title: Influence of low-dose nicotine on bone healing.
abstract: BACKGROUND
  Nicotine at a low concentration was suggested as a new topical drug for clinical application. It has been reported to be capable of enhancing skin wound healing. This study was designed to assess the effect of nicotine administration at a low dose on bone regeneration using a rabbit model of mandibular distraction osteogenesis.
  
  
  METHODS
  Twenty New Zealand white rabbits were randomly assigned to nicotine group and control group. A total of 0.75 g, 60-day time release, nicotine pellets or placebos were implanted in the neck subcutaneous tissue of the rabbits. The nicotine or placebo exposure time for all the animals was 7 weeks. Unilateral mandibular distraction osteogenesis was performed. Five animals in each group were killed on week 2 and week 4 of consolidation, respectively. The mandibular samples were subjected to radiographic, histologic, and immunohistochemical analysis.
  
  
  RESULTS
  Nicotine at low dose showed no significant effect on the expression of bone morphogenetic protein-2 and on the radiodensity of bone regeneration. However, the delayed bone healing was detected in the nicotine group by histologic examination.
  
  
  CONCLUSIONS
  These findings imply a potential risk of compromised bone healing in patients taking nicotine medication. Further clinical studies are necessary to assess the risk of nicotine medication on reconstructive surgery.
authors.affiliation: Faculty of Dentistry, Oral and Maxillofacial Surgery, The University of Hong Kong, China.
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.forename: Mai Har
authors.initials: MH
authors.lastname: Sham
authors.forename: Li Wu
authors.initials: LW
authors.lastname: Zheng
authors.forename: Lim Kwong
authors.initials: LK
authors.lastname: Cheung
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects*; D007150:Immunohistochemistry; D008334:Mandible / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000601:surgery*; D009538:Nicotine / Q000494:pharmacology*; D019857:Osteogenesis, Distraction; D010919:Placebos; D011817:Rabbits; D011897:Random Allocation; D055114:X-Ray Microtomography
chemical_list: D010919:Placebos; D009538:Nicotine