## 4 Discussion
[19] PRF is an important reservoir of growth factors that promote angiogenesis, above all VEGF, but also PDGF and TGF-\(\theta\). In our study, we chose A-PRF because it releases VEGF at higher levels compared to L-PRF (Leukocyte-Platelet-rich Fibrn). [14] VEGF is largely produced by the leukocytes [31] and is crucial for the promotion of angiogenesis during tissue repair. Indeed, reduced expression and rapid proteolytic degradation of VEGF are considered partially responsible for poor wound healing, for example in diabetic wounds, because these effects result in poor angiogenesis during GT formation. Thus, the angiogenesis induced by VEGF and other factors represents a significant step in the treatment of non-healing wounds and other ischemic processes, where clotting has failed to induce the healing, as in AO. The acceleration of wound healing in our study is confirmed by the fact that the GT appeared clearly after only three days after treatment (mean 3.25). Previous studies have indicated that bacteria may play an important role in the pathogenesis of AO [9]. In our study, the post-operative recovery was uneventful, and no surgical sites showed any signs of infection or mucositis. In addition to their tissue-forming and proliferative effects, growth factors released by A-PRF exhibit a chemotactic effect that causes the migration of macrophages and neutrophils, adding an antimicrobial component to the wound site. All the patients in our sample suffering from dry socket experienced severe pain with a median VAS pain score of 8.5 on the day of presentation. Indeed, it is a well-established fact that the pain associated with AO is severe, continuing throughout the night and responding poorly to analgesics [36]. The pain for all the patients decreased statistically in the first day. None of the patients needed to take analgesic drugs and therefore we can assume a predominant role of PRF in the reduction of pain. This result is in accordance with other studies supporting the antinociceptive role of platelet concentrates [30; 31; 32]. Despite the encouraging results obtained, several limitations should be acknowledged. The nature of the study (a case series) and the lack of a control group may compromise the validity of the final results. The low sample size is due to the infrequent diagnosis of \"true\" AO, which is often erroneously confused with socket infection accompanied by pain. In addition, the prospective nature of the study makes it difficult to perform a sample size calculation and control group. However, the only comparison that we can make is \begin{table}
\begin{tabular}{c c c c c c} \hline  & **N Patients** & **AO Site** & **Type of APC Used** & **Pain** & **Wound Healing** \\ \hline [PERSON] et al. [23] & 40 & NR & CGF & \begin{tabular}{c} Reduction of pain on 4 th \\ and 7 th post-op day \\ \end{tabular} & \begin{tabular}{c} GT formation by \\ day 4 \\ \end{tabular} \\ [PERSON] et al. [24] & 15 & NR & CGF & \begin{tabular}{c} Reduction of pain on 2 nd \\ and 7 th post-op day \\ \end{tabular} & \begin{tabular}{c} GT formation by \\ day 4 \\ \end{tabular} \\ [PERSON] [33] & 10 & Any tooth & PRF & \begin{tabular}{c} Reduction of pain by the \\ 1 st post-op day \\ \end{tabular} & NR \\ [PERSON] et al. [34] & 100 & \begin{tabular}{c} Mandibular and \\ maxillary molars \\ \end{tabular} & PRF & \begin{tabular}{c} Reduction of pain on 3 rd \\ and 7 th post-op day \\ \end{tabular} & \begin{tabular}{c} Better WH by the \\ end of 2 nd week \\ \end{tabular} \\ [PERSON] et al. [35] & 20 & Third molars & A-PRF & \
\begin{tabular}{c} Reduction of pain by the \\ 1 st post-op day \\ \end{tabular} &
\begin{tabular}{c} Better Soft tissue \\ healing by day 7 \\ \end{tabular} \\ \hline \end{tabular}  
* APC: Autogenous Platelet Concentrates; WH: Wound healing; NR: Not reported; CGF: Concentrated growth factor; GT: Granulation tissue.  
\end{table} 
Table 3: Summary of literature review. with previous treatment of AO performed in our department with the use of debridement and saline solution washing.