A new approach for Y-TZP surface treatment: evaluations of roughness and bond strength to resin cemen

Abstract

Objective This study aims to evaluate the effect of sonochemical treatment on the surface of yttria-stabilized tetragonal zirconia (Y-TZP) before and after the final sintering. Material and Methods Twenty-eight Y-TZP discs were divided into four groups (n=7), according to surface treatment: PRE: pre-sintering sonication with 30% nominal power for 15 min; POS: post-sintering sonication with 30% nominal power for 15 min; JAT: air abrasion with 50-μm alumina particles; and CON: control group with no treatment. The POS and JAT groups were sintered before sonication and the PRE group after sonication. Surface roughness was analyzed using confocal microscopy, after which resin cement cylinders were placed on the surface of the Y-TZP discs and subjected to mechanical microshear bond strength test until fracture. Surface roughness and microshear bond strength values underwent ANOVA and the Tukey tests. Results The surface roughness values for the PRE group (299.91 nm) and the POS group (291.23 nm) were not significantly different (p≥0.05), statistically, and the surface roughness value of the JAT group (925.21 nm) was higher than those of PRE and POS (p=0.007) groups. The mechanical microshear bond strength test showed that there was no statistically significant difference between the groups (p=0.08). Conclusions Therefore, the results showed that sonochemical treatment modifies the Y-TZP surface and is similar to the well-established sandblasting surface treatment regarding the strength of the bond with the resin cement.

Effect of silica coating and laser treatment on the flexural strength, surface characteristics, and bond strength of a dental zirconia

“…Each treatment group was allocated 49 specimens for assessment of outcomes. Outcomes were: surface roughness and surface loss (13), immediate and long‐term bond strength (6), surface topography and phase transformation (22), and biaxial flexural strength (BFS) (24), which were analysed using eight, eight, three, and 30 specimens, respectively, from each group.…”

“…Despite the superior mechanical properties of 3Y‐TZP, it remains a challenge to cement this ceramic onto dental preparations because it is resistant to hydrofluoric acid etching (4). Some studies (5,6) recommended air abrasion with a stream of aluminum oxide particles or the tribochemical silica coating. On the other hand, previous studies (7) demonstrated that alumina particles might induce superficial microcracks, adversely affecting the mechanical properties of zirconia and thus reducing its long‐term stability.…”

Evaluation of zirconia surfaces and shear bond strength after acid–etching with ultrasonic vibration

“…When it comes to ultrasonic cleaning, ultrasonic waves directly and indirectly act on liquid and dirt through their cavitation, acceleration, and direct inflow effects in the liquid, so that the dirt layer is dispersed, emulsified, and peeled off to achieve cleaning [14]. In the study of Marlyni Aparecida ZENS, the sound waves would modify the Y-TZP surface, finally improve the adhesion of Y-TZP with resin cement and cause less damage to the Y-TZP surface [15]. Ultrasonic cleaning is usually set as a routine step in the preparation of Y-TZP ceramic samples, while its role as a possible experimental influencing factor has been ignored.…”

Surface Roughness Assessment of the Sandblasted and Acid- Etched Zirconia Ceramic

“…Sandblasting with 50-125 µm AL2O3 particles was identified as an essential step in establishing a durable bond between the resin cement and the zirconia (6,8) . Several authors reported that air abrasion with aluminum oxide (Al2O3) particles is needed before luting zirconia, even when applied novel primers and universal adhesives (14,15,16) .…”

“…Few studied evaluated the possible surface roughness of the sintered zirconia surface when treated with a citric acidic solution in comparison to those treated with aluminum particle abrasion. (14,26) As acidic etching may produce microscopical changes while those surfaces subjected to sandblasting may show macroscopical alteration. In this study the hypothesis to be tested that both acid etching and sandblasting would not modify the zirconia ceramic surface roughness.…”