# Review of Professionally Applied Fluorides for Preventing Dental Caries in Children and Adolescents
## 3 Results and Discussions
### Fluoride Varnishes  
There are three principal fluoride varnishes most commonly used: Duraphat (Colgate Oral Pharmaceuticals, Cologne, Germany) containing sodium fluoride with 2.26% F (22,600 ppm), Fluor Protector (Ivoclar Vivadent, Schaan, Liechtenstein) containing 0.9% diffusilane with 0.1% [1000 ppm] F, and Bifluoride (Voco, Cuxhaven, Germany) containing sodium fluoride with 5.6% F [17; 21; 34; 35]. For a single application, 0.2 to 0.5 mL of fluoride varnish is usually used, and this amount contains approximately 5 to 10 mg of total fluoride ion [16]. High-concentration fluoride varnish is applied by dental professionals directly onto the teeth and sets in a few seconds when it comes into contact with saliva [16; 17; 36]. Fluoride varnish is not intended to adhere permanently to the teeth; a small amount of varnish painted on the teeth maintains a highly concentrated topical fluoride in contact with the superficial layer of enamel for some time [17]. Through the varnish, the fluoride uptake increases in the superficial and deeper layers of the enamel [16]. Varnishes must be reapplied at regular intervals, effective caries protection requiring two applications per year [17]. Fluoride varnish has been frequently used as an anticaries agent in North America and Europe since the 1970s [22]. Several studies have reported that fluoride varnish and fluoride gel have a similar effect regarding caries prevention [2; 17; 23; 35]. According to U.S. Preventive Services Task Force, in-office application of fluoride varnish in children should start with the eruption of primary teeth [37]. There is no evidence in the specialty literature to point at professionally applied fluoride varnish as a risk factor for dental fluorosis, even among children younger than 6 years of age [17]. Single-dose applications of fluoride varnish are recommended for children. The total amount of fluoride swallowed is reduced by a proper application technique and is favored by the varnish capacity of wearing off the teeth over a period of hours [38]. Fluoride varnishes allow better control of patients' exposure to fluoride, less chair time being required than that needed for foams and gels [39]. No noticeable side effects were observed after using these products. Because asthmatic patients could have an allergic reaction, fluoride varnishes are contraindicated in these patients. Another side effect, especially noticed for Duraphat varnish, is the transient discoloration of the tooth, easily removed by professional brushing [23]. [PERSON] et al. (2021) published a network meta-analysis about professionally and self-applied topical fluorides for early childhood caries (ECC) prevention, and they concluded that 3-month applications of 0.9% diffusilane (DFS) and 6-month applications of 5% sodium fluoride varnish were effective in preventing caries occurrence in primary teeth in children younger than 6 years [40]. A meta-analysis performed by [PERSON] et al. (2016) on four studies about the effect of 5% NaF varnish on early enamel caries showed that the overall percentage of remineralised enamel caries was 63.6% (95% CI: 36.0-91.2%; \(p<\) 0.001) [41]. Moreover, [PERSON] et al. (2016) systematically reviewed the role of fluoride varnish in the prevention of early childhood caries. They found a caries preventive fraction of 6.4% to 30% when 1% varnish was applied, and 5% to 63% when the 5% concentration of fluoride was used [42]. In 2013, [PERSON] et al. performed a meta-analysis on topically-applied fluoride varnishes: 13 trials for permanent teeth and 10 trials for primary teeth. The pooled D(M)FS PF estimate comparing fluoride varnish with placebo or no treatment was 43% (95% confidence interval (CI) 30% to 57%; \(p<\) 0.0001). The pooled d(e/m)fs PF estimate was 37% (95% CI 24% to 51%; \(p<\) 0.0001) [43]. [PERSON] et al.