METHODS: Databases including Medline, Embase and bibliographies were searched from inception to 1 April 2023. Randomized controlled trials (RCTs) with 7 days or longer duration of oil pulling with edible oils in comparison to chlorhexidine or other mouthwashes or oral hygiene practice concerning the parameters of plaque index scores (PI), gingival index scores (GI), modified gingival index scores (MGI) and bacteria counts were included. Cochrane's Risk of Bias (ROB) tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework were employed to determine the quality of evidence. Two authors independently conducted study selection and data extraction. Meta-analyses of the effect of oil pulling on the parameters were conducted using an inverse-variance random-effects model.

RESULTS: Twenty-five trials involving 1184 participants were included. Twenty-one trials comparing oil pulling (n = 535) to chlorhexidine (n = 286) and non-chlorhexidine intervention (n = 205) were pooled for meta-analysis. More than half of the trials (n = 17) involved participants with no reported oral health issues. The duration of intervention ranged from 7 to 45 days, with half of the trials using sesame oil. When compared to non-chlorhexidine mouthwash interventions, oil pulling clinically and significantly improved MGI scores (Standardized mean difference, SMD = -1.14; 95% confidence interval [CI]: -1.31, -0.97). Chlorhexidine was more effective in reducing the PI scores compared to oil pulling, with an SMD of 0.33 (95% CI: 0.17, 0.49). The overall quality of the body of evidence was very low.