Effects of the ratio of silane to 10-methacryloyloxydecyl dihydrogenphosphate (MDP) in primer on bonding performance of silica-based and zirconia ceramics

Thin, non-retentive, monolithic restorations fabricated from novel translucent zirconia ceramics are widely used in contemporary dentistry. Because of the chemical inertness of zirconia, debonding of such restorations remains the main clinical complication. Limited evidence on the bonding performance of novel translucent zirconia exists; therefore, the present study aimed to evaluate, in vitro, the shear-bond strength (SBS) of translucent zirconia modified with a nanostructured alumina coating (NAC). The SBS of resin cement to translucent zirconia, materials containing 3, 4 or 5 mol.% of yttria modified with NAC, was measured and related to airborne-particle abraded (APA) zirconia surfaces. Half of each of the specimen groups (n = 20) were subjected to 37,500 thermocycles in water. In addition, to evaluate the effect of NAC on thin translucent zirconia discs (n = 10), the translucency parameter (TP) was measured and compared with APA. The results were statistically analyzed using a t-test and one-way ANOVA. NAC provided higher resin-zirconia SBS compared to APA, not affecting the zirconia optical properties. APA, on the other hand, lowered TP for all types of zirconia. NAC did not impair the mechanical or optical properties of translucent zirconia materials and should be regarded as a zirconia pretreatment alternative to APA.

Download Full-text

Bonding performance of self-adhesive luting agents to highly translucent zirconia ceramics

Asian Pacific Journal of Dentistry ◽

10.47416/apjod.20-0276 ◽

2020 ◽

Vol 20 (2) ◽

pp. 29-33

Author(s):

Toyoaki Kobayashi ◽

Tomohiro Takagaki ◽

Rena Takahashi ◽

Masaomi Ikeda ◽

Junji Tagami

Keyword(s):

Zirconia Ceramics ◽

Bonding Performance ◽

Luting Agents ◽

Adhesive Luting

Download Full-text

Strain analysis in composite ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144012 ◽

1986 ◽

Vol 44 ◽

pp. 494-497

Author(s):

W. M. Kriven

Keyword(s):

Strain Field ◽

Strain Analysis ◽

Processing Temperature ◽

Transformation Toughening ◽

Zirconia Ceramics ◽

Volume Increase ◽

Analysis Technique ◽

Fundamental Understanding ◽

Contrast Analysis ◽

Elastic Strain Field

Significant progress towards a fundamental understanding of transformation toughening in composite zirconia ceramics was made possible by the application of a TEM contrast analysis technique for imaging elastic strains. Spherical zirconia particles dispersed in a large-grained alumina matrix were examined by 1 MeV HVEM to simulate bulk conditions. A thermal contraction mismatch arose on cooling from the processing temperature of 1500°C to RT. Tetragonal ZrO2 contracted amisotropically with α(ct) = 16 X 10-6/°C and α(at) = 11 X 10-6/°C and faster than Al2O3 which contracted relatively isotropically at α = 8 X 10-6/°C. A volume increase of +4.9% accompanied the transformation to monoclinic symmetry at room temperature. The elastic strain field surrounding a particle before transformation was 3-dimensionally correlated with the internal crystallographic orientation of the particle and with the strain field after transformation. The aim of this paper is to theoretically and experimentally describe this technique using the ZrO2 as an example and thereby to illustrate the experimental requirements Tor such an analysis in other systems.

Download Full-text