title: A histologic and histometric assessment of the influence of nicotine on alveolar bone loss in rats.
abstract: BACKGROUND
  Cigarette smoking has long been recognized as a risk factor for periodontal disease. The aim of this study was to perform quantitative and qualitative analyses of bone loss in the furcation region of periodontally healthy rats after daily systemic administration of nicotine or saline solution.
  
  
  METHODS
  Thirty adult male Wistar rats were assigned randomly to twice daily subcutaneous injections of saline solution (control, group C) or nicotine (group N). The animals were sacrificed at 37, 44, or 51 days after the first subcutaneous injection. The specimens were processed for serial histologic sections, and the area of bone loss in the furcation region of the second molar was analyzed histometrically.
  
  
  RESULTS
  Greater bone loss was detected in group N compared to group C on day 37 (16.36 +/- 5.84 mm(2) and 7.24 +/- 2.66 mm(2)), day 44 (15.12 +/- 4.57 mm(2) and 7.76 +/- 1.35 mm(2)), and day 51 (18.80 +/- 3.71 mm(2) and 8.74 +/- 2.61 mm(2)), respectively (P <0.05). Extension of bone loss appeared greater in the furcation region of group N where a thinner trabeculae bone was found. After day 37, bone loss did not increase significantly.
  
  
  CONCLUSIONS
  Daily systemic administration of nicotine resulted in significantly greater bone loss in the furcation region compared to saline solution. This indicated a close association between nicotine and periodontal morbidity in rats.
authors.affiliation: Department of Surgery and Integrated Clinic, Division of Periodontics, Dental School of Araçatuba, University of the State of São Paulo Júlio de Mesquita Filho, Araçatuba, SP, Brazil. afbosco@pop.com.br
authors.forename: Alvaro Francisco
authors.initials: AF
authors.lastname: Bosco
authors.forename: Samara
authors.initials: S
authors.lastname: Bonfante
authors.forename: Juliano Milanezi
authors.initials: JM
authors.lastname: de Almeida
authors.forename: Danielle Shima
authors.initials: DS
authors.lastname: Luize
authors.forename: Maria José Hitomi
authors.initials: MJ
authors.lastname: Nagata
authors.forename: Valdir Gouveia
authors.initials: VG
authors.lastname: Garcia
mesh_terms: D016301:Alveolar Bone Loss / Q000139:chemically induced*; D000704:Analysis of Variance; D000818:Animals; D017823:Furcation Defects / Q000139:chemically induced; D008297:Male; D009538:Nicotine / Q000633:toxicity*; D018722:Nicotinic Agonists / Q000633:toxicity*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012907:Smoking / Q000009:adverse effects*
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine