Objectives: This study aimed to evaluate the effect of 0.12% chlorhexidine gluconate on the salivary load of SARS‐CoV‐2.Materials and Methods: A randomized, double‐blind, placebo‐controlled trial was performed on 100 participants positive for SARS‐CoV‐2. In the test group (n = 50), volunteers gargled with a mouthwash containing 15 ml of 0.12% chlorhexidine gluconate for 1 min, while the control group (n = 50) used a placebo. Saliva samples were obtained before (baseline) and 5 and 60 min after using the solutions. Real‐time reverse transcription polymerase chain reaction assays (qRT‐PCR) were carried out and the cycle threshold (Ct) was computed. The chi‐square test and t‐test were used for group comparison (p ≤ 0.05).Results: The differences in Ct values between the 5‐min evaluation and baseline (test group: 2.19 ± 4.30; control: −0.40 ± 3.87, p = 0.002) and between 60 min and baseline (test group: 2.45 ± 3.88; control: 0.76 ± 4.41, p = 0.05) were significantly greater in the test group, revealing a reduction of viral load. Furthermore, there was a reduction in the load of SARS‐CoV‐2 in 72% of the volunteers using chlorhexidine versus 30% in the control group (p = 0.001).Conclusions: Chlorhexidine gluconate (0.12%) was effective in reducing salivary SARS‐CoV‐2 load for at least 60 min.

Background: There is a positive correlation between the course of periodontal disease and psychosocial stress status. Stress leads to activation of the hypothalamic‐pituitary‐adrenal axis, resulting in increased cortisol release. The present study evaluates the effect of two different hydrocortisone concentrations on mRNA expression of matrix metalloproteinases (MMPs) and tissue inhibitor of matrix metalloproteinases (TIMPs) in cultured, human gingival fibroblasts.Methods: Gingival fibroblasts were stimulated with 10⁻⁷ or 10⁻⁹ M hydrocortisone for 24 hours; untreated cells served as controls. Alterations in the expression of MMP‐1, ‐2, ‐3, ‐7, ‐11 and TIMP‐1 and ‐2 were evaluated using real‐time polymerase chain reaction and Western blotting. β‐actin mRNA expression was used as a reference to normalize gene expression.Results: Although the higher hydrocortisone concentration upregulated MMP‐1, ‐2, ‐7, ‐11, and TIMP‐1 (P 0.0‐).Conclusions: Hydrocortisone produced a dose‐dependent regulation of MMP and TIMP expression. The higher hydrocortisone concentration significantly upregulated expression of MMP‐1, ‐2, ‐7, and ‐11 and TIMP‐1 in human gingival fibroblasts, which may constitute a mechanism underlying the increased periodontal breakdown associated with psychosocial stress status.