Evaluation of tensile retention of Y-TZP crowns after long-term aging: effect of the core substrate and crown surface conditioning.

This study evaluated the effect of the core substrate type (dentin and composite resin) on the retention of crowns made of yttrium oxide stabilized tetragonal zirconia polycrystal (Y-TZP), submitted to three inner surface conditionings. For this purpose, 72 freshly extracted molars were embedded in acrylic resin, perpendicular to the long axis, and prepared for full crowns: 36 specimens had crown preparations in dentin; the remaining 36 teeth had the crowns removed, and crown preparations were reconstructed with composite resin plus fiber posts with dimensions identical to the prepared dentin. The preparations were impressed using addition silicone, and 72 Y-TZP copings for the tensile test were produced. Cementation was performed with a dual-cured cement containing phosphate monomers. For cementation, the crown preparation (dentin or resin) was conditioned with the adhesive system, and the ceramic was subjected to one of three surface treatments: isopropyl alcohol, tribochemical silica coating, or thin low-fusing glassy porcelain layer application plus silanization. After 24 hours, all specimens were submitted to thermocycling (6000 cycles) and placed in a special tensile testing device in a universal testing machine to determine failure loads. The failure modes of all samples were analyzed under a stereomicroscope. Two-way analysis of variance showed that the surface treatment and substrate type (α=0.05) affected the tensile retention results. The dentin substrate presented the highest tensile retention values, regardless of the surface treatment. When the substrate was resin, the tribochemical silica coating and low-fusing glaze application plus silanization groups showed the higher retention values.

[1]  Xiaohui Chen,et al.  Development and testing of multi-phase glazes for adhesive bonding to zirconia substrates. , 2010, Journal of dentistry.

[2]  E. Swift,et al.  Evaluation of new methods for composite repair. , 1992, Dental materials : official publication of the Academy of Dental Materials.

[3]  G. H. Johnson,et al.  The effect of a resin-based sealer on crown retention for three types of cement. , 2004, The Journal of prosthetic dentistry.

[4]  M Heller,et al.  Mechanical properties and short-term in-vivo evaluation of yttrium-oxide-partially-stabilized zirconia. , 1989, Journal of biomedical materials research.

[5]  L. Valandro,et al.  Bonding of Y-TZP to dentin: effects of Y-TZP surface conditioning, resin cement type, and aging. , 2014, Operative dentistry.

[6]  M. Özcan,et al.  Comparison of alternative adhesive cementation concepts for zirconia ceramic: glaze layer vs zirconia primer. , 2012, The journal of adhesive dentistry.

[7]  G. H. Johnson,et al.  Retention of zirconium oxide ceramic crowns with three types of cement. , 2006, The Journal of prosthetic dentistry.

[8]  Moustafa N. Aboushelib,et al.  Strength influencing variables on CAD/CAM zirconia frameworks. , 2008, Dental materials : official publication of the Academy of Dental Materials.

[9]  L. Valandro,et al.  Air-particle abrasion on zirconia ceramic using different protocols: effects on biaxial flexural strength after cyclic loading, phase transformation and surface topography. , 2013, Journal of the mechanical behavior of biomedical materials.

[10]  A. Mainjot,et al.  Clinical risk factors related to failures with zirconia-based restorations: an up to 9-year retrospective study. , 2013, Journal of dentistry.

[11]  E. Swift,et al.  Surface fluorination of zirconia: adhesive bond strength comparison to commercial primers. , 2012, Dental materials : official publication of the Academy of Dental Materials.

[12]  L. Valandro,et al.  Microtensile bond strength of a resin cement to glass infiltrated zirconia-reinforced ceramic: the effect of surface conditioning. , 2006, Dental materials : official publication of the Academy of Dental Materials.

[13]  Ş. Canay,et al.  Effect of preparation taper and height on strength and retention of zirconia crowns. , 2012, The International journal of prosthodontics.

[14]  L. Correr-Sobrinho,et al.  Influence of glazed zirconia on dual-cure luting agent bond strength. , 2012, Operative dentistry.

[15]  L. Valandro,et al.  Adhesive quality of self-adhesive and conventional adhesive resin cement to Y-TZP ceramic before and after aging conditions. , 2010, Operative dentistry.

[16]  J. Knowles,et al.  The development and testing of glaze materials for application to the fit surface of dental ceramic restorations. , 2009, Dental materials : official publication of the Academy of Dental Materials.

[17]  M. Bottino,et al.  Effects of cement thickness and bonding on the failure loads of CAD/CAM ceramic crowns: multi-physics FEA modeling and monotonic testing. , 2012, Dental materials : official publication of the Academy of Dental Materials.

[18]  B. Willershausen,et al.  In vitro retentive strength of zirconium oxide ceramic crowns using different luting agents. , 2005, The Journal of prosthetic dentistry (Print).

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

[20]  P. Lambrechts,et al.  Unreacted Methacrylate Groups on the Surfaces of Composite Resins , 1982, Journal of dental research.

[21]  C. Piconi,et al.  Zirconia as a ceramic biomaterial. , 1999, Biomaterials.

[22]  Moustafa N. Aboushelib,et al.  Innovations in bonding to zirconia-based materials: Part I. , 2008, Dental materials : official publication of the Academy of Dental Materials.

[23]  A. Watanabe,et al.  Effect of an internal coating technique on tensile bond strengths of resin cements to zirconia ceramics. , 2009, Dental materials journal.

[24]  R. Scotti,et al.  Clinical evaluation of 1,132 zirconia-based single crowns: a retrospective cohort study from the AIOP clinical research group. , 2013, The International journal of prosthodontics.

[25]  Moustafa N. Aboushelib,et al.  Bonding to zirconia using a new surface treatment. , 2010, Journal of prosthodontics : official journal of the American College of Prosthodontists.

[26]  L. Valandro,et al.  Evaluation of resin bond strength to yttria-stabilized tetragonal zirconia and framework marginal fit: comparison of different surface conditionings. , 2014, Operative dentistry.

[27]  J. Griggs,et al.  Fatigue behavior in water of Y-TZP zirconia ceramics after abrasion with 30 μm silica-coated alumina particles. , 2011, Dental materials : official publication of the Academy of Dental Materials.