Oral Hygiene Interventions and Pneumonia Prevention in Critical Care: An Integrative Review of Evidence and Practice

Ventilator-associated pneumonia (VAP) and non-ventilator hospital-acquired pneumonia (NVHAP) remain among the most common and serious infections in adult critical care settings. Despite strong biological plausibility, oral care is inconsistently specified and rarely measured as a preventive strategy. This review synthesizes evidence on oral hygiene practices in critically ill adults, examines their relationship to VAP and NVHAP, and proposes a pragmatic and dentistry-informed oral-care bundle for clinical use.

An integrative review was conducted using a structured literature search in PubMed, Scopus, and Web of Science from 2005 to 2025. Search terms combined pneumonia-related concepts, critical care setting and oral health. Eligible sources included studies addressing oral health and the prevention of VAP or NVHAP in adult critical care settings. Only full-text publications in English or with an available English translation were included.

The database search identified 935 records. After removing 224 duplicates, 711 studies were selected for title and abstract screening. Furthermore, studies focused exclusively on non-oral pneumonia prevention strategies, those without an oral health-related component, or those not conducted in an acute hospital or intensive care unit (ICU) setting were excluded during the synthesis phase, resulting in 20 studies included in the final synthesis. The evidence synthesis was conducted narratively, organized around domains corresponding to the review objectives such as pathophysiologic mechanisms along the oral-lung axis; current oral care practices; modality-specific interventions; assessment and documentation; implementation and workforce factors; safety, equity, and feasibility.

Oral hygiene occupies a modifiable point along the oral-lung axis, where simple bedside interventions can reduce pneumonia risk; however, clinical practice remains heterogeneous and under-specified. Structured oral care practices reduce VAP incidence and represent a reliable and scalable contribution to safer critical and acute care.