Poor Oral Hygiene and Infective Endocarditis: a Case Control Study

Objectives: Infective endocarditis (IE) is an uncommon infection of the heart, particularly the heart valves, yet it is a condition associated with high morbidity and mortality, and one for which there is a lack of preventive strategies. Most IE prevention guidelines recommend maintaining good oral hygiene for IE prevention, but currently, no data exist that directly support this recommendation. The purpose of this case-control study was to determine if poor oral hygiene is associated with the subsequent development of IE among those considered at moderate risk for IE.
Methods: Dental calculus (primary outcome measure), and other measures of oral hygiene and periodontal disease, were assessed among patients at moderate risk for IE who were recently hospitalized with IE (cases) and compared with matched controls, who were also at moderate IE risk, but had not developed IE. Blood cultures were obtained for all IE cases.
Results: Case patients (n=62) had 53% greater mean dental calculus (difference = 0.29, 95% CI:0.11, 0.48; p=0.002) and 26% greater mean dental plaque (difference = 0.18, 95%CI: 0.01,0.36; p=0.043) than controls (n=119). Cases had fewer dentist and dental hygiene visits than controls (p= 0.013) and fewer dental visits in the 12 weeks prior to enrollment (p=0.023). There were no significant differences between cases and controls in self-reported frequency of toothbrushing, flossing, or gingival bleeding on toothbrushing. Common oral bacteria were identified from blood cultures in 27/62 (44%) IE cases.
Conclusions: Poorer oral hygiene, as reflected by increased calculus and plaque scores, and less frequent dental and dental hygiene care, was associated with the subsequent development of IE in this study. These results strengthen the rationale for recommending good oral hygiene as a means of reducing the risk of developing IE in all individuals considered to be at increased IE risk.