## 4 Discussion  
In the light of the results presented in this paper, we conclude that our initial hypothesis, where the properties of PRF surpass those of acetylslicylic cones, is confirmed, especially in reference to pain relief after application. This seems to be the most important practical advantage for a patient suffering from severe pain. Overall, the distinct reduction in pain observed in our study is similar to that observed by other researchers who applied PRF in diagnosed alveolar osteitis [5; 10; 15]. However, [PERSON] et al. [16], who used this material after a third molar extraction and assessed pain using the VAS scale from the first to seventh day post application, stated that, although the VAS score decreased over time, the difference was statistically significant (\(p<0.05\)) only on the seventh day. According to our study, a \(p\)-value of 0.003 implied that pain relief during the first 24 h after treatment with PRF was significantly high. Our findings comply with those of [PERSON] et al. [17] who conducted a split-mouth study of PRF versus placebo and showed that the intensity of post-extraction pain was significantly less in the study group, starting from first 24 h after PRF application. Our finding that the pain relief was significantly lower with aspirin cones than with PRF is in contrast with the results of [PERSON], [PERSON] and [PERSON] [13], who studied the comparison between zinc oxide eugenol dressing and gelatin sponge soaked in PRF for dry socket treatment. They found that symptomatic pain relief was faster in the group treated with zinc oxide eugenol dressing starting from day 1 of the application. PRF may show a potential antimicrobial effect because it contains platelets with a high concentration of growth factors [10; 18], such as platelet-derived growth factor, transforming growth factor beta 1, platelet-derived endothelial growth factor, vascular endothelial growth factor, and platelet-derived angiogenesis factor. Platelet-derived growth factor (PDGF) occurs in two isoforms, PDGF-AB and PDGF-BB, and is responsible for the angiogenesis and proliferation of stem cells. This protein is present in the highest concentration and plays a significant role in the fast healing of oral wounds [19; 20]. According to [PERSON] et al., the level of PDGF-AB increases 7 days after collection, whereas PDGF-BB is released at high levels just after preparation, with a second increase after 14 days [20]. The role of the transforming growth factor beta (TGF-\(\beta\)) should also be emphasized--it is a factor that affects many functions of cells, especially their proliferation, differentiation and apoptosis. These roles are crucial for healing wounds; during injured tissues regeneration, there are many types of cells that must be stimulated in order to achieve a successful healing result [21]. The TGF-\(\beta\) appears to be usually stimulated 7 days after collection [20]. Finally, the vascular endothelial growth factor (VEGF) plays a key role in blood vessels formation, either angiogenesis or vasculogenesis [22]. It was reported that VEGF particularly increases7 days after collection and decreases after the next 7 days. [20]. In the context of this information, the PDGF-BB is the factor with the highest-released concentration in the period of our study. It is worth mentioning that there is also an exceptional variety of PRF--L-PRF (leukocyte-platelet rich fibrin) which is considered to be a second generation of platelet concentrates and was introduced by [PERSON] et al. in 2006 [23]. Using a special centrifugation technique, a fibrin network is obtained with almost 95% of the platelets embedded in it, which ensures the slow release of growth factors. This property not only enhances the healing of soft tissues but also provides a better bone quality, as reported by [PERSON] et al. [24] in the context of post-extraction socket treatment before implant placement. In our study, the use of L-PRF is worthy of a further investigation in the area of alveolar osteitis treatment.