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Frequent dental scaling was associated with decreased risk of periprosthetic joint infection requiring resection arthroplasty in a cohort of patients undergoing total knee arthroplasty in Taiwan

July 12, 2016

Oral bacteremia is often cited as a potentially important risk factor for surgical-site infection following total knee arthroplasty (TKA).  Analysis of data from Taiwan's National Health Insurance Research Database (NHIRD) found an association between frequent and regular dental scalings and a decreased risk of periprosthetic joint infection following TKA.1  Using a nested, case-control study design, researchers from National Cheng Kung University compared the frequency of dental scalings in 1,291 TKA patients who underwent resection arthroplasty for infected TKA to 5,004 controls (matched for age and sex) without infection in the NHIRD TKA cohort. For the primary analysis, the risk of surgical-site infection between patients who had ever and those who had never received dental scaling was compared. The secondary analysis further classified frequency of dental scaling as 1 to 4 times versus 5 to 6 times in 3 years to determine whether there was a dose-response relationship between dental scaling and infection risk. For the purposes of the study, the authors defined TKA infection as requiring resection arthroplasty due to severe periprosthetic infection plus use of antibiotics. Patients with superficial infection or deep infection treated with only antibiotics and debridement were not included in the definition.

A number of chronic conditions, including rheumatoid arthritis, diabetes mellitus, cardiovascular diseases, and chronic lung diseases were all more frequent at baseline in the post-TKA infection group than in the control group, while there were no significant between-group differences in hypertension, peripheral vascular disease, heart failure, hyperlipidemia, ischemic stroke, transient ischemic attack, or gingival and periodontal diseases. Multiple conditional logistic regression was used to assess the frequency of dental scaling and the risk of TKA infection requiring resection arthroplasty. The primary data analysis showed that patients who received dental scaling had a 20% lower risk for infection than patients who did not undergo scaling (adjusted odds ratio [OR], 0.80; 95% confidence interval [CI], 0.68 to 0.93). Compared with patients who never received dental scaling, patients who had undergone scaling 1 to 4 times in 3 years had an OR for infection requiring resection arthroplasty of 0.84 (95% CI, 0.71 to 0.99), while patients who had undergone scaling 5 to 6 times in 3 years (i.e., “regular scaling”) had an OR for infection requiring resection arthroplasty of 0.69 (95% CI, 0.52 to 0.89, or a 31% reduction in risk). The results suggested that the more frequently patients underwent dental scaling, the lower their risk of infection requiring resection arthroplasty. Limitations of the study include the strict definition of post-TKA infection (which likely resulted in an underestimation in the incidence of infection) and lack of information on the causal pathogens of TKA infection (i.e., pathogens identified as coming from the oral cavity versus not) from the database.


  1. Tai TW, Lin TC, Ho CJ, Kao Yang YH, Yang CY. Frequent Dental Scaling Is Associated with a Reduced Risk of Periprosthetic Infection following Total Knee Arthroplasty: A Nationwide Population-Based Nested Case-Control Study. PLoS One 2016;11(6):e0158096.

Prepared by: Center for Scientific Information, ADA Science Institute

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Science in the News is a service by the American Dental Association (ADA) to its members to present current information about science topics in the news. The ADA is a professional association of dentists committed to the public's oral health, ethics, science and professional advancement; leading a unified profession through initiatives in advocacy, education, research and the development of standards. As a science-based organization, the ADA's evaluation of the scientific evidence may change as more information becomes available. Your thoughts would be greatly appreciated.