The Stain Reduction and Whitening Efficacy of an Enzyme-Enhanced Mouthwash: A Comparative Study

Objective: To compare the stain-removing and whitening efficacy of GuruNanda™ enzyme-enriched whitening mouthwash formulations with those of a commercially available comparator and a placebo mouthwash. Methods: Eighty bovine enamel blocks were prepared and embedded in auto-polymerizing polymethyl methacrylate resin. Baseline tooth shade was digitally measured using a calibrated Vita EasyShade Advance spectrophotometer under standardized lighting conditions. Enamel surfaces were lightly etched (5 secs) with 32% phosphoric acid and then cycled several times between stain solution and natural saliva for pellicle formation over 24 hours, simulating extrinsic discoloration. The shade of stained tooth blocks was re-measured (post-staining shade). After staining, samples were randomly assigned to four experimental mouthwashes (n = 20): Gurunanda™ 6-Month-Aged-Enzyme (6M-GN-ENZ), Gurunanda™ Fresh-Enzyme (GN-ENZ), Comparator Whitening mouthwash (Comparator), and Placebo. Treatments simulated twice-daily with 2-minute swishing followed by 2-minute of toothbrushing with de-ionized distilled water (DDW) over 1, 4, and 8-week intervals. Post-treatment color measurements were obtained at each point. Data were analyzed statistically using Kruskal–Wallis, and ANOVA tests (α = 0.05). Results: At each evaluation period, all active mouthwashes produced statistically significantly greater stain reduction than the placebo (p < 0.05). The mean percentage stain reduction differed significantly (p < 0.01) between time points (1, 4, 8 weeks) with 6M-GN-ENZ (38.96%, 47.58%, 52.35%) and GN-ENZ (28.69%, 37.95%, 39.95%). While Comparator (35.62%, 40.23%, 40.23%) and Placebo (0%, 14.62%, 21.87) showed no significant change over time. Conclusion: Swishing with GuruNanda™ enzyme-enhanced mouthwashes effectively removed extrinsic stains on teeth surfaces at a comparable rate to Comparator mouthwash but significantly outperforming the placebo. Keywords: GuruNanda™ mouthwash, enzyme mouthwash, oral rinse, tooth stains, stain removal, tooth whitening