Effects of gender and acute dental pain on thermal pain responses

Objective: Considerable research suggests that females exhibit greater sens itivity to laboratory pain procedures than do males; however, whether the p resence of acute clinical pain influences this sex difference in pain sensi tivity has not been investigated. The present experiment investigated the e ffects of sex and acute dental pain on laboratory pain responses. Design: Thermal pain onset and tolerance were determined in 46 dental patie nts (15 male, 31 female) experiencing pain due to acute irreversible pulpit is and in 33 healthy controls (13 male, 20 female). In addition, measures o f mood and coping were obtained in all participants. All subjects participa ted in two experimental sessions. The first session took place immediately before the patients underwent endodontic treatment for relief of pulpal pai n. The second session took place approximately 1-2 weeks later, when pulpit is patients were pain free after treatment. During each session, thermal pa in onset and tolerance were assessed with a 1-cm(2) contact thermode applie d to the right volar forearm using an ascending method of limits. Results: During both sessions, thermal pain onset and tolerance were lower in control females than in control males; however, male and female pulpitis patients did not differ in their thermal pain responses during either sess ion. Pulpitis patients also showed greater affective distress than controls . Conclusions: These data suggest that the sex difference in thermal pain sen sitivity frequently reported in pain-free subjects appears to be absent in patients presenting with acute dental pain. However, this effect cannot be explained solely based on the presence of clinical pain because the effect on pain threshold and tolerance persisted into session 2, when pulpitis pat ients were pain free. Potential explanations for these results are discusse d.