The oral hygiene method commonly used in intubated patients orotracheal is tooth brushing (mechanical removal) and washing the oral cavity and the orotracheal tube (TOT) with digluconate solution chlorhexidine (CLX). However, recent studies have demonstrated that the use of CLX in these conditions may expose the patient to a potential increased risk of mortality. Recent recommendations made by international bodies related to hospital biosafety no longer include the use of CLX in ICU oral hygiene routine. A question not yet answered in the literature is whether the absence of CLX in the critical patient's oral hygiene routine predisposes increased accumulation of dental plaque or microbial colonization related to the risk of systemic complications, such as pneumonia and sepsis. The cost-effectiveness of this protocol change also needs to be evaluated, as the withdrawal of CLX may result in changes in the risk profile morbidity and mortality during hospitalization. The present study aims to investigate whether brushing the oral cavity with mineral water changes the pattern of biofilm accumulation and clinical appearance of the oral mucosa in relation to brushing done with CLX. Microbiological analysis of the oropharyngeal biofilm and cost-effectiveness impact assessment will also be carried out.