Preventing caries on occlusal surfaces of molars is a key preventive care objective in all patients, but especially for children and those from lower socioeconomic groups. A new study compared fluoride varnish (FV) and pit-and-fissure sealant (FS) for caries prevention in these children.
Fluoride varnish and sealants are used in some community- and school-based oral health programs to reduce or prevent caries in children, but their relative clinical effectiveness is unknown. In a new study of more than 800 children, researchers from the U.K. directly compared these two preventive treatments on first permanent molars (FPM) and, somewhat surprisingly, found that the fluoride varnish was as effective as the sealant.
"The current trial clearly showed that while [fewer than] 1 in 5 children had developed decay into dentine in their FPMs at 36 months, there was no clinically important difference in the proportion of children developing decay on any FPM whether treated with FS or FV," the authors wrote (Journal of Dental Research, April 10, 2017).
The study was led by Ivor Chestnutt, BDS, MPH, PhD, a professor in the division of applied clinical research and public health and also an associate dean for postgraduate studies at the Cardiff University School of Dentistry.
Direct comparison
Children, and their teeth, vary in their susceptibility to dental caries, but caries prevalence is often linked to social and economic disadvantage. The occlusal surface of first permanent molars is particularly prone to caries, especially soon after the tooth erupts.
Both sealant and fluoride varnish have proved to be effective in preventing caries when compared with no treatment, but which is more clinically effective? The U.K. researchers wanted to compare these two treatments in preventing dental caries in first permanent molars in 6- to 7-year-olds.
For their randomized clinical trial, the researchers started with more than 1,000 children from 66 primary schools in Wales. These schools were located in areas of social and economic deprivation as designated by the Welsh government. All children in these schools are considered to be at high risk for caries and qualified for sealant or varnish application. Caries status was assessed in these children at baseline and 12, 24, and 36 months by trained dentists.
The children were randomized to either receive a resin-based sealant or fluoride varnish. The sealant (Delton, Dentsply Sirona) was applied to caries-free FPMs and maintained at six-month intervals. The varnish (Duraphat 50 mg/mL, Colgate-Palmolive) also was applied at baseline and six-month intervals for three years.
At 36 months, 835 (82%) children remained in the study with 417 in the sealant arm and 418 in the varnish arm. The main outcome measures were the proportion of children who developed caries into dentine on any one of up to four treated FPMs after three years.
Less than 20% of children in each group developed caries. The caries rate for children who received the fluoride varnish was 17.5%, compared with 19.6% for the sealant group, a nonstatistically significant difference, according to the study authors.
The researchers also found no difference between the proportion of boys and girls who developed caries in the study.
Result a surprise?
This was the largest study to address the clinical effectiveness and cost-effectiveness of both pit-and-fissure sealant and fluoride varnish, according to the authors.
The results of this study might surprise pediatric and public health dentists, because a 2016 systematic review (Cochrane Database of Systematic Reviews, January 18, 2016) suggested that sealants might be clinically superior to fluoride varnish, they noted. The evidence available for that review, however, was considered to be of low quality, according to authors of the Cochrane review.
In addition, the authors of the current study noted that both the department of health in the U.K. and the American Dental Association recommend sealant use for effective caries prevention, but the findings of the new study suggest that six-month application of fluoride varnish is comparable to sealant use, which may contradict their recommendations of preferring sealants over fluoride varnish to prevent occlusal caries.
"In a community oral health program, semiannual application of FV resulted in caries prevention that was not significantly different from that obtained by applying and maintaining FS after 36 months," the authors concluded.
