## 4 Discussion
Therefore, it is possible to state that literature homogeneously indicates a favorable effect in the pre-surgical administration of prophylactic antibiotics. The efficacy of the exclusively pre-surgical administration of penicillin antibiotics was evaluated based on 5 studies, for a total of 398 surgeries performed (see Figure S3 in the Supplementary material section). This modality of prophylaxis showed a significant benefit, with a slight and insignificant heterogeneity, and an NNT equal to 13. Therefore, it can be stated that from the analysis of the literature, the results homogeneously indicate a favorable effect in favor of pre-surgical prophylactic penicillin antibiotics administration. The meta-analysis of the data regarding pre-surgical prophylaxis with non-penicillin antibiotics, included 4 studies for a total of 283 surgeries (see Figure S4 in the Supplementary material section). The RR was significantly in favor of administering prophylaxis with both the fixed and random models, with an identical value. Furthermore, the heterogeneity of the data was found to be zero and the number of patients to be treated to obtain a therapeutic benefit was equal to 6. Therefore, it can be stated that from the analysis of the literature the results homogeneously indicate a favorable effect of pre-surgical administration of non-penicillin antibiotics. Overall, therefore, the pre-surgical administration of antibiotics for the prophylaxis of surgical wound infections following the extraction of the mandibular third molar has a significant efficacy, homogeneously highlighted by the literature and with a significant clinical impact. The pre- and post-surgical administration, considering all types of antibiotics, analyzed data from 7 different studies, for a total of 940 surgeries performed (see Figure S5 in the Supplementary material section). The results showed a significant benefit in favor of prophylaxis with a heterogeneity of zero but with an NNT of 28. The latter result is significantly higher than those relating to the exclusively pre-surgical modality. Pre- and post-surgical administration analysis, considering only amoxicillin, considered the data from 4 studies, for a total of 612 surgeries (see Figure S6 in the Supplementary material section). The results indicated a significant benefit in favor of prophylaxis with zero heterogeneity, but NNT was 68. The latter result is significantly higher than those relating to the exclusively pre-surgical modality. Pre- and post-surgical administration analysis, considering non-penicillin antibiotics only, considered the data from 3 studies, for a total of 328 surgeries (see Figure S7 in the Supplementary material section). The results showed a significant benefit in favor of prophylaxis with mild and insignificant heterogeneity; the NNT was equal to 13. The latter result is significantly higher than the one relating to the exclusively pre-surgical modality for the same antibiotic. Overall, the pre- and post-surgical administration of prophylactic antibiotics has shown significant efficacy in the prevention of surgical site infections, shown in a consistent manner by the studies in the literature, but with a lower clinical impact than the exclusively pre-surgical administration. Post-surgical administration analysis, considering all types of antibiotics, included the data from 4 studies, for a total of 1130 surgeries performed (see Figure S8 in the Supplementary material section). The results indicated a significant benefit in favor of prophylaxis but with a high heterogeneity (79%, \(p<0.01\)); the NNT was equal to 15. Although the result is significantly in favor of antibiotic prophylaxis, the high heterogeneity indicates that the studies conducted show discordant results. Post-surgical administration, considering amoxicillin only, included the data of 4 studies, for a total of 1069 surgeries performed (see Figure S9 in the Supplementary material section).