Challenges Quaternary ammonium compounds: limitations for use in the dental office

Dental offices are places constantly exposed to contaminations. This is due to the fact of high human exchange during the day and excessive volume of aerosols which come directly from patients mouth and respiratory tract. Therefore, dental practitioners continuously expose themselves and patients to pathogens and should pay attention to the risk of possible cross-contamination. One of the most common disinfection chemistry used in dental offices is quaternary ammonia compounds, which are used for surface and instruments disinfection as well as for aspiration system decontamination. However, only a limited number of dentists are aware of their drawbacks.

QACs are old fashion chemistry

Since their introduction around 100 years ago, by the 1940s quaternary ammonium compounds gained a strong position in the market and nowadays are count as the most common disinfectant covering more than 50% of disinfectant retail. While they possess quite a broad spectrum of antimicrobial activity they cannot sufficiently cover all microbes within the realistic contact time. The efficiency of QACs is influenced by their carbon chain. Important here is to note is that QACs with twin alkyl chains are more efficient than the one chained, as well that single alkyl chain containing between 12 and 16 carbon molecules presents stronger activity than the one with another number of carbons in the chain. But how do the QACs work? They are detergents or so-called surface-active compounds thanks to their amphiphilic nature. This means that they target the membrane of bacteria or lipid layer of enveloped virus causing its destabilization and permeabilization.

Antibiotic resistance following QACs exposure

An inadvertent consequence of QAC usage, especially caused by the availability of the compound in diluted concentration in wastewater or clinical settings, is raising tolerance or resistance to certain QACs and development of cross-tolerance to other QACs formulations among pathogenic bacteria. Moreover, due to slow perturbation of the membrane, a horizontal gene transfer can occur and allow bacteria to incorporate resistance genes. This phenomenon is especially interesting in the current era of the global threat of AMR and the high importance of antibiotic and biocides stewardship. Therefore, we should not omit this problem as AMR might cost us another pandemic.

Biofilm issue: QACs are not protecting against it

In general, disinfectants’ efficacy against biofilm depends on the active ingredient. It is well described that hydroxy peroxide is efficient against biofilm, the same goes for enzymes. However, there is a significant defect in biofilm disruption while treated with quaternary ammonium disinfectants. Why? Penetration of QAC to the center of some of the biofilm clusters can take up to 60 times longer than other biocides. Moreover, some pathogens are not only able to avoid the killing effect of QACs but also form biofilm in the presence of this chemical.

Environmental factor: QACs affect aquatic life

We should take into account that solutions containing QACs will end up in the environment. There is strong evidence including the analysis of aquatic ecotoxicity data as well as literature studies or waterbodies agencies reports that suggest potential risk toward aquatic life due to QACs presence in the water. The processes that are known to facilitate the degradation of QACs also indicate potential opportunities to improve treatment, limit environmental releases, and minimize environmental impacts. However, they should be further developed.

Safe alternatives

Recent scientific developments demonstrated a potent way to overcome the main issues mentioned above. In the dental office, we can distinguish three main different applications: surfaces, instruments, and suction systems decontamination. Each of them should be addressed in a different targetted way. For surfaces, we recommend ou Sanitizer Surface S1; based on boosted H2O2 as an active substance. This solution presents a broad antimicrobial spectrum and acts fast with proven environmental safety features and biofilm disruption. For instruments and suction systems we propose a novel hyper enzymatic solution. Sanicleaner Instruments P and Sanicleaner Aspiration present outstanding detergency proprieties thanks to 6 different hyper-concentrated enzymes. Enzymes are active proteins obtained in a natural process called fermentation are efficient against biofilm formation and are proved to be safe for aquatic life.


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