title: Is There a Correlation Between Tensile Strength and Retrievability of Cemented Implant-Retained Crowns Using Artificial Aging?
abstract: OBJECTIVE
  The main goal of this in-vitro study was to evaluate whether tensile strength and retrievability of cemented implant-retained crowns correlate when using artificial aging.
  
  
  METHODS
  A total of 128 crowns were fabricated from a cobalt-chromium alloy for 128 tapered titanium abutments (6 degrees taper, 4.3 mm diameter, 4 mm length, Camlog). The crowns were cemented with glass-ionomer (Ketac Cem, 3M) or resin cements (Multilink Implant, Telio CS Cem [Ivoclar Vivadent], Retrieve [Parkell]). Multilink Implant was used without priming. The experimental groups were subjected to either 37,500 thermal cycles between 5°C and 55°C, 1,200,000 chewing cycles, or a combination of both. Control groups were stored for 10 days in deionized water. The crowns were removed with a universal testing machine or a clinically used removal device (Coronaflex, KaVo). Data were statistically analyzed using nonparametrical tests.
  
  
  RESULTS
  Retention values were recorded between 31 N and 362 N. Telio CS Cem showed the lowest retention values, followed by Retrieve, Ketac Cem, and Multilink Implant (P≤.0001). The number of removal attempts with the Coronaflex were not significantly different between the cements (P>.05). Thermal cycling and chewing simulation significantly influenced the retrieval of Retrieve Telio CS Cem, and Ketac Cem specimens (P≤.05). Only for Multilink Implant and Telio CS Cem correlations between removal with the universal testing machine and the Coronaflex could be revealed (P≤.0001).
  
  
  CONCLUSIONS
  Ketac Cem and Multilink Implant (without silane) can be used for a semipermanent cementation. Retrieve and Telio CS Cem are recommendable for a temporary cementation.
authors.forename: Christian
authors.initials: C
authors.lastname: Mehl
authors.forename: Shurouk
authors.initials: S
authors.lastname: Ali
authors.forename: Shadi
authors.initials: S
authors.lastname: El Bahra
authors.forename: Sönke
authors.initials: S
authors.lastname: Harder
authors.forename: Oliver
authors.initials: O
authors.lastname: Vollrath
authors.forename: Matthias
authors.initials: M
authors.lastname: Kern
mesh_terms: D001732:Bite Force; D002484:Cementation / Q000379:methods*; D002858:Chromium Alloys / Q000737:chemistry; D017076:Computer-Aided Design; D003442:Crowns; D000044:Dental Abutments; D017005:Dental Debonding / Q000295:instrumentation; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000295:instrumentation; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D002858:Chromium Alloys; D015921:Dental Implants; D003764:Dental Materials; D005899:Glass Ionomer Cements; D019279:Resin Cements; D014867:Water; D014025:Titanium