The effect of age on bacterial penetration of radicular dentin.

The aim of this study was to determine the effects of patient's age on the prevalence and depth of bacterial penetration inside dentinal tubules. Fifty-six single-rooted teeth were divided in two groups based on the patient's age: young (ages 18-25) and old (age >or=60). Teeth were instrumented and inoculated with a standardized bacterial load and incubated for 20 days. Histological analysis was performed to determine the degree of infection of the dentinal tubules by counting the number of invaded tubules and the depth of penetration of bacteria inside the tubules. A significantly higher number of tubules were invaded by bacteria in the young group compared with the old group (p = 0.014). Also, the depth of invasion by bacteria was significantly higher in the young than in the old group (p = 0.033). These results suggest that bacterial infection of dentinal tubules occur to a lesser extent in older patients.