Effect of platelet-rich fibrin in reducing postoperative complications after impacted third molar surgery : a prospective , randomized controlled clinical trial

OBJECTIVE: The first aim of this study was to evaluate the effect of platelet-rich fibrin (PRF) on pain, swelling, and trismus after mandibular impacted third molar surgery without the use of postoperative antibiotics. A second aim was to evaluate the patients’ quality of life (QOL) during the postoperative period. MATERIALS AND METHOD: Forty patients, who had bony impacted, mesio-angular mandibular third molars that were fully covered with mucosa, were selected. Patients were divided into two groups: PRF was placed in the socket in the first group and, traditional surgery was performed in the second group (the socket was left empty). The same surgeon performed all surgeries under local anesthesia. No antibiotics were prescribed after surgery. The outcome variables were pain, swelling, trismus, and QOL over a follow-up period of seven days. Results: The mean age of the patients was 23.3 (±3.9) years in the first group, and 23.3 (±4.6) years in the second group. Statistical analyses of the postoperative results showed that there were no significant differences between the groups with regard to pain, swelling, trismus, and QOL scores (p>0.05). CONCLUSION: The present study showed that PRF use had no significant effect on the postoperative pain, swelling, trismus, and QOL after impacted third molar surgery.


INTRODUCTION
Third molar surgery is one of the most commonly performed procedures in oral surgery.Pain, swelling, and trismus are the usual complications of this procedure, and they are thought to be a result of inflammatory response. 1These complications can not only affect a patient's quality of life but also lead to labor loss. 2 Therefore, investigations for providing comfort to patients undergoing this procedure are becoming increasingly important.
Recently, autologous platelet concentrates such as platelet-rich plasma (PRP) or platelet-rich fibrin (PRF) have been widely used in treatment procedures. 3,4PRF was identified for the first time in 2006 as a second-generation platelet concentrate that contains various autologous cytokines, immune cells, and growth factors. 5,68][9] However, there are only few studies regarding the effect of PRF on complications following third molar surgery. 4,10e aim of this study was to evaluate the effect of PRF on postoperative pain, swelling, and trismus following impacted third molar surgery.Furthermore, patient's quality of life (QOL) was assessed postoperatively.

MATERIALS AND METHOD
This study was approved by the Ethics Committee of Dentistry Faculty of Necmettin Erbakan University (document no: 2015/006) and was performed between December 14, 2015 and May 13, 2016 at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Necmettin Erbakan University.Forty patients (14 males and 26 females; age range: 18-33 years) with bony impacted, fully mucosa-covered, mesio-angular mandibular third molars were selected.The patients had no systemic disease that could affect the surgery or wound healing, and there was no pathological radiolucency around the teeth.Pregnant or lactating women were excluded.
Informed consent was obtained from all patients and they were randomly divided into two groups.All surgeries were performed under local anesthesia by the same surgeon (A.E.) using a standard operating technique.Briefly, a triangular mucoperiosteal flap was raised, and bone was removed using a round bur cooled with physiological saline solution (0.9% NaCl).After the tooth was separated, it was removed, and the socket was thoroughly irrigated with the physiological saline solution.The wound was closed using (3-0) silk sutures (Troge, Troge Medical Gmbh, Hamburg, Germany).In the first group (20 patients), preoperatively, 20 mL of venous blood was drawn and centrifuged at 3000 rpm for 10 min to prepare PRF.After tooth removal, PRF was placed into the socket before flap closure.No PRF was applied in the second group (20 patients), and the socket was left empty.Operation times were also recorded for each group.
All patients were provided two forms.The first form contained two verbal rating scales ranging from 0 (no pain and no swelling) to 5 (unbearable pain and extremely severe swelling), showing the degree of pain and swelling records.Patients were asked to complete the form on the first, third, and seventh postoperative days.The second form contained numbers from 0 to 100 indicating the QOL.Scores ranged from extremely poor (0) to excellent quality of life (100).Patients were asked to complete the second form on the seventh postoperative day.
Interincisal distance was measured using a ruler preoperatively and on the seventh postoperative day.Another surgeon (D.M.) who was blinded to the operative procedures in order to eliminate inappropriate bias performed the postoperative assessments.
Statistical analyses were performed using Sigma-Plot software (v12.5, Systat Software Inc., Richmond CA, USA).Pain, swelling, and QOL scores were analyzed using Mann-Whitney U test.Preoperative and postoperative mouth opening measurements were compared using Student's t-test.Significance level was set at p<0.05.

RESULTS
The mean age of the sample population was 23.3±3.9 years in the first group, and 23.3±4.6 years in the second group.There were 12 females and 8 males in the first group, and 14 females and 6 males in the second group.No significant differences were observed between the two groups regarding age, gender distribution, and operation time (p>0.05;Table 1).Moreover, there were no significant differences among the groups regarding postoperative pain, swelling, mouth opening, and QOL scores (p>0.05;Tables 2 and 3).

DISCUSSION
Impacted third molar surgery is a commonly performed procedure in oral surgery.Some complications that reduce patients' QOL, such as pain, swelling, and trismus, may occur following the surgery.Therefore, clinical trials are necessary to identify methods for improving patient's QOL after surgery. 11In this study, we applied PRF to the socket of the extracted tooth in the first group.Our goal was to examine whether the symptoms of pain, swelling, and trismus in the immediate postoperative period were relieved.
Pain, swelling, and trismus are common complications of third molar surgery.Pain may be related to the healing process in general, and the postoperative healing depends on different variables such as age, bone removal, surgeon experience, and operation time.In the present study, tooth separation and bone removal were performed by the same surgeon in all the patients.Besides, there were no significant differences between the two groups regarding age distribution and operation time.
Swelling is also a common complaint caused by edema associated with surgical trauma.It reaches the maximum level on the second or third postoperative day and normally diminishes by the fourth day.It should be completely resolved by the seventh day. 12In the present study, maximum swelling scores were observed on the third postoperative day in both groups, but no significant differences were found between the groups.Furthermore, there was no significant difference between the groups regarding trismus.A decrease in the mouth opening was observed in both groups postoperatively.Kumar et al. 4 evaluated the effect of PRF on postoperative sequel after third molar surgery.They reported that the application of PRF decreased pain, swelling, and trismus on the first postoperative day.Ozgul et al. 10 also investigated the efficacy of PRF in the reduction of pain and swelling after impacted third molar surgery, and they reported more swelling in the control group on the third postoperative day; however, there was no significant difference regarding pain between the groups.Singh et al. 13 also indicated that the use of PRF did not reduce postoperative pain.In the present study, we did not find significant differences between the two groups regarding pain, swelling, and trismus.Our findings are consistent with the findings of two previous studies 10,13 but different from the findings of one study. 4Different results have been presented in the literature on the effects of PRF on postoperative pain, swelling, and trismus after third molar surgery. 4,10,13The disparities may be related to the use of subjective data in these studies. 3,4,13 the aforementioned studies, postoperative antibiotics were prescribed.There are some clinical studies concerning the use of antibiotics after third molar surgery.Arteagoitia et al. 14 reported that antibiotic therapy was effective for pain relief, reduction of edema, and enabling better mouth opening after third molar sur-gery; some other studies have also stated that the use of postoperative antibiotics affected the postoperative sequelae after third molar surgery. 15,16In this study, we considered that the use of antibiotics may affect the postoperative sequel; hence, we did not prescribe antibiotics.
Regarding the use of PRF following impacted third molar surgery, the studies on soft and hard tissue healing are also outstanding in the literature.Kumar et al. 4 reported that bone density scores at 3 months postoperatively were higher in the PRF group than in the control group; however, this difference was not significant.The same authors found that the use of PRF in the socket reduced the periodontal pocket depth.In another clinical study by Singh et al. 13 improved healing of both soft tissue and bone was observed.Kumar et al. 17 also concluded that PRF improved healing of both soft and hard tissue.They stated that although osseous healing did not differ significantly between the groups, healing of soft tissue, as judged by the pain score, was significantly better in the PRF group.In contrast, Gürbüzer et al. 18 reported that PRF did not seem to increase scintigraphically-detectable enhanced bone healing within the extraction sockets of soft tissue-impacted third molars at 4 weeks postoperatively.

CONCLUSION
The present study showed that the use of PRF had no significant effect on postoperative pain, swelling, trismus, and QOL after impacted third molar surgery.

Table 1 .
Demographic information of the patients and mean operation time PRF: platelet-rich fibrin; SD: standard deviation

Table 2 .
Pain and swelling scores of the groups at the 1st, 3rd and 7th days after the surgery *Mann-Whitney U test; PRF: platelet-rich fibrin