Mid-term Results of Revision Total Hip Arthroplasty Using Delta Ceramic-on-Ceramic Bearing

Young-Kyun Lee,Yong-Chan Ha,Samuel Jaeyoon Won,Jin-Hak Kim,Jung-Wee Park,Kyung-Hoi Koo 대한정형외과학회 2023 Clinics in Orthopedic Surgery Vol.15 No.1

Background: Delta ceramic-on-ceramic (CoC) articulation affords excellent outcomes in primary total hip arthroplasty (THA). However, the safety and reliability of this bearing in revision THA need more evidence. This study aimed to report complications, radiological changes, clinical results, and survivorship of revision THA using Delta CoC articulation at minimum 5-year follow-up. Methods: We reviewed 118 revision THAs (113 patients: 68 men and 45 women) performed with use of Delta CoC bearing. Their mean age was 58.7 years (range, 30–90 years) and their mean body mass index was 24.6 kg/m2 (range, 15.2–32.5 kg/m2). These patients were followed up for 5–12 years (mean, 7.2 years). We evaluated squeak, grinding sensation, ceramic fracture, dislocation, periprosthetic joint infection (PJI), periprosthetic fracture, prosthetic loosening, ceramic wear, osteolysis, modified Harris hip score (mHHS), and survivorship with any reoperation after the revision as the endpoint. Results: Two patients (1.7%) had grinding sensation, but no patient had ceramic fracture. Reoperations were necessary in 9 hips (7.6%) due to PJIs in 2, stem loosening in 2, cup loosening in 2, recurrent dislocation in 2, and periprosthetic fracture in 1. No hip had measurable wear or osteolysis. The average mHHS improved from 53.3 points before the revision to 82.3 points at the final follow-up. Survivorship was 91.6% (95% confidence interval, 86.3%–96.9%) at 12 years. Conclusions: The Delta ceramic bearing appeared a reliable option for revision THA, showing encouraging mid-term results with acceptable survivorship and a low complication rate.

$YBaCo_2O_{5+{\delta}}$ 세라믹 분리막의 산소투과 특성

표대웅,김종표,박정훈,Pyo, Dae-Woong,Kim, Jong-Pyo,Park, Jung-Hoon 한국막학회 2012 멤브레인 Vol.22 No.2

$YBaCo_2O_{5+{\delta}}$조성의 산화물을 고상반응법을 이용하여 합성하였으며, 합성된 분말은 압축 성형 후 $1,180^{\circ}C$에서 소결하여 치밀한 분리막을 제조하였다. $YBaCo_2O_{5+{\delta}}$ 분리막은 X-선 회절분석기(XRD)와 전자 주사 현미경(SEM)을 이용하여 분석하였다. XRD 분석결과 $1,150^{\circ}C$ 이상에서 다른 불순물 없이 이중층 페롭스카이트 구조가 얻어졌다. 산소투과량은 분리막 양면에 산소분압 차이에 따라 $750{\sim}950^{\circ}C$ 온도범위에서 측정하였다. 산소투과량은 온도와 산소분압이 증가할수록 증가하였고, 두께 1.0 mm의 $YBaCo_2O_{5+{\delta}}$ 분리막은 $950^{\circ}C$, $PO_2$ = 0.42 atm에서 약 0.15 mL/$cm^2{\cdot}min$의 최대 투과량을 보였다. 산소투과에 대한 활성화 에너지는 산소 분압이 감소할수록 감소하였고 $PO_2$ = 0.21 atm의 조건에서 76.0 kJ/mol이었다. $YBaCo_2O_{5+{\delta}}$ oxide was synthesized by solid state reaction and a typical dense membrane has been prepared using as-prepared powder by unilateral pressing and sintering at $1,180^{\circ}C$. The $YBaCo_2O_{5+{\delta}}$ membraneswas analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). XRD analysis showed the double layered perovskite structure was observed over $1,150^{\circ}C$ without impurities. Oxygen permeation was measured in the temperature range from 750 to $950^{\circ}C$ according to oxygen partial pressure difference between feed and permeation side. The oxygen permeation flux increased with increasing temperature and oxygen partial pressure and the maximum oxygen flux of $YBaCo_2O_{5+{\delta}}$ membrane with 1.0 mm thickness was about 0.15 mL/$cm^2{\cdot}min$ at $950^{\circ}C$ and $PO_2$ = 0.42 atm. The activation energy for oxygen permeation decreased with decreasing oxygen partial pressure to be 76.0 kJ/mol at the condition of $PO_2$ = 0.21 atm.

$PrBa_{0.9}Sr_{0.1}Co_2O_{5+{\delta}}$ 세라믹 분리막의 제조 및 산소투과 특성

표대웅,김종표,손수환,박정훈,Pyo, Dae-Woong,Kim, Jong-Pyo,Son, Su-Hwan,Park, Jung-Hoon 한국막학회 2011 멤브레인 Vol.21 No.4

$PrBa_{0.9}Sr_{0.1}Co_2O_{5+{\delta}}$ 조성의 산화물을 고상반응법을 이용하여 합성하였다. 합성된 분말은 압축 성형 후 $1,250^{\circ}C$에서 소결하여 치밀한 세라믹 분리막을 제조하였다. 제조된 $PrBa_{0.9}Sr_{0.1}Co_2O_{5+{\delta}}$분리막은 XRD분석 결과 이중 페롭스카이트 (double perovskite)구조를 보였다. 밀봉재료로는 pyrex ring을 사용하여 가스누출 실험 및 산소투과 분석을 하였다. 산소투과량 분석은 $850{\sim}950^{\circ}C$범위에서 측정되었다. 산소투과실험 결과, 투과량은 온도증가에 따라 0.15에서 $0.32mL/cm^2{\cdot}min$로 증가하였다. $PrBa_{0.9}Sr_{0.1}Co_2O_{5+{\delta}}$ oxide was synthesized by soild state reaction method. Dense ceramic membrane was prepared using as-prepared powder by pressing and sintering at $1250^{\circ}C$. XRD result of membrane showed double perovskite structure. Leakage and oxygen permeation test were conducted on the membrane sealed by pyrex ring as a sealing material. Oxygen permeation was measured in the temperature range from 850 to $950^{\circ}C$. The oxygen flux of $PrBa_{0.9}Sr_{0.1}Co_2O_{5+{\delta}}$ membrane was increased with the temperature from 0.15 to $0.32mL/cm^2{\cdot}min$.

포스트의 종류에 따른 Empress 2 도재관의 색상에 관한 비교연구

이영수,유동엽,Lee Young-Soo,Yoo Dong-Yeob 대한치과보철학회 2001 대한치과보철학회지 Vol.39 No.2

Development of new ceramics and esthetic needs of patients increase the use of all ceramic restorations. Fractured teeth often need metal post and core as foundation for final restoration. When all ceramic restorations are planned, metal post and core may lead to compromised esthetics because of opacity and gray color of metal post and core. Many techniques have been proposed to solve this problem such as application of an opaque porcelain to the metal core or all ceramic post and core. This study was performed to evaluate effect on color of Empress 2 crown according to various post systems. Color was evaluated by the CIE $L^*a^*b^*$ systems and measured by spectrophotometer (Model CM-3500, Minolta, Japan). Specimens were divided into 4 groups as follows Group 1 : gold cast post specimen + Empress 2 crown specimen Group 2 : application of an opaque porcelain to gold cast post specimen + Empress 2 crown specimen Group 3 : cosmopost specimen + Empress 2 crown specimen Group 4 : In-ceram post specimen + Empress 2 crown specimen. The results obtained as follows, 1. $L^*$ Values showed that group 2, 3, 4 were higher than group 1 with significant difference and group 2, 3, 4 were not significantly different. 2. $a^*$ Values and $b^*$ values also showed that group 2. 3, 4 were higher than group 1 with significant difference and group 2, 3, 4 were not significantly different. 3. ${\Delta}E^* ab$ Values showed that ${\Delta}E^* ab$ 3 was the highest value and ${\Delta}E^* ab$ 5 was the lowest value.

Hydrogen Permeance of Ce_1-xY_xO_2-_δ Membranes According to Yttrium Content

Song, Da-Heoi,Jung, Mie-Won The Korean Ceramic Society 2013 한국세라믹학회지 Vol.50 No.6

Porous ceramic membranes consisting of $Ce_{1-x}Y_xO_{2-{\delta}}$ were developed for hydrogen permeation tests. Various amounts (x = 0, 0.05, 0.1, 0.2) of yttrium were doped to ceria to study the effect of yttrium doping on ceria membranes on various properties, including hydrogen permeability. $Ce_{1-x}Y_xO_{2-{\delta}}$ powder was synthesized by the sol-gel method. These membranes were fabricated by pressing and sintering at $1300^{\circ}C$ for 6 h. As the amount of yttrium increased, the grain size of the membrane decreased. Hydrogen permeability was improved as the yttrium content increased. Selective permeability of hydrogen compared to CO is explained by electric conductivity. As the temperature rose, both the hydrogen perm-selectivity and electric conductivity on $Ce_{0.8}Y_{0.2}O_{1.9}$ improved.

저온소결 8/65/35 PLZT 세라믹의 전기열량 효과

최승훈,라철민,류주현,Choi, Seung-Hun,Ra, Cheol-Min,Yooa, Ju-Hyun 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.10

In this study, in order to develop the composition ceramics with the excellent electrocaloric properties, 8/65/35 PLZT ceramics were fabricated by the conventional solid-state method with the addition of $Bi_2O_3$, CuO, $Li_2CO_3$ and the variation of sintering temperature from $930^{\circ}C$ to $990^{\circ}C$. The XRD pattern of all specimens indicated general perovskite structure and the rhombohedral phase were observed. Curie temperature ($T_c$) of all specimens was observed in the vicinity of about $190^{\circ}C$. Density, coercive field and remnant polarization of the specimen sintered at $950^{\circ}C$ was $7.55g/cm^3$, 8.895 kV/cm, $11.22{\mu}C/cm^2$, respectively. EC effect of PLZT ceramics was measured by indirect method and the temperature change ${\Delta}T$ due to the electrocaloric effect was calculated by Maxwell's relations. ${\Delta}T$ of ceramic sintered at $950^{\circ}C$ was $0.21^{\circ}C$ under application of 40 kV/cm at $190^{\circ}C$.

Zn-B-O 글라스 첨가에 의한 Ca[(Li_1/3Nb_2/3)_0.2Ti_0.8]O_3-δ 세라믹스의 마이크로파 유전특성

인치승,김시연,여동훈,신효순,남산,In, Chi-Seung,Kim, Shi Yeon,Yeo, Dong-Hun,Shin, Hyo-Soon,Nahm, Sahn 한국전기전자재료학회 2016 전기전자재료학회논문지 Vol.29 No.12

With trend of the miniaturization and the high-functionalizing of mobile communication system, low-loss microwave dielectric materials are widely used for high frequency communication components. These dielectric materials should be co-sintered with highly electric-conducting metal such as silver or copper for high-frequency and thick film process application. Sintering temperature of $Ca(Li_{1/3}Nd_{2/3})_{0.2}Ti_{0.8}]O_{3-{\delta}}$, which has excellent dielectric properties such as ${\varepsilon}_r$ above 40, quality factor ($Q{\cdot}f_0$) above 16,000 GHz, and TCF (temperature coefficient of resonant frequency) of $-20{\sim}-10ppm/^{\circ}C$, is reported as high as $1,175^{\circ}C$, so it could not be co-sintered with silver or copper. Therefore in this study, low-temperature melting glasses of Zn-B-O and Zn-B-Si-O systems were added to $Ca[(Li_{1/3}Nb_{2/3})_{0.8}Ti_{0.2}]O_{3-{\delta}}$ to lower its sintering temperature under $900^{\circ}C$ without losing excellency of dielectric properties. With 15 weight % of Zn-B-Si-O glass and sintered at $875^{\circ}C$, specimen showed density of $4.11g/cm^3$, ${\varepsilon}_r$ of 40.1, $Q{\cdot}f_0$ of 4,869 GHz, and TCF of $-5.9ppm/^{\circ}C$. With 15 weight % of Zn-B-O glass and sintered at $875^{\circ}C$, specimen showed density of $4.14g/cm^3$, ${\varepsilon}_r$ of 40.4, $Q{\cdot}f_0$ of 7,059 GHz, and TCF of $-0.92ppm/^{\circ}C$.