title: Low- and high-yield cigarette smoke inhalation potentiates bone loss during ligature-induced periodontitis.
abstract: BACKGROUND
  It is well recognized that cigarette consumption is a strong risk factor for periodontitis. Tobacco companies have developed a cigarette with low levels of toxic compounds; however, its effect on periodontium has not been investigated. The aim of this study was to verify the impact of smoke produced by low- and high-yield cigarettes on bone loss resulting from ligature-induced periodontitis.
  
  
  METHODS
  A total of 36 male Wistar rats were used in the study. A ligature was placed around one of the mandibular first molars (ligated teeth) of each animal, and they were assigned randomly to one of three groups: group 1: control (N = 10), group 2: 30 days' inhalation of smoke produced by high-yield cigarettes (N = 13), and group 3: 30 days' inhalation of smoke produced by low-yield cigarettes (N = 13). The animals were sacrificed 30 days after ligature placement, and the specimens were processed for decalcified sections.
  
  
  RESULTS
  Intergroup analysis of unligated teeth (without periodontal disease) did not show a significant difference regarding periodontal ligament area (2.40 +/- 0.5 mm(2), 2.72 +/- 0.7 mm(2), and 2.61 +/- 0.4 mm(2) for groups 1, 2, and 3, respectively; P >0.05). Conversely, significant differences were noted in ligated teeth (with periodontitis); bone loss was directly proportional to the level of toxic compounds in the cigarettes (5.74 +/- 0.5 mm(2), 7.40 +/- 0.50 mm(2), and 6.51 +/- 0.50 mm(2) for groups 1, 2, and 3, respectively; P <0.05).
  
  
  CONCLUSIONS
  Low- and high-yield cigarettes potentiated bone loss during experimental periodontitis in a directly proportional fashion.
authors.affiliation: Division of Periodontics, School of Dentistry, Bahian Foundation for Science Development, BA, Brazil. nogueira-filho@uol.com.br
authors.forename: Getúlio da R
authors.initials: Gda R
authors.lastname: Nogueira-Filho
authors.forename: Bruno Trevisan
authors.initials: BT
authors.lastname: Rosa
authors.forename: João B
authors.initials: JB
authors.lastname: César-Neto
authors.forename: Roberto S
authors.initials: RS
authors.lastname: Tunes
authors.forename: Urbino da R
authors.initials: Uda R
authors.lastname: Tunes
mesh_terms: D016301:Alveolar Bone Loss / Q000139:chemically induced*; D000818:Animals; D007166:Immunosuppressive Agents / Q000009:adverse effects*; D008297:Male; D008336:Mandibular Diseases / Q000139:chemically induced; D010518:Periodontitis / Q000209:etiology*; D051381:Rats; D017208:Rats, Wistar; D012906:Smoke / Q000009:adverse effects*; D013638:Tars / Q000009:adverse effects*
chemical_list: D007166:Immunosuppressive Agents; D012906:Smoke; D013638:Tars; C024746:tobacco tar