Health-care associated (hospital-acquired, or nosocomial)
pneumonia occurs in patients in intensive
care units and institutionalized individuals, such as nursing
home residents.1 Pneumonia is a common infection in elderly
people and the most common cause of mortality from
nosocomial infection in elderly patients, with a mortality
rate of up to 25%.1,2 Bacterial species that normally do not
colonize the oropharynx frequently cause health care–
associated pneumonia, and the oral cavity has been suggested
as an important reservoir for these respiratory
pathogens.1 Elderly patients in nursing homes often have
poor oral health due to difficulties in maintaining a sufficient
level of personal oral hygiene and difficulties in accessing
professional dental care.3 Hence, a relationship
between poor oral hygiene and bacterial pneumonia or
lower respiratory tract infections has been suggested in the
literature.4–6 A plausible mechanism of health care–associated
pneumonia could be aspiration of oral pathogens into
the lungs.7 Clinical trials have sought to determine whether
oral care reduces the incidence of pneumonia, respiratory
tract infections, and mortality in pneumonia in elderly people,
and a relatively recent systematic review concluded that
better oral hygiene and frequent professional oral care reduce
the progression or occurrence of respiratory tract diseases
in high-risk elderly people living in nursing homes and
intensive care units.8 This study was initiated to further
elucidate and systematically summarize the effect estimates
and the methodological quality of available randomized
controlled trials (RCTs) linking oral hygiene status to pneumonia
and respiratory tract infections in elderly people and
to provide an overview of additional clinical studies in this
area.