Use of dental disinfectants: the chemical and biological risks

Disinfectants are used in the dental environment with the main purpose of preventing cross-infections. According to the literature, cross-infections are considered to rank among the major healthcare-related complications; they affect 5-10% of hospitalised patients, incurring an estimated annual cost of about $4.5 billion in the United States (1).

In a dental care setting, it is difficult to provide an estimate for this, but the risk of cross-infection is nonetheless present (2). It is present not only between healthcare staff and patients, but also from one patient to another and may even involve the dental technician, associates and/or technical support staff who visit the practice occasionally (3).

Risks and dangers associated with the use of disinfectants in dentistry

The use of disinfectants in the dental surgery is therefore of considerable importance and is mandatory. However, there are risks and dangers associated with their use, (4) which must be carefully considered by healthcare professionals (dental assistants, receptionists and dentists) when applying them.

These risks, depending on the legislation in force in the country in which they are sold, are generally reported on the label, in the instructions for use and in the product safety data sheet. (5)

Prevention and protection in the use of dental disinfectants

First of all, it is important to emphasise how the risks associated with the use of disinfectants very often result from incorrect use.

For this reason, it is essential to carefully read the instructions for use and the label, where the risks associated with improper use and exposure to the products are specified. These instructions should be read carefully before using the specific products in clinical practice.

Then, once informed about what the risks are, it is equally important to know what action to take following any accidental exposure to disinfectants (6,7). Depending on the type of exposure and the part of the body that comes into contact with disinfectants, different effects may occur in terms of severity and type, which may be short- or long-term.

Effects of exposure to disinfectants in dentistry

Certainly, in the dental environment, the skin, the eyes and the airways are the organs most affected by immediate lesions related to disinfectants, especially if contact is repeated and prolonged.

The most common skin lesions are irritant or even allergic dermatitis following direct contact with chemical substances contained in disinfectants, such as alcohol, glutaraldehyde, hypochlorite or even specific allergens, usually flavourings or preservatives. (8) Burns can also be caused by advanced skin erosions  after prolonged contact or exposure to highly concentrated alcohol-based disinfectants, a phenomenon that has received particular attention during the COVID pandemic (9).

Eye and respiratory injuries caused by dental disinfectants

Among the eye injuries, however, we recognise damage caused by acid or alkaline chemical agents. Among these, alkaline agents are the most dangerous and are associated with more serious damage because, due to their pH, they are able to penetrate the ocular tissues more easily, possibly causing a variety of signs and symptoms such as severe pain similar to a burn, corneal opacity, tissue necrosis and intense tearing (10).

Inhalation of disinfectants or direct contact with the corrosive substances contained within them can, however, cause various lesions to both the upper and lower airways. (11) Airway irritation is the main symptom that occurs following inhalation and may include burning or pain in the nose and throat, a sensation of nasal and/or oral dryness, and a persistent dry cough sometimes accompanied by difficulty speaking. (11)

When contact is prolonged or in the case of exposure to an allergen, there may also be swelling of the airways, which will cause breathing difficulties and possibly even a narrowing of the glottis in the most serious cases. Bronchitis and subsequent acute pneumonia may occur if contact with the irritant/harmful substance (particularly organic solvents) is prolonged and especially when it is not removed from the respiratory tract (12).

Disinfectants in dentistry: the importance of PPE

In summary, these are the main chemical and biological risks that can be encountered during the use of dental disinfectants, but other possible conditions can still manifest themselves. It is therefore useful and protective to correctly use personal protective equipment (PPE) such as gloves, glasses, masks and gowns, which are essential in the dental practice not only to protect against cross-infections, but also to reduce the risks associated with the use of disinfectants for those carrying out disinfection and sterilisation tasks.

Finally, it is equally essential to comply with the instructions for use and provide adequate training to the designated staff. Proper management of the use of disinfectants guarantees not only individual protection, but also a safe environment for all those attending the dental practice.

References:

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