Preprocedural mouthwashes for infection control in dentistry-an update.

OBJECTIVES: Aerosols and splatter are routinely generated in dental practice and can be contaminated by potentially harmful bacteria or viruses such as SARS-CoV-2. Therefore, preprocedural mouthwashes containing antiseptic agents have been proposed as a potential measure for infection control in dental practice. This review article aims to summarize the clinical (and, if insufficient, preclinical) evidence on preprocedural mouthwashes containing antiseptic agents and to draw conclusions for dental practitioners. METHODS: Literature on preprocedural mouthwashes for reduction of bacterial or viral load in dental aerosols was searched and summarized. RESULTS: Preprocedural mouthwashes, particularly those containing chlorhexidine digluconate (CHX), cetylpyridinium chloride (CPC), or essential oils (EO), can significantly reduce the bacterial load in dental aerosols. With respect to viruses such as HSV-1, there are too little clinical data to draw any clear recommendations. On the other hand, clinical data is consolidating that CPC-containing mouthwashes can temporarily reduce the intraoral viral load and infectivity in SARS-CoV-2 positive individuals. Nevertheless, potential risks and side effects due to regular antiseptic use such as ecological effects or adaptation of bacteria need to be considered. CONCLUSIONS: The use of preprocedural mouthwashes containing antiseptics can be recommended according to currently available data, but further studies are needed, particularly on the effects on other viruses besides SARS-CoV-2. When selecting a specific antiseptic, the biggest data basis currently exists for CHX, CPC, EO, or combinations thereof. CLINICAL RELEVANCE: Preprocedural mouthwashes containing antiseptics can serve as part of a bundle of measures for protection of dental personnel despite some remaining ambiguities and in view of potential risks and side effects.

Is chlorhexidine mouthwash effective in lowering COVID-19 viral load? A systematic review.

OBJECTIVE: This review aims to determine whether there is considerable evidence that mouthwashes containing chlorhexidine (CHX) lower the COVID-19 virus load in saliva. MATERIALS AND METHODS: A comprehensive literature search was carried out in PubMed/Medline, EMBASE, LILACS, Scopus, Web of Science and Cochrane Library, Google Scholar, Open Gray, and ProQuest electronic databases using the keywords: "coronavirus infections" or "coronavirus" or "covid 2019" or "sars 2" or "sars-cov-2" or "sars-cov-19" or "severe acute respiratory syndrome coronavirus 2" or "coronavirus infection" or "severe acute respiratory pneumonia outbreak" and "CHX" or "CHX Hydrochloride" or "CHX Digluconate." A manual search of the articles was also conducted utilizing the reference lists of articles. The in vitro experimental and clinical studies that tested CHX mouthwash were included. Study selection was not restricted or limited to a specific gender, age, ethnicity of individuals, or time of publication. A mix of keywords and proper truncations were used to search for databases. RESULTS: Twelve studies (7 clinical and 5 in vitro) published between 2020 and 2021 were included in this systemic review. Five randomized controlled trials and one clinical case series demonstrated the effectiveness of CHX in reducing the oral viral load; one was inconclusive. Of the five in vitro studies, three showed that CHX is effective against SARS-CoV-2, and two studies denied the effectiveness of CHX. All in vitro studies tested CHX activity concentrations of 0.2, 0.12, and 0.1%. One study reported more than a 99.9% reduction in SARS-CoV-2 viral load in a minimal contact time of 30 seconds. CHX exhibited potent antiviral activity at higher concentrations without cytotoxicity. CONCLUSIONS: Despite differences in the published research, CHX at different concentrations may be effective in lowering the SARS-COV-2 viral load in saliva.

Preprocedural mouth rinses for preventing transmission of infectious diseases through aerosols in dental healthcare providers.

BACKGROUND: Aerosols and spatter are generated in a dental clinic during aerosol-generating procedures (AGPs) that use high-speed hand pieces. Dental healthcare providers can be at increased risk of transmission of diseases such as tuberculosis, measles and severe acute respiratory syndrome (SARS) through droplets on mucosae, inhalation of aerosols or through fomites on mucosae, which harbour micro-organisms. There are ways to mitigate and contain spatter and aerosols that may, in turn, reduce any risk of disease transmission. In addition to personal protective equipment (PPE) and aerosol-reducing devices such as high-volume suction, it has been hypothesised that the use of mouth rinse by patients before dental procedures could reduce the microbial load of aerosols that are generated during dental AGPs. OBJECTIVES: To assess the effects of preprocedural mouth rinses used in dental clinics to minimise incidence of infection in dental healthcare providers and reduce or neutralise contamination in aerosols. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 4 February 2022. SELECTION CRITERIA: We included randomised controlled trials and excluded laboratory-based studies. Study participants were dental patients undergoing AGPs. Studies compared any preprocedural mouth rinse used to reduce contaminated aerosols versus placebo, no mouth rinse or another mouth rinse. Our primary outcome was incidence of infection of dental healthcare providers and secondary outcomes were reduction in the level of contamination of the dental operatory environment, cost, change in mouth microbiota, adverse events, and acceptability and feasibility of the intervention. DATA COLLECTION AND ANALYSIS: Two review authors screened search results, extracted data from included studies, assessed the risk of bias in the studies and judged the certainty of the available evidence. We used mean differences (MDs) and 95% confidence intervals (CIs) as the effect estimate for continuous outcomes, and random-effects meta-analysis to combine data  MAIN RESULTS:  We included 17 studies with 830 participants aged 18 to 70 years. We judged three trials at high risk of bias, two at low risk and 12 at unclear risk of bias.  None of the studies measured our primary outcome of the incidence of infection in dental healthcare providers.  The primary outcome in the studies was reduction in the level of bacterial contamination measured in colony-forming units (CFUs) at distances of less than 2 m (intended to capture larger droplets) and 2 m or more (to capture droplet nuclei from aerosols arising from the participant's oral cavity). It is unclear what size of CFU reduction represents a clinically significant amount. There is low- to very low-certainty evidence that chlorhexidine (CHX) may reduce bacterial contamination, as measured by CFUs, compared with no rinsing or rinsing with water. There were similar results when comparing cetylpyridinium chloride (CPC) with no rinsing and when comparing CPC, essential oils/herbal mouthwashes or boric acid with water. There is very low-certainty evidence that tempered mouth rinses may provide a greater reduction in CFUs than cold mouth rinses. There is low-certainty evidence that CHX may reduce CFUs more than essential oils/herbal mouthwashes. The evidence for other head-to-head comparisons was limited and inconsistent.  The studies did not provide any information on costs, change in micro-organisms in the patient's mouth or adverse events such as temporary discolouration, altered taste, allergic reaction or hypersensitivity. The studies did not assess acceptability of the intervention to patients or feasibility of implementation for dentists.  AUTHORS' CONCLUSIONS: None of the included studies measured the incidence of infection among dental healthcare providers. The studies measured only reduction in level of bacterial contamination in aerosols. None of the studies evaluated viral or fungal contamination. We have only low to very low certainty for all findings. We are unable to draw conclusions regarding whether there is a role for preprocedural mouth rinses in reducing infection risk or the possible superiority of one preprocedural rinse over another. Studies are needed that measure the effect of rinses on infectious disease risk among dental healthcare providers and on contaminated aerosols at larger distances with standardised outcome measurement.

The short-term effect of different chlorhexidine forms versus povidone iodine mouth rinse in minimizing the oral SARS-CoV-2 viral load: An open label randomized controlled clinical trial study.

Several investigations evaluated the possibility of different types of mouth wash rinse in minimizing the SARS-CoV-2 load. However, results still controversial. The study aim is to assess the short-term efficiency of several over-the-counter mouth rinses and lozenges in minimizing the salivary viral load for SARS-CoV-2 in patients with confirmed COVID-19 in comparison to saline. This is a randomized controlled clinical trial with 4 arms. The recruited cases were randomized using a simple randomization technique and were assigned to chlorhexidine digluconate mouth rinse (CHX mouth rinse), 2 mg of chlorhexidine digluconate lozenges (CHX lozenges), povidone iodine mouth rinse (PVP-I mouth rinse) or saline as a control group. Saliva were collected from all study subjects by passive drool technique at two time points. First, prior to intervention with mouth rinse or the lozenges, the baseline saliva sample was collected. Second saliva samples were collected immediately after the mouth rinse. Real time PCR was conducted and the value threshold cycle (Ct) for each sample was recorded. Majority of the participants had an education level of high school or less (60%), were married (68.3), males (58.3%), and non-smokers (58.5%). No statistically significant differences between groups at the two times test (P > .05). However, a significant decrease of salivary viral load in all four groups combined (P-value for E genes = .027, and for S genes = .006), and in PVP-I mouth rinse specifically (P = .003 and P = .045, respectively). Povidone iodine mouth rinse showed a potential influence on the reduction of the viral load on a short-term basis. However, longer-term studies of the effect of these products should be conducted.

Efficacy of antiseptic mouthrinses against SARS-CoV-2: A prospective randomized placebo-controlled pilot study.

OBJECTIVES: Coronavirus-disease-19 (COVID-19) continues to affect millions of individuals worldwide. Antiviral activity of mouthrinses remains an important research area as the oral cavity is a site of SARS-CoV-2 initial replication. The aim of this study was to assess the effectiveness of three different mouthrinses in reducing the oral/oropharyngeal SARS-CoV-2 viral load. METHODS: Adult patients, hospitalized with confirmed COVID-19 were recruited for the study. Oral/oropharyngeal baseline SARS-CoV-2 samples were collected and analyzed by Real-Time-PCR. Subsequently, patients were instructed to rinse with 1 % hydrogen peroxide (H2O2), 0.12 % chlorhexidine (CHX), 1 % povidone­iodine (PVP-I) or Sodium Chloride 0.9 % (placebo). Viral loads were measured right after (T1), and at 45 min (T2) from the rinse. RESULTS: In the PVP-I 1 % group, 5/8 (62.5 %) patients at T1, and 3/8 (37.5 %) patients at T2, SARS-CoV-2 was not detectable in the swab specimens. In the H2O2 1 % group, 2/11 (18.2 %) patients at T1, and 2/11 (18.2 %) other patients at T2 showed no SARS-CoV-2 loads. One (12.5 %) patient in the CHX 0.12 % group showed SARS-CoV-2 negativity at T2. One (9.1 %) patient at T1, and another (9.1 %) patient at T2 showed no SARS-CoV-2 loads in the placebo group. CONCLUSIONS: Oral SARS-CoV-2 loads were reduced at T1 in the PVP-I 1 % and H2O2 1 % groups. CLINICAL RELEVANCE: PVP-I 1 % was the most effective rinse especially in patients with low viral copy numbers at baseline.

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

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.

Review of the use of nasal and oral antiseptics during a global pandemic.

A review of nasal sprays and gargles with antiviral properties suggests that a number of commonly used antiseptics including povidone-iodine, Listerine®, iota-carrageenan and chlorhexidine should be studied in clinical trials to mitigate both the progression and transmission of SARS-CoV-2. Several of these antiseptics have demonstrated the ability to cut the viral load of SARS-CoV-2 by 3-4 log10 in 15-30 s in vitro. In addition, hypertonic saline targets viral replication by increasing hypochlorous acid inside the cell. A number of clinical trials are in process to study these interventions both for prevention of transmission, prophylaxis after exposure, and to diminish progression by reduction of viral load in the early stages of infection.

Preliminary model assessing the cost-effectiveness of preoperative chlorhexidine mouthwash at reducing postoperative pneumonia among abdominal surgery patients in South Africa.

BACKGROUND: Pneumonia is a common and severe complication of abdominal surgery, it is associated with increased length of hospital stay, healthcare costs, and mortality. Further, pulmonary complication rates have risen during the SARS-CoV-2 pandemic. This study explored the potential cost-effectiveness of administering preoperative chlorhexidine mouthwash versus no-mouthwash at reducing postoperative pneumonia among abdominal surgery patients. METHODS: A decision analytic model taking the South African healthcare provider perspective was constructed to compare costs and benefits of mouthwash versus no-mouthwash-surgery at 30 days after abdominal surgery. We assumed two scenarios: (i) the absence of COVID-19; (ii) the presence of COVID-19. Input parameters were collected from published literature including prospective cohort studies and expert opinion. Effectiveness was measured as proportion of pneumonia patients. Deterministic and probabilistic sensitivity analyses were performed to assess the impact of parameter uncertainties. The results of the probabilistic sensitivity analysis were presented using cost-effectiveness planes and cost-effectiveness acceptability curves. RESULTS: In the absence of COVID-19, mouthwash had lower average costs compared to no-mouthwash-surgery, $3,675 (R 63,770) versus $3,958 (R 68,683), and lower proportion of pneumonia patients, 0.029 versus 0.042 (dominance of mouthwash intervention). In the presence of COVID-19, the increase in pneumonia rate due to COVID-19, made mouthwash more dominant as it was more beneficial to reduce pneumonia patients through administering mouthwash. The cost-effectiveness acceptability curves shown that mouthwash surgery is likely to be cost-effective between $0 (R0) and $15,000 (R 260,220) willingness to pay thresholds. CONCLUSIONS: Both the absence and presence of SARS-CoV-2, mouthwash is likely to be cost saving intervention for reducing pneumonia after abdominal surgery. However, the available evidence for the effectiveness of mouthwash was extrapolated from cardiac surgery; there is now an urgent need for a robust clinical trial on the intervention on non-cardiac surgery.

Use of chlorhexidine to eradicate oropharyngeal SARS-CoV-2 in COVID-19 patients.

As public distribution of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is underway, prevention of coronavirus disease 2019 (COVID-19) relies on minimizing spread. In this study, chlorhexidine gluconate was investigated as a topical antimicrobial agent against SARS-CoV-2. This was a randomized, prospective cohort study using chlorhexidine as an oral rinse and posterior oropharyngeal spray in hospitalized COVID-19 patients. The primary outcome was presence or absence of laboratory-confirmed SARS-CoV-2 in the oral and oropharyngeal cavities after 4 days of chlorhexidine use and standard of care (study group) or standard of care only (control group). SARS-CoV-2 was eliminated from the oropharynx in 62.1% of patients who used chlorhexidine as an oral rinse, versus 5.5% of the control group patients. Among patients who used a combination of oral rinse and oropharyngeal spray, 86.0% eliminated oropharyngeal SARS-CoV-2, versus 6.3% of control patients. Chlorhexidine is a simple and safe addition to current COVID-19 prevention guidelines and may play a significant role in reducing disease spread.

Could antiseptic gargling prevent COVID-19?

Coronavirus Disease 2019 (COVID-19) has infected more than 8 million people globally since its discovery in December 2019. For COVID-19 prevention, the World Health Organization recommended regular handwashing with soap, cough etiquette, mask wearing and social distancing. However, COVID-19 is rather difficult to contain because of its high transmissibility property. Gargling is effective for reducing infection in the respiratory tract. Most antiseptic gargles have antimicrobial properties against common respiratory pathogens. No published study on the effectiveness of antiseptic gargling among COVID-19 patients has been available to date. This article reviewed available literature on methods and solutions available for gargling and their effect on respiratory tract infections.

Efficacy of commercial mouth-rinses on SARS-CoV-2 viral load in saliva: randomized control trial in Singapore.

PURPOSE: One of the key approaches to minimize the risk of COVID-19 transmission would be to reduce the titres of SARS-CoV-2 in the saliva of infected COVID-19 patients. This is particularly important in high-risk procedures like dental treatment. The present randomized control trial evaluated the efficacy of three commercial mouth-rinse viz. povidone-iodine (PI), chlorhexidine gluconate (CHX) and cetylpyridinium chloride (CPC), in reducing the salivary SARS-CoV-2 viral load in COVID-19 patients compared with water. METHODS: A total of 36 SARS-CoV-2-positive patients were recruited, of which 16 patients were randomly assigned to four groups-PI group (n = 4), CHX group (n = 6), CPC group (n = 4) and water as control group (n = 2). Saliva samples were collected from all patients at baseline and at 5 min, 3 h and 6 h post-application of mouth-rinses/water. The samples were subjected to SARS-CoV-2 RT-PCR analysis. RESULTS: Comparison of salivary Ct values of patients within each group of PI, CHX, CPC and water at 5 min, 3 h and 6 h time points did not show any significant differences. However, when the Ct value fold change of each of the mouth-rinse group patients were compared with the fold change of water group patients at the respective time points, a significant increase was observed in the CPC group patients at 5 min and 6 h and in the PI group patients at 6 h. CONCLUSION: The effect of decreasing salivary load with CPC and PI mouth-rinsing was observed to be sustained at 6 h time point. Within the limitation of the current study, as number of the samples analyzed, the use of CPC and PI formulated that commercial mouth-rinses may be useful as a pre-procedural rinse to help reduce the transmission of COVID-19. ISRCTN (ISRCTN95933274), 09/09/20, retrospectively registered.