title: Stress may enhance nicotine effects on periodontal tissues. An in vivo study in rats.
abstract: OBJECTIVE
  Diabetes mellitus and smoking have been described as important risk factors that may affect the initiation and progression of periodontitis. Recent studies have pointed to potentially periodontal risk indicators, which include stress. The present study investigated the effects of stress associated with nicotine administration on periodontal breakdown resulting from ligature-induced periodontitis in rats.
  
  
  METHODS
  Twenty adult male Wistar rats were used. After anesthesia, both mandibular first molars received a cotton ligature in the dento-gingival area. The animals were randomly assigned to one of the following experimental groups: A - saline solution, B - 0.73 mg of nicotine/kg/d (intraperitoneal), C - stress (immobilization - 2 h/d/40 d) associated with an intraperitoneal administration of saline solution, and D - stress (immobilization - 2 h/d/40 d) associated with an intraperitoneal injection of 0.73 mg of nicotine/kg/d. Forty days later, the animals were sacrificed and the specimens routinely processed for serial decalcified sections.
  
  
  RESULTS
  Intergroup analysis (ANOVA) revealed a greater bone loss (P < 0.05) in the animals of group D compared with the animals from groups A, B and C. In addition, the data revealed a significant effect of nicotine (group B) compared with groups A and C (P < 0.05), and no difference between groups A and C (P > 0.05).
  
  
  CONCLUSIONS
  Within the limits of the present study, although stress did not affect periodontitis by itself, it significantly enhanced the effects of nicotine on the periodontal tissues.
authors.affiliation: Department of Prosthodontics and Periodontics, Division of Periodontics, School of Dentistry at Piracicaba, UNICAMP, São Paulo, Brazil.
authors.forename: Bruno Braga
authors.initials: BB
authors.lastname: Benatti
authors.forename: Getúlio R
authors.initials: GR
authors.lastname: Nogueira-Filho
authors.forename: Marcelo Carvalho
authors.initials: MC
authors.lastname: Diniz
authors.forename: Enilson Antonio
authors.initials: EA
authors.lastname: Sallum
authors.forename: Antonio Wilson
authors.initials: AW
authors.lastname: Sallum
authors.forename: Francisco H
authors.initials: FH
authors.lastname: Nociti
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology; D000704:Analysis of Variance; D000818:Animals; D007274:Injections, Intraperitoneal; D008297:Male; D009538:Nicotine / Q000008:administration & dosage / Q000009:adverse effects*; D018722:Nicotinic Agonists / Q000008:administration & dosage / Q000009:adverse effects*; D010518:Periodontitis / Q000209:etiology*; D010519:Periodontium / Q000187:drug effects / Q000503:physiopathology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012307:Risk Factors; D018709:Statistics, Nonparametric; D013312:Stress, Physiological / Q000150:complications*
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine