## 3 Results
Overall, the microhardness of specimens cured with the Ha light-curing unit showed significantly lower values for all materials except SDR and XT compared to the other units at the 4 mm depth for each material, separately. Furthermore, no statistically significant differences were observed in the microhardness ratio at the 4 mm depth among each material and curing unit separately, except for the Filtek light cured by the halogen LCU, which presented significantly lower values (\(p<0.05\)). \begin{table}
\begin{tabular}{c c c c} \hline
**Depth (mm)** & **Bs** & **Ha** & **Va** & **De** \\ \hline
2 & 94.6 \(\pm\) 12.3 1,\({}^{\alpha}\) & 95.2 \(\pm\) 3.1 1,\({}^{\alpha}\) & 92.2 \(\pm\) 6.1 1,\({}^{\alpha}\) & 102.3 \(\pm\) 3.1 1,\({}^{\alpha}\) \\
3 & 88 \(\pm\) 8.3 1,\({}^{1,2}\) & 93.7 \(\pm\) 6.5 1,\({}^{\alpha}\) & 83.4 \(\pm\) 9.9 1,\({}^{\alpha}\) & 104.1 \(\pm\) 2.7 1,\({}^{\alpha}\) \\
4 & 76.8 \(\pm\) 7.5 1,\({}^{\alpha}\)2,\({}^{\alpha}\)c,d & 90.5 \(\pm\) 4.4 1,2,b,c & 77.8 \(\pm\) 6.7 1,\({}^{\alpha}\)c,d & 104.2 \(\pm\) 8.1 1,\({}^{\alpha}\) \\
5 & 62.4 \(\pm\) 20.6 2,\({}^{\alpha}\)c & 85.6 \(\pm\) 4.8 1,2,b,c & 71.1 \(\pm\) 13.1 1,2,\({}^{\alpha}\)c & 100.3 \(\pm\) 13.8 1,\({}^{\alpha}\) \\
6 & 53 \(\pm\) 1.6 3,\({}^{\alpha}\)d & 81.9 \(\pm\) 7.6 2,\({}^{\alpha}\)b & 53.1 \(\pm\) 10 2,\({}^{\alpha}\)c,d & 98.9 \(\pm\) 12.4 1,\({}^{\alpha}\) \\
7 & - & - & - & - \\
8 & - & - & - & - \\ \hline \multicolumn{4}{c}{**Xtra-Base**} \\ \hline
**Depth (mm)** & **Bs** & **Ha** & **Va** & **De** \\ \hline
2 & 96 \(\pm\) 5.1 1,\({}^{\alpha}\) & 104.6 \(\pm\) 10.6 1,\({}^{\alpha}\) & 96.6 \(\pm\) 8.8 1,\({}^{\alpha}\) & 98.3 \(\pm\) 5.7 1,\({}^{\alpha}\) \\
3 & 87 \(\pm\) 12.7 1,\({}^{\alpha}\)a & 100.4 \(\pm\) 17.3 1,\({}^{\alpha}\) & 91.6 \(\pm\) 11.3 1,\({}^{\alpha}\) & 96.3 \(\pm\) 7.9 1,\({}^{\alpha}\) \\
4 & 73 \(\pm\) 17 1,\({}^{\alpha}\)d & 90.7 \(\pm\) 10 1,\({}^{\alpha}\)b & 80.6 \(\pm\) 8.6 1,2,b,c & 92.3 \(\pm\) 6.1 2,\({}^{\alpha}\)b \\
5 & 54.5 \(\pm\) 18 2,\({}^{\alpha}\)d,d & 87.1 \(\pm\) 11.3 1,2,\({}^{\alpha}\)c & 68.8 \(\pm\) 11.2 3,\({}^{\alpha}\)c & 80.2 \(\pm\) 5.3 2,3,b,c \\
6 & 34.8 \(\pm\) 7.2 3,\({}^{\alpha}\)d & 66.8 \(\pm\) 11.2 2,\({}^{\alpha}\)b & 54.2 \(\pm\) 6.6 3,\({}^{\alpha}\)c & 72.8 \(\pm\) 6.5 3,\({}^{\alpha}\)b,c \\
7 & - & - & 39.6 \(\pm\) 3.7 4,\({}^{\alpha}\)c & 61.3 \(\pm\) 10 4,\({}^{\alpha}\)b \\
8 & & & \\ \hline \multicolumn{4}{c}{**Venus Bulk Fill**} \\ \hline
**Depth (mm)** & **Bs** & **Ha** & **Va** & **De** \\ \hline
2 & 103.7 \(\pm\) 20.2 1,\({}^{\alpha}\) & 99.4 \(\pm\) 3.8 1,\({}^{\alpha}\) & 100.2 \(\pm\) 3.6 1,\({}^{\alpha}\) & 107.1 \(\pm\) 16.4 1,\({}^{\alpha}\) \\ \hline
3 & 104.1 \(\pm\) 24.2 1,\({}^{\alpha}\) & 98.6 \(\pm\) 4.8 1,\({}^{\alpha}\) & 101.5 \(\pm\) 3.5 1,\({}^{\alpha}\) & 102.3 \(\pm\) 20.2 1,\({}^{\alpha}\) \\ \hline
4 & 99.7 \(\pm\) 20.6 1,\({}^{\alpha}\)b & 97.7 \(\pm\) 5.4 1,\({}^{\alpha}\)b & 98.3 \(\pm\) 3.2 1,\({}^{\alpha}\)b & 99.6 \(\pm\) 16.3 1,\({}^{\alpha}\)b \\ \hline
5 & 93.72 \(\pm\) 23.2 1,\({}^{\alpha}\)b & 94.7 \(\pm\) 6 1,\({}^{\alpha}\)b & 96.3 \(\pm\) 3.2 1,\({}^{\alpha}\)b & 98.2 \(\pm\) 15.3 1,\({}^{\alpha}\)b \\ \hline
6 & 79.1 \(\pm\) 7.8 1,2,\({}^{\alpha}\)c & 86.7 \(\pm\) 5.3 2,\({}^{\alpha}\)b & 95.6 \(\pm\) 3.3 1,\({}^{\alpha}\)b & 91.1 \(\pm\) 17 1,\({}^{\alpha}\)b \\ \hline
7 & 58. 2 \(\pm\) 18.4 2,\({}^{\alpha}\)b & 71.1 \(\pm\) 6.6 3,\({}^{\alpha}\)a,\({}^{\alpha}\) & 81.8 \(\pm\) 3.7 2,\({}^{\alpha}\)c & 81.3 \(\pm\) 17.9 1,\({}^{\alpha}\) \\ \hline
8 & - & - & 68.6 \(\pm\) 2.8 3 & - \\ \hline \end{tabular}
\end{table} 
Table 5: _Cont._Statistically significant differences in the microhardness ratio among the different materials polymerized by different curing lights were found at the 4 mm depth for SonicFill when cured with the Valo LCU, Tetric when cured with the Bluephase Style and Valo LCU, and Xtra-base when cured with the Bluephase Style LCU, which showed significantly lower values (_p_ < 0.05), as well as for Tetric when cured with Demi Ultra, which demonstrated a higher value (_p_ < 0.05) (Table 5).