## 3 Results  
The Shapiro-Wilk test was employed to assess the normality of various variables. Results presented in Table 1 indicate that all variables, including the incidence of cracks, ARI scores (0, 1, 2, and 3), mixed mode of bond failure for metal bracket, bracket/adhesive mode of bond failure for metal bracket and no failure-success (100%), demonstrated statistically significant deviations from normality (\(p<0.01\)). These findings suggest that the assumption of normality is violated for these variables, necessitating caution when employing parametric statistical tests that assume normality. Non-parametric alternatives may be more appropriate for analyzing these variables to ensure accurate and reliable results. The analysis of crack incidence within the thermocycling and non-thermocycling groups yielded interesting findings regarding the presence or absence of cracks among different experimental conditions (Table 2). In the thermocycling groups, while group 2: control group demonstrated no incidence of cracks, the experimental groups exhibited varying degrees of crack formation. However, the differences were not statistically significant (\(p=0.077\)). Notably, group 5: g5_curing technique1 showed 100% cracks. Conversely, group 6: g5_curing technique2 and group 10: g7_curing technique2 displayed a 50% incidence of cracks, indicating a moderate susceptibility to crack formation with these curing techniques. In contrast, group 9: g7_curing technique2 showed a 75% incidence of cracks, suggesting a higher susceptibility to crack formation than the other experimental groups. On the other hand, in the non-thermocycling groups, crack formation was observed in some group 1: control and experimental samples, with no statistically significant differences observed across the groups (\(p=0.111\)). In group 2: the control group, no cracks were observed, indicating a lack of crack formation under standard conditions. However, varying degrees of crack formation were evident among the experimental groups. For instance, group 3: g5_curing technique1 and group 7: g7_curing technique1 exhibited a 50% incidence of cracks, suggesting a moderate susceptibility to crack formation with these curing techniques. In contrast, group 4: g5_curing technique2 displayed a higher incidence of cracks at 75%, indicating a greater susceptibility to crack formation than the other experimental groups. Interestingly, group 8: g7_curing technique2 mirrored group 2: control group, with no observed cracks, suggesting a potential protective effect or minimal impact on crack formation with this curing technique. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Items**} & \multicolumn{4}{c}{**Shapiro–Wilk**} \\ \cline{2-4}  & **Statistic** & **df** & **\(p\)-Value** \\ \hline Incidence of cracks & 0.634 & 40 & 0.000 ** \\ Adhesive Remnant Index & & & \\ (ARI) scores (0) & 0.621 & 16 & 0.000 ** \\ Adhesive Remnant Index & & & \\ (ARI) scores (1) & 0.591 & 16 & 0.000 ** \\ Adhesive Remnant Index & & & \\ (ARI) scores (2) & 0.273 & 16 & 0.000 ** \\ Adhesive Remnant Index & & & \\ (ARI) scores (3) & 0.172 & 32 & 0.000 ** \\ Mode of bond failure for & & & \\ metal bracket: Mixed & & & \\ Mode of bond failure for & & & \\ metal bracket: & 0.172 & 32 & 0.000 ** \\ Bracket/Adhesive & & & \\ No failure–Success (100\%) & 0.637 & 16 & 0.000 ** \\ \hline \hline \end{tabular}  
* Significant at a significance level of 0.01.  
\end{table} 
Table 1: Normality testing results for various variables. In comparing crack formation between thermocycling and non-thermocycling conditions, the \(p\)-value of 0.289 indicates no significant difference in crack incidence between the two groups. Figure 4 showcases the occurrence of crack formations (crack1, crack2, and crack3) in various groups under thermocycling and non-thermocycling conditions, alongside the corresponding \(p\)-values for each comparison.