The question of this study according to the principles of the PICO is as follows: in aging adults (population), does chronic apical periodontitis lesions as biomarkers (intervention) have a risk effect on the immunoexpression of pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) (outcome) compared to adults (control)? This evidence concerns the gene IL1B and chronic apical periodontitis.