Is chlorhexidine mouthwash effective as an adjunct to scaling and root planing?

Chlorhexidine (CHX) mouthwash as an adjunct to scaling and root planing (SRP) does produce measurable benefits, though the clinical magnitude is modest. A meta-analysis found that adjunctive CHX mouthrinse resulted in significantly greater probing depth (PD) reduction than SRP alone at 40-60 days (0.33 mm) and 180 days (0.24 mm), though the authors noted these differences, while statistically significant, could be considered clinically slight, and the effect on clinical attachment level (CAL) was negligible ^[1][2]. A Cochrane review similarly confirmed high-quality evidence of a large reduction in dental plaque and a reduction in gingivitis with CHX mouthrinse used adjunctively over 4-6 weeks and 6 months, though the gingivitis reduction was not considered clinically relevant in individuals with mild inflammation ^[3].

For locally delivered CHX forms, subgingival xanthan-based CHX gel as an adjunct to SRP at selected sites showed a slight but significant improvement in PPD reduction (mean difference 0.15 mm), with no significant difference in CAL gain ^[4]. CHX chips showed some gingival index benefit over other local antimicrobials at three months, though other antimicrobials outperformed CHX chips on probing depth reduction at one and three months ^[5].

Clinicians should weigh these modest clinical gains against well-documented adverse effects including extrinsic tooth staining, taste disturbance, mucosal irritation, and potential calculus build-up, all of which may affect patient compliance ^[1][3][6]. There is currently no evidence that one concentration of CHX rinse is more effective than another ^[3].