Adhesion to Y-TZP ceramic: Study of silica nanofilm coating on the surface of Y-TZP

Abstract

This study evaluated the influence of silica-based film coatings on the surface of yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP), in particular on the durability of the bond strength between the ceramic and resin cement. Eighty Y-TZP (In-Ceram YZ, Vita) blocks (4 × 4 × 3 mm) were obtained and divided into four groups according to the surface treatments (n = 20): tribochemical silica coating (TBS; Cojet, 3M/ESPE), 5 nm SiO2 nanofilm and silanization (F-5), 500 nm SiO2 nanofilm and silanization (F-500), and 500 nm SiO2 nanofilm + hydrofluoric-acid-etching + silanization (F-500HF). Specimens of composite resin (3.25 mm in diameter and 3 mm in height) were cemented to Y-TZP blocks using resin cement (Relyx ARC). Half of the specimens from each group were tested 24 h after adhesion (B: baseline condition), and the other half were subjected to aging (A: storage for 90 days and 10,000 thermal cycles). The specimens were subjected to shear testing (SBS) (1 mm/min). After testing, the surfaces were analyzed with a stereomicroscope and scanning electron microscope. Micromorphologic and elemental chemical analyses of the treated Y-TZP surface were made by X-ray energy dispersive spectroscopy. Bond strength data were statistically analyzed by Kruskal-Wallis/Mann-Whitney tests (α = 0.05). The surface treatment showed significant differences for B (p = 0.0001) and A (p = 0.0000) conditions. In both storage conditions, TBS and F-5 groups promoted the significantly highest bond strength. Most of the specimens presented adhesive failure. The X-ray energy dispersive spectroscopy analysis depicted the highest peak of silica in the TBS, F-5, and F-500 groups. The adhesion to zirconia can be improved if the surface receives a 5 nm layer of SiO2 nanofilm or is subjected to sandblasting with silica particles, followed by silanization.

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.…”

“…Therefore, many studies have been carried out in an effort to improve the bond strength of the zirconiaporcelain interface with different zirconia surface treatments to reduce the amount of chipping and/or delamination of porcelain material veneered on yttriumstabilized polycrystal zirconia (3Y-TZP) (10)(11)(12)(13).…”

“…After presputtering, the substrate holder is placed over the target, thus initiating the deposition process, controlling the time required for exposure of the substrate to the plasma to the desired film thickness. Such treatments on 3Y-TZP can create a more gradual interface between zirconia and ceramics, preventing and/or diminishing porcelain delamination and chipping (13).…”

Mechanical properties of composite resin blocks for CAD/CAM

“…Immersion in water caused water penetration into the resin matrix of the composite resin blocks, softening the polymer 15) . Moreover, it may be hypothesized that the absorbed water would cause hydrolysis of the interfacial silane coupling agent, especially in case of zirconium silicate that is not effectively silanized due to the high crystalline content 26) . Accordingly, the flexural strength and modulus of zirconia-containing composite resin blocks, especially BLO and ULT, decreased after 7-day water storage and thermocycling.…”