title: Crestal Bone Changes Around Implants with Implant-Abutment Connections at Epicrestal Level or Above: Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  The aim of this systematic review and meta-analysis was to evaluate crestal bone changes around implants when placing the implant-abutment connection at the crestal bone level or above.
  
  
  METHODS
  Medline (Pubmed), EMBASE, and Cochrane Library up to January 2014 were electronically and hand searched for any publications that evaluated radiographic crestal bone changes around nonsubmerged, rough-surfaced implants placed in healed sites in humans and loaded for a minimum of 1 year.
  
  
  RESULTS
  The search yielded 1,122 publications; 1,106 could not be included. After 16 full-text articles were read and subjected to inclusion and exclusion criteria, four were included. The mean difference was -0.29 mm (95% CI, -0.58 mm to -0.01 mm). Heterogeneity between studies was observed (I2 = 95%). Significantly more crestal bone change was seen in the epicrestal implant-abutment (bone level) connection group when compared to implants with the prosthetic connection above the crestal bone level (tissue level) (P < .00001).
  
  
  CONCLUSIONS
  Dental implants at bone level show significantly less crestal bone change after 1 year of loading than tissue-level implants.
authors.forename: Paul Ja
authors.initials: PJ
authors.lastname: van Eekeren
authors.forename: Ali
authors.initials: A
authors.lastname: Tahmaseb
authors.forename: Daniel
authors.initials: D
authors.lastname: Wismeijer
mesh_terms: D000539:Alveolar Process / Q000000981:diagnostic imaging*; D016723:Bone Remodeling / Q000502:physiology; D059605:Dental Implant-Abutment Design; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D017267:Dental Prosthesis Design; D006801:Humans; D011859:Radiography; D013499:Surface Properties
chemical_list: D015921:Dental Implants