Prophylaxis versus pre-emptive antibiotics in third molar surgery: a randomised control study

This study was carried out to compare the efficacy of preoperative single bolus antibiotics with a 5 day- postoperative antibiotic regimen in reducing pain, swelling, and trismus, surgical site infection (SSI) and alveolar osteitis (AO) after third molar surgery. A randomised experiment was done involving eighty-four patients. The patients were divided into two groups consisting of 42 patients each. A preoperative group was given an oral bolus of 2g amoxycillin capsules and 1g metronidazole tablets one hour before extraction, while those in the postoperative group were given a five-day regimen oral 500mg amoxycillin capsules thrice daily and 400mg metronidazole tablets thrice daily. The occurrence of postoperative pain, swelling, trismus, SSI and AO were compared between the groups. Seventy-nine patients completed the study; 38 patients in the preoperative group and 41 patients in the postoperative group. There was no difference between the groups in respect of the inflammatory complications. The four cases of AO occurred in the preoperative group. Single bolus antibiotic prophylaxis should be adequate for most cases of third molar surgery as the degree of degree of postoperative pain, swelling and trismus was similar in both groups. The use of single bolus antibiotic prophylaxis would also help reduce the cost of treatment in developing countries as well as reduce the risk of development of resistant strains. However, a five-day postoperative antibiotic regimen is advised in patient with risk factors for AO.