title: Comparative evaluation of bond strength of all-metal crowns with different luting agents after undergoing various modes of surface treatments: An in-vitro study.
abstract: OBJECTIVE
  This study includes a comparative evaluation of the various surface treatments of the intaglio surface of crowns in combination with various luting agents for maximal retention.
  
  
  METHODS
  Totally, 150 dies of a standard complete crown preparation were fabricated. Wax pattern with a loop on the occlusal surface was prepared on each die using standard procedures, and then crowns were cast with nickel-chromium alloy. These crowns were randomly divided into five groups as per the surface of the intaglio surface of the metal copings. The crowns in each group were again subdivided randomly into three groups as per the luting agents used resin-modified glass ionomer cement, glass ionomer cement, and zinc phosphate cement. Retention was measured (MPa) by separating the metal crowns from the metallic die under tension on a Universal testing machine.
  
  
  METHODS
  The data were recorded and statistically analyzed using one-way analysis of variance followed by Tukey's test.
  
  
  RESULTS
  The retention differed both with surface treatment and type of luting agents. Untreated group showed the least bond strengths < sandblasting with 50 µm alumina < sandblasting with 50 µm alumina with ultrasonic cleaning < sandblasting with 110 µm alumina < sandblasting with 110 µm alumina along with ultrasonic cleaning. For luting agents, glass ionomer cement showed least bond strength because there was no chemical bonding present between metal crown and metallic die, followed by zinc phosphate cement and maximum bond strength were found for resin-modified glass ionomer cement.
  
  
  CONCLUSIONS
  Among all types of surface treatments used in this study, maximum bond strength was yielded by sandblasting with 110 µm alumina + ultrasonic cleaning and the best luting agent was resin-modified glass ionomer cement.
authors.affiliation: Department of Prosthodontics, Manav Rachna Dental College, Faridabad, Haryana, India.
authors.forename: Shivam Singh
authors.initials: SS
authors.lastname: Tomar
authors.affiliation: Department of Prosthodontics, Gurunanak Institute of Dental Sciences and Research, Kolkata, West Bengal, India.
authors.forename: Jayanta
authors.initials: J
authors.lastname: Bhattacharyya
authors.affiliation: Department of Prosthodontics, Gurunanak Institute of Dental Sciences and Research, Kolkata, West Bengal, India.
authors.forename: Soumitra
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Department of Prosthodontics, Gurunanak Institute of Dental Sciences and Research, Kolkata, West Bengal, India.
authors.forename: Preeti
authors.initials: P
authors.lastname: Goel
authors.affiliation: Department of Prosthodontics, Gurunanak Institute of Dental Sciences and Research, Kolkata, West Bengal, India.
authors.forename: Samiran
authors.initials: S
authors.lastname: Das
authors.affiliation: Department of Prosthodontics, Manav Rachna Dental College, Faridabad, Haryana, India.
authors.forename: Kaplia
authors.initials: K
authors.lastname: Chakarvarty
keywords: Luting agents; retention; sandblasting; surface treatment; ultrasonic cleaning