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As clinicians, prescribing chlorhexidine (CHX) mouthwash after dental surgery is almost second nature. For decades, itʼs been our gold standard for promoting healing, reducing microbial load, and preventing complications when mechanical cleaning is difficult or contraindicated. We trust it to work.
But in a crowded marketplace, weʼre faced with a growing number of formulations: the classic 0.12%, the potent 0.2%, alcohol-free versions, and newer systems claiming an “anti-discoloration” (ADS) or “anti-staining” effect. We often assume these variations are minor, but do they deliver equal efficacy?
A recent quadruple-blind randomized pilot trial published in 3 Biotech (Chye et al., 2025) puts this very question to the test, and its findings might make you reconsider your go-to prescription.
The researchers conducted a robust, quadruple blind RCT the gold standard of study design to evaluate the short-term effectiveness, side effects, and patient acceptability of three common commercial CHX formulations against a placebo.
Twenty-one patients were randomly assigned to one of four groups for two weeks following dental surgery:
The researchers measured plaque (FMPS) and gingival bleeding (FMMBS) at baseline and after two weeks.
The results were not subtle.
After two weeks, only Group A (0.2% alcohol-free CHX) demonstrated statistically significant reductions in both plaque and gingival bleeding. The median Full-Mouth Plaque Score (FMPS) in this group plummeted from 10.7% to 3.9%, and the Full-Mouth Bleeding Score (FMMBS) dropped from 3.4% to just 0.5%.
This is a powerful win for the 0.2% concentration, suggesting that for high- stakes, short-term post-surgical care, maximum efficacy is found here.
Perhaps more startling, however, was the performance of Group D (0.2% CHX + ADS). This formulation, designed to mitigate the dreaded CHX staining, not only failed to produce a statistically significant reduction in plaque or bleeding but also finished the trial with the highest median plaque score (15.8%) of all four groups. This finding raises a serious clinical question: in creating a formulation to solve the side effect of staining, has the primary therapeutic benefit been compromised?
As we all know, efficacy is only half the battle. If the patient won’t use it, the formulation is useless. This is where the 0.2% CHX showed its weakness.
Taste Alteration: 100% of patients in the highly effective Group A reported taste disturbance.
Staining: Extrinsic tooth staining is the hallmark side effect we all warn our patients about. In this trial, staining was observed in all three CHX groups, with Group A (0.2% CHX) showing the most pronounced discoloration. While the difference was not statistically significant in this pilot study, it aligns with our clinical experience the most potent formula often carries the highest price in aesthetics.
This pilot trial, while small, provides critical, high-quality data. It suggests that if our primary, non-negotiable goal for a two-week post-surgical window is maximum reduction in plaque and inflammation, the 0.2% alcohol-free CHX formulation is the most effective agent.
However, this efficacy comes at a direct cost to patient acceptability, with universal taste alteration and a high staining propensity. Furthermore, the trial serves as a powerful warning against assuming all formulations are created equal. The poor performance of the anti-discoloration system in plaque reduction is a major red flag.
This study encourages us to have a more nuanced conversation with our patients, balancing the clear clinical need for efficacy against the very real side effects that impact compliance.
Chye RML, Sharma A, Rincon J, Hui WL, Sharma LA, Alavi SE, Quaranta A. Effectiveness of chlorhexidine-based mouthwashes after dental surgery: a quadruple-blind randomized pilot trial. 3 Biotech. 2025 Nov;15(11):385. doi: 10.1007/s13205-025-04559-0. Epub 2025 Oct 13. PMID: 41098693; PMCID: PMC12518726.
