title: A Long-Term Prospective Evaluation of Marginal Bone Level Change Around Different Implant Systems.
abstract: OBJECTIVE
  The purpose of this prospective study was to assess the change of marginal bone level around three different types of external-hex implants after 5 years using radiography.
  
  
  METHODS
  Included in this study were 54 patients randomly put into three different groups; rough-surface implants (Brånemark), machined coronal aspect implants (Restore), and microthreaded coronal aspect implants (Hexplant). Clinical and radiographic assessments were performed contemporaneously with implant loading (baseline) and at 1, 3, and 5 years post-functional loading. A mixed-model analysis was employed to examine mean marginal bone change significance in the three treatment groups.
  
  
  RESULTS
  In a total of 31 out of 54 patients, 81 of 135 implants remained to the end of the study. At 5 years, the microthreaded coronal aspect implants had 0.61 ± 0.32 mm mean crestal bone loss; the rough-surface implants without microthread, 0.99 ± 0.38 mm; and the machined coronal aspect implants, 1.06 ± 0.39 mm. The rough-surface implants and the machined coronal aspect implants did not exhibit statistically significantly different marginal bone loss, whereas the microthreaded coronal aspect implants exhibited significantly less marginal bone loss (P = .0015).
  
  
  CONCLUSIONS
  In this research, rough-surface implants with microthreads showed positive long-term effects in preserving peri-implant bone level against functional loads when compared with implants lacking these aspects at the coronal part. Most of the bone loss was shown within 1 year of loading, and all types of implants stabilized after 1 year.
authors.forename: Su-Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Jai-Young
authors.initials: JY
authors.lastname: Koak
authors.forename: Seong-Kyun
authors.initials: SK
authors.lastname: Kim
authors.forename: In-Chul
authors.initials: IC
authors.lastname: Rhyu
authors.forename: Young
authors.initials: Y
authors.lastname: Ku
authors.forename: Seong-Joo
authors.initials: SJ
authors.lastname: Heo
authors.forename: Chong-Hyun
authors.initials: CH
authors.lastname: Han
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000473:pathology*; D000539:Alveolar Process / Q000473:pathology / Q000601:surgery; D003758:Dental Implantation, Endosseous / Q000009:adverse effects / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery; D008875:Middle Aged; D011446:Prospective Studies; D013499:Surface Properties
chemical_list: D015921:Dental Implants