Single-dose intra-alveolar chlorhexidine gel application, easier surgeries, and younger ages are associated with reduced dry socket risk

Purpose: Although dry socket (DS) is commonly investigated, many of its risk factors remain highly controversial. In addition, few studies are available to show the preventive effect of chlorhexidine gel on DS. Moreover, multivariable analyses of DS risk factors are scarce, and their interactions have not been assessed previously. Therefore, the simultaneous effect of chlorhexidine gel and 4 DS risk factors and their interactions were analyzed within a multivariable framework.

Materials and methods: Using a split-mouth randomized clinical trial design, the investigators enrolled a cohort of patients requiring extraction of 2 mandibular third molars. The primary predictor variable was extraction socket treatment status, classified as experimental or standard. Experimental treatment was the insertion of chlorhexidine gel (0.2%) into the extraction socket. Each patient had 1 third molar randomly selected as the treatment site. The contralateral third molar served as the control socket and was treated in the usual manner. The primary outcome variable was DS status, present or absent, assessed on postoperative day 3. Other study variables were categorized as demographic, smoking, and surgical difficulty according to the Pederson scale. Appropriate bivariate and multiple logistic regression statistics were used to measure the association between risk for DS and chlorhexidine gel use, age, gender, smoking, and surgical difficulty and their interactions (α = 0.05).

Results: The sample consisted of 90 bilateral extraction sockets in 45 patients (24 men; 21 smokers; mean age, 21.1 ± 2.7 yr). Regression analysis showed that when other factors and their interactions were controlled for, chlorhexidine gel application lowered the risk of DS (odds ratio [OR] = 0.05; P = .004). Increasing age (OR = 2.9; P = .030) was associated with an increased risk for DS. A similar association existed between increased difficulty level of extraction and DS risk (OR = 3.8; P = .051). The effect of gender was marginally significant (P = .091), whereas smoking did not have a significant influence (P = .4).

Conclusions: Intra-alveolar application of chlorhexidine gel and practicing less traumatic surgeries are advocated, particularly in older patients. Smoking seems unlikely to affect DS frequency. The role of gender is inconclusive.