Dental Scaling and Risk Reduction in Infective Endocarditis: A Nationwide Population-Based Case-Control Study

Background: Infective endocarditis (IE) is an uncommon but potentiallylife-threatening disease. Poor oral hygiene has been assumed asan important risk factor for IE. We aimed to investigate whether theimprovement of oral hygiene through dental scaling could reduce therisk of IE. Methods: From January 1, 2000 to December 31, 2009, a total of736 patients with newly diagnosed IE were identified from the NationalHealth Insurance Research Database. On the same date ofenrollment, 10 patients (without IE) with matched age, sex, and underlyingdiseases were selected to be the control group for each studypatient. The frequency of dental scaling before the enrollment wasanalyzed and compared between the study and the control groups. Results: The percentages of patients who ever received dental scalingbefore the enrollment were higher in the control group than that in thestudy group. For patients who received dental scaling once in 2 years, unadtherisk of IE can be reduced by about 15% (odds ratio, 0.845; 95%confidence interval, 0.693-1.012) with a borderline P value (P =0.058). Moreover, the risk of IE decreased significantly among patientswho received dental scaling at least once per year, with an odds ratioof 0.696 (95% confidence interval, 0.542-0.894; P=0.005). Conclusions: Improvement of oral hygiene by dental scaling may reducethe risk of IE. More frequent and regular dental scaling (at leastonce per year) was associated with a significant decrease in IE.