## 5 Discussion  
Despite the remarkable developments of restorative dentistry, there have been demands for ion-releasing restorative materials, especially fluoride, owing to their inherent functions. In hypomineralized conditions, such as molar incisor hypomineralization,  
Figure 4: Mean scores of microleakage analysis of the experimental groups. Different lower letters on top of the long bar denote statistically significant difference among groups (\(p\) = 0.001). Navy lines mean statistically difference between the marked sub-groups (\(p\) < 0.05). \begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**Groups**} & **Margin** & \multicolumn{1}{c}{\(p\) **Value**} & \multirow{2}{*}{**pH 4**} & \multirow{2}{*}{**pH 7**} & \multirow{2}{*}{**pH 10**} & \multicolumn{1}{c}{\(p\) **Value**} \\  & **Location** & & & & & **with pH** \\ \hline \multirow{2}{*}{G a} & Oclusal & \multirow{2}{*}{0.001} & 2.857 \(\pm\) 1.069 & 2.714 \(\pm\) 0.756 & 2.428 \(\pm\) 0.787 & 0.796 \\  & Gingival & & 4.286 \(\pm\) 1.380 & 3.143 \(\pm\) 0.535 & 4.714 \(\pm\) 1.254 & 0.120 \\ \hline \multirow{2}{*}{R b} & Oclusal & \multirow{2}{*}{0.001} & 1.571 \(\pm\) 0.535 & 2.000 \(\pm\) 0.577 & 2.143 \(\pm\) 0.690 & 0.212 \\  & Gingival & & 1.000 \(\pm\) 0.000  & 1.143 \(\pm\) 0.378  & 0.032 \\ \hline \multirow{2}{*}{A b} & Oclusal & \multirow{2}{*}{0.001} & 1.714 \(\pm\) 0.756  & 1.429 \(\pm\) 0.787  & 0.0212 \\  & Gingival & \multirow{2}{*}{0.001} & 1.143 \(\pm\) 0.378  & 1.429 \(\pm\) 0.535  & 0.032 \\ \hline \multirow{2}{*}{A b} & Oclusal & \multirow{2}{*}{0.001} & 1.714 \(\pm\) 0.756  & 0.0212 \\  & Gingival & \multirow{2}{*}{0.001} & 1.143 \(\pm\) 0.378  & 1.429 \(\pm\) 0.535  & 0.032 \\ \hline \multirow{2}{*}{A b} & Oclusal & \multirow{2}{*}{0.001} & 1.714 \(\pm\) 0.756  & 0.212 \\  & Gingival & \multirow{2}{*}{0.001} & 1.429 \(\pm\) 0.535  & 0.032 \\ \hline \end{tabular}
\end{table} 
Table 3: Microleakage score assessment. -enamel hypoplasia, amelogenesis imperfeta, and white spot lesions, fluoride-releasing materials are considered anti-caries agents [22; 23]. Several fluoride-containing restorative materials are available on the market, including RMGI, compomers, giomers, and bioactive composite resins. These hybrid materials have been introduced to overcome the problems associated with conventional glass ionomers and composite resins and maintain their clinical advantages [7]. Fluoride-releasing materials have some limitations, such as insufficient physical properties and brittleness in high-stress-bearing areas. The need to improve fluoride-releasing dental materials has led to increasing research efforts focused on reinforcement techniques. In this study, the bond strengths of three different ion-releasing materials were evaluated under various pH conditions. There was no significant difference in bond strength among the materials. For RMGI and alkasite, there was no difference in bond strength among the specimens immediately tested and those tested after storage under different pH conditions. However, for giomer, the bond strength after storage in a pH 4 buffer was significantly lower than for those immediately tested or tested after pH 7-storage. Some functional monomers in dentin adhesives, especially 10-MDP, can produce an acid-base resistant zone (ABRZ) on the adhesive interface [24]. This is characterized as a structure at the resin- dentin interface that is resistant to acid-base challenges and differs from the hybrid layer [25]. In universal dentin adhesives, a thin ABRZ was observed in a self-etch application with a thick hybrid layer, and no ABRZ was observed in the etch-and-rinse mode [26]. In situations of acid challenge, ABRZ might be a protective layer against attack. Although the giomer exhibited a comparable bonding performance under other pH conditions (pH 7 and 10) in this study, it showed a significantly lower bond strength under acidic conditions at pH 4.