Chlorhexidine Versus Normal Saline Socket Irrigation for Prevention of Dry Socket After Lower Wisdom Tooth Extraction (CHX-AO)

Alveolar osteitis, commonly known as dry socket, is a painful postoperative complication that may occur following tooth extraction. It is characterised by moderate to severe pain at the extraction site and may be associated with delayed healing and other local clinical signs. The condition generally develops within the first few days following extraction and may cause considerable discomfort to patients.

The development of alveolar osteitis has been associated with breakdown or loss of the blood clot within the extraction socket. Local fibrinolytic activity and bacterial factors have been proposed as contributing mechanisms. Surgical trauma, bacterial contamination and other patient- and procedure-related factors may increase the risk of alveolar osteitis.

Normal saline is commonly used for irrigation of extraction sockets after surgical tooth removal. Chlorhexidine has antimicrobial and antiseptic properties and has been investigated for its potential role in reducing the occurrence of alveolar osteitis. Previous studies have reported lower frequencies of dry socket following chlorhexidine use compared with saline or other postoperative measures. However, the effectiveness of immediate post-extraction socket irrigation with chlorhexidine compared with normal saline requires further evaluation in the local clinical setting.

This single-blinded randomized controlled trial will compare the effect of immediate post-extraction socket irrigation with chlorhexidine versus normal saline on the frequency of dry socket following surgical extraction of impacted lower wisdom teeth.

Eligible patients will be recruited from the Oral and Maxillofacial Surgery Department, CMH Medical College and Institute of Dentistry, Lahore. Participants will be adults aged 18-50 years who are classified as ASA physical status I or II and who require surgical extraction of impacted lower wisdom teeth with slight to moderate difficulty according to Pederson's scale.

After informed consent is obtained, eligible participants will be randomly allocated to one of two treatment groups using a lottery method. One group will receive immediate irrigation of the extraction socket with chlorhexidine, while the other group will receive immediate irrigation with normal saline. The allocated irrigation solution will be applied after completion of the tooth extraction and before closure of the extraction socket. The extraction procedure will be performed by a single surgeon under local anaesthesia.

Participants will remain unaware of the irrigation solution allocated to them. Postoperative assessment will be performed by a co-researcher to reduce the potential for assessment bias. Standard postoperative instructions and postoperative medications will be provided according to the study protocol.

Participants will be evaluated on postoperative days 2, 3, and 5 for clinical features of alveolar osteitis. Dry socket will be diagnosed when at least three predefined diagnostic criteria are present. The criteria include mild to severe pain, trismus, halitosis, an inflamed or hyperaemic gingival area, exposed or bare bone with an empty socket, radiating pain to the ear or temporal region, and ipsilateral lymphadenopathy.

Trismus will be assessed by measuring the maximum inter-incisal distance in millimetres. A value below 35 mm will be considered indicative of trismus.

The primary purpose of the study is to determine whether immediate post-extraction socket irrigation with chlorhexidine reduces the frequency of alveolar osteitis compared with normal saline. The findings may provide evidence regarding the effectiveness of chlorhexidine as an alternative to normal saline for immediate socket irrigation following surgical extraction of impacted lower wisdom teeth.