Chlorhexidine mouthwash reduces the salivary viral load of SARS‐CoV‐2: A randomized clinical trial

Abstract

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.

Efficacy of Pre-Procedural Mouthwashes against SARS-CoV-2: A Systematic Review of Randomized Controlled Trials

“…In these studies, rinsing times ranged between 30 s and 1 min. In the placebo group, distilled water [ 14 , 22 , 23 , 24 , 25 ], saline [ 26 ], and an unspecified inactive substance [ 27 ] were used. The control group in one study did not receive treatment [ 28 ].…”

“…The control group in one study did not receive treatment [ 28 ]. In the test group several active compounds were used: CDCM ® (0.1% beta-cyclodextrin and 0.1% Citrox ® ) ( n = 1 [ 14 ]); hydrogen peroxide (HP) at 1% [ 25 , 26 ] or 1.50% [ 22 ]; chlorhexidine (CHX) at 0.12% [ 22 , 25 , 26 , 27 , 28 ] or 0.20% [ 23 , 24 ]; a combination of 0.12% CHX and 1.50% HP [ 22 ]; cetylpyridinium chloride (CPC) 0.07% [ 25 ] and 0.075% [ 23 ]; a combination of 0.075% CPC and 0.28% Zinc (Zn) [ 22 ]; and povidone iodine (PVP-I) at 0.50% [ 23 , 26 ], 1% [ 24 ] and 2% [ 25 ]. All the studies investigated the effect of oral rinses, except for one article [ 28 ] which studied the combination of an oral rinse with an oropharyngeal spray.…”

“…The number of saliva samples after interventions varied among the studies. Two studies collected one sample of saliva after intervention [ 24 , 28 ], three collected two samples [ 22 , 26 , 27 ], and three collected three samples [ 14 , 23 , 25 ]. A summary of the findings of the included articles are described in Table 1 .…”

“…Costa et al [ 27 ] (2021) recruited 100 patients for a randomized double-blind control trial evaluating 0.12% CHX as a mouthwash vs. a control group (an inactive substance). Saliva samples were taken at baseline, 5 min and 60 min after rinsing, and were evaluated through RT-PCR.…”

Virucidal Activity of Different Mouthwashes against the Salivary Load of SARS-CoV-2: A Narrative Review

“…There are multiple recent RCTs performed evaluating the virucidal activity of CHX against salivary SARS-CoV-2. A study by Costa et al [ 24 ] evaluated the efficacy of 0.12% CHX at 5 and 60 min after rinsing for 1 min. They found that there was a significant reduction (72%) in the salivary load at both 5 and 60 min after rinsing compared with the control.…”