Mouth care for preventing pneumonia in nursing homes

Review question

Does oral (mouth) care cut down pneumonia (a lung infection) in nursing homes? We aimed to summarise the findings from studies known as 'randomised controlled trials' in order to identify whether mouth care helped prevent pneumonia in elderly people living in nursing homes or other care facilities, and which approach to mouth care was best.


Pneumonia is common among elderly people living in nursing homes. Nursing home-acquired pneumonia (NHAP) is a bacterial infection of the lung that occurs in residents of long-term care facilities and nursing homes. Poor oral hygiene is considered to contribute to the likelihood of contracting an infection. Professional mouth care is a combination of brushing teeth and mucosa, cleaning dentures, using mouthrinse, and check-up visits to a dentist, while usual mouth care is generally less intensive, and is self-administered, or provided by nursing home staff without special training in oral hygiene.

Study characteristics

This review was carried out through Cochrane Oral Health. We searched scientific databases for relevant studies, up to 15 November 2017. We included four studies, with a total of 3905 participants randomly assigned to treatment or usual care. Participants were long-term-care elderly residents in nursing homes who did not have pneumonia at the beginning of the studies. Some of the participants had dementia or systemic diseases. All studies focused on the comparison between 'professional' mouth care and 'usual' mouth care. None of the studies evaluated oral care versus no oral care.

Key results

We identified four studies, all of which compared professional mouth care to usual mouth care in nursing home residents.

From the limited evidence, we could not tell whether professional oral mouth care was better or worse than usual mouth care for preventing pneumonia. The evidence for death from any cause was inconclusive, but the studies did suggest that professional mouth care may reduce the number of deaths caused by pneumonia, compared to usual mouth care, when measured after 24 months.

Only one study measured negative effects of the interventions, and reported that there were no serious events. The most common non-serious events reported were damage to the mouth and tooth staining.

Quality of the evidence

The quality of the evidence is low or very low, because of the small number of studies and problems with their design. Therefore, we cannot rely on the findings, and further research is required.

Authors' conclusions: 

Although low-quality evidence suggests that professional oral care could reduce mortality due to pneumonia in nursing home residents when compared to usual care, this finding must be considered with caution. Evidence for other outcomes is inconclusive. We found no high-quality evidence to determine which oral care measures are most effective for reducing nursing home-acquired pneumonia. Further trials are needed to draw reliable conclusions.

Read the full abstract...

Pneumonia occurring in residents of long-term care facilities and nursing homes can be termed 'nursing home-acquired pneumonia' (NHAP). NHAP is the leading cause of mortality among residents. NHAP may be caused by aspiration of oropharyngeal flora into the lung, and by failure of the individual's defence mechanisms to eliminate the aspirated bacteria. Oral care measures to remove or disrupt oral plaque might be effective in reducing the risk of NHAP.


To assess effects of oral care measures for preventing nursing home-acquired pneumonia in residents of nursing homes and other long-term care facilities.

Search strategy: 

Cochrane Oral Health’s Information Specialist searched the following databases: Cochrane Oral Health’s Trials Register (to 15 November 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 10), MEDLINE Ovid (1946 to 15 November 2017), and Embase Ovid (1980 to 15 November 2017) and Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1937 to 15 November 2017). The US National Institutes of Health Trials Registry ( and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. We also searched the Chinese Biomedical Literature Database, the China National Knowledge Infrastructure, and the Sciencepaper Online to 20 November 2017.

Selection criteria: 

We included randomised controlled trials (RCTs) that evaluated the effects of oral care measures (brushing, swabbing, denture cleaning mouthrinse, or combination) in residents of any age in nursing homes and other long-term care facilities.

Data collection and analysis: 

At least two review authors independently assessed search results, extracted data, and assessed risk of bias in the included studies. We contacted study authors for additional information. We pooled data from studies with similar interventions and outcomes. We reported risk ratio (RR) for dichotomous outcomes, mean difference (MD) for continuous outcomes, and hazard ratio (HR) for time-to-event outcomes, using random-effects models.

Main results: 

We included four RCTs (3905 participants), all of which were at high risk of bias. The studies all evaluated one comparison: professional oral care versus usual oral care. We did not pool the results from one study (N = 834 participants), which was stopped at interim analysis due to lack of a clear difference between groups.

We were unable to determine whether professional oral care resulted in a lower incidence rate of NHAP compared with usual oral care over an 18-month period (hazard ratio 0.65, 95% CI 0.29 to 1.46; one study, 2513 participants analysed; low-quality evidence).

We were also unable to determine whether professional oral care resulted in a lower number of first episodes of pneumonia compared with usual care over a 24-month period (RR 0.61, 95% CI 0.37 to 1.01; one study, 366 participants analysed; low-quality evidence).

There was low-quality evidence from two studies that professional oral care may reduce the risk of pneumonia-associated mortality compared with usual oral care at 24-month follow-up (RR 0.41, 95% CI 0.24 to 0.72, 507 participants analysed).

We were uncertain whether or not professional oral care may reduce all-cause mortality compared to usual care, when measured at 24-month follow-up (RR 0.55, 95% CI 0.27 to 1.15; one study, 141 participants analysed; very low-quality evidence).

Only one study (834 participants randomised) measured adverse effects of the interventions. The study identified no serious events and 64 non-serious events, the most common of which were oral cavity disturbances (not defined) and dental staining.

No studies evaluated oral care versus no oral care.