title: An in vitro evaluation of ZiReal abutments with hexagonal connection: in original state and following abutment preparation.
abstract: OBJECTIVE
  Laboratory processing of implant-supported prostheses may alter the surface of the abutment in contact with the implant head, with potential repercussions for the interface fit. The purpose of this study was to assess changes at the implant interface of high-strength zirconia ceramic esthetic abutments with a hexagonal connection (ZiReal; 3i/Iimplant Innovations, Palm Beach Gardens, FL) following abutment preparation for single-tooth restorations.
  
  
  METHODS
  The depth (d) and width (w) of the titanium hexagonal portion of the abutment, the apical diameter of the abutment (D), and the rotational freedom (R) of the abutment were assessed for 20 ZiReal abutments prior to preparation (time 0) and following abutment preparation (time 1) to detect any eventual change of fit of the abutment on the top of the implant hexagon.
  
  
  RESULTS
  No significant differences relative to any study parameter (d, w, D, and R) were observed between time 0 and time 1 (P = .9542).
  
  
  CONCLUSIONS
  The hexagonal misfit of the titanium machined ZiReal abutment on the implant hexagon may be implicated in screw joint loosening. The results of this report suggest that if all laboratory steps are carefully observed, changes at the implant/ZiReal abutment do not occur. The maintenance of the original features of the ZiReal abutment may reduce the risk of screw loosening.
authors.affiliation: Department of Clinical Odontostomatology, University of Padova, Institute of Clinical Dentistry, Padova, Italy. paolovigolo@virgilio.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Vigolo
authors.forename: Fulvio
authors.initials: F
authors.lastname: Fonzi
authors.forename: Zeina
authors.initials: Z
authors.lastname: Majzoub
authors.forename: Giampiero
authors.initials: G
authors.lastname: Cordioli
mesh_terms: D002516:Ceramics; D000044:Dental Abutments; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D017755:Prosthesis Fitting; D015040:Zirconium
chemical_list: D015040:Zirconium; C028541:zirconium oxide