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

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: postsintering 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

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

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: postsintering 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

Evaluation of surface treatment by sonochemical the bond strength between Yttria-Stabilized Tetragonal Zirconia Polycrystals and resin cement

O objetivo deste estudo foi avaliar o efeito do tratamento ultrassônico como tratamento de superfície da zircônia tetragonal policristalina estabilizada por ítria (YTZP) e depois da sinterização final, por meio de mensuração da rugosidade superficial e teste de resistência adesiva por microsisalhamento. Para tanto, discos de Y-TZP foram confeccionados e distribuídos em 4 grupos (n=7), conforme o tratamento de superfície: 1-PRE: sonicação pré-sinterização; 2-POS: sonicação póssinterização; 3-JAT: jateamento com partículas óxido de alumínio 50μm; 4-CON: sem tratamento. Os espécimes foram polidos e padronizados e posteriormente submetidos aos tratamentos de acordo com cada grupo. Os grupos POS, JAT e COM foram sinterizados previamente ao tratamento e o grupo PRE após a sonicação. Os grupos PRE e POS foram submetidos a tratamento em processador ultrassonico (Sonics VCX-750) em potência nominal de 30% durante 15 minutos. O grupo JAT foi jateado com partículas de alumínio 50μm a uma distância de 15 cm, enquanto o grupo CON não recebeu nenhum tratamento. A mensuração de rugosidade superficial média (Ra) foi feita em Microscópio Confocal (MC), em seguida cilindros de cimento resinoso foram preparados e fotoativados na superfície do Y-TZP para serem submetidos ao ensaio mecânico de microcisalhamento realizado em máquina de ensaios universal (INSTRON). Os valores de rugosidade superficial e resistência de união obtidos foram submetidos a ANOVA a um critério e teste de Tukey. Quanto aos valores de rugosidade superficial, o grupo PRE (299,91 Mpa) e POS (291,23 Mpa) não apresentaram diferença estatística significante e o grupo JAT (925,21 Mpa) mostrou maiores valores de rugosidade superficial quando comparado ao PRE e POS. Para o teste de microcisalhamento não foram observadas diferenças estatisticamente significantes entre os grupos. Por meio dos resultados obtidos foi possível observar que o tratamento ultrassonico é capaz de alterar a superfície da Y-TZP e influenciar na resistência adesiva ao cimento resinoso.The objective of this study was to evaluate the effect of ultrasonic treatment as surface treatment of Y-TZP before and after the final sintering, through measurement of surface roughness and bond strength by microshear test. Therefore, Y-TZP discs were made and distributed in 4 groups (n = 7), as surface treatment: 1-PRE: Presintering sonication; 2-POS: Post-sintering sonication; 3-JAT: air abrasion with aluminum oxide particles 50μm; 4-CON: no treatment. The specimens were polished and standardized and subsequently submitted to the treatments according to each group. The POS, JAT and CON groups been previously sintered to treatment and the PRE group after sonication. The PRE and POS groups were submitted to Ultrasonic Processor treatment (Sonics VCX-750) at 30% power for 15 minutes. The JAT group received air abrasion with aluminum particles 50μm at distance of 15 cm, while group received no treatment. The measurement of surface roughness was made in Confocal Microscope (MC), then resin cement cylinders were prepared and polymerized in Y-TZP surface to be subjected to mechanical testing microshear performed on universal testing machine (INSTRON). The values of surface roughness and bond strength were subjected to ANOVA and Tukey testAbout the values of surface roughness, the PRE group (299.91 MPa) and POS (291.23 MPa) showed no statistically significant difference and the JAT group (925.21 MPa) showed higher surface roughness values when compared to PRE and POS. For icroshear test statistically significant differences were observed between the groups. Through the results it was observed that the ultrasonic treatment is able to change the surface of the Y-TZP and influence the bond strength to resin cement