RT Journal Article SR Electronic T1 Review: enhanced oral hygiene prevents respiratory infection in elderly people in hospitals and nursing homes JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 80 OP 80 DO 10.1136/ebm.14.3.80 VO 14 IS 3 YR 2009 UL http://ebm.bmj.com/content/14/3/80.abstract AB