The clinical manifestation of this dysbiosis is gingivitis, a plaque-induced inflammatory response of the gingival tissue. If plaque persists, the inflammatory response can progress to periodontitis, where the host immune response drives irreversible destruction of the periodontal ligament and alveolar bone. This progression involves a self-sustaining loop in which inflammation creates an environment favouring pathogenic bacteria, which in turn amplifies destructive inflammation. Periodontal disease is also independently associated with systemic conditions including diabetes mellitus, atherosclerotic cardiovascular disease, and chronic obstructive pulmonary disease, underscoring the broader health significance of effective plaque control.¹

Mechanical plaque removal through thorough toothbrushing and interdental cleaning remains the cornerstone of prevention.¹ However, conventional toothbrushing with fluoride toothpaste alone does not fully restore the microbiome differences associated with gingivitis, and adjunctive measures may be needed to substantially alter the microbial community.²

A Cochrane systematic review demonstrated that chlorhexidine mouthrinse, when added to routine mechanical oral hygiene for 4-6 weeks or longer, produced a substantial reduction in dental plaque and a moderate reduction in gingivitis compared with placebo, with no consistent difference in efficacy between commonly studied concentrations including 0.12% and 0.2%.³ A randomised crossover trial found that 0.12% chlorhexidine gluconate mouthrinse used twice daily with toothbrushing produced significantly greater reductions in plaque and gingival inflammation than toothbrushing plus dental floss or toothbrushing alone.⁴ Chlorhexidine exerts immediate bactericidal action during application followed by prolonged bacteriostatic activity, with oral substantivity of up to 12 hours.^4,5

The 0.12% concentration demonstrates clinical and microbiological efficacy comparable to 0.2%, while producing fewer local side effects including less staining, taste disturbance and mucosal irritation, with better patient compliance.⁶ A 21-day randomised trial reported that 0.12% chlorhexidine achieved relative reductions of 90.9% in plaque index and 91.9% in gingival index scores.⁵ When combined with thorough subgingival debridement, 0.12% chlorhexidine reduced bacterial colony counts by up to 97%.⁶ Furthermore, when chlorhexidine was used adjunctively with regular toothbrushing, plaque and gingival scores remained similarly low across all tested concentrations.⁷ Antiseptic mouthrinses have also been shown to be at least as effective as dental floss in controlling interproximal gingivitis, with the additional advantage of reaching surfaces less accessible to mechanical cleaning.⁴

Pharmacy professionals are well positioned to identify patients who may benefit from enhanced plaque-control measures, including those presenting with gingival inflammation, visible plaque accumulation, or with risk factors such as diabetes¹ or smoking.² Counselling should reinforce twice-daily brushing with fluoride toothpaste, daily interdental cleaning, regular dental check-ups and the appropriate, time-limited use of evidence-based oral antiseptics where indicated. Patients should be advised that chlorhexidine may be associated with tooth staining and temporary taste alteration with prolonged use, and should therefore be used only as directed or as recommended by a healthcare professional.^3,5,6