This study aimed to analyze the efficacy of an anti-calculus mouth rinse and its possible adverse effects on the mucosa and teeth. This randomized double-blind placebo-controlled clinical trial included 40 patients with treated and managed periodontal disease, all with a history of rapid calculus formation. Patients used a pyrophosphate-based test mouth rinse (B) or a placebo (A). A range of parameters were measured for: saliva (saliva flow, pH and chemical composition); calculus (Volpe-Manhold [V-M] index, weight, and volume); adverse effects on mucosa and teeth; and the patients? subjective perceptive of mouth rinse efficacy. The test mouth rinse B produced reductions in urea, uric acid, and phosphorous, calcium, saliva flow, and increases in pH. V-M index and calculus weight decreased after using the test mouth rinse. Calculus volume decreased with both mouth rinses. No changes to the mucosa or teeth were observed. Patients perceived that the test mouth rinse was more effective. The test/B and placebo mouth rinses both modified certain parameters in saliva composition, particularly reductions in urea, uric acid, and phosphorous. Calcium tended to increase after using the test-B mouth rinse. The results did not demonstrate the anticalculus efficacy of the pyrophosphate-based mouth rinse or positive effects on saliva flow or composition. This field requires further research, as no product has been developed that prevents calculus formation completely.