• The Journal of Advanced Prosthodontics
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• 제3권4호
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• pp.221-228
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• 2011

PURPOSE. Veneering porcelain might be delaminated from underlying zirconia-based ceramics. The aim of this study was the evaluation of the effect of different surface treatments and type of zirconia (white or colored) on shear bond strength (SBS) of zirconia core and its veneering porcelain. MATERIALS AND METHODS. Eighty zirconia disks (40 white and 40 colored; 10 mm in diameter and 4 mm thick) were treated with three different mechanical surface conditioning methods (Sandblasting with $110{\mu}m$ $Al_2O_3$ particle, grinding, sandblasting and liner application). One group had received no treatment. These disks were veneered with 3 mm thick and 5 mm diameter Cercon Ceram Kiss porcelain and SBS test was conducted (cross-head speed = 1 mm/min). Two and one way ANOVA, Tukey's HSD Past hoc, and T- test were selected to analyzed the data (${\alpha}=0.05$). RESULTS. In this study, the factor of different types of zirconia ceramics (P=.462) had no significant effect on SBS, but the factors of different surface modification techniques (P=.005) and interaction effect (P=.018) had a significant effect on SBS. Within colored zirconia group, there were no significant differences in mean SBS among the four surface treatment subgroups (P=0.183). Within white zirconia group, "Ground group" exhibited a significantly lower SBS value than "as milled" or control (P=0.001) and liner (P=.05) groups. CONCLUSION. Type of zirconia did not have any effect on bond strength between zirconia core and veneer ceramic. Surface treatment had different effects on the SBS of the different zirconia types and grinding dramatically decreased the SBS of white zirconia- porcelain.

• 대한치과기공학회지
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• 제36권2호
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• pp.83-89
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• 2014

Purpose: This study is to evaluate the effect of modeling liquid on the shear-bond strength between zirconia core and veneering ceramic. Methods: Disk-shaped (diameter: 12.0mm; height: 3.0mm) zirconia were randomly divided into six groups according to the surface conditioning method and whether modeling liquid is used or not to be applied (N=60, n=10 per group): group 1-control group with distilled water(ZD); group 2-control group with modeling liquid(ZM); group 3-airborne particle abrasion with $110-{\mu}m$ $Al_2O_3$(AD) with distilled water; group 4-airborne particle abrasion with $110-{\mu}m$ $Al_2O_3$ with modeling liquid(AM); group 5-liner with distilled water(LD); group $6{\pounds}{\neq}liner$ with modeling liquid(LM). Contact angles were determined by the sessile drop method at room temperature using a contact angle measurement apparatus. The specimens were prepared using dentin veneering ceramics, veneered, 3mm high and 2.8mm in diameter, over the cores. The shear bond strength test was performed in a Shear bond test machine. Load was applied at a cross-head speed of 0.50mm/min until failure. The fractured zirconia surfaces were evaluated by using stereomicroscope (${\times}30$). Collected data were analyzed using SPSS(Statistical Package for Social Sciences) Win 12.0 statistics program. Results: ZD showed the highest contact angle($50.6{\pm}5.4^{\circ}$) and LD showed the lowest value($6.7{\pm}1.3^{\circ}$). Control groups and zirconia liner groups were significantly higher contact angle than liner groups(p<0.05). LD was the highest shear bond strength($43.9{\pm}3.8MPa$) and ZD was the lowest shear bond strength($24.8{\pm}4.9MPa$). Shear bond strengths of control groups and contact angle of liner groups were not significantly different((p>0.05). Liner groups presented adhesive failures. The others groups showed cohesive and adhesive failures. Conclusion: Modeling liquid groups showed lower contact angles and lower shear bond strength compared to those of distilled water groups.

• 대한치과기공학회지
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• 제37권3호
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• pp.121-127
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• 2015

Purpose: This study was intended to investigate the effect of applying liner for chemical bonding and physical surface roughness created on zirconia by using a sandpaper before sintering on the bond strength between the two materials. Methods: Zirconia blocks were cut using a low-speed cutter. Plate-shaped specimen($6mm{\times}6mm{\times}3mm$) was fabricated by sintering after giving surface roughness according to four kinds of sandpapers. Depending on whether or not to use liner, 60 specimens were divided into two groups ZN(non-liner), ZL(liner), and the two groups were subdivided into four groups respectively in accordance with sandpaper used, totaling eight groups (n=10). The surface roughness (Ra) values and shapes before sintering were observed, and shear bond strength after pressing ceramic plasticity was measured with a universal testing machine. For a test of the significance, a one-way ANOVA was performed, and Tukey's multiple comparison test was conducted. Results: The observation of the surface roughness was SB04($2.22{\pm}1.16{\mu}m$), SB08($2.98{\pm}0.33{\mu}m$), SB12($2.44{\pm}1.32{\mu}m$), SB20($2.34{\pm}0.59{\mu}m$) and SA04($2.34{\pm}0.67{\mu}m$), SA08($1.28{\pm}0.90{\mu}m$), SA12($2.03{\pm}1.60{\mu}m$), SA20($2.19{\pm}1.73{\mu}m$). In the case of ZN Group, the shear bond strength was ZN04($23.26{\pm}3.83MPa$), ZN08($21.76{\pm}2.33MPa$), ZN12($20.49{\pm}3.01MPa$), ZN20($24.98{\pm}4.22MPa$)(p<0.05). As for ZL Group, the shear bond strength was ZL04($25.09{\pm}5.67MPa$), ZL08($22.98{\pm}2.26MPa$), ZL12($21.54{\pm}5.70MPa$), ZL20($23.98{\pm}3.23MPa$)(p<0.05). Conclusion: The research results showed that the bond strength of Zirconia core and Pressing ceramic was further improved by physical surface treatment before sintering, rather than by chemical bonding through liner surface treatment.

• 한국산학기술학회논문지
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• 제15권7호
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• pp.4329-4335
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• 2014

본 연구의 목적은 금속 도재관과 지르코니아 도재관 보철물의 하부 구조물인 금속과 상부 도재의 결합강도 (금속군), 하부 구조물인 지르코니아와 상부 도재의 전단결합강도 (지르코니아군)를 결정함에 있어서 각각 하부 구조물인 금속과 지르코니아의 표면 처리를 다르게 하였을 때, 전단결합강도에 미치는 영향을 평가하고자 한다. 금속군에서는 금속 표면에 각각 아무 처리를 하지 않은 집단(NM), 모래분사를 실시한 집단(SM), 불투명 도재를 도포한 집단(OM), 모래분사와 함께 불투명 도재를 도포한 집단(SOM) 총 4집단으로 나누어 실시하였고, 지르코니아군에서는 아무 처리를 하지 않은 집단(NZ), 표면에 모래 분사를 실시한 집단(SZ), 지르코니아 표면에 이장재(지르라이너)를 처리한 집단(LZ), 모래분사와 이장재 처리를 함께한 집단(SLZ) 총 4집단으로 시편을 제작하였다. 금속군과 지르코니아군 각각의 4집단의 표면 처리에 따른 전단결합강도에 영향이 있는지 알아보기 위하여 SPSS를 사용하여 일원배치 분산분석을 시행하였다. 금속 도재관의 경우 하부 구조물인 금속 표면에 모래분사를 한 후 불투명 도재를 도포하는 것이 가장 권장되며, 지르코니아 도재관의 경우 하부 구조물인 지르코니아 표면에 모래분사를 한 후 지르라이너를 도포하는 것이 권장된다.

• The Journal of Advanced Prosthodontics
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• 제8권6호
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• pp.479-488
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• 2016

PURPOSE. The aim of this study was to test the modulus of elasticity (E) across the interfaces of yttria stabilized zirconia (YTZP) / veneer multilayers using nanoindentation. MATERIALS AND METHODS. YTZP core material (KaVo-Everest, Germany) specimens were either coated with a liner (IPS e.max ZirLiner, Ivoclar-Vivadent) (Type-1) or left as-sintered (Type-2) and subsequently veneered with a pressable glass-ceramic (IPS e.max ZirPress, Ivoclar-Vivadent). A $5{\mu}m$ (nominal tip diameter) spherical indenter was used with a UMIS CSIRO 2000 (ASI, Canberra, Australia) nanoindenter system to test E across the exposed and polished interfaces of both specimen types. The multiple point load - partial unload method was used for E determination. All materials used were characterized using Scanning Electron Microscopy (SEM) and X - ray powder diffraction (XRD). E mappings of the areas tested were produced from the nanoindentation data. RESULTS. A significantly (P<.05) lower E value between Type-1 and Type-2 specimens at a distance of $40{\mu}m$ in the veneer material was associated with the liner. XRD and SEM characterization of the zirconia sample showed a fine grained bulk tetragonal phase. IPS e-max ZirPress and IPS e-max ZirLiner materials were characterized as amorphous. CONCLUSION. The liner between the YTZP core and the heat pressed veneer may act as a weak link in this dental multilayer due to its significantly (P<.05) lower E. The present study has shown nanoindentation using spherical indentation and the multiple point load - partial unload method to be reliable predictors of E and useful evaluation tools for layered dental ceramic interfaces.

• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.485-493
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• 2013

PURPOSE. To evaluate the effects of surface treatments on shear bond strength (SBS) between microwave and conventionally sintered zirconia core/veneers. MATERIALS AND METHODS. 96 disc shaped Noritake Alliance zirconia specimens were fabricated using YenaDent CAM unit and were divided in 2 groups with respect to microwave or conventional methods (n=48/group). Surface roughness (Ra) evaluation was made with a profilometer on randomly selected microwave (n=10) and conventionally sintered (n=10) cores. Specimens were then assessed into 4 subgroups according to surface treatments applied (n=12/group). Groups for microwave (M) and conventionally (C) sintered core specimens were as follows; $M_C$,$C_C$: untreated (control group), $M_1,C_1:Al_2O_3$ sandblasting, $M_2,C_2$:liner, $M_3,C_3:Al_2O_3$ sandblasting followed by liner. Veneer ceramic was fired on zirconia cores and specimens were thermocycled (6000 cycles between $5^{\circ}-55^{\circ}C$). All specimens were subjected to SBS test using a universal testing machine at 0.5 mm/min, failure were evaluated under an optical microscope. Data were statistically analyzed using Shapiro Wilk, Levene, Post-hoc Tukey HSD and Student's t tests, Two-Way-Variance- Analysis and One-Way-Variance-Analysis (${\alpha}$=.05). RESULTS. Conventionally sintered specimens ($1.06{\pm}0.32{\mu}m$) showed rougher surfaces compared to microwave sintered ones ($0.76{\pm}0.32{\mu}m$)(P=.046), however, no correlation was found between SBS and surface roughness (r=-0.109, P=.658). The statistical comparison of the shear bond strengths of $C_3$ and $C_1$ group (P=.015); $C_C$ and $M_C$ group (P=.004) and $C_3$ and $M_3$ group presented statistically higher (P=.005) values. While adhesive failure was not seen in any of the groups, cohesive and combined patterns were seen in all groups. CONCLUSION. Based on the results of this in-vitro study, $Al_2O_{3-}$ sandblasting followed by liner application on conventionally sintered zirconia cores may be preferred to enhance bond strength.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2003년도 학술대회지
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• pp.91-94
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• 2003

Ceramic femoral heads in the total hip replacement have been developed to reduce the polyethylene liner wear. Alumina and zirconia (3Y-TZP) are using in clinical application worldwide and there are many good test reports. However, alumina has a risk of catastrophic failure, and zirconia has the low temperature degradation in spite of enhanced fracture toughness. Recently, novel zirconia/alumina composite having low temperature degradation-free character and high fracture tough . was developed and it leads the lower wear 3f polyethylene than alumina and zirconia. In the present study, in order to optimise the microstructure of low temperature degradation (LTD)-free zirconia/alumina composite for the best wear resistance of polyethylene, various compositions of (LTD)-free zirconia/alumina composites were fabricated, and the sliding wear of UHMWPE against these novel composites were examined and compared with that against alumina and zirconia ceramics used for total hip joint heads.

• 대한치과보철학회지
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• 제47권2호
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• pp.199-205
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• 2009

연구목적: 지르코니아 코어의 표면처리가 비니어링 세라믹과 전단결합강도에 미치는 영향을 알아보고자 한다. 연구 재료 및 방법: 지르코니아 블록(IPS e. max ZirCAD; Ivoclar vivadent, N=40, n=10, $10mm{\times}10mm{\times}3mm$)를 제조사의 지시에 따라 소성한 후 세척하였다. 대조군, 샌드블라스팅(4기압하 $50{\mu}m$ 알루미늄옥사이드) 처리군, 라이너(Zirliner; Ivoclar vivadent) 처리군, 샌드블라스팅과 라이너 처리군 네 개의 군으로 나누어 각 각 표면처리한 후 3 mm 두께로 세라믹(IPS e. max Ceram; Ivoclar vivadent)을 축조한다. 인스트론 만능시험기로 전단결합강도를 측정한 후, 일원변량 분산분석(One way ANOVA)과 $Scheff{\acute{e}}$검정법(P<.05)를 시행하였다. 결과: 지르코니아 코어와 세라믹 간 평균 전단결합강도는 샌드블라스팅과 라이너 동시 처리군에서 가장 높게 나타났으며, 지르코니아 코어에 샌드블라스팅과 라이너 단독 표면처리는 결합력에 통계적으로 유의한 차이를 보이지 않았으나(P>.05), 샌드블라스팅과 라이너 동시 표면처리는 두 재료 간 결합력에 통계적으로 유의한 차이를 보였다(P<.05). 결론: 지르코니아 코어에 샌드블라스팅과 라이너 동시 처리시 전단결합강도의 증가를 보였다.

• 대한치과보철학회지
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• 제56권4호
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• pp.269-277
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• 2018

목적: 본 연구는 글라스 용융침투 처리가 지르코니아와 초저온 소성 전장도재와의 전단결합강도에 미치는 영향을 평가하였다. 재료 및 방법: 표면처리 방법에 따라 대조군 (처리 안함), ZirLiner처리군 (ZL군), 글라스 용융침투처리군 (ZG군), 글라스 용융침투 후 Sandblasting 처리군 (ZGS군)으로 분류하였다 (n = 12). 모든 실험군은 초저온 소성 전장도재를 사용하여 지름 6 mm ${\times}$ 두께 3 mm가 되도록 축성하고 소성하였다. 지르코니아와 전장도재 사이의 결합강도는 만능시험기를 이용하여 측정하였고 지르코니아 시편의 결합계면, 도재파절 양상은 SEM과 EDX로 관찰하였다. 결과: 지르코니아 표면처리 방법에 따라 전장도재와의 결합강도가 ZirLiner군, 대조군, 글라스 용융침투군 순으로 나타났으나 통계학적으로 유의한 차이는 없었다 (P > .05). 글라스 용융침투 후 Sandblasting 처리군은 다른 모든 군에 비해 유의하게 낮은 전단결합강도를 보였다 (P < .05). 결론: 글라스 용융침투 지르코니아의 Sandblasting처리는 초저온 소성 전장도재와의 현저한 결합력 감소를 야기시키므로 사용이 제한되어야 할 것으로 사료된다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.355-361
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• 2004

Ceramic femoral heads in the total hip replacement have been developed to reduce the polyethylene liner wear, Alumina and zirconia (3Y-TZP) having the excellent tribological properties are coupled against acetabular cups of polyethylene and are used in clinical application worldwide. However, alumina has a risk of catastrophic failure, and zirconia has the low temperature degradation in spite of enhanced fracture toughness. Recently, novel zirconia/alumina composite is very attractive due to the low temperature degradation (LTD)-free character and high fracture toughness. In the present study, we focus on the wear of ceramic on ceramic, which are able to be used as femoral heads and acetabular cups. Therefore, LTD-free zirconia/alumina composites with three compositions are made in a form of disk and cylinder, and the wear of the composites is performed on pin-on-disk type wear tester. The wear is conducted with or without lubricant. All the composites fabricated with the different composition show the good wear resistance.