## 3 Results  
### Results for Radiological Variables  
Using Albira Suite software, high definition 2D and 3D reconstructions were obtained. Images of the peripheral pristine bone (PPB) were taken and used as a reference for radiological analysis (Figure 3). Bone quantification variables were measured, in which after 3 weeks there were no statistically significant differences across the PSB, SB and CONTROL groups in the Total SUM, Averaged and % Healthy Bone variables. The PS group was the one which obtained the least significant values for these three variables (Tables 1 and 2). Three weeks later histological evaluations were made of the four groups (Table 3 and Figure 4). The bone height variable showed no statistically significant differences across the groups after 3 weeks of healing. Two histological stainings, Von Kossa and fluorescence, were carried out (Figure 5). The first was used to observe mineralised bone. The bone area [BA], area percentage [%BA] and bone perimeter [BP] were observed. The Von Kossa staining revealed that the PSB group presented statistically higher BA and BP than the other groups. The %BA was higher in the CONTROL group although not significantly compared to all the groups, the sample size being very small. The fluorescence staining was employed to measure the aforementioned variables in newly deposited bone. No statistically significant differences were observed across the groups for the BA and %BA variables after 3 weeks. In the SB group the bone perimeter was significantly higher, the PSB group being the one which showed a significantly lower value. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **PSB** & **PS** & **SB** & **CONTROL** \\ \hline Total [SUM] & 624,660.31 \(\pm\) & \(-\)1,639,444.22 \(\pm\) & 133,306.39 \(\pm\) & \(-\)75,755.14 \(\pm\) \\  & 2,250,130.64 ** & 2,777,161.44 ** & 3,121,502.01 * & 2,975,902.80 \\ Averaged [HU] & 105.17 \(\pm\) 378.54 ** & \(-\)276.21 \(\pm\) 467.589 ** & 22.33 \(\pm\) 524.53 * & \(-\)12.58 \(\pm\) 501.389 \\ \% Healthy Bone & 68.44 \(\pm\) 25.11 * & 44.65 \(\pm\) 29.38 ** & 61.15 \(\pm\) 31.60 & 61.98 \(\pm\) 33.69 ** \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Radiological results (total HU of bone density of the area studied per group, median of said measurement per group and % of regenerated bone per group) after 3 weeks. The statistically significant differences are shown in the same row by pairs of similar symbols (*, **; \(p\) \(<\) 0.05). \begin{table}
\begin{tabular}{c c c} \hline \hline  & **BONE** & **AIR** \\ \hline Total [SUM] & 3,760,926.76 \(\pm\) 858,429.84 & \(-\)5,942,171.43 \(\pm\) 15,026.42 \\ Averaged [HU] & 632.91 \(\pm\) 144.35 & \(-\)1000 \(\pm\) 0.00 \\ \% Healthy Bone & 100 \(\pm\) 6.34 & 0.00 \(\pm\) 0.00 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Radiological results after 3 weeks of bone and air. Both groups have been analysed for reference use but were not compared with the rest of the study groups. Figure 3: 3D reconstructions of the PPB (**A**,**B**) and SB group after 3 weeks (**C**,**D**). Region of interest (ROI) on image D with new bone formation inside the defect (arrow). The images present a calibration of 1 \(\upmu\)m. The colour range oscillates between 250–1000 HU. Figure 4: Graph chart of the three variables measured with Von Kossa and fluorescence stains after 3 weeks. The statistically significant differences between groups are shown with (*) symbol (\(p<0.05\)).