Comparative Efficacy of Amoxicillin, Metronidazole, and Chlorhexidine in Preventing Alveolar Osteitis Following Lower Third Molar Extraction: A Three-Arm Double-Blinded Randomized Controlled Trial

Alveolar osteitis, commonly known as dry socket, is a frequent postoperative complication following lower third molar extraction and may cause significant pain and delayed healing. This study will compare the efficacy of amoxicillin, metronidazole, and chlorhexidine in preventing alveolar osteitis following lower third molar extraction.

This is a three-arm, double-blinded randomized controlled trial to be conducted at the Department of Oral and Maxillofacial Surgery, Khyber College of Dentistry, Peshawar. Patients aged 18-40 years who require extraction of an impacted or partially erupted mandibular third molar under local anesthesia and meet the study eligibility criteria will be considered for participation.

Eligible participants who provide written informed consent will be randomly allocated to one of three groups: Group A will receive amoxicillin, Group B will receive metronidazole, and Group C will receive chlorhexidine as the control intervention. A computer-generated randomization sequence and sequentially numbered, opaque, sealed envelopes will be used for allocation concealment. Placebo tablets and placebo gel will be used to maintain blinding of participants and outcome assessors.

Following extraction, participants will receive standardized postoperative instructions according to their assigned intervention. Participants will be assessed on Days 3 and 7 following extraction. A blinded assessor will evaluate the extraction site for alveolar osteitis using Blum's criteria. The presence or absence of alveolar osteitis will be recorded as a binary outcome. Postoperative pain will also be assessed using a Visual Analogue Scale, and additional postoperative complications or adverse effects will be documented.

The primary objective is to compare the incidence of alveolar osteitis among patients receiving prophylactic amoxicillin, metronidazole, or chlorhexidine following lower third molar extraction. The overall comparison among the three groups will be performed using the Chi-square test, with Fisher's exact test used when appropriate. Planned pairwise comparisons will include amoxicillin versus chlorhexidine, metronidazole versus chlorhexidine, and amoxicillin versus metronidazole, with Bonferroni correction for multiple comparisons.