title: Pain and immunologic response to root canal treatment and subsequent health outcomes.
abstract: OBJECTIVE
  This study examined the effects of pain and stress associated with a dental procedure, root canal treatment (RCT), on natural killer cell cytotoxicity (NKCC) and the subsequent development of symptoms of upper respiratory illness during the following month.
  
  
  METHODS
  Patients (N = 33) were recruited from those scheduled for RCT appointments. Subjects for a non-RCT comparison group (N = 14) were also recruited from dental clinic patients. Peripheral blood was drawn by use of an indwelling catheter three times: just before RCT, 30 minutes after injection of a local anesthetic, and 30 minutes after RCT (a parallel time course was followed for the comparison group.) Blood was assayed for cortisol and NKCC. Subjects completed a health diary in the month after RCT.
  
  
  RESULTS
  Patients showed a significant increase in NKCC between baseline and RCT and a significant decrease from RCT to after RCT, whereas the comparison group did not. The NKCC following the RCT was negatively correlated with the pain level during RCT (r = -0.48, p < .01) and pain levels 2 and 6 hours after RCT (r = -0.43, p < .05; r = -0.44 p < .05, respectively). The patient group reported significantly more illness episodes 2 weeks after RCT than the comparison group (Wilcoxon rank sum = 4.78, p = .03). Discriminant function analysis correctly classified 88% of the subjects into the illness category using predictor variables of post-RCT NKCC, stress, and pain levels during RCT (F(3,21) = 8.23, p < .001).
  
  
  CONCLUSIONS
  Transitory changes in NKCC associated with pain and stress may be implicated in the development of infectious disease episodes after an acute stressful event.
authors.affiliation: Division of Public Health Services and Research, University of Florida, Gainesville 32610, USA. hlogan@dental.ufl.edu
authors.forename: H L
authors.initials: HL
authors.lastname: Logan
authors.forename: S
authors.initials: S
authors.lastname: Lutgendorf
authors.forename: H L
authors.initials: HL
authors.lastname: Kirchner
authors.forename: E M
authors.initials: EM
authors.lastname: Rivera
authors.forename: D
authors.initials: D
authors.lastname: Lubaroff
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000276:immunology*; D010147:Pain Measurement; D010482:Periapical Abscess / Q000628:therapy*; D012390:Root Canal Therapy / Q000009:adverse effects*
chemical_list: D006854:Hydrocortisone