## 4 Results  
Table 1 shows the analysis of chromatic change values between T0 and T1 for the four different brackets both in the VITA and Master scales, already converted in absolute values, and in the brightness scale.  
The Wilcoxon tests are summarised in Table 2.  
The IH3 DB resulted in being statistically significant with a large effect size. Moreover, the Damon Clear brackets were found to be statistically significant only for the brightness values with a large effect size.  
On the other hand, Synovate C brackets were found to be not statistically significant in all scales.  
Finally, Crystal brackets were found to be statistically significant only for the brightness values with a small effect size.  
However, analysing the differences in values in the VITA and the Master scales between T0 and T1, Table 1 shows that the colour difference in absolute values for the IH3 DB brackets ranges from a minimum value of 15 to a maximum value of 16, but, despite this, the \(p\)-value was statistically significant (Table 2). On the other hand, the Synovate C brackets' range from a maximum value at T0 of 2 to a maximum value at T1 of 14 (Table 1)  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline  & **n** & **Scale** & \multicolumn{2}{c}{**Minimum**} & \multicolumn{2}{c}{**Maximum**} & \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**Median**} & \multicolumn{2}{c}{**Standard Deviation**} \\ \cline{3-13}  & & & **T0** & **T1** & **T0** & **T1** & **T0** & **T1** & **T0** & **T1** & **T0** & **T1** \\ \hline \multirow{3}{*}{IH3 DB} & \multirow{3}{*}{10} & VITA & 15 & 15 & 15 & 16 & 15 & 15.8 & 15 & 16 & 0 & 0.42163702 \\  & & Master & 15 & 15 & 16 & 16 & 15 & 15.8 & 15 & 16 & 0.4714045 & 0.42163702 \\  & & Brightness & 23 & 23 & 21 & 26 & 20.3 & 24.3 & 21 & 24 & 1.2516656 & 0.8232726 \\ \hline \multirow{3}{*}{Damon} & \multirow{3}{*}{10} & VITA & 6 & 6 & 18 & 14 & 5.9 & 8.7 & 2 & 7 & 6.0635523 & 3.68329563 \\  & & Master & 4 & 4 & 11 & 14 & 4.4 & 5 & 1 & 4 & 4.7187569 & 3.16227766 \\  & & Brightness & 8 & 8 & 6 & 15 & 4.7 & 10.7 & 5 & 10 & 1.1595018 & 2.35937845 \\ \hline \multirow{3}{*}{Crystal} & \multirow{3}{*}{10} & VITA & 1 & 1 & 1 & 1 & 1 & 1 & 1 & 1 & 0 & 0 \\  & Master & 1 & 1 & 2 & 1 & 1.1 & 1 & 1 & 1 & 0.3162278 & 0 \\  & & Brightness & 1 & 1 & 4 & 1 & 3 & 1 & 3 & 1 & 0.4714045 & 0 \\ \hline \multirow{3}{*}{Synovate C} & \multirow{3}{*}{10} & VITA & 1 & 1 & 2 & 14 & 1.3 & 2.7 & 1 & 1.5 & 0.4830459 & 4.00138865 \\  & & Master & 1 & 1 & 9 & 9 & 5 & 3.4 & 5 & 1 & 4.2163702 & 3.86436713 \\ \cline{1-1}  & & Brightness & 1 & 1 & 1 & 2 & 1 & 1.1 & 1 & 1 & 0 & 0.31622777 \\ \hline \hline \end{tabular} n: number.  
\end{table}
Table 1: Descriptive analysis with minimum, maximum, mean, median and standard deviation at T0 and T1 brushing values.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Bracket** & **n** & **Scale** & **Z** & **\(p\)-Value** & **Effect Size** \\ \hline \multirow{3}{*}{IH3 DB} & \multirow{3}{*}{10} & VITA & 2.828 & 0.005 * & 0.894 \\  & & Master & 2.530 & 0.011 * & 0.8 \\  & & Brightness & 2.823 & 0.005 * & 0.892 \\ \hline \multirow{3}{*}{Damon Clear (Polycrystalline alumina)} & \multirow{3}{*}{10} & VITA & 1.278 & 0.201 & - \\  & & Master & 0.259 & 0.796 & - \\  & & Brightness & 2.812 & 0.005 * & 0.889 \\ \hline \multirow{3}{*}{Synovate C (Ceramic)} & \multirow{3}{*}{10} & VITA & 1.141 & 0.157 & - \\  & & Master & 1.00 & 0.317 & - \\ \hline \multirow{3}{*}{Crystal (Composite)} & \multirow{3}{*}{10} & VITA & 0.00 & 1.00 & - \\  & & Master & 1.00 & 0.317 & - \\ \cline{1-1}  & & Brightness & 2.970 & 0.003 * & 0.939 \\ \hline n: number; * \(p<0.05\). & & & & & & \\ \end{tabular}
\end{table}
Table 2: Wilcoxon test for different brackets and the VITA, Master and brightness values.  
was not statistically significant (Table 2). This difference occurs because, from a statistical point of view, the small variability of measurements may be a limitation that affects the analysis's significance.