## 3 Results  
Three-way ANOVA showed that all experimental factors and their interactions had a significant effect on the \(\upmu\)SBS (\(p\) < 0.0001).  
Concerning X-tra fil (Table 2), light curing against the polyester strip revealed the highest \(\upmu\)SBS after 24 h-storage, but was statistically insignificant with FBM+, S/FBM+, CRS and S/CB (\(p\) > 0.05). Meanwhile, AB showed the lowest \(\upmu\)SBS, which was not statistically significant with S/AB (\(p\) > 0.05). On the other hand, after 6-month storage time, S/FBM+ exhibited the highest \(\upmu\)SBS, which was statistically similar to FBM+, CRS and S/CB (\(p\) > 0.05). When the material was treated with AB, it yielded the lowest \(\upmu\)SBS value, which was statistically insignificant with M (\(p\) > 0.05). In all surface treatments, \(\upmu\)SBS results significantly dropped when tested after 6 months of storage compared to 24 h testing time (\(p\) < 0.05).  
\begin{table}
\begin{tabular}{c c c c c} \hline  & **24 h** & **6 Months** & **Percentage Drop** & \(p\)**-Value** \\ \hline
**OIL** & 21.5 \(\pm\) 4.8 \({}^{\text{bCA}}\) & 16.2 \(\pm\) 1.9 \({}^{\text{bB}}\) & 24.65\% & 0.011 \\
**M** & 28.3 \(\pm\) 4.3 \({}^{\text{aA}}\) & 10.9 \(\pm\) 2.8 \({}^{\text{cB}}\) & 61.48\% & \textless{}0.001 \\
**FBM+** & 25.1 \(\pm\) 3.6 \({}^{\text{aB}}\) & 17.3 \(\pm\) 2.1 \({}^{\text{aB}}\) & 31.07\% & \textless{}0.001 \\
**S/FBM+** & 27.4 \(\pm\) 5.0 \({}^{\text{aB}}\) & 21.2 \(\pm\) 2.9 \({}^{\text{aB}}\) & 22.63\% & 0.009 \\
**AB** & 14.1 \(\pm\) 2 \({}^{\text{dA}}\) & 10.4 \(\pm\) 2 \({}^{\text{cB}}\) & 26.24\% & 0.004 \\
**S/AB** & 19.3 \(\pm\) 4.1 \({}^{\text{cA}}\) & 15.3 \(\pm\) 2.1 \({}^{\text{bB}}\) & 20.73\% & 0.035 \\
**CRS** & 26.3 \(\pm\) 5.1 \({}^{\text{aB}}\) & 20.5 \(\pm\) 3.5 \({}^{\text{aB}}\) & 22.05\% & 0.020 \\
**S/CB** & 25.2 \(\pm\) 3.0 \({}^{\text{abCA}}\) & 18.6 \(\pm\) 2.6 \({}^{\text{aB}}\) & 26.19\% & \textless{}0.001 \\ \hline \end{tabular}  
* Means with same superscript lowercase letters within each column and same superscript uppercase letters within each row are not statistically significant at \(p\) = 0.05.  
\end{table}
Table 2: Mean \(\pm\) standard deviation of \(\upmu\)SBS in MPa for the effect surface treatment within each storage time, and the effect of storage time within each surface treatment; and percentage drop in \(\upmu\)SBS of \(X\)-tra fil resin composite.  
Regarding Admira Fusion X-tra (Table 3), there was no statistically significant difference at 24 h between S/FBM+, CRS, AB, S/CB and OIL, which yielded the highest \(\upmu\)SBS values (\(p>0.05\)). However, S/AB and FBM+ showed the lowest \(\upmu\)SBS values after 6 months and were statistically insignificant (\(p>0.05\)). In all surface treatments, there was a statistically significant difference between 24 h and 6 months (\(p<0.05\)), except for S/CB, which showed no significant difference between both storage times (\(p=0.860\)).  
For the effect of material type (Table 4), there was a statistically significant difference between the two materials (\(p<0.05\)) at 24 h and 6-month storage times. Only AB surface treatment produced no statistically significant difference between the two materials either at 24 h or 6 months (\(p=0.275\) and \(p=0.06\), respectively).