The demographic information of the patient and the classification of mandibular third molar were recorded before surgery.
The surgeries were conducted by a standard technique. The surgical technique for both sides was similar due to similar classification of the three molars of each participant, but if any changes in the protocol such as additional anesthesia were needed in the first surgery, the assistant documented it so the same protocol was performed for the second surgery. If the modifications occurred in the second surgery, the treatment was completed however the data were not analyzed. Furthermore, the duration of surgery from the first incision to the last suture was recorded.
A 10% povidone-iodine solution (Betadaine®, Nanokimia, Yazd, Iran) were used to disinfect the surgical site before surgery. The 3.6 ml of 2% lidocaine with epinephrine 1:80,000 (Xylopen®, Exir, Tehran, Iran) and 1.8 ml of 4% articaine with 1:100,000 (Dentacaine®, Exir, Boroujerd, Iran) were injected for inferior alveolar, long buccal, and lingual nerve block. A scalpal incision followed by a mesial releasing incision was made by means of blade number 15 (Novacut®, China) according to the tooth position and the full-thickness flap was elevated through Molt periosteal elevator number 9. The osteotomy of bone around the impacted tooth was performed by round carbide bur (Dentsplay, Ballaigues, Switzerland) attached to a low-speed surgical handpiece (NSK, Tokyo, Japan) as needed. Then, the tooth was sectioned employing a fissure bur (Dentsplay, Ballaigues, Switzerland) under irrigation to preserve bone as much as possible.
The proper hemostasis was achieved in the socket and the soft tissue was sutured by a violet braided synthetic absorbable polyglycolate 3.0 suture and 3/8 circle reverse cutting needle (SUPABON, Tehran, Iran). The sutures were removed after 1 week. The postoperative consideration was given in a written form designed by the first therapist. The patients were advised to have soft food on the day of surgery and the next day. Patients were asked to use an ice pack in a 20-min sequence for 24 h but not more as it is of no effect. In addition, they were told to avoid brushing the surgical site or using mouthwash, or spitting on the surgery day. They were suggested to brush the day after surgery but be careful of the sutured site. 400 mg Ibuprofen (Gelofen®, Dana, Tabriz, Iran) every 6 h for 5 days was prescribed postoperatively to reduce pain.
If the patient experienced severe pain, he/she was permitted to take 325 mg acetaminophen-codeine but his/her data were excluded from the study.