Toothbrushing Tied to Lower Rates of Pneumonia

Researchers have found an inexpensive tool that may help reduce rates of pneumonia for hospitalized patients — and it comes with bristles on one end. 

A new study by investigators from Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system, and Harvard Pilgrim Health Care Institute examined whether daily toothbrushing among hospitalized patients is associated with lower rates of hospital-acquired pneumonia and other outcomes. 

The team combined the results of 15 randomized clinical trials that included more than 2,700 patients and found that hospital-acquired pneumonia rates were lower among patients who received daily toothbrushing compared to those who did not. The results were especially compelling among patients on mechanical ventilation. Their results are published in JAMA Internal Medicine.

Hospital-acquired pneumonia occurs when bacteria in the mouth enter a patient’s airways and infect their lungs. Patients experiencing frailty or patients with a weakened immune system are particularly susceptible to developing hospital-acquired pneumonia during their hospital stay.

However, adopting a daily toothbrushing regimen can decrease the amount of bacteria in the mouth, potentially lowering the risk of hospital-acquired pneumonia from occurring.

The team conducted a systematic review and meta-analysis to determine the association between daily toothbrushing and hospital-acquired pneumonia.

Using a variety of databases, the researchers collected and analyzed randomized clinical trials from around the world that compared the effect of regular oral care with toothbrushing versus oral care without toothbrushing on the occurrence of hospital-acquired pneumonia and other outcomes.

The team’s analysis found that daily toothbrushing was associated with a significantly lower risk for hospital-acquired pneumonia and ICU mortality.

In addition, the investigators identified that toothbrushing for patients in the ICU was associated with fewer days of mechanical ventilation and a shorter length of stay in the ICU. Most of the studies in the team’s review explored the role of a teeth-cleaning regimen in adults in the ICU. Only two of the 15 studies included in the authors’ analysis evaluated the impact of toothbrushing in non-ventilated patients.

The researchers are hopeful that the protective effect of toothbrushing will extend to non-ICU patients but additional studies focusing on this population are needed to clarify if in fact this is the case.


Selina Ehrenzeller, Michael Klompas. Association Between Daily Toothbrushing and Hospital-Acquired Pneumonia. JAMA Internal Medicine, 2023; DOI: 10.1001/jamainternmed.2023.6638

Brigham and Women’s Hospital. (2023, December 18). Toothbrushing tied to lower rates of pneumonia among hospitalized patients. ScienceDaily. Retrieved December 20, 2023 from

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