The effect of mouthrinses against oral microorganisms

A new pharmacological approach based on remdesivir aerosolized administration on SARS-CoV-2 pulmonary inflammation: A possible and rational therapeutic application

The new zoonotic coronavirus (SARS-CoV-2) responsible for coronavirus disease (COVID-19) is a new strain of coronavirus not previously seen in humans and which appears to come from bat species. It originated in Wuhan, Hubei Province, China, and spread rapidly throughout the world, causing over 5,569,679 global cases and 351,866 deaths in almost every country in the world, including Europe, particularly Italy. In general, based on existing data published to date, 80.9% of patients infected with the virus develop mild infection; 13.8% severe pneumonia; 4.7% respiratory failure, septic shock or multi-organ failure; 3% of these cases are fatal. Critical patients have been shown to develop acute respiratory distress syndrome (ARDS) and hospitalization in intensive care units. The average age of patients admitted to hospital is 57-79 years, with one third half with an underlying disease. Asymptomatic infections have also been described, but their frequency is not known. SARS-CoV-2 transmission is mainly airborne from one person to another via droplets. The data available so far seem to indicate that SARS-CoV-2 is capable of producing an excessive immune reaction in the host. The virus attacks type II pneumocytes in the lower bronchi through the binding of the Spike protein (S protein) to viral receptors, of which the angiotensin 2 conversion enzyme (ACE2) receptor is the most important. ACE2 receptor is widely expressed in numerous tissues, including the oropharynx and conjunctiva, but mostly distributed in ciliated bronchial epithelial cells and type II pneumocytes in the lower bronchi. The arrival of SARS-CoV-2 in the lungs causes severe primary interstitial viral pneumonia that can lead to the "cytokine storm syndrome", a deadly uncontrolled systemic inflammatory response triggered by the activation of interleukin 6 (IL-6), whose effect is extensive lung tissue damage and disseminated intravascular coagulation (DIC), that are life-threatening for patients with COVID-19. In the absence of a therapy of proven efficacy, current management consists of off-label or compassionate use therapies based on antivirals, antiparasitic agents in both oral and parenteral formulation, anti-inflammatory drugs, oxygen therapy and heparin support and convalescent plasma. Like most respiratory viruses can function and replicate at low temperatures (i.e. 34-35 °C) and assuming viral thermolability of SARS-CoV-2, local instillation or aerosol of antiviral (i.e. remdesivir) in humid heat vaporization (40°-41 °C) in the first phase of infection (phenotype I, before admission), both in asymptomatic but nasopharyngeal swab positive patients, together with antiseptic-antiviral oral gargles and povidone-iodine eye drops for conjunctiva (0,8-5% conjunctival congestion), would attack the virus directly through the receptors to which it binds, significantly decreasing viral replication, risk of evolution to phenotypes IV and V, reducing hospitalization and therefore death.

Periodontal disease and its prevention, by traditional and new avenues

One of the most prevalent diseases affecting humans are those which affect the oral cavity. Several diseases can affect the mouth, such as oral cancer, dental caries, Lichen Planus and, of course, periodontal disease with its variants. This review discusses gingivitis, periodontitis and peri-implantitis with a brief focus on the different primary prevention aids, such as mechanical, chemical and the new generation of potential products to be used in the future dental market, products that are prepared from natural sources, the general trend worldwide. In this review, not all new inventions will be mentioned, yet, the role of aged garlic extract (AGE) will be described in addition to a new toothpaste which originates from the Dead Sea and the Purecare dental which produces the Ozone (H3) for the prevention of periodontal disease.

Clinical efficacy of a new cetylpyridinium chloride-hyaluronic acid-based mouthrinse compared to chlorhexidine and placebo mouthrinses-A 21-day randomized clinical trial

OBJECTIVE

To compare the effectiveness of a novel cetylpyridinium chloride (CPC)-hyaluronic acid (HA)-based mouthrinse with chlorhexidine (CHX) and placebo mouthrinses in preventing plaque and gingivitis. The secondary outcomes were calculus, extrinsic stains, oral malodour and occurrence of adverse events.

METHODS

A 21-day randomized, double-blind, three-arm parallel study with random allocation of young dental students to any of the three mouthrinse groups. Thorough prophylaxis was done at baseline followed by a baseline examination for oral malodour, extrinsic stains, calculus, gingivitis and plaque by a single examiner. All the subjects used the allocated mouthrinse twice daily for 21 days and were examined again at the end of the experimental period. They were also interviewed for adverse events. Change in the scores of clinical indices was calculated and compared between the groups.

RESULTS

A total of 75 subjects were included and completed the experiment. There was a significant difference for change in plaque index scores between the groups (P = .015); subjects in the placebo group experienced higher levels of plaque accumulation than the other groups. Teeth staining increased in the CHX (P < .001) and placebo groups (P = .002), but not in CPC-HA users (P = .573). No significant differences were found between the three experimental groups for change in the gingival index (P = .08), calculus scores (P = .494), oral malodour (P = .870) and reporting of adverse events (P = .249).

CONCLUSIONS

CPC-HA and CHX had similar effectiveness in preventing plaque accumulation, while no differences were observed between the mouthrinses for preventing gingivitis. Dental staining was caused by CHX and the placebo mouthrinses but not by CPC-HA mouthrinse.

Antimicrobial Potential of Plant Extracts and Chemical Fractions of Sideroxylon obtusifolium (Roem. & Schult.) T.D. Penn on Oral Microorganisms

AIM

The aim of this study is to evaluate the in vitro antimicrobial activity of plant extracts and chemical fractions of Sideroxylon obtusifolium T.D. Penn on Streptococcus mutans, Streptococcus oralis, Streptococcus salivarius, Streptococcus parasanguinis, and Candida albicans as well as to identify the chemical classes found in the bioactive extracts possessing better activity.

MATERIALS AND METHODS

Freeze-dried hydroalcoholic extracts of the bark and leaves (LC and LF respectively) and ethanol extracts of bark and leaves (EC and EF respectively) of S. obtusifolium were assessed for antimicrobial potential by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration, and minimum fungicidal concentration (MFC). The tests were performed by microdilu-tion method (in triplicate) in three independent experiments. Phytochemical characterization was performed by quantification of total polyphenols, total flavonoids, and condensed tannins.

RESULTS

The EC extract presented weak antimicrobial potential on the growth of S. mutans (MIC = 1000 μg/mL); all extracts showed moderate inhibitory activity on the growth of C. albicans (MIC = 500 μg/mL). The dichloromethane and n-butanol fractions of LF extracts showed moderate growth inhibitory activity (MIC = 250 μg/mL) on C. albicans and fungicide potential (MFC/MIC = 2). The phytochemical characterization revealed a predominance of total polyphenols (EC = 29.23%; LC = 25.98%) and condensed tannins (LC = 38.84%; LF = 17.78%).

CONCLUSION

The dichloromethane and n-butanol fractions of S. obtusifolium LF extract showed antifungal activity against C. albicans, with the potential for bioprospection of phytocom-pounds for the treatment of periodontal fungal diseases caused by this microorganism. The effect may be related to phyto-chemical compounds from the polyphenol and condensed tannin classes.

CLINICAL SIGNIFICANCE

Research for new oral microbial disease treatment alternatives in bioactive compounds from medicinal plants is of clinical relevance and scientific interest since many therapeutic antifungal agents do not obtain the effectiveness expected due to microbial resistance, or to adverse effects on human tissues.

A combination of cis-2-decenoic acid and chlorhexidine removes dental plaque

OBJECTIVES

To investigate the ability of cis-2-decenoic acid (C2DA) to induce dispersion in single-species biofilms formed by Streptococcus mutans and Candida albicans, as well as to remove their bacterial-fungal dual-species biofilms when combined with low concentrations of chlorhexidine (CHX).

METHODS

For biofilm dispersal bioassays, single-species biofilms of S. mutans and C. albicans were grown on the inside surface of petri dishes, using a semi-batch culture method in which the medium was replaced every 24h for 5 days. Biofilms were then treated with very low concentrations of C2DA (100 and 310 nM) for 1h to release cells into the bulk liquid and to evaluate dispersed cell number by measuring the optical density (OD). To assess the ability of C2DA combined CHX treatments to remove tested microorganisms' dual-species biofilms, they were grown on saliva-coated hydroxyapatite (sHA) discs for 48 h and then were treated with three different concentrations of CHX (0.08%, 0.06% and 0.04%) alone or in combination with indicated concentrations of C2DA for 1 min twice daily for 3 subsequent days. Biofilms were then either subjected to the field emission scanning electron microscopy (FESEM) analysis or harvested and colony forming units (CFUs) were counted after plating on agar.

RESULTS

Treatment of pre-established biofilms with 310 nM C2DA caused an approximately two-fold increase in the number of planktonic cells in both cultures. A combination of 310 nM C2DA and 0.04% CHX resulted in significant removal (p-value <0.05) of dual-species biofilms from sHA discs surface.

CONCLUSIONS

Anti-biofilm characteristic of C2DA boosts the action of CHX even at low concentrations.