title: Retention of cast crown copings cemented to implant abutments.
abstract: BACKGROUND
  The cementation of crowns to dental implant abutments is an accepted form of crown retention that requires consideration of the properties of available cements within the applied clinical context. Dental luting agents are exposed to a number of stressors that may reduce crown retention in vivo, not the least of which is occlusal loading. This study investigated the influence of compressive cyclic loading on the physical retention of cast crown copings cemented to implant abutments.
  
  
  METHODS
  Cast crown copings were cemented to Straumann synOcta titanium implant abutments with three different readily used and available cements. Specimens were placed in a humidifier, thermocycled and subjected to one of four quantities of compressive cyclic loading. The uniaxial tensile force required to remove the cast crown copings was then recorded.
  
  
  RESULTS
  The mean retention values for crown copings cemented with Panavia-F cement were statistically significantly greater than both KetacCem and TempBond non-eugenol cements at each compressive cyclic loading quantity. KetacCem and TempBond non-eugenol cements produced relatively low mean retention values that were not statistically significantly different at each quantity of compressive cyclic loading. Compressive cyclic loading had a statistically significant effect on Panavia-F specimens alone, but increased loading quantities produced no further statistically significant difference in mean retention.
  
  
  CONCLUSIONS
  Within the limitations of the current in vitro conditions employed in this study, the retention of cast crown copings cemented to Straumann synOcta implant abutments with a resin, glass ionomer and temporary cement was significantly affected by cement type but not compressive cyclic loading. Resin cement is the cement of choice for the definitive non-retrievable cementation of cast crown copings to Straumann synOcta implant abutments out of the three cements tested.
authors.affiliation: Faculty of Health Sciences, School of Dentistry, The University of Adelaide, South Australia. james.dudley@adelaide.edu.au
authors.forename: J E
authors.initials: JE
authors.lastname: Dudley
authors.forename: L C
authors.initials: LC
authors.lastname: Richards
authors.forename: J R
authors.initials: JR
authors.lastname: Abbott
mesh_terms: D002484:Cementation; D019245:Compressive Strength; D003442:Crowns; D000044:Dental Abutments; D003738:Dental Cements; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis; D005899:Glass Ionomer Cements; D006047:Gold Alloys; D008277:Magnesium Oxide; D011076:Polycarboxylate Cement; D011897:Random Allocation; D019279:Resin Cements; D015034:Zinc Oxide
chemical_list: D003738:Dental Cements; D005899:Glass Ionomer Cements; D006047:Gold Alloys; C438843:Panavia-Fluoro; D011076:Polycarboxylate Cement; D019279:Resin Cements; C474196:Tempbond NE; D008277:Magnesium Oxide; C040235:Ketac-cem; D015034:Zinc Oxide