An interventional study of Mechanical Oral Hygiene and Chlorhexidine in Oral Bacterial Colonization and Oral Hygiene, sponsored by University of Zagreb. Enrolling by invitation at 1 site in Croatia. Per ClinicalTrials.gov, last updated 2026-10-09.
Sponsored by University of Zagreb · Not applicable, Interventional, and Prevention
Patients in intensive care may develop changes in the bacteria found in their mouths. Some of these bacteria can cause infections, and patients who cannot clean their own teeth depend on staff to provide oral care.
This study compares three oral hygiene protocols to assess their effects on potentially harmful bacteria in the mouths of intensive care patients. All three protocols include cleaning the mouth with a toothbrush or sponge and fluoride toothpaste. One protocol uses this cleaning alone, one adds chlorhexidine, and one adds hexetidine. Chlorhexidine and hexetidine are antiseptics used to reduce microorganisms in the mouth. Trained nursing staff provide oral care twice daily.
Saliva samples are collected before the first study oral care procedure, within 24 hours of intensive care admission, and again on the third day. The samples are examined to identify and count selected bacteria and yeasts. Bacteria are also tested for resistance to antibiotics.
The study also examines whether antibiotic use, previous hospital stays, the type of breathing support, and oral hygiene at admission are associated with the presence of these microorganisms. The findings may help improve oral care protocols for intensive care patients.
This single-center comparative interventional study evaluates the effects of three oral hygiene protocols on oral colonization by Gram-negative bacteria in patients admitted to the medical intensive care unit of Sestre milosrdnice University Hospital Center, Zagreb, Croatia.
The study includes patients admitted with pneumonia, exacerbation of chronic obstructive pulmonary disease, pulmonary embolism, or cardiac decompensation. Patients receiving and not receiving antibiotic therapy are included, as are patients breathing spontaneously or receiving noninvasive or invasive mechanical ventilation.
Before the intervention begins, an oral examination is performed to assess visible dental plaque and identify oral mucosal lesions. Nursing staff receive standardized training in the oral care procedures to promote consistent delivery of the interventions. Oral hygiene is performed twice daily for three minutes using suction toothbrushes or sponges, according to the patient's dentition, and fluoride toothpaste without sodium lauryl sulfate. The three protocols comprise mechanical cleaning alone, mechanical cleaning with the addition of 0.2% chlorhexidine, and mechanical cleaning with the addition of hexetidine.
Unstimulated saliva is collected within the first 24 hours after intensive care admission, before the first oral hygiene procedure, and again on day 3 before oral care. Samples are cultured to identify and quantify selected Gram-negative bacteria, including Klebsiella pneumoniae, Escherichia coli, Citrobacter species, Proteus species, Enterobacter species, Serratia species, Acinetobacter baumannii complex, and Pseudomonas aeruginosa. Candida species are also assessed. Microbial counts are expressed as colony-forming units per milliliter of saliva. Antimicrobial susceptibility testing is performed on recovered bacterial isolates, with additional investigation of carbapenem resistance where indicated.
The analysis compares changes in microbial colonization within and between the oral hygiene groups. It also examines associations with recent hospitalization, antibiotic use during the preceding three months, antibiotic treatment at admission, baseline oral hygiene, and the type of respiratory support. The study aims to inform the standardization of oral hygiene procedures and the selection of antiseptics for intensive care patients.
Participants were assigned consecutively to the three oral hygiene protocols according to a predefined repeating sequence (Protocol 1, Protocol 2, Protocol 3). No random allocation sequence or allocation concealment was used.
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This study's planned enrollment of 86 is close to the median of 90 across 1,003 interventional studies indexed under Critical Illness.
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Patients of either sex are eligible, regardless of age. Patients receiving or not receiving antibiotic therapy may participate. Patients breathing spontaneously or receiving noninvasive or invasive mechanical ventilation are eligible.
Exclusion Criteria:
Participants receive oral cleaning with a suction toothbrush or sponge, according to their dentition, and fluoride toothpaste without sodium lauryl sulfate. Trained nursing staff perform oral care twice daily for three minutes. No additional antiseptic is used.
Procedure: Mechanical Oral Hygiene
Participants receive oral cleaning with a suction toothbrush or sponge, according to their dentition, and fluoride toothpaste without sodium lauryl sulfate, followed by application of 0.2% chlorhexidine using sterile gauze and a spatula. Trained nursing staff perform oral care twice daily for three minutes.
Procedure: Mechanical Oral Hygiene · Drug: Chlorhexidine
Participants receive oral cleaning with a suction toothbrush or sponge, according to their dentition, and fluoride toothpaste without sodium lauryl sulfate, followed by application of hexetidine using sterile gauze and a spatula. Trained nursing staff perform oral care twice daily for three minutes.
Procedure: Mechanical Oral Hygiene · Drug: Hexetidine
Oral cleaning with a suction toothbrush or sponge, according to the participant's dentition, and fluoride toothpaste without sodium lauryl sulfate. Oral care is performed by trained nursing staff twice daily for three minutes.
Application of 0.2% chlorhexidine to the oral cavity using sterile gauze and a spatula after mechanical cleaning, twice daily.
Application of hexetidine to the oral cavity using sterile gauze and a spatula after mechanical cleaning, twice daily.
Change in Salivary Gram-Negative Bacterial Counts From Baseline to Day 3
Change in the concentration of culturable Gram-negative bacteria in unstimulated saliva from baseline to day 3, compared among the three oral hygiene groups. Bacterial counts are expressed as colony-forming units per milliliter (CFU/mL), determined by quantitative culture on MacConkey agar. Assessed organisms include Klebsiella pneumoniae, Escherichia coli, Citrobacter species, Proteus species, Enterobacter species, Serratia species, Acinetobacter baumannii complex, and Pseudomonas aeruginosa. Baseline saliva is collected within 24 hours of intensive care admission, before the first study oral hygiene procedure. The day 3 sample is collected before oral hygiene.
Time frame: Baseline (within 24 hours of intensive care admission) and day 3
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Plan to share: No — There is currently no plan to share individual participant data with other researchers. Study findings will be disseminated through scientific publications presenting aggregate results.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Chlorhexidine
University of Zagreb