Effect of ZrO2 paste, surface treatments, and storage on Weibull characteristics and resin bond strength to zirconia.

The objective is to evaluate the effect of different surface treatments and storage on the shear strength of ultratranslucent zirconia. 36 blocks of ultra-translucent zirconia were fabricated (7x7x2mm) and sintered. Then, divided into 12 groups according to the "surface treatment" (C -Primer; Al -Sandblasting with Al2O3 + Primer; Si -Silicate + Primer; Gl -Glaze + HF + Primer; Z -Zirlink; Zp -Zirlink + Primer) and "storage" factors (ST-with 150 days/37º and without). After surface treatment, five cylinders (Ø=2mm; h=2.0mm) of resin cement (n=15) were constructed in each ceramic block; at the end, the shear strength test was performed (1mm/min, 50Kgf), and analysis of surface failures. 60 additional samples (2x2x2mm) were made for extras analysis (surface roughness, MEV, and EDS). Bond strength and surface roughness data were statistically evaluated by ANOVA (2 factors/1 factor), Tukey test (5%), and Weibull analysis, respectively. ANOVA (2-way) revealed that all factors were statistically significant for bond strength. The silicatization groups (SiST: 30.47AMPa; Si: 29.21AMPa) showed the highest bond strength values, regardless of storage (Tukey's test). While the groups treated with Zirlink (ZST: 2.76FMPa; Z: 5.27EFMPa) showed the lowest values, just similar to the GlST group (5.14EFMPa). The Weibull modulus (m) showed a statistical difference between groups (p=0.000). ANOVA (1 factor) revealed that the "surface treatment" factor (p=0.0000) was statistically significant for surface roughness. Therefore, the application of Zirlink and Glaze on pre-sintered zirconia did not promote efficient adhesion of the ultratranslucent zirconia to the resin cement, even when associated with a primer containing MDP.

Effect of ZrO2 paste, surface treatments, and storage on Weibull characteristics and resin bond strength to zirconia

Abstract The objective is to evaluate the effect of different surface treatments and storage on the shear strength of ultratranslucent zirconia. 36 blocks of ultra-translucent zirconia were fabricated (7x7x2mm) and sintered. Then, divided into 12 groups according to the "surface treatment" (C -Primer; Al -Sandblasting with Al2O3 + Primer; Si -Silicate + Primer; Gl -Glaze + HF + Primer; Z -Zirlink; Zp -Zirlink + Primer) and "storage" factors (ST-with 150 days/37º and without). After surface treatment, five cylinders (Ø=2mm; h=2.0mm) of resin cement (n=15) were constructed in each ceramic block; at the end, the shear strength test was performed (1mm/min, 50Kgf), and analysis of surface failures. 60 additional samples (2x2x2mm) were made for extras analysis (surface roughness, MEV, and EDS). Bond strength and surface roughness data were statistically evaluated by ANOVA (2 factors/1 factor), Tukey test (5%), and Weibull analysis, respectively. ANOVA (2-way) revealed that all factors were statistically significant for bond strength. The silicatization groups (SiST: 30.47AMPa; Si: 29.21AMPa) showed the highest bond strength values, regardless of storage (Tukey's test). While the groups treated with Zirlink (ZST: 2.76FMPa; Z: 5.27EFMPa) showed the lowest values, just similar to the GlST group (5.14EFMPa). The Weibull modulus (m) showed a statistical difference between groups (p=0.000). ANOVA (1 factor) revealed that the "surface treatment" factor (p=0.0000) was statistically significant for surface roughness. Therefore, the application of Zirlink and Glaze on pre-sintered zirconia did not promote efficient adhesion of the ultratranslucent zirconia to the resin cement, even when associated with a primer containing MDP.

Resumo O objetivo é avaliar o efeito de diferentes tratamentos superficiais e do envelhecimento na resistência ao cisalhamento da zircônia ultratranslúcida. Foram confeccionados 36 blocos de zircônia ultratranslúcida (7x7x2mm) e sinterizados. Em seguida, divididos em 12 grupos de acordo com o "tratamento de superfície" (C-Primer; Al-Jateamento com Al2O3+Primer; Si-Silicato+Primer; Gl -Glaze+HF+Primer; Z-Zirlink; Zp-Zirlink+Primer) e fatores de "armazenamento" (ST-com, 150 dias/37º e sem). Após o tratamento superficial, foram construídos cinco cilindros (Ø=2mm; h=2,0mm) de cimento resinoso (n=15) em cada bloco cerâmico; ao final foi realizado o ensaio de resistência ao cisalhamento (1mm/min, 50Kgf) e análise de falhas superficiais. Foram confeccionadas 60 amostras adicionais (2x2x2mm) para análises extras (rugosidade superficial, MEV e EDS). Os dados de resistência de união e rugosidade superficial foram avaliados estatisticamente por ANOVA (2 fatores/1fator), teste de Tukey (5%) e análise de Weibull, respectivamente. ANOVA (2 fatores) revelou que todos os fatores foram estatisticamente significativos para a resistência de união. Os grupos de silicatização (SiST: 30,47AMPa; Si: 29,21AMPa) apresentaram os maiores valores de resistência de união, independente do armazenamento (Tukey). Enquanto os grupos tratados com Zirlink (ZST: 2,76FMPa; Z: 5,27EFMPa) apresentaram os valores mais baixos, apenas semelhantes ao grupo GlST (5,14EFMPa). O módulo de Weibull (m) apresentou diferença estatística entre os grupos (p=0,000). A ANOVA (1 fator) revelou que o fator "tratamento superficial" (p=0,0000) foi estatisticamente significativo para rugosidade superficial. Portanto, a aplicação de Zirlink e do Glaze na zircônia pré-sinterizada não promoveu adesão eficiente da zircônia ultratranslúcida ao cimento resinoso, mesmo quando associada a primer contendo MDP.

Efeito de diferentes protocolos de acabamento/polimento na resistência à fadiga e módulo de Weibull de diferentes tipos de zircônia / Effect of different finishing/polishing protocols on the fatigue strength and Weibull modulus of different types of zirconia

Objetivo: Avaliar o efeito de diferentes protocolos de acabamento/polimento na resistência à fadiga das novas gerações de zircônia. Materiais e Métodos: Foram confeccionados noventa (N=90) discos cerâmicos (Ø:12mm; 1,2 mm-ISO 6872), sendo 45 em zircônia ultratranslúcida (UT- VITA, Vita Zahnfabrik) e 45 de uma cerâmica de zircônia híbrida 3Y-TZP e 5Y-PSZ com gradiente de translucidez (GT- e.max Zircad prime GT, Ivoclar). Após a sinterização dos discos cerâmicos, estes foram divididos em 6 grupos (n=15), de acordo com fatores "cerâmica (zircônia UT e zircônia GT)" e "Protocolo de acabamento e polimento" (Pontas Diamantadas + Borrachas; Borrachas; Controle). Os discos foram submetidos ao ensaio de resistência à fadiga pelo método stepwise stress (5Hz para 10.000 ciclos), com um step de 57 MPa e 80 MPa, começando em 170 e 240 MPa, para a zircônia UT e GT, respectivamente, e prosseguindo até 100.000 ciclos ou a detecção da fratura. Foram realizadas também análises extras de Difração de raios X (DRX), microscopia de força atômica (AFM) e rugosidade superficial. Os dados de resistência à fadiga (MPa) e rugosidade (µm) foram avaliados estatisticamente através de ANOVA 2 fatores e teste de Tukey (5%). Foi realizada a análise de "Kaplan-Meier" seguida pelo teste de Mantel-Cox (Log Rank test) e pela comparação múltipla aos pares, todos com nível de significância de 5%. Além disso, também foi utilizada a análise de Weibull. Resultados: ANOVA (2 fatores) revelou que o fator "Protocolo de Acabamento e Polimento" (p=0,0006), "tipo de zircônia" (p=0,000) e a interação dos dois (p=0,0000) apresentaram significância estatística para a resistência à fadiga. A zircônia GT (761,47 MPa) obteve valores médios de resistência superiores a zircônia UT (385,87 MPa), independentemente do tipo de acabamento e polimento. Para zircônia UT o acabamento com pontas diamantadas reduziu os valores de resistência à fadiga (273,44DMPa) comparados ao grupo controle (503,96CMPa) e estatisticamente semelhante ao grupo polidos apenas com borracha (308,22DMPa). Na zircônia GT o polimento com borrachas melhorou a resistência do material (871,35A MPa) quando comparado ao grupo controle (664,29B MPa) que, por sua vez, foi semelhante ao grupo com acabamento com pontas diamantadas (748,78B MPa). Foi possível observar que o tipo de protocolo de acabamento e polimento influenciou a fratura em fadiga das duas cerâmicas, porém, o número de ciclo de sobrevida só foi significativo para a zircônia UT. Conclusão: A resistência à fadiga das duas zircônias foi influenciada pelos diferentes protocolos de acabamento e polimento. Para zircônia UT o polimento com borrachas e pontas diamantadas reduziu a resistência mecânica, já para a zircônia GT, todos os protocolos de acabamento e polimento melhoraram as propriedades mecânicas do material (AU).

Objective: To evaluate the effect of different finishing/polishing protocols on the fatigue strength of new generations of zirconia. Materials and Methods: Ninety (N=90) ceramic discs (Ø:12mm; 1.5mm-ISO 6872) were made, 45 of ultra-translucent zirconia (UT-VITA, Vita Zahnfabrik) and 45 of a hybrid zirconia ceramic 3Y-TZP and 5Y-PSZ with translucency gradient (GT-e.max Zircad prime GT, Ivoclar). After sintering, the ceramic discs were divided into 6 groups (n=15), according to the factors "ceramic (UT and GT)" and "Finishing and polishing protocol" (Diamond burs + Rubbers; Rubbers and Control). The discs were subjected to the fatigue resistance test by the stepwise stress method (5Hz for 10,000 cycles) with a step increment of 57 MPa and 80 MPa, starting at 170 and 240 MPa, for UT and GT zirconia, respectively, and continuing up to 100,000 cycles or failure detection. Complementary analyzes of X-ray Diffraction (XRD), atomic force microscopy (AFM) and surface roughness were also carried out. Results were statistically evaluated using 2-way ANOVA, Tukey test (5%) and Weibull analysis. The results of fatigue resistance and roughness were statistically evaluated using 2-way ANOVA and Tukey test (5%). The "Kaplan-Meier" analysis was performed followed by the Mantel-Cox test (Log Rank test) and the multiple comparison in pairs, all with a significance level of 5%. In addition, Weibull analysis was also carried out. Results: ANOVA (2-way) revealed that the factor "Finishing and Polishing Protocol" (p=0.0006), "type of zirconia" (p=0.000) and the interaction between them (p=0.0000) were statistically significant for resistance to fatigue. GT zirconia (761.47 MPa) had higher resistance values than UT zirconia (385.87 MPa), regardless of the type of finishing and polishing. For UT zirconia, finishing with diamond burs reduced the values of resistance to fatigue (273.44DMPa) compared to the control group (503.96CMPa) and statistically similar to the group polished only with rubber (308.22DMPa). In GT zirconia, polishing with rubbers improved the resistance of the material (871.35A MPa) when compared to the control group (664.29B MPa), which, in turn, was similar to the group finished with diamond burs (748.78B MPa). The Weibull modulus did not show statistical significance between the groups (p=0.300) but the characteristic strength showed statistically significant differences (p=0.0000). It was possible to observe that the type of finishing and polishing protocol influenced the fatigue fracture of the two ceramics, however, the number of survival cycles was only significant for the UT zirconia. Conclusion: The fatigue strength of the two zirconia was influenced by the different finishing and polishing protocols. For UT zirconia, polishing with rubbers and diamond burs reduced the mechanical resistance, whereas for GT zirconia, all finishing and polishing protocols improved the mechanical properties of the material (AU).

Effect of different surface treatments and multimode adhesive application on the Weibull characteristics, wettability, surface topography and adhesion to CAD/CAM lithium disilicate ceramic.

METHODOLOGY: This paper aims to evaluate the effect of different surface treatments on surface topography, wettability, and shear bond strength of resin cement to glass ceramic. For SBS test, 32 blocks (7x7x2 mm) of lithium disilicate were obtained and randomly divided into eight groups (four blocks per group) according to each surface treatment (HF 20 s, 60 s, 120 s + silanization/S or Scotch Bond Universal/ SBU) and the Monobond Etch & Prime - MEP application followed or not by SBU. On each treated surface ceramic block, up to four dual-curing resin cement cylinders were prepared and light-cured for 40s (N=120/n=15). The specimens were thermocycled (10,000 cycles, 5-55°C, 30 s) and the SBS test (50KgF, 0.5 mm/min) was performed. Furthermore, failure analysis, wettability, AFM, and SEM were carried out. SBS data (MPa) were analyzed using Student's t-test, two-way ANOVA, Tukey's test (5%) and Weibull's analysis. RESULTS: For HF experimental groups, two-way ANOVA presented the factors "etching time" and "bonding agent" as significant (p<0.05). After silane application, the HF groups presented similar bond strength. SBU application compromised the SBS, except for 120s etching time (HF120sS: 23.39ᵃ±6.48 MPa; HF120sSBU: 18.76ᵃ±8.81MPa). For MEP groups, SBU application did not significantly affect the results (p=0.41). The MEP group presented the highest Weibull modulus (4.08A) and they were statistically different exclusively from the HF20sSBU (0.58B). CONCLUSION: The HF 20s, 60s, 120 s followed by silane, promoted similar resin-bond strength to ceramic and the SBU application after HF or MEP did not increase the SBS.

Effect of different surface treatments and multimode adhesive application on the Weibull characteristics, wettability, surface topography and adhesion to CAD/CAM lithium disilicate ceramic

Abstract This paper aims to evaluate the effect of different surface treatments on surface topography, wettability, and shear bond strength of resin cement to glass ceramic. Methodology: For SBS test, 32 blocks (7x7x2 mm) of lithium disilicate were obtained and randomly divided into eight groups (four blocks per group) according to each surface treatment (HF 20 s, 60 s, 120 s + silanization/S or Scotch Bond Universal/ SBU) and the Monobond Etch & Prime - MEP application followed or not by SBU. On each treated surface ceramic block, up to four dual-curing resin cement cylinders were prepared and light-cured for 40s (N=120/n=15). The specimens were thermocycled (10,000 cycles, 5-55°C, 30 s) and the SBS test (50KgF, 0.5 mm/min) was performed. Furthermore, failure analysis, wettability, AFM, and SEM were carried out. SBS data (MPa) were analyzed using Student's t-test, two-way ANOVA, Tukey's test (5%) and Weibull's analysis. Results: For HF experimental groups, two-way ANOVA presented the factors "etching time" and "bonding agent" as significant (p<0.05). After silane application, the HF groups presented similar bond strength. SBU application compromised the SBS, except for 120s etching time (HF120sS: 23.39ᵃ±6.48 MPa; HF120sSBU: 18.76ᵃ±8.81MPa). For MEP groups, SBU application did not significantly affect the results (p=0.41). The MEP group presented the highest Weibull modulus (4.08A) and they were statistically different exclusively from the HF20sSBU (0.58B). Conclusion: The HF 20s, 60s, 120 s followed by silane, promoted similar resin-bond strength to ceramic and the SBU application after HF or MEP did not increase the SBS.