DENTAL SCALING REDUCES THE RISK OF PERIPROSTHETIC INFECTION FOLLOWING TOTAL KNEE ARTHROPLASTY: A NATIONWIDE POPULATION-BASED NESTED CASE-CONTROL STUDY

BACKGROUND Periprosthetic infection is the most challenging complication following total knee arthroplasty (TKA). Poor oral hygiene has been assumed as an important risk factor for TKA infection. We aimed to investigate whether the improvement of oral hygiene through dental scaling could reduce the risk of TKA infection. METHODS A nested case control study was conducted and enrollees in the National Health Insurance Research Database (NHIRD) aged above 40 years who had received total knee arthroplasty (TKA) between 1999–2002 were included as the TKA cohort. The cases were patients who underwent resection arthroplasty for infected TKA, and each case was matched by 4 controls from the TKA cohort by gender, using incidence density sampling method. The frequency of dental scaling before the index date was analyzed and compared between the case and the control groups. Multiple conditional logistic regression was used to assess the frequency of dental scaling and the risk of TKA infection. RESULTS The percentages of patients who ever received dental scaling before the end of follow-up were higher in the control group than that in the TKA infection group. As compared with patients never received dental scaling, there was a trend that patients who received dental scaling once within 2 years, may have 9% lower risk in TKA infection (adjusted odds ratio, 0.91; 95% confidence interval, 0.76–1.08). Moreover, the risk of TKA infection can be reduced significantly in patients who had dental scaling at least once per year, with an odds ratio of 0.71 (95% confidence interval, 0.53–0.95). CONCLUSIONS Improvement of oral hygiene by more frequent and regular dental scaling (at least once per year) may reduce the risk of TKA infection. TKA Patients should be advised to check their oral hygiene regularly.