title: A 10-year retrospective analysis of marginal bone-level changes around implants in periodontally healthy and periodontally compromised tobacco smokers.
abstract: OBJECTIVE
  to compare the 10-year marginal bone loss rates around implants supporting single-unit crowns in tobacco smokers with and without a history of treated periodontitis.
  
  
  METHODS
  in this retrospective controlled study, 40 tobacco smokers were divided into four groups of 10 patients each. Two groups of periodontally compromised (PC) patients and two groups of periodontally healthy (PH) patients were established. PC patients had been treated for their periodontal conditions before implant placement. All patients were enrolled in a regular, individually tailored maintenance care program. For the rehabilitation of PC and PH patients, two different types of implants were used (Nobel Biocare AB; Straumann Dental Implant System). The radiographic bone loss rate was calculated by subtracting the bone levels at the time of crown delivery from the bone levels at the 10-year follow-up.
  
  
  RESULTS
  the mean age, mean full-mouth plaque score and full-mouth bleeding score and implant location were similar for the four groups. Implant survival rates ranged between 70% and 100%, without statistically significant differences between the four groups (P>0.05). Implants placed in PC patients yielded statistically significantly higher marginal bone loss rates compared with those in PH patients (P<0.05), independent of the implant system used.
  
  
  CONCLUSIONS
  after 10 years, implants placed in tobacco smokers with a history of treated periodontitis and enrolled in a supportive therapy program yielded lower survival rates and higher marginal bone loss rates compared with those of implants placed in PH smokers. These outcomes were independent of the implant system installed or the healing modality applied.
authors.affiliation: School of Dental Medicine, Department of Periodontology, University of Bern, Bern, Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Aglietta
authors.forename: Vincenzo Iorio
authors.initials: VI
authors.lastname: Siciliano
authors.forename: Giulio
authors.initials: G
authors.lastname: Rasperini
authors.forename: Carlo
authors.initials: C
authors.lastname: Cafiero
authors.forename: Niklaus P
authors.initials: NP
authors.lastname: Lang
authors.forename: Giovanni E
authors.initials: GE
authors.lastname: Salvi
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology*; D003442:Crowns; D003758:Dental Implantation, Endosseous / Q000009:adverse effects* / Q000379:methods; D019250:Dental Implants, Single-Tooth / Q000009:adverse effects*; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010518:Periodontitis / Q000150:complications*; D011859:Radiography; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects*; D018709:Statistics, Nonparametric; D013499:Surface Properties