Does full-mouth disinfection give better results than quadrant-wise scaling?

The evidence comparing full-mouth disinfection (FMD) and quadrant-wise scaling and root planing (Q-SRP) is mixed, and any advantages of FMD appear modest. A 2016 meta-analysis found FMD produced statistically significant but clinically small additional benefits over Q-SRP, specifically a 0.25 mm greater probing pocket depth (PPD) reduction and 0.33 mm greater clinical attachment level (CAL) gain in moderate pockets of single-rooted teeth, while no significant differences were found in other subanalyses ^[1]. The 2022 Cochrane review, including 20 RCTs and 944 participants, found no clear evidence that FMD provides additional clinical benefit over conventional Q-SRP for change in PPD, CAL gain, or BOP reduction at 6-8 months, rating the certainty of evidence as low to very low ^[2].

Some individual studies do report advantages for FMD. A 2024 RCT found FM-SI significantly outperformed Q-SI in PPD reduction and periodontal pathogen reduction at 6 months, with higher baseline PPD and Porphyromonas gingivalis levels negatively influencing FM-SI outcomes ^[3]. In stage III/IV periodontitis, FMD with adjunctive erythritol air-polishing showed significantly greater PPD reduction and pocket closure than Q-SRP over 6 months, and full-mouth protocols as a group were more time-efficient (6-17 min per closed pocket) than Q-SRP ^[4]. In patients with generalized aggressive periodontitis, FMD demonstrated significantly higher pocket closure and greater reductions in bacterial load compared to both Q-SRP and full-mouth scaling without antiseptic ^[5].

Regarding the role of chlorhexidine in FMD, one study suggested the additional clinical and microbiological benefits stem primarily from completing all instrumentation within 24 hours rather than from the chlorhexidine adjunct itself ^[6]. Overall, all three approaches are effective and safe, and the Cochrane review recommends that the choice between them should incorporate patient preference and scheduling convenience ^[2].