title: An evaluation of retention and marginal seating of Ni-Cr alloy cast restorations using three different luting cements: an in vitro study.
abstract: BACKGROUND
  Clinical and laboratory studies regarding performance of recently introduced luting cements: Adhesive resin cement and resin-modified glass ionomer cement (GIC), are limited.
  
  
  OBJECTIVE
  To compare the retention and marginal seating of Ni-Cr alloy restorations using newer luting cements: Resin-modified GIC and adhesive resin cement with those of the oldest cement, zinc phosphate.
  
  
  METHODS
  Thirty maxillary premolars of similar sizes were prepared to receive cast metal copings. Copings were placed on the prepared teeth and the marginal opening was examined using a Nikon Measuroscope. The specimens were randomly assigned to three groups. Group I castings were luted with zinc phosphate, Group II castings luted with resin-modified GIC, and Group III castings luted with adhesive resin cement. After cementation marginal seating was measured. Tensile loads required to dislodge the crowns were obtained using MTS machine.
  
  
  METHODS
  Tukey's test, Analysis of Variance (ANOVA).
  
  
  RESULTS
  For zinc phosphate cement, mean marginal seating was 31 microns. Mean retentive strength was 287 Newtons. For resin-modified GIC, mean marginal seating was 29.6 microns. Mean retentive strength was 610 Newtons. For adhesive resin cement, mean marginal seating was 49 microns. Mean retentive strength was 613 Newtons.
  
  
  CONCLUSIONS
  Marginal seating of adhesive resin cement was significantly greater than that of zinc phosphate and resin-modified GIC. Retentive strength of adhesive resin cement and resin-modified GIC was significantly greater than that of zinc phosphate There was no significant difference of retentive strength between adhesive resin cement and resin-modified GIC.
authors: Department of Prosthodontics, Rungta College of Dental Sciences and Research Centre, Bhilai, Chhattisgarh, India.
authors: Bikash K
authors: BK
authors: Pattanaik
authors: S J
authors: SJ
authors: Nagda
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002484:Cementation / Q000379:methods; D002858:Chromium Alloys / Q000737:chemistry*; D003442:Crowns; D001840:Dental Bonding; D003734:Dental Casting Investment / Q000737:chemistry*; D003738:Dental Cements / Q000737:chemistry*; D018772:Dental Marginal Adaptation; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis / Q000295:instrumentation; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D019231:Tooth Preparation, Prosthodontic / Q000295:instrumentation; D015036:Zinc Phosphate Cement / Q000737:chemistry
chemical_list: D002858:Chromium Alloys; D003734:Dental Casting Investment; D003738:Dental Cements; D005899:Glass Ionomer Cements; D011109:Polymethacrylic Acids; C528569:Rely-X; C462240:RelyX ARC; D019279:Resin Cements; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D015036:Zinc Phosphate Cement