title: Cigarette smoke inhalation increases the alveolar bone loss caused by primary occlusal trauma in a rat model.
abstract: OBJECTIVE
  Occlusal trauma (OT) and smoking are both factors that alter alveolar bone metabolism and therefore could synergistically act on alveolar bone loss. The aim of this experimental study was to evaluate the influence of short-term cigarette smoke inhalation (CSI) on inter-radicular alveolar bone loss promoted by primary OT in a rat model.
  
  
  METHODS
  Forty-eight animals were randomly assigned to one of three groups based on treatment type: OT + CSI (n = 16), animals were exposed to CSI three times per day, for 8 min per exposure, and they concomitantly received unilateral vertical augmentation creating an occlusal interference inducing experimental OT; OT (n = 16), animals received only unilateral vertical augmentation; negative control (NC; n = 16), animals maintained for equal periods to achieve periodontal baseline values of periodontal ligament dimension. Each group was divided into two subgroups (n = 8) based on treatment length: 7 or 14 d.
  
  
  RESULTS
  After 7 d, the OT + CSI group exhibited significantly higher bone loss compared to the NC group (p = 0.0022). After 14 d, the OT (p < 0.0001) and OT + CSI (p < 0.0001) groups presented significantly higher bone loss compared to the NC group, and OT + CSI resulted in significantly higher bone loss than OT alone (p = 0.0241). The number of tartrate-resistant acid phosphatase-positive cells on the linear surface of the bone crest after 7 d was significantly higher in the OT + CSI group as compared to the NC and OT groups (p < 0.0001 and p = 0.0045, respectively) and remained significantly higher in the OT + CSI group after 14 d, compared to the OT group (p < 0.0001).
  
  
  CONCLUSIONS
  Short-term CSI increases early bone loss in association with OT after 7 d, and this worsens in severity after 14 d of exposure.
authors.affiliation: Department of Prosthodontics and Periodontics, Division of Periodontics, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, Brazil.
authors.forename: M L G
authors.initials: ML
authors.lastname: Campos
authors.forename: M G
authors.initials: MG
authors.lastname: Corrêa
authors.forename: F H N
authors.initials: FH
authors.lastname: Júnior
authors.forename: M Z
authors.initials: MZ
authors.lastname: Casati
authors.forename: E A
authors.initials: EA
authors.lastname: Sallum
authors.forename: A W
authors.initials: AW
authors.lastname: Sallum
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis; D016301:Alveolar Bone Loss / Q000209:etiology* / Q000473:pathology; D000539:Alveolar Process / Q000473:pathology; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D003769:Dental Occlusion, Traumatic / Q000150:complications*; D004195:Disease Models, Animal; D018450:Disease Progression; D017823:Furcation Defects / Q000209:etiology / Q000473:pathology; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012907:Smoking / Q000009:adverse effects*; D000071681:Tartrate-Resistant Acid Phosphatase; D013997:Time Factors
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase
keywords: alveolar bone loss; cigarette smoking; rats; traumatic dental occlusion