## 3 Results
### Immunohistochemical Analysis  
Two weeks after surgery, the highest number of BMP-2-positive cells was identified in group IV (Figure 3d). Immunohistochemical analysis showed a significant increase in positively stained BMP-2 cells in group IV in comparison to groups I, II, and III (\(p\) < 0.001) (Figure 3). After four weeks of healing, we observed a significantly higher number of BMP-2-positive cells between groups III and IV in comparison to group I (\(p\) < 0.001), as well as in group IV in comparison to group II (\(p\) < 0.001) (Figure 3). Figure 3: Immunohistochemical analysis of the BMP-2-positive cells in the defects after 2 (**a–d**) and 4 (**e–h**) weeks postoperatively: (**a,e**)–group I-\(\beta\)-TCP; (**b,f**)—group II-plasma-treated \(\beta\)-TCP; (**c,g**)—group III-\(\beta\)-TCP and PDLSCs; (**d,h**)–group IV-plasma-treated \(\beta\)-TCP and PDLSCs. (**i**) Median values of immunostaining calculated by determining the BMP-2-positive areas (brown-colored cells) are presented on the graph. The magnification in all the micrographs is 40\(\times\). ***, \(p\) < 0.001—compared with group I; ***, \(p\) < 0.001—compared with group III. Two weeks postoperatively, the number of BMP-4 immunopositive cells detected in group IV (Figure 4d) was higher than in groups I, II (\(p<0.001\)), and III (\(p<0.05\)). A significantly higher number of BMP-4 positive cells was also detected in group III when compared to group I (\(p<0.05\)) (Figure 4). After four weeks, a significantly higher number of BMP-4 positive cells was noticed in group IV in comparison to groups I (\(p<0.01\)) and II (\(p<0.001\)) (Figure 4). Runx-2 immunopositive cells dominated in group IV, both two and four weeks after surgery (Figure 5d,h). We detected a significantly higher number of Runx-2 immunopositive cells in group IV in comparison to group I after two weeks and after four weeks in comparison to groups I and II (\(p<0.05\)) (Figure 5). Figure 4: Immunohistochemical analysis of the BMP-4-positive cells in the defects after 2 (**a–d**) and 4 (**e–h**) weeks postoperatively: (**a,e**)—group I—\(\beta\)-TCP; (**b,f**)—group II—plasma-treated \(\beta\)-TCP; (**c.g**)—group III—\(\beta\)-TCP and PDLSCs; (**d,h**)—group IV—plasma-treated \(\beta\)-TCP and PDLSCs. (**i**) Median values of immunostaining calculated by determining the BMP-4-positive areas (brown-colored cells) are presented on the graph. The magnification in all the micrographs is 40\(\times\). * \(p<0.05\); **\(p<0.01\); *** \(p<0.001\)—compared with group I; *** \(p<0.001\)—compared with group II; + \(p<0.05\)—compared with group III. The number of collagen-1 cells, after two weeks, was significantly higher in groups II, III, and IV when compared to group I (\(p<0.001\)) (Figure 6a-d). Collagen-1 immunohistochemical staining showed that the highest number of positive cells found was four weeks after surgery in group IV (Figure 6h) and significantly more compared to group III (\(p<0.01\)) (Figure 6). Figure 5: Immunohistochemical analysis of the Runx-2-positive cells in the defects after 2 (**a–d**) and 4 (**e–h**) weeks postoperatively: (**a,e**)—group I—\(\beta\)-TCP; (**b,f**)—group II—plasma-treated \(\beta\)-TCP; (**c,g**)—group III—\(\beta\)-TCP and PDLSCs; (**d,h**)—group IV—plasma-treated \(\beta\)-TCP and PDLSCs. (**i**) Median values of immunostaining calculated by determining the Runx-2-positive areas (brown-colored cells) are presented on the graph. The magnification in all the micrographs is 40\(\times\). *\(p<0.05\)—compared with group I; #\(p<0.05\)—compared with group II. Two weeks postoperatively, we did not find any significant difference in the number of osteonectin-positive cells between the four groups. However, after four weeks, the numbers of positive cells in groups II (\(p<0.001\)) and IV (\(p<0.01\)) were significantly higher compared to group I.