Calcium and phosphate added to fluoride varnishes without silver dot to fight tooth decay in children, study finds

In a recent study published in the journal Scientific Reportsresearchers examined the effect of sodium fluoride varnishes containing phosphates and calcium on Streptococcus mutans and Lactobacillus fermentum measures in caries-free and carious children with and without cavitary lesions and compared it with the effect of conventional sodium fluoride varnishes.

Study: Effect of fluoride varnishes on oral bacteria of preschool children with cavitated and non-cavitated caries lesions: a randomized clinical trial. Image Credit: Created with the help of DALL·E 3

Record

Early childhood caries is highly prevalent in children worldwide and bacterial growth in dental biofilms is the etiological basis of this multifactorial microbial disease. Furthermore, despite significant emphasis on dental health, millions of children suffer from caries in their primary teeth. Disruption of the overall enamel continuity is graded for severity based on the presence or absence of pitting lesions. Several studies have examined the role of demineralization in the formation of cavitated lesions, but there is a lack of longitudinal studies examining how noncavitated lesions become cavitated.

Tooth enamel demineralization occurs when biofilm microorganisms interact with sugars and produce aids that lower the pH of the tooth surface and lead to the loss of phosphate and calcium ions. Saliva exerts some protective effect due to its antimicrobial properties, mineral ion content and pH neutralizing ability. However, the presence of pathogenic microbes such as L. fermentum and S. mutans plays an important role in the onset and development of caries, and these microbes are considered risk markers for early childhood caries.

About the study

In the present study, researchers compared the effectiveness of sodium fluoride varnishes with phosphate and calcium versus that of conventional sodium fluoride varnishes in reducing L. fermentum and S. mutans measured in the biofilm and saliva of caries-free and carious preschool children with non-cavitated or cavitated lesions. They also used a quantitative real-time polymerase chain reaction (qRT-PCR) approach with species-specific primers to accurately detect the amounts of pathogenic microbes.

Participants were selected for the study from non-profit kindergartens in Hong Kong using a random sampling method. They included children aged between three and four years with no pre-existing medical conditions, long-term medication requirements or special health needs. Those who had undergone antibiotic treatment of any kind in the last month or professional fluoride treatment at any time in the previous six months, had tooth enamel hypoplasia, were sensitive to any of the varnish components, or did not cooperate during the study were excluded.

Caries diagnoses were made by a dentist based on the International Caries Detection and Evaluation System II. The children were divided into three groups – those without caries, those with caries but non-cavitated lesions and those with caries. The intervention initially consisted of eight applications of the chosen varnish applied every four months for 24 months, but due to school closures due to the 2019 coronavirus pandemic (COVID-19) and safety concerns, it had to be reduced to three to six applications . .

Saliva and supragingival biofilm samples were collected at baseline and follow-up for deoxyribonucleic acid (DNA) extraction and qRT-PCR analysis. Species-specific oligonucleotide primer pairs were used for quantification L. fermentum and S. mutans of all samples and samples that had cycle threshold (Ct) values ​​below the detection level determined from the DNA standard curves were considered negative.

Results

The findings indicate that sodium fluoride varnishes containing calcium and phosphate did not significantly improve L. fermentum and S. mutans counts found in saliva and biofilm samples compared to conventional sodium fluoride varnishes.

However, while previous studies have examined the effect of fluoride varnishes on the biofilms of children with and without caries, they have not explicitly examined differences in microbial levels between noncavitated and cavitated lesions. The present study examined the three groups of children separately. He used a precise qRT-PCR technique to quantify the number of bacteria, which sheds more light on the microbe’s role in the creation and progression of caries.

conclusions

In summary, the study compared the effects of conventional sodium fluoride varnishes with those containing added phosphates and calcium in reducing L. fermentum and S. mutans measured in saliva and biofilm samples from preschool children. The results showed that sodium fluoride varnishes with added phosphate and calcium were not significantly different from conventional sodium fluoride varnishes in reducing bacterial growth in biofilms, and this highlights the need for more research to find effective ways to control early childhood caries. .