Fracture strength of yttria-stabilized tetragonal zirconia polycrystals crowns with different design: an in vitro study.

OBJECTIVES The aim of this study was to evaluate the effect of different types and design of zirconia frameworks as well as the effect of different veneering ceramics on the fracture strength of crowns. The importance of different abutment materials was also evaluated. MATERIALS AND METHODS Eighty cores, 40 in a fully-sintered zirconia material and 40 in a pre-sintered zirconia material were made. Twenty cores of each material were made with a core of even thickness shape (ES) and 20 were made with a core with anatomical shape (AS). The cores were divided into subgroups and veneered with one of two different veneering ceramics: a porcelain and a glass-ceramic material. In total eight groups of 10 crowns were made. They were all cemented onto abutments made of resin. One extra group of 10 AS, pre-sintered zirconia cores veneered with glass-ceramic were made and cemented onto titanium abutments. All crowns underwent thermocycling and mechanical pre-load and were finally loaded until fracture. RESULTS AS crowns withstood significantly higher loads than ES crowns (P-value <0.001), and crowns with titanium abutments withstood significantly higher loads than crowns supported by abutments made of inlay pattern resin (P-value <0.001). Three types of fracture were noted: minor and major fracture of the veneering ceramic, and complete fracture through core and veneer. ES crowns showed significantly more major fractures of the veneering ceramic than AS crowns. CONCLUSIONS This in vitro study indicates that the design of the core, as well as the abutment support, significantly influences fracture load and fracture mode of yttria-stabilized tetragonal zirconia polycrystals crowns.

[1]  N. Lang,et al.  Biological and technical complications and failures with fixed partial dentures (FPD) on implants and teeth after four to five years of function. , 2001, Clinical oral implants research.

[2]  N. Ferree,et al.  Which mechanical and physical testing methods are relevant for predicting the clinical performance of ceramic-based dental prostheses? , 2007, Clinical oral implants research.

[3]  M. Stiesch-Scholz,et al.  Influence of cyclic fatigue in water on the load-bearing capacity of dental bridges made of zirconia. , 2008, Acta biomaterialia.

[4]  Á. Della Bona,et al.  The clinical success of all-ceramic restorations. , 2008, Journal of the American Dental Association.

[5]  M. Molin,et al.  Five-year clinical prospective evaluation of zirconia-based Denzir 3-unit FPDs. , 2008, The International journal of prosthodontics.

[6]  P. Vult von Steyern,et al.  A prospective study of implant-supported full-arch yttria-stabilized tetragonal zirconia polycrystal mandibular fixed dental prostheses: three-year results. , 2010, The International journal of prosthodontics.

[7]  E. D. Rekow,et al.  Laboratory Simulation of Y-TZP All-ceramic Crown Clinical Failures , 2009, Journal of dental research.

[8]  P Carlson,et al.  All-ceramic fixed partial dentures designed according to the DC-Zirkon technique. A 2-year clinical study. , 2005, Journal of oral rehabilitation.

[9]  P. Pospiech,et al.  Zirconium dioxide implant abutments for posterior single-tooth replacement: first results. , 2009, Journal of periodontology.

[10]  J R Kelly,et al.  Perspectives on strength. , 1995, Dental materials : official publication of the Academy of Dental Materials.

[11]  J R Kelly,et al.  Clinically relevant approach to failure testing of all-ceramic restorations. , 1999, The Journal of prosthetic dentistry.

[12]  G. Sjögren,et al.  Fracture resistance of yttrium oxide partially-stabilized zirconia all-ceramic bridges after veneering and mechanical fatigue testing. , 2005, Dental materials : official publication of the Academy of Dental Materials.

[13]  Kenneth J Anusavice,et al.  Clinical performance of a lithia disilicate-based core ceramic for three-unit posterior FPDs. , 2004, The International journal of prosthodontics.

[14]  G. Sjögren,et al.  A comparison of fracture strength of yttrium-oxide- partially-stabilized zirconia ceramic crowns with varying core thickness, shapes and veneer ceramics. , 2004, Journal of oral rehabilitation.

[15]  M V Swain,et al.  Unstable cracking (chipping) of veneering porcelain on all-ceramic dental crowns and fixed partial dentures. , 2009, Acta biomaterialia.

[16]  Ariel J Raigrodski,et al.  The efficacy of posterior three-unit zirconium-oxide-based ceramic fixed partial dental prostheses: a prospective clinical pilot study. , 2006, The Journal of prosthetic dentistry.

[17]  H Knode,et al.  In-Ceram fixed partial dentures: three-year clinical trial results. , 1998, Journal of the California Dental Association.

[18]  P. Vult von Steyern,et al.  Use of abutment-teeth vs. dental implants to support all-ceramic fixed partial dentures: an in-vitro study on fracture strength. , 2005, Swedish dental journal.

[19]  B. Lang,et al.  Shear strength of core-veneer interface in bi-layered ceramics. , 2004, The Journal of prosthetic dentistry.

[20]  N. Heussen,et al.  Clinical behavior of zirconia-based fixed partial dentures made of DC-Zirkon: 3-year results. , 2008, The International journal of prosthodontics.

[21]  M Rosentritt,et al.  In vitro fracture force and marginal adaptation of ceramic crowns fixed on natural and artificial teeth. , 2000, The International journal of prosthodontics.

[22]  M. A. van 't Hof,et al.  A meta-analysis of durability data on conventional fixed bridges. , 1994, Community dentistry and oral epidemiology.

[23]  M. Yoshinari,et al.  Fracture strength of all-ceramic crowns. , 1994, The International journal of prosthodontics.

[24]  B. Lawn,et al.  Lifetime-limiting Strength Degradation from Contact Fatigue in Dental Ceramics , 2000, Journal of dental research.

[25]  Krister Nilner,et al.  All-ceramic two- to five-unit implant-supported reconstructions. A randomized, prospective clinical trial. , 2006, Swedish dental journal.

[26]  M. Zwahlen,et al.  Comparison of survival and complication rates of tooth-supported fixed dental prostheses (FDPs) and implant-supported FDPs and single crowns (SCs). , 2007, Clinical oral implants research.

[27]  K. Akca,et al.  CAD/CAM ZIRCONIA VS. SLIP-CAST GLASS-INFILTRATED ALUMINA/ZIRCONIA ALL-CERAMIC CROWNS: 2-YEAR RESULTS OF A RANDOMIZED CONTROLLED CLINICAL TRIAL , 2009, Journal of applied oral science : revista FOB.

[28]  L. Pröbster.  Survival rate of In-Ceram restorations. , 1993, The International journal of prosthodontics.

[29]  M. Behr,et al.  Influence of substructure design and spacer settings on the in vitro performance of molar zirconia crowns. , 2009, Journal of dentistry.

[30]  M Rosentritt,et al.  Influence of stress simulation parameters on the fracture strength of all-ceramic fixed-partial dentures. , 2006, Dental materials : official publication of the Academy of Dental Materials.

[31]  J A Tesk,et al.  Failure of All-ceramic Fixed Partial Dentures in vitro and in vivo: Analysis and Modeling , 1995, Journal of dental research.

[32]  L. Gauckler,et al.  In vitro lifetime of dental ceramics under cyclic loading in water. , 2007, Biomaterials.

[33]  M. Stiesch-Scholz,et al.  Load-bearing capacity of all-ceramic posterior four-unit fixed partial dentures with different zirconia frameworks. , 2007, European journal of oral sciences.

[34]  P. Vult von Steyern,et al.  Five-year evaluation of posterior all-ceramic three-unit (In-Ceram) FPDs. , 2001, The International journal of prosthodontics.

[35]  Anders Ortorp,et al.  A 3-year retrospective and clinical follow-up study of zirconia single crowns performed in a private practice. , 2009, Journal of dentistry.

[36]  Irena Sailer,et al.  Five-year clinical results of zirconia frameworks for posterior fixed partial dentures. , 2007, The International journal of prosthodontics.