## 3 Results
### Micro-CT Results  
The three-dimensional reconstructions obtained by micro-CT showed bone formation starting from the edges of the critical-size bone defect towards the center in all groups. Additionally, they revealed bone formation involving the granules of the xenogeneic graft used in the positive control group (PC) and the positive test group (  
After 4 weeks, the NT and PT groups exhibited greater bone volume (BV) and new bone formation (NBF) compared to the NC group. Statistically significant differences were observed between the NT and the NC groups. The residual xenogeneic bone graft (RG) was larger in the PT group compared to the PC group, with a significant difference between these groups. After 8 weeks, the PT group showed the largest BV and NBF among all groups. Significant differences were found between the PT group and the NC and PC groups. The NT group also showed greater BV and NBF compared to the NC group. A positive correlation was observed between bone volume (0.81) and new bone formation (0.80) in the groups that used a membrane (NT and PT). The RG percentages decreased over time but showed no significant differences between groups or time points. The quantitative data are summarized in Table 1 and Figure 4.  
The quality of the newly formed bone was assessed by evaluating three parameters: trabecular number (Tb.N), trabecular separation (Tb.Sp), and trabecular thickness (Tb.Th). The measured values for each parameter are presented in Table 2 and illustrated in Figures 6-8. The results are reported as the mean \(\pm\) standard deviation. \begin{table}
\begin{tabular}{c c c c c} \hline
**Groups (\(n\) = 48)** & **Period (wk)** & **BV (mm\({}^{3}\))** & **NBF (\%)** & **RG (\%)** \\ \hline NC & 4 & 0.24 \(\pm\) 0.13 & 2.05\% \(\pm\) 1.28\% & - \\  & 8 & 0.46 \(\pm\) 0.17 & 3.30\% \(\pm\) 0.13\% & - \\ PC & 4 & 0.54 \(\pm\) 0.21 & 4.48\% \(\pm\) 1.56\% & 15.38\% \(\pm\) 1.86\% \\  & 8 & 0.62 \(\pm\) 0.35 & 4.51\% \(\pm\) 1.11\% & 8.41\% \(\pm\) 1.02\% \\ NT & 4 & 0.84 \(\pm\) 0.31 & 7.12\% \(\pm\) 2.48\% & - \\  & 8 & 1.05 \(\pm\) 0.43 & 11.41\% \(\pm\) 3.73\% & - \\ PT & 4 & 0.82 \(\pm\) 0.26 & 5.68\% \(\pm\) 2.02\% & 23.96\% \(\pm\) 2.15\% \\ \hline  & 8 & 1.46 \(\pm\) 0.44 & 7.58\% \(\pm\) 0.79\% & 16.53\% \(\pm\) 6.43\% \\ \hline \end{tabular}
\end{table} 
Table 1: Micro-CT results of the NC, PC, NT, and PT groups at 4 and 8 weeks of repair. Bone volume (BV) values. Percentage of newly formed bone (NBF). Percentage of residual graft (RG). Figure 5: Three-dimensional reconstructed micro-CT images of negative control group (NC), positive control group (PC), negative test group (NT), and positive test group (PT) samples at 4 weeks and 8 weeks post-surgery. The gray color represents newly formed bone, and the blue color represents the remaining graft granules. These images were obtained using CT Analyzer software. The positive test group demonstrated higher trabecular number (Tb.N) values at both evaluation periods, with 1.54 \(\pm\) 0.54 at 4 weeks and 3.05 \(\pm\) 0.60 at 8 weeks, showing a statistically significant difference compared to the negative control and negative test groups in 4 weeks and a statistically difference compared to the other groups in 8 weeks. (\(p\) < 0.05). Regarding trabecular thickness (Tb.Th), the negative test group exhibited higher values, with 0.0675 \(\pm\) 0.0096 at 4 weeks and 0.0875 \(\pm\) 0.0126 at 8 weeks, also displaying a statistically significant difference compared to the other groups (\(p\) > 0.05).