title: Retentive strength of metal copings on prefabricated abutments with five different cements.
abstract: BACKGROUND
  Despite their wide use in implant dentistry, there is insufficient information concerning the retentive strength of cement-retained superstructures.
  
  
  OBJECTIVE
  This study compared the retentive strength of metal copings on prefabricated abutments with five different luting cements.
  
  
  METHODS
  Eight prefabricated abutments were placed on titanium screw implants torqued to 35 Ncm. Metal copings were cast with Au-Pt-Pd alloy (DeguDent Universal, Degussa, Hanau, Germany) using burnt-out plastic copings. Cements used were zinc oxide-eugenol-free temporary (ZO), zinc phosphate (ZP), glass ionomer (GI), resin-reinforced glass ionomer (RG), and composite resin (CR) cements. Retentive strength was measured with a universal testing machine. The means of each group were compared by one-way analysis of variance and Tukey-Kramer multiple-comparison intervals at a significance level of p < .05.
  
  
  RESULTS
  The mean +/- SD retentive strength of the cements in Newtons was ZO 56 +/- 12 (Tukey group C), ZP 158 +/- 79 (Tukey group B), GI 132 +/- 29 (Tukey group B), RG 477 +/- 52 (Tukey group A), and CR 478 +/- 50 (Tukey group A).
  
  
  CONCLUSIONS
  The retentive strength of metal copings on implant abutments is somewhat different from those of conventional cemented restorations on natural teeth. These differences may be influenced by differences in surface roughness and the height of the abutment.
authors.affiliation: Division of Fixed Prosthodontics and Oral Rehabilitation, Nagasaki University Graduate School of Biomedical Sciences, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Maeyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Sawase
authors.forename: Ryo
authors.initials: R
authors.lastname: Jimbo
authors.forename: Koji
authors.initials: K
authors.lastname: Kamada
authors.forename: Naoki
authors.initials: N
authors.lastname: Suketa
authors.forename: Junichi
authors.initials: J
authors.lastname: Fukui
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Atsuta
mesh_terms: D003188:Composite Resins / Q000737:chemistry; D000044:Dental Abutments; D003722:Dental Alloys / Q000737:chemistry*; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis; D005899:Glass Ionomer Cements / Q000737:chemistry; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D010165:Palladium / Q000737:chemistry; D010984:Platinum / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D019415:Torque; D015034:Zinc Oxide / Q000737:chemistry; D015036:Zinc Phosphate Cement / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003722:Dental Alloys; D003738:Dental Cements; D005899:Glass Ionomer Cements; D006047:Gold Alloys; D019279:Resin Cements; C449162:zinc oxide-non-eugenol cement; D010984:Platinum; D010165:Palladium; D015036:Zinc Phosphate Cement; D014025:Titanium; D015034:Zinc Oxide