title: Site-specific treatment outcome in smokers following non-surgical and surgical periodontal therapy.
abstract: OBJECTIVE
  To evaluate the effect of smoking at patient, tooth, and site level following non-surgical and surgical periodontal therapy.
  
  
  METHODS
  Eighty chronic periodontitis patients, 40 smokers and 40 non-smokers, were recruited to this single-arm clinical trial. Smoking status was validated by measuring serum cotinine levels. Periodontal examinations were performed at baseline (T0) and 3 months following non-surgical and surgical periodontal therapy (T1). At T0 and T1, subgingival plaque samples were collected from the deepest periodontal pocket in each patient and analysed using checkerboard DNA-DNA hybridization. Probing depth (PD) ≥ 5 mm with bleeding on probing (BoP) was defined as the primary outcome. Unadjusted and adjusted logistic regression analyses, corrected for clustered observations within patients and teeth, were conducted comparing smokers with non-smokers.
  
  
  RESULTS
  Clinical parameters significantly improved in both groups (p < 0.001). An association was revealed between smoking and PD ≥ 5 mm with BoP (OR= 1.90, CI: 1.14, 3.15, p = 0.013), especially for plaque-positive sites (OR= 4.14, CI: 2.16, 7.96, p < 0.001). A significant reduction of red complex microbiota was observed for non-smokers only (p = 0.010).
  
  
  CONCLUSIONS
  Smokers respond less favourably to non-surgical and surgical periodontal therapy compared with non-smokers, in particular at plaque-positive sites.
authors.affiliation: Faculty of Medicine and Dentistry, Department of Clinical Dentistry, University of Bergen, Bergen, Norway.
authors.forename: Dagmar F
authors.identifier: http://orcid.org/0000-0002-8592-7467
authors.initials: DF
authors.lastname: Bunaes
authors.affiliation: Faculty of Medicine and Dentistry, Department of Clinical Dentistry, University of Bergen, Bergen, Norway.
authors.forename: Stein Atle
authors.initials: SA
authors.lastname: Lie
authors.affiliation: Faculty of Dentistry, Institute of Oral Biology, University of Oslo, Oslo, Norway.
authors.forename: Morten
authors.initials: M
authors.lastname: Enersen
authors.affiliation: Faculty of Medicine and Dentistry, Department of Clinical Dentistry, University of Bergen, Bergen, Norway.
authors.forename: Anne Nordrehaug
authors.initials: AN
authors.lastname: Aastrøm
authors.affiliation: Faculty of Medicine and Dentistry, Department of Clinical Dentistry, University of Bergen, Bergen, Norway.
authors.forename: Kamal
authors.initials: K
authors.lastname: Mustafa
authors.affiliation: Faculty of Medicine and Dentistry, Department of Clinical Dentistry, University of Bergen, Bergen, Norway.
authors.forename: Knut N
authors.initials: KN
authors.lastname: Leknes
mesh_terms: D000328:Adult; D000368:Aged; D003774:Dental Plaque Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000628:therapy; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000628:therapy; D010518:Periodontitis / Q000628:therapy*; D012907:Smoking; D016896:Treatment Outcome
keywords: chronic periodontitis; cluster analysis; microbiology; periodontal therapy; smoking