Donald L. Chi D.D.S., PhD
Silver diamine fluoride (SDF) is more effective than, and as safe as, fluoride varnish in arresting and preventing dental caries.
The results of two studies, only one of which was a nonrandomized study that directly compared silver diamine fluoride and fluoride varnish, suggest that silver fluoride diamine fluoride is more effective at arresting and preventing caries on primary maxillary anterior teeth.
Compared to fluoride varnish, is silver diamine fluoride a) more effective at arresting and preventing caries? and b) safer?
The authors searched five databases (MEDLINE, LILACS, EMBASE, Cochrane Library, Brazilian Dental Library) for studies that met the following criteria: 1) assessed silver diamine fluoride as a caries-preventive therapy in humans; 2) published between 1966 and 2006; 3) published in English, Spanish, or Portuguese; 4) adopted a randomized controlled trial, cohort trial, or case-control design; 5) analyzed patients as the unit of observation; and 5) reported variance estimates. Two investigators conducted the review and a third investigator resolved disagreements. Data from the studies were used to calculate two outcomes: prevented fraction (caries arrest or prevention in the treatment group compared to the control group) and the numbers needed to treat (number of children who would need to be treated to prevent one additional decayed tooth surface).
The authors identified 110 unique studies, from which 12 relevant studies were selected for further review. After reviewing the bibliographies of these 12 studies, three additional studies were selected for review. Two of the 15 studies met all the inclusion criteria. The first was a 30-month prospective cohort trial (N=308) that compared SDF to fluoride varnish. The second was a 36-month prospective cohort trial (N=373) that compared SDF to no treatment. Data from the two studies were not aggregated to generate pooled outcome measures. The reported prevented fractions for arresting active caries ranged from 55.6 percent to 122 percent for SDF and 14.2 percent to 21.3 percent for fluoride varnish. The reported prevented fractions for preventing new caries ranged from 63.6 percent to 83.5 percent (SDF) and 43.7 percent to 55.7 percent (fluoride varnish). For both outcome measures, compared to controls (either water or no treatment), the reported numbers needed to treat were 0.6 to 10 (SDF) and 1.1 to 5.6 (fluoride varnish). Neither study reported significant differences in adverse outcomes between the treatment and control groups.
Silver diamine fluoride is more effective than fluoride varnish at arresting active caries and preventing new caries. SDF is equally as safe as fluoride varnish.
Source of Funding:
Fulbright Program and The Forsyth Institute.
Importance and Context:
Although chemotherapeutic agents such as fluoride varnish are known to inhibit dental caries by decreasing acid solubility, high caries rates persist in certain population subgroups (Brickhouse et al. 2008; Parker et al. 2010). High caries rates have stimulated efforts to identify chemotherapeutic agents that will control the infection. To date, a systematic review has not been conducted to assess the effectiveness and safety of SDF.
Strengths and Weaknesses of the Systematic Review:
The reviewers used accepted methods to identify and select studies on SDF based on a priori inclusion criteria and the two studies reached similar conclusions. The reported preventive fractions and numbers needed to treat in the systematic review did not compare the SDF to fluoride varnish, and instead compared outcomes for SDF and fluoride varnish to the control groups.
Strengths and Weaknesses of the Evidence:
Both studies in the review were prospective studies with relatively large numbers of subjects in each study group, which was the main strength. While one of the studies compared SDF to no treatment, the other compared SDF to fluoride varnish. In addition, Chu and colleagues (2002) did not estimate trial sample sizes using a priori power calculations. Safety outcome measures associated with SDF were not clearly defined. There are potential problems with concluding that SDF is safe based on results from a study that may not be adequately powered to detect differences in adverse outcomes that are rare. Lastly, one study assessed the effectiveness of SDF on primary maxillary anterior teeth while the other focused on primary canines, primary molars, and permanent first molars.
Implications for Dental Practice:
Results from two studies suggest that SDF is a promising chemotherapeutic agent that arrests and prevents caries in children. However, SDF has not been approved by the FDA for clinical use in the United States. Additional studies are needed to assess safety. There are also concerns associated with staining caused by SDF, which can be addressed by restoring the SDF-treated teeth with glass ionomer. SDF may have the potential to be used in clinical settings as a chemotherapeutic agent to effectively control and reduce dental caries in high-risk populations.
Brickhouse TH, Rozier RG, Slade GD. Effects of enrollment in medicaid versus the state children's health insurance program on kindergarten children's untreated dental caries. Am J Public Health. 2008 May;98(5):876-81. Epub 2008 Apr 1
Parker EJ, Jamieson LM, Broughton J, Albino J, Lawrence HP, Roberts-Thomson K. The oral health of Indigenous children: a review of four nations. J Paediatr Child Health. 2010 Sep;46(9):483-6. doi: 10.1111/j.1440-1754.2010.01847.x.