Discussion
The study found that the two calcium and phosphate-containing NaF varnishes have a similar effect on Previous studiesAnother similar studyUnlike earlier studies assessing the bacterial levels using CFU counts via stereomicroscope/colony counterThe study had a few limitations, like parent’s refusal of varnish application due to the fear of COVID-19 transmission and closure of kindergartens, resulting in the inability to comply with the intended number and frequency of varnish applications, which could have caused the variability in the microbial assessment outcome and comparison among groups. However, sensitivity analysis was performed and found no significant effect of the different number of fluoride varnish applications received by the children on the microbial change over the follow-up period. Whereas the effect of the time gap between varnish applications could not be explored, which might have impacted the influence of fluoride varnish applications on the bacterial counts and needs to be considered while interpreting the results of the study. In addition, the effect of fluoride on bacterial count may be underestimated based on the study findings, as the current study did not evaluate the immediate effect of fluoride on microbial level, as fluoride has shown to have an initial antibacterial effect on cariogenic microorganisms while lacking the sustainability effect. Also, our study had a longer follow-up than most of the earlier studies, which raises an important concern of fluoride resistance to Within the limitations of this 24-month randomized clinical trial, the following conclusions can be made:The two calcium and phosphate-containing NaF varnishes have a similar antibacterial effect on The current study findings raise doubt for the need for newer fluoride varnishes with additives and recommend that more well-designed clinical trials be conducted with a head-to-head comparison of different varnishes for their antimicrobial effect.