title: Comparison of 3 luting agents on retention of implant-supported crowns on 2 different abutments.
abstract: BACKGROUND
  For fixed prostheses, retention is one of the most important factors for clinical success. It is unknown whether grooves that increase surface area of implant abutment while retaining the diameter and wall height provide greater uniaxial retention force. The purpose of this study was to determine the retention of 3 different cements on 2 implant abutments with different surface configurations.
  
  
  METHODS
  Thirty samples on 2 different abutments (a total of 60 crowns) with different margin and axial walls configuration and surface area were used. Metal crowns were fabricated on the abutment and cemented with 3 different (zinc-phosphate [ZP], glass ionomer [GI], or eugenol-free zinc oxide [ZO]) cements. After cementation, implant-abutment-casting assemblies were thermal cycled 1000 times with 1-minute dwell-time between 5°C and 55°C then subjected to tensile test with universal testing machine until decementation occurred. The mean force required to dislodge castings from abutment was determined.
  
  
  RESULTS
  The luting agents influenced retention of castings on implant abutments, whereas different surface configurations and total surface area of the abutments did not influence the uniaxial retention forces. Among the cements tested, ZP exhibited higher values of retention, followed by GI and eugenol-free ZO.
  
  
  CONCLUSIONS
  The increase in surface area of abutment did not result in improved retention. The present results suggest using ZP rather than GI and eugenol-free ZO in implant-supported crowns to provide higher retention.
authors.affiliation: Department of Dentistry, Acibadem Kadikoy Hospital, Istanbul, Turkey.
authors.forename: M Bariş
authors.initials: MB
authors.lastname: Güncü
authors.forename: Umut
authors.initials: U
authors.lastname: Cakan
authors.forename: Senay
authors.initials: S
authors.lastname: Canay
mesh_terms: D002484:Cementation / Q000379:methods; D003442:Crowns; D000044:Dental Abutments / Q000145:classification*; D003738:Dental Cements / Q000737:chemistry*; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention / Q000379:methods*; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000295:instrumentation; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D015034:Zinc Oxide / Q000737:chemistry; D015036:Zinc Phosphate Cement / Q000737:chemistry
chemical_list: D003738:Dental Cements; D005899:Glass Ionomer Cements; C449162:zinc oxide-non-eugenol cement; D015036:Zinc Phosphate Cement; D015034:Zinc Oxide