title: Retention of Implant Supported Metal Crowns Cemented with Different Luting Agents: A Comparative Invitro Study.
abstract: BACKGROUND
  To overcome limitations of screw-retained prostheses, cement-retained prostheses have become the restoration of choice now a days. Selection of the cement hence becomes very critical to maintain retrievability of the prostheses.
  
  
  OBJECTIVE
  The purpose of this study was to assess and compare the retention of base metal crowns cemented to implant abutments with five different luting cements.
  
  
  METHODS
  Ten implant analogs were secured in five epoxy resin casts perpendicular to the plane of cast in right first molar and left first molar region and implant abutments were screwed. Total of 100 metal copings were fabricated and cemented. The cements used were zinc phosphate, resin modified glass ionomer cement, resin cement, non-eugenol acrylic based temporary implant cement & non-eugenol temporary resin cement implant cement. Samples were subjected to a pull-out test using an Instron universal testing machine at a crosshead speed of 0.5mm/min. The load required to de-cement each coping was recorded and mean values for each group calculated and put to statistical analysis.
  
  
  RESULTS
  The results showed that resin cement has the highest retention value 581.075N followed by zinc phosphate luting cement 529.48N, resin modified glass ionomer cement 338.095 N, non-eugenol acrylic based temporary implant cement 249.045 N and non-eugenol temporary resin implant cement 140.49N.
  
  
  CONCLUSIONS
  Within the limitations of study, it was concluded that non-eugenol acrylic based temporary implant cement and non-eugenol temporary resin implant cement allow for easy retrievability of the prosthesis in case of any failure in future. These are suitable for cement retained implant restorations. The results provide a possible preliminary ranking of luting agents based on their ability to retain an implant-supported prosthesis and facilitate easy retrieval.
authors.affiliation: Post Graduate Student, Department of Prosthodontics and Crown & Bridge, Sri Guru Ram Das Institute of Dental Sciences and Research , Sri Amritsar, India .
authors.forename: Roohi
authors.initials: R
authors.lastname: Kapoor
authors.affiliation: Professor and Head, Department of Prosthodontics and Crown & Bridge, Sri Guru Ram Das Institute of Dental Sciences and Research , Sri Amritsar, India .
authors.forename: Kavipal
authors.initials: K
authors.lastname: Singh
authors.affiliation: Reader, Department of Prosthodontics and Crown & Bridge, Sri Guru Ram Das Institute of Dental Sciences and Research , Sri Amritsar, India .
authors.forename: Simrat
authors.initials: S
authors.lastname: Kaur
authors.affiliation: Reader, Department of Prosthodontics and Crown & Bridge, Sri Guru Ram Das Institute of Dental Sciences and Research , Sri Amritsar, India .
authors.forename: Aman
authors.initials: A
authors.lastname: Arora
keywords: Implant restorations; Luting cement; Retention test; Retrievability