## 3 Results
### Main Study Outcomes  
The objective of this study was to assess the fluoride release of different materials, after applying a coating agent. The findings across studies revealed diverse outcomes. Various materials and coatings were used to measure the amount of the cumulative fluoride ions released. In most papers, the most frequently examined material is glass ionomer [17; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47], while the next common material is composite [34; 38; 40; 41; 45; 47]. In four studies, gioomers were mentioned [33; 36; 40; 45], two studies analyzed polymers [38; 48], and only one study was conducted on bioactive glass [46]  
In terms of a system to check the amount of released fluoride, SEM analysis was used, in addition to a fluoride ion-selective electrode type 96-09 (Boston, MA, USA) and a microprocessor analyzer ORION EA 940 (Orion Res Inc., Salt Lake City, UT, USA). Nevertheless, twelve papers [32; 38; 39; 40; 41; 42; 43; 44; 45; 47; 48; 49; 53] provided a clear answer, affirming that uncoated materials presented significantly greater fluoride release in comparison with coated specimens. In those articles [52], it was noted that even high fluoride release and neutralization capacity are unable to stop secondary caries around the fillings. In one article, the authors stated that freshly set glass ionomer released the highest number of fluoride ions, which decreased every 24 h till day 21 st [43]. In another study, we found data indicating that sealant emission led to the highest fluoride ion release during the first day, which then steadily decreased until the fifteenth day [33] (see Table 1). \begin{table}
\begin{tabular}{p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt}} \hline \hline
**Study** & **Studied Material** & **Type of Coating (Composition)** & **Experimental Medium** & **Fluoride Release Measurement Technique** & **Length of Measurement Period** & **Amount of Cumulative Fluoride Ion Released (Coated vs. Non-Coated Specim)** \\ \hline \multirow{6}{*}{[PERSON] et al. [32]} & \multirow{6}{*}{Glas ionomer Equa Force Film} & 1. Equia Forte Coat (EC) (low-viscosity) & \multirow{6}{*}{A fluoride ion-selective electrode type 96-09 (Boston, MA, USA)} & \multirow{6}{*}{Equia + EC (66.01 mg/L) \(<\) EQUIA \(<\) ECUIA \(<\) PC} \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ \hline \multirow{6}{*}{[PERSON] et al. [32]} & \multirow{6}{*}{Glas ionomer Equa Force Film} & \multirow{6}{*}{Clas ionomer Equa Force Film} & \multirow{6}{*}{Delioized water} & \multirow{6}{*}{Delioized water} & \multirow{6}{*}{64 days} & \multirow{6}{*}{(123.54 mg/L) \(<\) EQUIA} \\  & & & & & & \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \hline \multirow{6}{*}{[PERSON] et al. [33]} & \multirow{6}{*}{1. GIS (Fuji VII), 2. resin sealant (Voco Ivvinky star), 3. Gioner sealant (Bohra & 1. Cheerio gel fluoride toothpaste (pH 5.3). & An expandable ion analyzer and a fluoride ion selective electrode & 30 days & 2) (Seatants with varnish) CIS \(>\) oligomer \(>\) resin sealant \\ \cline{1-1}  & & & & &  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Study** & **Studied Material** & **Type of Coating** & **Experimental** & **Fluoride Release** & **Length of** & **Amount of Cumulative** \\  & & **(Composition)** & **Medium** & **Measurement** & **Measurement** & **Fluoride Ion Released** \\  & & & & **Technique** & **Period** & **(Coated vs. Non-Coated** \\ \hline  & & & & Combination of & & The GIC-based sealant \\  & & & & fluoride electrode & & Fuji Tiage/GC \(>\) Fissurit \\  & 1. Fuji Tiage & & & Orion Orion Cr 1/S/N & & FX/Voo> Grandio \\  & (glass-isomomer & & & 13824, Orion & Soil/Voo) & \\  & (cement) & 1. Profluorid & & Research, Inc., & & The sealants tested were \\ [PERSON] et al. [34] & 2. Fissurit FX & & 2. MI Paste Plus & & & \\  & (composite resin) & & & & \\  & 3.