Does a Single Dose of Systemic Antibiotics Prevent Postoperative Inflammatory Complications After Lower Third Molar Surgery? A Randomized Controlled Trial

Study design and sample description This prospective study was performed at the Department of Oral Surgery of Clinical Hospital Dubrava, Zagreb, Croatia, in the period from April 2010. through November 2016. All patients voluntarily agreed and written consent to participate in the study was obtained from each participant. The study was approved by Ethics Committee of the School of Dental Medicine, Zagreb, Croatia (81-2009). The identity of the subjects was protected in all phases of the study.

The exclusion criteria in this study were systematic diseases, with developing local infections, current smokers, pregnant women, lactating females, patients using oral contraceptive drugs and those under any antibiotic coverage.

The sample consisted of systematically healthy subjects between 18 to 40 years (both gender) and having semi-impacted lower third molars indicated for surgical removal randomly divided into two main groups of patients. Unlike the patients from the second group, the first group of patients had never been diagnosed inflammation prior the surgical procedure. The main tested groups were further divided in two subgroups (control and tested): the tested subgroup (100 patients) received a prophylactic single dose of 2 g amoxicillin an hour prior the procedure, while the second control subgroup (100 patients) received a placebo. The selection of third molars for control and study subgroup was made according to Pederson difficulty index (9). According to this index (Table 1), the patients are classified into 3 groups: easy, moderate and difficult. The patients from this study who were classified into a difficult group were excluded from the study due to a longer and complicated surgical procedure with an expected prolonged recovery period and possible postoperative complications.

The patients were recalled for follow-up on post-operative days one and seven. In all tested groups data had been obtained by using identical questionnaire. The following symptoms were assessed: pain, swelling, wound healing (AO, SSI), maximum inter-incisal opening of mouth, increased body temperature and hemorrhage. A postoperative follow-up was done always by the single experienced therapist. Patients evaluated their postoperative pain with grades from 0-10 using according to visual analogue scale (VAS) where the end points were marked as "no pain" (0) and "unbearable pain" (10). Surgeon evaluated the type of post-extraction alveolus healing as following normal healing, acute inflammation followed by infected alveolus and dry socket. The surgeon who assessed wound swelling did not know to which group the patient was allocated. The method of assessing the swelling was described in our previous study (10). The post-operative swelling was assessed on postoperative days 1 and 7, using four-point scale as 0=no swelling, 1=mild swelling, 2=moderate swelling, 3=severe swelling.

The maximum inter-incisal opening of the mouth was calculated from the mesioincisal angle of the ipsilateral mandibular central incisor to the mesioincisal angle of the ipsilateral mandibular central incisor using digital calliper (Caliper-Digital; Salvin Dental Specialties, Inc, Charlotte, NC).