title: The influence of cigarette smoke inhalation and its cessation on the tooth-supporting alveolar bone: a histometric study in rats.
abstract: OBJECTIVE
  It has been previously shown that smoking may enhance periodontal breakdown and impair bone healing around titanium implants. However, there is a lack of information concerning the effect of smoking on the tooth-supporting alveolar bone. Thus, the aim of this study was to histometrically evaluate the influence of cigarette smoke inhalation and its cessation on tooth-supporting alveolar bone.
  
  
  METHODS
  Sixty male Wistar rats were randomly assigned to one of the following groups: group 1 - control (n = 15), group 2 - 2 months of cigarette smoke inhalation (n = 13), group 3 - 3 months of cigarette smoke inhalation and 2 months without exposure to cigarette smoke inhalation (n = 16) and group 4 - 5 months of cigarette smoke inhalation (n = 16). Five months after the beginning of cigarette smoke inhalation regime (2 months for group 2), the animals were killed and the mandible was removed and prepared for histological sections. The proportion of mineralized tissue in the furcation area (i.e. a 1000 microm zone under the furcation and between the roots) was obtained.
  
  
  RESULTS
  Data analysis demonstrated that the animals continuously exposed to cigarette smoke inhalation presented a decreased proportion of mineralized tissue (groups 2 and 4), when compared to control and cessation groups (groups 1 and 3) (p < 0.05). Similar levels of proportion of mineralized tissue were observed in groups 1 and 3, showing a beneficial effect of cigarette smoke inhalation cessation on proportion of mineralized tissue.
  
  
  CONCLUSIONS
  Within the limits of the present study, it can be concluded that cigarette smoke inhalation may affect the tooth-supporting bone as early as 2 months after the initial exposure, and that smoke exposure cessation may revert its negative impact on the alveolar bone.
authors.affiliation: Department of Prosthodontics and Periodontics, Division of Periodontics, School of Dentistry at Piracicaba, University of Campinas, São Paulo, Brazil.
authors.forename: João Batista
authors.initials: JB
authors.lastname: César-Neto
authors.forename: Bruno Braga
authors.initials: BB
authors.lastname: Benatti
authors.forename: Enilson Antônio
authors.initials: EA
authors.lastname: Sallum
authors.forename: Márcio Zaffalon
authors.initials: MZ
authors.lastname: Casati
authors.forename: Francisco Humberto
authors.initials: FH
authors.lastname: Nociti
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology*; D000704:Analysis of Variance; D000818:Animals; D015519:Bone Density; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012907:Smoking / Q000009:adverse effects*; D016540:Smoking Cessation; D013997:Time Factors