Evaluation of Resin Bond Strength to Yttria-stabilized Tetragonal Zirconia and Framework Marginal Fit: Comparison of Different Surface Conditionings

Abstract

The low-fusing glass application followed by hydrofluoric acid etching and silanization seems to be a promising method for improving the resin bond strength to yttria-stabilized tetragonal zirconia, but the adhesion to this substrate is still a challenge. SUMMARYThe purpose of this study was to evaluate the effect of different surface treatments of yttriastabilized tetragonal zirconia (Y-TZP) on bond strength durability and marginal discrepancies. For adhesion testing, 144 specimens of VITA In-Ceram YZ ceramic for InLab were obtained (5.2533.7534.5 mm) and divided into six groups (n=24) according to the surface treatment: 1) Control (CRTL): untreated; 2) SIL: tribochemical silica coating (CoJet system, 3M/ESPE AG); 3) V1+HF: spray application of low-fusing porcelain glaze (V1, VITA Akzent Spray Glaze) followed by etching with hydrofluoric acid (HF) (one minute); 4) V1+SIL: V1 glazing (VITA Akzent Spray Glaze) followed by tribochemical silica coating; 5) V2+HF: brush application of low-fusing porcelain glaze (VITA Akzent Glaze) plus etching with HF (one minute); and 6) V2+SIL: V2 glazing (VITA Akzent Glaze) plus tribochemical silica coating. After all treatments, the surfaces were silanized for five minutes (ESPE-SIL) and cementation was performed using Panavia F (Kuraray). Half of the specimens in each treatment were tested 24 hours after cementation (dry), with the other half subjected to storage (150 days) and thermocycling (12,0003) (aging), and then a shear test was carried out (1 mm/ min). The micromorphological (digital optical profilometry and scanning electron microscopy) and elemental analyses of the treated surfaces were performed. The inner surfaces of 60 Y-TZP infrastructures were conditioned and marginal fit was evaluated. The statistical analysis revealed that the groups treated via surface glaze application followed by hydrofluoric acid etching and silanization showed the highest bond strength (in dry and aging conditions), but the bond strengths were affected by aging. The highest marginal discrepancies were observed in the groups receiving glaze (117.4 6 29.6 to 105.8 6 12.2 lm) when compared to other groups (55.3 6 8.7 and 55 6 8.5 lm). Low-fusing porcelain glaze + hydrofluoric acid etching changed the morphology of the Y-TZP ceramic and improved the adhesion to the resin cement, but obtaining high and stable bond values to Y-TZP remains challenging. Marginal discrepancies increased with glazing.

Low-Fusing Porcelain Glaze Application on 3Y-TZP Surfaces can Enhance Zirconia-Porcelain Adhesion

“…Surface treatments have been studied on zirconia to improve bond compatibility between the two ceramics and appear to be important to improving bond strength (13,(15)(16)(17)(18)(19). The present work found that porcelain glaze application on the zirconia core before veneering porcelain cylinder build-up promoted zirconia-porcelain bond improvements, while the untreated group showed the lower bond strength result.…”

“…In addition, the thickness and chemical composition of the film can also be controlled. Another positive factor of the nano-coating is its nanometer thickness (13,19) . A previous study showed that nanofilm could be a favorable alternative to the deposition of silica on the Y-TZP (13), promoting high bonding strength among ceramics.…”

Effects of cementation surface modifications on fracture resistance of zirconia

“…A strong resin bond can be established by the application of a silane coupling agent followed by a resin-based adhesive system. Other non-air-abrasion approaches to obtain chemical bond to zirconia using silane plus resin adhesives have been reported, including low fusion glass coating [38], silica-based chemical coating [39], and vapor phase deposition [40]. However, the stability of the interfacial bond among zirconia, coating, and cement and the influence of the coating on the fitting of the restoration are still questionable.…”

A Review of Surface Treatment Methods to Improve the Adhesive Cementation of Zirconia-Based Ceramics

“…Recent studies has shown promising results on bond strengths of Y-TZP/resin cement after glazed ceramic surface is subjected to air-particle abrasion with aluminum oxide and silanization [1] or etching with hydrofluoric acid [75], but a stable bond promoted by these methods is questionable and needs more studies.…”