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Adhesion promotion of resin to zirconia by silicon nitride hydrolysis
d e n t a l m a t e r i a l s 3 0 S ( 2 0 1 4 ) e1–e180
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in the surface morphology of zirconia after various surface treatments. EDX analysis results showed that the highest silica content was obtained for 48 h immersion. Conclusion: A new method of surface treatment of zirconia was developed. The results showed that durable resin zirconia bonding could be achieved.
Adhesion promotion of resin to zirconia by silicon nitride hydrolysis C.Y.K. Lung, D.L.J.K.H. Tsoi, J.P. Matinlinna ∗ Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, PR China Purpose: To investigate the effect of surface treatment on zirconia by silicon nitride hydrolysis on resin zirconia bonding. Methods and materials: Yttria-stabilized zirconia samples (Upcera, Liaoning, China) were immersed in a 4 M sodium hydroxide solution and heated to 90 ◦ C. A 0.6 wt% silicon nitride dispersion was prepared by adding silicon nitride nanopowder (US Research Nanomaterials, Houston, USA) into the solution. The zirconia samples were immersed into the dispersion for 6, 24, and 48 h. After the coating process, the zirconia samples underwent a thermal treatment at 1400 ◦ C for 2 h. Another control test group was surface treated by sandblasting using a 100 m silica-coated alumina powder (3M ESPE, Seezle, Germany). Resin stubs were bonded to silicacoated zirconia samples. Four test groups (n = 8) were prepared. Each test group was divided into three subgroups and subjected to test in three storage conditions: dry, 30 d water aging at 37 ◦ C, and thermo-cycled for 6000 cycles between 5.0 ± 0.5 ◦ C and 55.0 ± 0.5 ◦ C. Shear bond strength tests for all test groups were performed on a universal testing machine (ElectroPulsTM E3000, Instron, USA). Data were analyzed by two-way ANOVA and Tukey HSD (p < 0.05). The surface roughness was measured by an electro-mechanical profilometer (Surtronic 3+, Taylor Hobson, Leicester, England). Five readings were taken at different regions for each sample surface. The surface morphology and composition of silica-coated zirconia samples were examined by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Results: Table 1 showed the results of mean shear bond strengths for all test groups. Two-way ANOVA analysis showed that there was a significant difference in mean shear bond strengths under various surface treatments (p < 0.001). There was no significant difference in storage conditions (p > 0.05). The average surface roughness, Ra (m), measured were: polished (0.3 ± 0.08), sandblasted (0.8 ± 0.13), silica-coated (6 h): (0.4 ± 0.07), silica-coated (24 h): (0.5 ± 0.07), silica-coated (48 h) (0.5 ± 0.1). The Ra of sandblasted zirconia surface was significantly higher than the other test groups of zirconia surfaces (p < 0.001). SEM micrographs showed that there were changes
Keywords: Zirconia; Surface treatment; Silicon nitride hydrolysis http://dx.doi.org/10.1016/j.dental.2014.08.030 30 The effect of clinical finish on the zirconia roughness surface J.R.C. Queiroz 1,∗ , M.B. Bandeira 1 , I.M.S. Queiroz 1 , B. Henriques 2 , A.E. Martinelli 2 , S.A. Souza 1 , A.F. Neto 1 , B.M.F. Pereira 1 , A.H.M. Dias 1 , A.C. Freitas Jr. 1 1
UNP – Laureate University, Brazil Universidade Federal Do Rio Grande Do Norte, Brazil
2
Purpose: Simulating an occlusal adjustment, the study evaluated the effect of the different clinical finish kits on the zirconia roughness surface. Methods and materials: Zirconia blocks (Zirkonzahn, Italy) were polished, sintered and divided among 3 groups according surface treatment (n = 10): GC, no treatment; GK, milled using a zirconia bur (CVDentus, Brazil) and finished using Kenda kit (Liechtenstein); GD, milled using a zirconia bur (CVDentus, Brazil) and finished with Diacera EVE kit (Germany). Scanning electron microscopy, 3D profilometry, atomic force microscopy (roughness analysis using Ra and Rz parameters) and X-ray diffraction were performed. The roughness results were analyzed using 1-way ANOVA and Tukey’s test (p = 0.05). Results: 1-way ANOVA revealed that all roughness parameters were significantly affected after surface treatments (p < 0.0005). Tukey’s test determined some difference between means. GD presented the lowest roughness results (Ra = 0.1 m; Rz = 1.8 m) and GC the highest values (Ra = 0.32 m; Rz = 3.5 m). The finished surface reduced the monoclinic phase thickness on the zirconia surface compared with milled surface. Conclusion: Both finish kits were able to produce a smooth surface after milled zirconia surface. However, the choice of kit can influence the roughness surface pattern and monoclinic phase concentration on the surface after milling. Keywords: Zirconia; Finish; Roughness
Table 1 Test group
Sandblasting 6 h immersion + 2 h 1400 ◦ C treatment 24 h immersion + 2 h 1400 ◦ C treatment 48 h immersion + 2 h 1400 ◦ C treatment
e15
Storage conditions Dry
Water storage (30 d)
Thermocycling
15.9 ± 1.2 7.1 ± 1.3
14.5 ± 2.4 9.0 ± 2.2
12.6 ± 2.2 9.5 ± 2.2
11.5 ± 1.8
6.0 ± 1.2
9.8 ± 2.0
11.0 ± 1.7
12.2 ± 1.2
9.6 ± 2.8
http://dx.doi.org/10.1016/j.dental.2014.08.031
29
in the surface morphology of zirconia after various surface treatments. EDX analysis results showed that the highest silica content was obtained for 48 h immersion. Conclusion: A new method of surface treatment of zirconia was developed. The results showed that durable resin zirconia bonding could be achieved.
Adhesion promotion of resin to zirconia by silicon nitride hydrolysis C.Y.K. Lung, D.L.J.K.H. Tsoi, J.P. Matinlinna ∗ Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, PR China Purpose: To investigate the effect of surface treatment on zirconia by silicon nitride hydrolysis on resin zirconia bonding. Methods and materials: Yttria-stabilized zirconia samples (Upcera, Liaoning, China) were immersed in a 4 M sodium hydroxide solution and heated to 90 ◦ C. A 0.6 wt% silicon nitride dispersion was prepared by adding silicon nitride nanopowder (US Research Nanomaterials, Houston, USA) into the solution. The zirconia samples were immersed into the dispersion for 6, 24, and 48 h. After the coating process, the zirconia samples underwent a thermal treatment at 1400 ◦ C for 2 h. Another control test group was surface treated by sandblasting using a 100 m silica-coated alumina powder (3M ESPE, Seezle, Germany). Resin stubs were bonded to silicacoated zirconia samples. Four test groups (n = 8) were prepared. Each test group was divided into three subgroups and subjected to test in three storage conditions: dry, 30 d water aging at 37 ◦ C, and thermo-cycled for 6000 cycles between 5.0 ± 0.5 ◦ C and 55.0 ± 0.5 ◦ C. Shear bond strength tests for all test groups were performed on a universal testing machine (ElectroPulsTM E3000, Instron, USA). Data were analyzed by two-way ANOVA and Tukey HSD (p < 0.05). The surface roughness was measured by an electro-mechanical profilometer (Surtronic 3+, Taylor Hobson, Leicester, England). Five readings were taken at different regions for each sample surface. The surface morphology and composition of silica-coated zirconia samples were examined by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Results: Table 1 showed the results of mean shear bond strengths for all test groups. Two-way ANOVA analysis showed that there was a significant difference in mean shear bond strengths under various surface treatments (p < 0.001). There was no significant difference in storage conditions (p > 0.05). The average surface roughness, Ra (m), measured were: polished (0.3 ± 0.08), sandblasted (0.8 ± 0.13), silica-coated (6 h): (0.4 ± 0.07), silica-coated (24 h): (0.5 ± 0.07), silica-coated (48 h) (0.5 ± 0.1). The Ra of sandblasted zirconia surface was significantly higher than the other test groups of zirconia surfaces (p < 0.001). SEM micrographs showed that there were changes
Keywords: Zirconia; Surface treatment; Silicon nitride hydrolysis http://dx.doi.org/10.1016/j.dental.2014.08.030 30 The effect of clinical finish on the zirconia roughness surface J.R.C. Queiroz 1,∗ , M.B. Bandeira 1 , I.M.S. Queiroz 1 , B. Henriques 2 , A.E. Martinelli 2 , S.A. Souza 1 , A.F. Neto 1 , B.M.F. Pereira 1 , A.H.M. Dias 1 , A.C. Freitas Jr. 1 1
UNP – Laureate University, Brazil Universidade Federal Do Rio Grande Do Norte, Brazil
2
Purpose: Simulating an occlusal adjustment, the study evaluated the effect of the different clinical finish kits on the zirconia roughness surface. Methods and materials: Zirconia blocks (Zirkonzahn, Italy) were polished, sintered and divided among 3 groups according surface treatment (n = 10): GC, no treatment; GK, milled using a zirconia bur (CVDentus, Brazil) and finished using Kenda kit (Liechtenstein); GD, milled using a zirconia bur (CVDentus, Brazil) and finished with Diacera EVE kit (Germany). Scanning electron microscopy, 3D profilometry, atomic force microscopy (roughness analysis using Ra and Rz parameters) and X-ray diffraction were performed. The roughness results were analyzed using 1-way ANOVA and Tukey’s test (p = 0.05). Results: 1-way ANOVA revealed that all roughness parameters were significantly affected after surface treatments (p < 0.0005). Tukey’s test determined some difference between means. GD presented the lowest roughness results (Ra = 0.1 m; Rz = 1.8 m) and GC the highest values (Ra = 0.32 m; Rz = 3.5 m). The finished surface reduced the monoclinic phase thickness on the zirconia surface compared with milled surface. Conclusion: Both finish kits were able to produce a smooth surface after milled zirconia surface. However, the choice of kit can influence the roughness surface pattern and monoclinic phase concentration on the surface after milling. Keywords: Zirconia; Finish; Roughness
Table 1 Test group
Sandblasting 6 h immersion + 2 h 1400 ◦ C treatment 24 h immersion + 2 h 1400 ◦ C treatment 48 h immersion + 2 h 1400 ◦ C treatment
e15
Storage conditions Dry
Water storage (30 d)
Thermocycling
15.9 ± 1.2 7.1 ± 1.3
14.5 ± 2.4 9.0 ± 2.2
12.6 ± 2.2 9.5 ± 2.2
11.5 ± 1.8
6.0 ± 1.2
9.8 ± 2.0
11.0 ± 1.7
12.2 ± 1.2
9.6 ± 2.8
http://dx.doi.org/10.1016/j.dental.2014.08.031