Novel fabrication method for zirconia restorations: Bonding strength of machinable ceramic to zirconia with resin cements

Abstract

A novel method was developed to fabricate all-ceramic restorations which comprised CAD/CAM-fabricated machinable ceramic bonded to CAD/CAM-fabricated zirconia framework using resin cement. The feasibility of this fabrication method was assessed in this study by investigating the bonding strength of a machinable ceramic to zirconia. A machinable ceramic was bonded to a zirconia plate using three kinds of resin cements: ResiCem (RE), Panavia (PA), and Multilink (ML). Conventional porcelain-fused-to-zirconia specimens were also prepared to serve as control. Shear bond strength test (SBT) and Schwickerath crack initiation test (SCT) were carried out. SBT revealed that PA (40.42 MPa) yielded a significantly higher bonding strength than RE (28.01 MPa) and ML (18.89 MPa). SCT revealed that the bonding strengths of test groups using resin cement were significantly higher than those of Control. Notably, the bonding strengths of RE and ML were above 25 MPa even after 10,000 times of thermal cycling -adequately meeting the ISO 9693 standard for metal-ceramic restorations. These results affirmed the feasibility of the novel fabrication method, in that a CAD/CAM-fabricated machinable ceramic is bonded to a CAD/CAM-fabricated zirconia framework using a resin cement.

Examination of bond strength and mechanical properties of Y-TZP zirconia ceramics with different surface modifications

“…From the graph showing the bond strength between the Y-TZP and the veneering porcelain ( Fig. 3-a, Table 5), it is seen that all of the surfacemodified groups and the control group show a bond strength of more than 25 MPa, the prescribed minimum of ISO 9693 27,28) . On the other hand, in case of aluminasandblasted, the bond strength of Al was not significantly different to Al.h and control.…”

“…The Y-TZP framework (25 [27][28][29] (Lava zirconia, 3M ESPE, Seefeld, Germany), and pre-sintered zirconium oxide blocks pre-sintered zirconium oxide blocks (Table 1) were milled using a CAD/CAM system (Lava, 3M ESPE, Seefeld, Germany), and they were cut into plates using an automatic precision cutter, (ISOMET ® , Buehler Ltd., IL, USA), then the plates polished under running water using #600, #1000, and #2500 waterproof abrasive papers (Buehler Ltd., IL, USA). They were then cleaned and dried, with a final sintering at 1,500°C for 5 h.…”

“…The bond strength between the Y-TZP framework and the veneering porcelain was calculated using the three-point bending test, according to the guidelines set forth in ISO 9693:1999 (E) [27][28][29] . It was assumed that the debonding/crack initiation strength standards of ISO 9693 are applicable to the bonding tests of zirconia and veneering porcelain, although this specification specifically prescribes the method for testing the bonding strength between a metal substrate and a veneering porcelain.…”

Bond strength of glass-ceramic cemented to a zirconia structure: influence of adhesive cementation strategy

“…Another possible restorative approach, which involves the cementing of the glass-ceramic to the zirconia structure, is in multi-element fixed prostheses that have been prepared by the multilayer process where, through the CAD/CAM system, a zirconia infrastructure and a glass-ceramic suprastructure, both adhesively cemented to one another, form a single structure, which can then be cemented to the abutments 11 . In both cases, cementation can be performed with either dual or light-cured self-adhesive or conventional resins [12][13][14] .…”

Compatibility of Ce-TZP/Al2O3 nanocomposite frameworks and veneering porcelains

“…Among them, the Schwickerath crack initiation test is regulated for the evaluation of metal-ceramic restorations and has been also available for all-ceramic restorations 8,26) . However, the evaluation of the bond strength of veneering porcelains to Ce-TZP/Al2O3 nanocomposite frameworks using the Schwickerath crack initiation test has not yet been published.…”