title: Marginal discrepancy of screw-retained and cemented metal-ceramic crowns on implants abutments.
abstract: This in vitro study quantified the marginal discrepancy of the implant-to-prosthetic-crown interface on nonsubmerged dental implants restored with either a cemented or a screw-retained approach. Metal-ceramic crowns were fabricated for 20 ITI 4.1 x 10 mm solid-screw titanium implants. Ten implants received octa abutments and screw-retained crowns fabricated on premachined gold cylinders. The remaining 10 implants were restored with 5.5-mm solid abutments and metal-ceramic crowns cemented alternately with a glass-ionomer or a zinc phosphate luting agent. Inspection of the implant-crown interface was conducted using light microscopy under x 50 magnification at selected stages in the process of crown fabrication. Statistical analysis revealed a significant difference (P < .001) in the mean marginal fit between screw-retained (8.5 +/- 5.7 microns) and luted implant-supported crowns. This difference was observed both before (54.4 +/- 18.1 microns) and after cementation with glass-ionomer (57.4 +/- 20.2 microns) or zinc phosphate (67.4 +/- 15.9 microns).
authors.affiliation: Harvard School of Dental Medicine, Boston, Massachusetts, USA. s_keith@hms.harvard.edu
authors.forename: S E
authors.initials: SE
authors.lastname: Keith
authors.forename: B H
authors.initials: BH
authors.lastname: Miller
authors.forename: R D
authors.initials: RD
authors.lastname: Woody
authors.forename: F L
authors.initials: FL
authors.lastname: Higginbottom
mesh_terms: D002484:Cementation; D003442:Crowns; D000044:Dental Abutments; D015921:Dental Implants; D003772:Dental Pins; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention / Q000295:instrumentation / Q000379:methods*; D005899:Glass Ionomer Cements; D006047:Gold Alloys; D006801:Humans; D016876:Metal Ceramic Alloys; D015036:Zinc Phosphate Cement
chemical_list: D015921:Dental Implants; D005899:Glass Ionomer Cements; D006047:Gold Alloys; D016876:Metal Ceramic Alloys; D015036:Zinc Phosphate Cement