Satish Kumar DDS, MDSc
Toothpastes with fluoride concentrations of 1000 ppm and above prevent caries in children and adolescents.
Good quality evidence supports the cariostatic effect of toothpastes (FT) with fluoride concentration of 1000 ppm and above in mixed/permanent dentition but limited evidence only suggests a similar effect in the deciduous dentition.
What is the relative effectiveness of fluoride toothpastes (FT) of different concentrations in preventing dental caries in children and adolescents and what are the potentially modifying effects of baseline caries level and supervised toothbrushing?
The authors searched 4 databases for literature published between 1950 and June 2009. Specific exclusion and inclusion criteria were used to address the clinical questions. The authors considered randomized controlled trials and cluster-randomized controlled trials comparing FT with placebo or FT of a different concentration in children up to 16 years of age with a follow-up period of 1 year . The primary outcome was caries increment in the permanent or deciduous dentition as measured by the change in decayed (D), missing (M), filled tooth surfaces (FS) from baseline. The primary effect measure was the prevented fraction (PF) defined as the caries increment of the control group minus the caries increment of the treatment group, expressed as a proportion of the caries increment in the control group. The secondary outcome measures included side effects such as soft tissue damage and tooth staining but not fluorosis. The authors used network meta-analysis, which facilitates indirect comparisons, network meta-regression or meta-analysis models to pool data where appropriate, and analyzed potential sources of heterogeneity.
The authors included 75 studies (83 trials). Of the 75 studies, 71 of them (79 trials totaling 73,000 children) contributed data to the network meta-analysis, network meta-regression or meta-analysis. In 66 studies (74 trials) that contributed to the network meta-analysis of D (M)FS in the mixed/permanent dentition, the caries prevented fraction increased significantly with higher fluoride concentrations as compared to placebo. This increase was 23% (95% credible interval [CrI]: 19% to 27%) at fluoride concentrations of 1,000, 1,055, 1,100 and 1,250 ppm. At fluoride concentrations of 2,400, 2,500, and 2,800 ppm, the increase was 36% (95% CrI: 27% to 44%). Only four studies evaluated fluoride concentrations of 440, 500, 550 ppm and lower. These studies showed no statistically significant effect when compared to placebo. Only 6 studies with different outcome measures assessed the effects of fluoride concentrations on the deciduous dentition. Again for fluoride concentrations at and above 1000 ppm, a cariostatic benefit was reported, although this was statistically significant only in 4 of these studies. The effect of FT also increased with baseline level of D(M)FS and with supervised brushing, though it was not statistically significant. There was minimal tooth staining (commonly noted with stannous fluoride) and soft tissue damage.
The efficacy of fluoride toothpastes to prevent caries in children and adolescents is significant at fluoride concentrations of 1000 ppm or higher. The relative caries preventive effects of FT of different concentrations increase with higher fluoride concentration. The decision of what fluoride levels to use for children under 6 years should be balanced with the risk of fluorosis.
Source of Funding:
School of Dentistry, The University of Manchester, UK; Department of Health Cochrane Review Incentive Scheme 2008, UK; National Institute for Health Research (NIHR), UK.
Importance and Context:
Prior systematic reviews of randomized, placebo-controlled trials have concluded that FT are effective in preventing caries when compared to nonfluoride toothpastes in children and adolescents. Higher fluoride concentrations increase the cariostatic benefit. However, a comparison of different fluoride concentration and their respective cariostatic benefits has not been directly evaluated.
Strengths and Weaknesses of the Systematic Review:
This systematic review used standardized methods to identify, select and analyze qualified studies published in all languages. Overall, this was an excellent review with few limitations. Studies done several years earlier precluded the review authors from seeking clarification of missing information and hence there could be possible bias in the results. One of the authors (Worthington, H) was involved in the design and analysis of 3 included trials and did not participate in the risk of bias assessment or the data extraction for these trials.
Strengths and Weaknesses of the Evidence:
Adequate evidence confirms the positive effect of toothpastes with fluoride concentrations at or above 1000 ppm to prevent caries in mixed/permanent dentition of children and adolescents. However, only 6 studies reported caries prevention in deciduous dentition with the use of toothpastes with fluoride concentrations at or above 1000 ppm. Although most of the studies in general were bias-free in many key areas, insufficient information was noted in 68 trials (81%) to classify the risk of bias solely in the areas of randomization, allocation concealment and outcome data. Most of the published studies focused on fluoride concentrations of 1,000 1,055, 1,100 and 1,250 ppm. This weakness and the relative lack of studies with lower and higher concentrations somewhat limits the generalizability of the results. Most studies had insufficient data on other clinically relevant factors such as nonfluoride toothpastes, anticaries agents and background exposure of fluoride.
Implications for Dental Practice:
For children and adolescents with mixed/permanent dentition, the use of FT with fluoride concentrations of 1,000 ppm or more helps to prevent dental caries. There is insufficient evidence to support the use of toothpastes with fluoride concentrations less than 1000 ppm in this population. For children with deciduous dentition alone, limited evidence suggests that toothpastes with fluoride concentrations at or above 1000 ppm prevent dental caries. However clinicians should note that the decision to use fluoride toothpaste containing 1,000 ppm or more fluoride should be carefully weighed against the potential risk of fluorosis1. Because the evidence is only suggestive of a cariostatic benefit of FT in deciduous teeth, oral health care professionals should also consider advising parents or caretakers to supervise toothbrushing of children for better caries protection with FT.
(1) Wong MC, Glenny AM, Tsang BW, Lo EC, Worthington HV, Marinho VC. Topical fluoride as a cause of dental fluorosis in children. Cochrane Database Syst Rev. 2010 Jan 20;(1):CD007693.