## 3 Results
The lowest level of cumulative F-ions release was observed after incubation in AS pH 7.0 and AS pH 6.0 (Table 2). We observed statistically significant correlations between selected time points and fluoride ions release in all tested incubation environments (\(p<0.001\)) (Table 2). The composite material Wave (W) revealed the highest cumulative release of fluoride ions to deionized water (\(8.00\pm 2.0\)\(\mathrm{\SIUnitSymbolMicro g}\) F/mm\({}^{2}\)), followed by an artificial saliva solution at pH 5.5 (\(6.8\pm 1.1\)\(\mathrm{\SIUnitSymbolMicro g}\) F/mm\({}^{2}\)) and saline (5.4 \(\pm\) 0.7 \(\mathrm{\SIUnitSymbolMicro g}\) F/mm\({}^{2}\)). The lowest emission was observed in artificial saliva solution with pH 7.0 (1.4 \(\pm\) 0.5) (Table 2). After the first hour, the material released fluoride the fastest to deionized water and 0.9% NaCl (1.5 \(\pm\) 0.1 \(\mathrm{\SIUnitSymbolMicro g}\) F/mm\({}^{2}\)/h), and the slowest to artificial saliva with the addition of calcium ions at pH 5.5 (0.4 \(\pm\) 0.1 \(\mathrm{\SIUnitSymbolMicro g}\) F/mm\({}^{2}\)/h), (Table 1). On average, the increase in fluoride emission was the highest in the deionized water, 0.9% NaCl, and pH 5.5 environments (0.4 \(\pm\) 0.6 \(\mathrm{\SIUnitSymbolMicro g}\) F/mm\({}^{2}\)/h). \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & **AS** & **AS** & **AS** & **AS** & **AS** & **AS** & **AS** & **AS** & **C2\({}^{\text{\text{\text{\textasci  
We showed statistically significant differences in F-ion release in time periods of compomer Freedom into tested incubation environments (\(p<0.0001\) for all) (Table 3 and Figure 5 right). The significantly highest levels of fluoride ions release was demonstrated after 1 h and 3 h of incubation for whole study groups, especially into AS pH 4.5 and AS pH 5.5 (Table 3). Also cumulated levels of fluoride ions release from compomer (F) were highest during incubation in AS pH 4.5 and AS pH 5.5, and significantly lower values of cumulated F-ions were observed in 0.9% NaCl and AS pH 7.0 solutions (Table 4, Figure 6 right). Significant correlations between time of incubation and release of F-ions were presented in all tested environments (\(p<0.001\)) (Table 4). The Freedom (F) compomer showed the highest cumulative release of fluoride ions into the artificial saliva solution at pH 4.5 (31.2 \(\pm\) 10.5 \(\upmu\)g F/mm\({}^{2}\)), followed by saliva at pH 5.5 (23.2 \(\pm\) 1.1 \(\upmu\)g F/mm\({}^{2}\)), and lowest into the solution saline (3.7 \(\pm\) 1.1 \(\upmu\)g F/mm\({}^{2}\)) (Table 4). In addition, the most differentiated increases in fluoride emission were observed both after 1 h and on average during the entire observation period in the environment of artificial saliva with pH 4.5 (5.7 \(\pm\) 2.5 \(\upmu\)g F/mm\({}^{2}\)/h and 1.7 \(\pm\) 2.5 \(\upmu\)g F/mm\({}^{2}\)/h, respectively) and in the solution saline (0.3 \(\pm\) 0.01 \(\upmu\)g F/mm\({}^{2}\)/h and 0.1 \(\pm\) 0.1 \(\upmu\)g F/mm\({}^{2}\)/h, respectively) (Table 3). The amounts of released fluoride from the Freedom (F) compomer were much higher compared to the Wave (W) composite material. The physiological saline solution and deionized water did not appear to favour the emission of fluoride ions, in their case the Freedom material (F) recorded low values of released fluoride. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline  & **AS** & **AS** & **AS** & **AS** & **AS** & **AS+ Ca\({}^{2+}\)** & **AS+ Ca\({}^{2+}\)** & **Deionized** & **0.9\% NaCl** \\
**Time** & **pH 4.5** & **pH 5.5** & **pH 6.0** & **pH 7.0** & **pH 7.5** & **pH 4.5** & **pH 5.5** & **H\({}_{2}\)O** & **(9)** \\
**(Hours)** & **(1)** & **(2)** & **(3)** & **(4)** & **(5)** & **(6)** & **(7)** & **(8)** & **(9)** \\  & **(ug/mm\({}^{2}\)  
Similarly in the case of the Wave material, artificial saliva solutions with a pH of 4.5 and 5.5 without the content of Ca\({}^{2+}\) ions turned out to be most suitable for the intensification of the fluoride release from the compomer (F).