## 4 Discussion
In addition, since it requires water with no additional chemicals, it can be used on textiles with no damage risk, and the risk of slippery surfaces is negligible. Lastly, an NTD system does not depend on the operator because it relies on a steam-generation device to ensure a standardized disinfection procedure [21,27,28,30,37]. On the other hand, the main limitation of overheated dry-saturated steam is the presence of visible traces of dirt and/or blood stains on the surfaces that must first be cleaned with chemicals. Caution should also be taken when disinfecting electrical equipment; the steam jet must not be directed toward live electronic devices or onto toxic substances and explosive liquids or powders [23; 37]. Although this is a pilot study, it represents a significant scientific contribution to disinfection protocols and measures that have to be adopted by DHCPs in order to reduce the risk of cross-infections in dental practices. The literature on this topic is still limited and the present study's findings enrich the current knowledge, primarily based on studies evaluating the efficacy of steam disinfection on selected pathogens grown in in vitro culture media [22; 23; 24; 25; 26; 27; 28]. The study was performed in a real dental setting and therefore provides relevant findings with a practical application in the dental practice's daily disinfection routine. These findings are even more important in a pediatric dental setting, such as the one in which the study was performed, where children frequently have respiratory symptoms that increase the risk of cross-infections. In addition, being a health-safe non-toxic disinfection system, it reduces the risk of allergies or adverse reactions to chemicals, which is not negligible among children who are prone to explore and first touch the chair surfaces and then their eyes, nose and/or mouth. Considering the obtained preliminary findings, the study design was adequate to achieve its purpose; anyway, as this was a pilot study, further research is needed to evaluate the overheated dry-saturated steam system's efficacy in the disinfection of other surfaces and/or devices in dental offices. In addition, since the ATP bioluminescence analysis does not provide information on the type of microorganisms e.g., bacteria, viruses and fungi present on the evaluated surface, microbiological studies on contaminated surfaces are necessarily required to deepen the knowledge on this topic. Nevertheless, by giving an immediate result of the ATP cellular amount of the evaluated surface, it is a very useful screening tool to monitor the hygienic quality of surfaces, especially in the healthcare setting. It may allow immediate intervention if surfaces are not adequately disinfected and also, by giving an immediate visible result of the efficacy of cleaning procedures, it may help increase professionals' awareness of the importance of proper disinfection especially in light of the COVID-19 pandemic [34; 35]. Lastly, comparing the efficacy of overheated dry-saturated steam versus conventional chemical disinfection measures in the disinfection of surfaces in dental offices might help draw specific conclusions and define new disinfection protocols in dental practice.