Association between dental factors and mortality

To study whether oral parameters such as endodontic infections, root canal fillings, number of teeth or wearing removable dentures at baseline are associated with cardiovascular- and all-cause mortality in a follow-up of approximately 8 years.

The Finnish Parogene cohort consists of 508 Finnish adults (mean age 63.3 years, SD 9.1) with cardiac symptoms, all of whom had undergone coronary angiography for accurate baseline coronary status. Extensive clinical and radiographic oral examinations were performed, and additional data were acquired from medical records and questionnaires. Root canal fillings and endodontic lesions, as well as their co-occurrence, were determined from panoramic radiographs. The mortality data were assessed via record linkage with the Finnish Causes of Death register (mean follow-up time 7.81 years, SD 1.45 years). A total of n = 471 dentate patients were included in the statistical analyses.

A total of n = 69 deaths were recorded, of which n = 41 were due to cardiovascular diseases (CVDs, ICD-10 I00-I99). The deceased had fewer root canal fillings (mean 1.57; SD 1.64 vs. mean 2.30; SD 2.34, P = 0.03) than the survivors. The number of missing teeth was associated with smoking, occluded coronary arteries and diabetes. Cox regression with Firth's penalized maximum-likelihood method using age as timescale revealed an inverse association (HR; 95%CI) between mortality and number of teeth (all-cause 0.91; 0.86-0.96, CVD mortality 0.89; 0.83-0.96), use of removable dentures (all-cause 0.24; 0.09-0.62, CVD mortality 0.20; 0.06-0.72), root canal fillings (all-cause 0.82; 0.70-0.94, CVD mortality 0.79; 0.63-0.96) and having root canal fillings in all teeth with apical rarefactions (all-cause 0.27; 0.06-0.79, CVD mortality 0.09; 0.01-0.63), when gender, smoking, occluded coronary arteries, periodontal inflammatory burden index and the number of teeth were adjusted for.

The number of missing teeth appeared to be the strongest predictor of mortality in this study, whereas endodontic infections per se had no independent association. Nevertheless, signs of professional intervention in these problems, such as root canal fillings and removable dentures, appeared to be associated with improved survival, which might partly be explained by the utilization of healthcare services.