; 2695 children, 905 older adults)
Compared to placebo or no treatment, SDF may help prevent new caries in the primary dentition (1 study, 373 participants), or on the coronal surfaces of permanent dentition (1 study, 373 participants) but the evidence is very uncertain. SDF likely prevents new root caries (mean difference (MD) −0.79 surfaces, 95% confidence interval (CI) −1.40 to −0.17; 3 studies, 439 participants; moderate-certainty evidence). SDF may help arrest caries in the primary dentition (MD 0.86 surfaces, 95% CI 0.39 to 1.33; 2 studies, 841 participants; low-certainty evidence) and the permanent dentition (coronal: 1 study, 373 participants; root: 1 study, 158 participants) but the evidence is very uncertain. The evidence is very uncertain for secondary prevention of caries (primary dentition: 1 study, 128 participants; permanent dentition (coronal): 1 study, 663 participants), for adverse effects (5 studies, 1299 participants), and aesthetics (1 study, 43 participants).
Different approaches to SDF application (5 studies, 1808 children)
Studies compared different frequencies or intervals of application, different concentrations of SDF, and different durations of treatment. Some studies included multiple comparisons of different approaches. Because of the different approaches, we could not combine findings from these studies. Due to very low-certainty evidence, we were unsure whether any approach to SDF application was better than another for caries arrest (4 studies, including 8 comparisons of different approaches, 1360 participants); secondary prevention of caries (1 study, 203 participants), or led to differences in adverse effects (3 studies, 1121 children) or aesthetics (1 study, 119 children).
SDF versus fluoride varnish (8 studies, 2868 children, 223 older adults)
Compared to flouride varnish, SDF may result in little or no difference to the prevention of new caries in the primary dentition (MD 0.00, 95% CI -0.26 to 0.26; 1 study, 434 participants; low-certainty evidence). The evidence is very uncertain for this outcome measure in the permanent dentition (coronal: 1 study, 237 participants; root: 1 study, 100 participants; very low-certainty evidence). Due to very low-certainty evidence, we were unsure whether or not there were any differences between flouride varnish (applied weekly for three applications) and SDF for caries arrest and secondary prevention of caries in the primary dentition (1 study, 309 participants). Similarly, we were unsure of adverse effects (3 studies, 980 children), dental pain or sensitivity (1 study, 62 children), or aesthetics (1 study, 263 children).
SDF versus sealants and resin infiltration (2 studies, 343 children)
Very low-certainty evidence in this comparison meant we were unsure if either treatment was better than the other for primary prevention of caries in permanent dentition (coronal: 1 study, 242 participants), or adverse effects (2 studies, 336 participants).
SDF versus atraumatic restorative treatment (ART) with glass ionomer cement (GIC) or GI material (4 studies, 610 children)
Very low-certainty evidence in this comparison meant we were unsure if either treatment was better than the other at arresting caries in the primary dentition (1 study, 143 participants). We were also unsure whether there were any differences between treatments in adverse effects (3 studies, 482 participants), dental pain or sensitivity (1 study, 234 participants), or aesthetics (2 studies, 248 participants).