title: A 5-year prospective radiographic evaluation of marginal bone levels adjacent to parallel-screw cylinder machined-neck implants and rough-surfaced microthreaded implants using digitized panoramic radiographs.
abstract: OBJECTIVE
  The purpose of this split-mouth study was to compare macro- and microstructure implant surfaces at the marginal bone level over five years of functional loading.
  
  
  METHODS
  From January to February 2006, 133 implants (70 rough-surfaced microthreaded implants and 63 machined-neck implants) were inserted in the mandible of 34 patients with Kennedy Class I residual dentitions and followed until December 2011. Marginal bone level was radiographically determined at six time points: implant placement (baseline), after the healing period, after six months, and at two years, three years, and five years follow-up.
  
  
  RESULTS
  Median follow-up time was 5.2 years (range: 5.1-5.4). The machined-neck group had a mean crestal bone loss of 0.5 mm (0.0-2.3) after the healing period, 1.1 mm (0.0-3.0) at two years follow-up, and 1.4 mm (0.0-2.9) at five years follow-up. The rough-surfaced microthreaded implant group had a mean bone loss of 0.1 mm (-0.4 to 2.0) after the healing period, 0.5 mm (0.0-2.1) at two years follow-up, and 0.7 mm (0.0-2.3) at five years follow-up. The two implant types showed significant differences in marginal bone levels.
  
  
  CONCLUSIONS
  Rough-surfaced microthreaded design caused significantly less loss of crestal bone levels under long-term functional loading in the mandible when compared to machined-neck implants.
authors: Department of Oral, Maxillary and Plastic Facial Surgery (Head: Prof. Dr. Dr. J.E. Zöller), University of Cologne, Kerpener Str. 62, G-50937 Cologne, Germany; Interdisciplinary Department of Oral Surgery and Implantology (Head: Prof. Dr. Dr. J.E. Zöller), University of Cologne, Kerpener Str. 62, G-50937 Cologne, Germany. Electronic address: Dr.A.Nickenig@t-online.de.
authors: Hans-Joachim
authors: HJ
authors: Nickenig
authors: Manfred
authors: M
authors: Wichmann
authors: Arndt
authors: A
authors: Happe
authors: Joachim E
authors: JE
authors: Zöller
authors: Stephan
authors: S
authors: Eitner
mesh_terms: D000328:Adult; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging; D000539:Alveolar Process / Q000000981:diagnostic imaging*; D002484:Cementation / Q000379:methods; D059605:Dental Implant-Abutment Design; D015921:Dental Implants; D017267:Dental Prosthesis Design; D003830:Denture, Partial, Fixed; D005500:Follow-Up Studies; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000534:rehabilitation / Q000601:surgery; D008334:Mandible / Q000601:surgery; D008875:Middle Aged; D011446:Prospective Studies; D019252:Radiography, Dental, Digital / Q000379:methods*; D011862:Radiography, Panoramic / Q000379:methods*; D013499:Surface Properties; D015036:Zinc Phosphate Cement / Q000737:chemistry
chemical_list: D015921:Dental Implants; D015036:Zinc Phosphate Cement
keywords: Alveolar bone loss; Split-mouth study; Surface properties