Effects of cigarette smoke inhalation on the immune‐inflammatory profile of experimental apical periodontitis in rats

Objective To evaluate the effects of cigarette smoke inhalation on the immune‐inflammatory profile of experimental apical periodontitis in rats. Methodology In total, 32 male Wistar rats were divided into four groups (n = 8): AP—induced apical periodontitis; S—cigarette smoke inhalation; APS—induced AP and cigarette smoke inhalation; and C (control)—neither AP nor cigarette smoke inhalation. To induce cigarette smoke inhalation, the animals were kept in a chamber filled with tobacco smoke for 8 min thrice a day for 50 days. AP was induced 20 days after inhalation initiation by exposing their coronary pulp to their oral environment for 30 days. After animals were euthanized, their right hemimaxillae were removed for histopathological, semi‐quantitative and immunohistochemical (F4/80, CD206 and iNOS) analyses. Results Quantitative data showed a moderate number of inflammatory infiltrates in AP and an intense number in APS (p .05). INOS+ immunostaining showed a significant increase in AP and APS, when compared with C and S (p