ProFile^®, ProTaper^TM 및 K^3TM Ni-Ti 파일의 과기구 조작이 치근단공 변위에 미치는 영향

양현,양인석,황윤찬,황인남,윤숙자,김원재,오원만,Yang, Hyun,Yang, In-Seok,Hwang, Yun-Chann,Hwang, In-Man,Yoon, Suk-Ja,Kim, Won-Jae,Oh, Won-Mann 대한치과보존학회 2007 Restorative Dentistry & Endodontics Vol.32 No.2

This study was done to evaluate transportation of the apical foramen after 0.5 mm overinstrumentation by ProFile, ProTaper and $K^3$ in simulated resin root canal. Sixty simulated resin root canal with a curvature of J and S-shape were divided into two groups. Each group consisted of three subgroups with 10 blocks according to the instruments used: $ProFile^{(R)},\;ProTaper^{TM},\;and\;K^{3TM}$. Simulated resin root canal was prepared by ProFile, ProTaper and $K^3$ with 300 rpm by the crown-down preparation technique. Pre- and post-instrumentation apical foramen images were overlapped and recorded with Image-analyzing microscope 100X (Camcope, Sometech Inc, Korea). The amounts of difference in width and dimension on overlapped images were measured after reference points were determined by Image Analysis program ($Image-Pro^{(R)}$ Express, Media Cybernetic, USA). Data were analyzed using Kruskal-Wallis and Mann-Whitney U-test. The results suggest that ProFile showed significantly less canal transportation and maintained original apical foramen shape better than $K^3$ and ProTaper. 본 연구는 ProFile, ProTaper 및 $K^3$를 이용하여 과잉 기구 조작에 의해 근관 성형 시 근관의 만곡형태와 Ni-Ti 파일의 종류에 따라 치근단공이 어떻게 변위 되는지를 비교 분석하고자 시행되었다. 본 실험에서는 레진모형근관으로 J자와 S자의 근관 형태가 재현된 ENDO-TRAINING BLOC을 사용하였다 근관성형 기구로는 $ProFile^{(R)},\;ProTaper^{TM},\;K^{3TM}$를 사용하였다. 총 60개의 레진모형근관을 사용하였으며, 사용된 레진모형근관 및 Ni-Ti 파일의 종류에 따라 10개씩 6개의 군으로 나누어 근관성형을 시행하였다. 근관 성형 전 후 이미지를 Image-analyzing microscope 100X를 이용하여 얻고 Photoshop 7.0 프로그램을 이용하여 중첩하였다. 이미지 분석 프로그램을 이용하여 근관 성형 전 후 치근단공의 중심으로부터의 직경 변화량과 면적을 측정한 결과 만곡된 근관의 성형시 치근단공이 주로 만곡의 외측으로 변위됨을 나타내며 ProFile이 ProTaper나 $K^3$보다 통계적으로 유의성이 있게 작은 변화량을 나타내어 근관성형시 바람직한 기구임을 시사한다.

Surface chemical structure and doping characteristics of boron-doped Si nanowires fabricated by plasma doping

Oh, Seung-Hoon,Ma, Jin-Won,Bae, Jung Min,Kang, Yu-seon,Ahn, Jae-Pyung,Kang, Hang-Kyu,Chae, Jimin,Suh, Dongchan,Song, Woobin,Kim, Sunjung,Cho, Mann-Ho Elsevier 2017 APPLIED SURFACE SCIENCE - Vol.419 No.-

<P><B>Abstract</B></P> <P>We investigated the conduction characteristics of plasma-doped Si nanowires (NWs) after various rapid thermal annealing (RTA) times. The plasma doping (PD) process developed a highly-deposited B layer at the NW surface. RTA process controls electrical conductivity by mediating the dopant diffusion from the surface layer. The surface chemical and substitutional states of the B plasma-doped Si NWs were analyzed by x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. To elucidate the detailed structure of the NWs, we analyzed the change in the optical phonon mode caused by the incorporated B atoms. For this purpose, we examined Fano resonance by the investigation of the asymmetry, line-width, and phonon wavenumber in Raman spectra. The changes in symmetry level of the Raman peak, phonon lifetime, and internal strain were closely related to the number of electrically activated borons, which was drastically increased with RTA time. The change in electrical and optical characterizations related to the doping characteristics of the NWs was investigated using a 4-point probe and terahertz time-domain spectroscopy (THz–TDS). The resistivity of the NWs was 3000 times lower after the annealing process compared to that before the annealing process, which is well consistent with the optical conductivity data. The data provide the potential utility of PD in conformal doping for three-dimensional nanodevices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dopant activations of plasma-doped (PD-) Si NWs are investigated with RTA time. </LI> <LI> Chemical states and Fano factor of PD-Si NWs are changed with the dopant activation. </LI> <LI> Both electrical and optical conductivity of PD-Si NWs increase greatly and coherently. </LI> <LI> Carrier generation by PD process is more effective at 1D Si NW than 2D Si substrate. </LI> </UL> </P>

Biocompatibility of experimental mixture of mineral trioxide aggregate and glass ionomer cement

Oh, Min-Jae,Jeong, Yu-Na,Bae, In-Ho,Yang, So-Young,Park, Bum-Jun,Koh, Jeong-Tae,Hwang, Yun-Chan,Hwang, In-Nam,Oh, Won-Mann 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.5

Objectives: The purpose of the present in vitro study was to evaluate the biocompatibility of mineral trioxide aggregate (MTA) mixed with glass ionomer cement (GIC), and to compare it with that of MTA, GIC, IRM and SuperEBA. Materials and Methods: Experimental groups were divided into 3 groups such as 1 : 1, 2 : 1, and 1 : 2 groups depending on the mixing ratios of MTA powder and GIC powder. Instead of distilled water, GIC liquid was mixed with the powder. This study was carried out using MG-63 cells derived from human osteosarcoma. They were incubated for 1 day on the surfaces of disc samples and examined by scanning electron microscopy. To evaluate the cytotoxicity of test materials quantitatively, XTT assay was used. The cells were exposed to the extracts and incubated. Cell viability was recorded by measuring the optical density of each test well in reference to controls. Results: The SEM revealed that elongated, dense, and almost confluent cells were observed in the cultures of MTA mixed with GIC, MTA and GIC. On the contrary, cells on the surface of IRM or SuperEBA were round in shape. In XTT assay, cell viability of MTA mixed with GIC group was similar to that of MTA or GIC at all time points. IRM and SuperEBA showed significantly lower cell viability than other groups at all time points (p < 0.05). Conclusions: In this research MTA mixed with GIC showed similar cellular responses as MTA and GIC. It suggests that MTA mixed with GIC has good biocompatibility like MTA and GIC. 연구목적: 본 연구의 목적은 glass ionomer cement (GIC)와 혼합된 mineral trioxide aggregate (MTA)의 생체친화성을 평가하고 이것을 MTA, GIC, IRM, SuperEBA와 비교해보는 것이다. 연구 재료 및 방법: 재료의 세포독성을 평가하기 위해 MG-63세포를 이용해 주사전자 현미경 관찰과 XTT assay를 실시하였다. 결과: 주사전자 현미경 관찰에서는 GIC와 혼합한 MTA, MTA, GIC의 표면에서 세포질 돌기를 가진 많은 세포들이 밀집되고 융합된 형태로 관찰되었다. 반면 IRM과 SuperEBA에서는 세포들의 수가 적고 둥근 양상을 보여주었다. XTT assay에서는 GIC와 혼합한 MTA에서의 세포 활성도는 모든 시점에서 MTA 또는 GIC와 유사하였다. 반면 IRM과 SuperEBA에서는 모든 시점에서 세포활성도가 다른 그룹에 비해 유의하게 더 낮았다. 결론: 본 연구에서 GIC와 혼합된 MTA는 MTA, GIC와 유사한 세포 반응을 나타냈다. 이것은 GIC와 혼합된 MTA가 MTA, GIC와 마찬가지로 좋은 생체친화성을 가진 재료라는 것을 시사한다.

Efficacy of Balloon-Guiding Catheter for Mechanical Thrombectomy in Patients with Anterior Circulation Ischemic Stroke

Oh, Jae-Sang,Yoon, Seok-Mann,Shim, Jai-Joon,Doh, Jae-Won,Bae, Hack-Gun,Lee, Kyeong-Seok The Korean Neurosurgical Society 2017 Journal of Korean neurosurgical society Vol.60 No.2

Objective : To evaluate the efficacy of balloon guiding catheter (BGC) during thrombectomy in anterior circulation ischemic stroke. Methods : Sixty-two patients with acute anterior circulation ischemic stroke were treated with thrombectomy using a Solitaire stent from 2011 to 2016. Patients were divided into the BGC group (n=24, 39%) and the non-BGC group (n=38, 61%). The number of retrievals, procedure time, thrombolysis in cerebral infarction (TICI) grade, presence of distal emboli, and clinical outcomes at 3 months were evaluated. Results : Successful recanalization was more frequent in BGC than in non-BGC (83% vs. 66%, p=0.13). Distal emboli occurred less in BGC than in non-BGC (23.1% vs. 57.1%, p=0.02). Good clinical outcome was more frequent in BGC than in non-BGC (50% vs. 16%, p=0.03). The multivariate analysis showed that use of BGC was the only independent predictor of good clinical outcome (odds ratio, 5.19 : 95% confidence interval, 1.07-25.11). More patients in BGC were successfully recanalized in internal carotid artery (ICA) occlusion with small retrieval numbers (<3) than those in non-BGC (70% vs. 24%, p=0.005). In successfully recanalized ICA occlusion, distal emboli did not occur in BGC, whereas nine patients had distal emboli in non-BGC (0% vs. 75%, p=0.001) and good clinical outcome was superior in BGC than in non-BGC (55.6% vs. 8.3%, p=0.01). Conclusion : A BGC significantly reduces the number of retrievals and the occurrence of distal emboli, thereby resulting in better clinical outcomes in patients with anterior circulation ischemic stroke, particularly with ICA occlusion.

Which One Is Better to Reduce the Infection Rate, Early or Late Cranioplasty?

Oh, Jae-Sang,Lee, Kyeong-Seok,Shim, Jai-Joon,Yoon, Seok-Mann,Doh, Jae-Won,Bae, Hack-Gun The Korean Neurosurgical Society 2016 Journal of Korean neurosurgical society Vol.59 No.5

Objective : Decompressive craniectomy is an effective therapy to relieve high intracranial pressure after acute brain damage. However, the optimal timing for cranioplasty after decompression is still controversial. Many authors reported that early cranioplasty may contribute to improve the cerebral blood flow and brain metabolism. However, despite all the advantages, there always remains a concern that early cranioplasty may increase the chance of infection. The purpose of this retrospective study is to investigate whether the early cranioplasty increase the infection rate. We also evaluated the risk factors of infection following cranioplasty. Methods : We retrospectively examined the results of 131 patients who underwent cranioplasty in our institution between January 2008 and June 2015. We divided them into early (${\leq}90days$) and late (>90 days after craniectomy) groups. We examined the risk factors of infection after cranioplasty. We analyzed the infection rate between two groups. Results : There were more male patients (62%) than female (38%). The mean age was 49 years. Infection occurred in 17 patients (13%) after cranioplasty. The infection rate of early cranioplasty was lower than that of late cranioplasty (7% vs. 20%; p=0.02). Early cranioplasty, non-metal allograft materials, re-operation before cranioplasty and younger age were the significant factors in the infection rate after cranioplasty (p<0.05). Especially allograft was a significant risk factor of infection (odds ratio, 12.4; 95% confidence interval, 3.24-47.33; p<0.01). Younger age was also a significant risk factor of infection after cranioplasty by multivariable analysis (odds ratio, 0.96; 95% confidence interval, 0.96-0.99; p=0.02). Conclusion : Early cranioplasty did not increase the infection rate in this study. The use of non-metal allograft materials influenced a more important role in infection in cranioplasty. Actually, timing itself was not a significant risk factor in multivariate analysis. So the early cranioplasty may bring better outcomes in cognitive functions or wound without raising the infection rate.

근관충전 CEMENT의 세포독성 실험

오원만(Won Mann Oh) 대한치과의사협회 1991 대한치과의사협회지 Vol.29 No.4

신장이식 환자에서 수술후 2 개월 이내의 핍뇨분석

권오상(Oh Sang Kwon),권영주(Young Joo Kwon),이영기(Young Gee Lee),정길만(Gil Mann Jung),김난희(Nan Hee Kim),장미경(Mi Kyoung Jang),김용섭(Yong Sub Kim),구자룡(Ja Ryong Ku),차대룡(Dae Ryong Cha),조원용(Won Yong Cho),표희정(Heui Jung P 대한내과학회 1998 대한내과학회지 Vol.54 No.1

N/A Objective: Graft survival rate has been improved due to newly developed immunosuppressive agents, care of recipient and operative method. However, since many risk factors are still threatening the graft survival, many studies have been underway to identify such factors, one of which has been on delayed graft function(DGF). Extending the definition of DGF to oliguria within 2 months postoperative period(POP), we began this study in order to evaluate what effects oliguria within 2 months POP have on graft survival and what are the risk factors involved. Methods: 103 patients who have had renal transplantation performed were divided into two groups (oliguric group and non-oliguric group), based on the presence or absence of oliguria within 2 months POP. Risk factors such as the recipient factors(age, gender), donor factors(age, gender), operative factors (warm ischemia time, intraoperative urine volume), HLA typing, postoperative hypotension, postoperative hypovolemia were compared between the two groups and the impact of oliguria on graft outcome was also analysed. Results: 1) 14 were Oliguric patients and 89 were non-oliguric patients. 2) One-year graft survival rate was 40% in the oliguric group and 98% in the non-oliguric group (P<0.05). 3) As the result of analyzing the risk factors, non living related donor(living non-related donor and cadaver donor) were 7(50%) in the oliguric group and 16(18%) in the non-oliguric group(P<0.05). The mean intraoperative urine volume was 442ml in the oliguric group and 774ml in the non-oliguric group (P<0.05). The occurrence of postoperative hypotension were 5(36%) in the oliguric group and 1 (1%) in the non-oliguric group(P<0.05). Other risk factors such as the recipient factors, donor factors, warm ischemia time, HLA typing and postoperative hypovolemia were not significantly different between the two groups. Conclusion: Graft survival rate in the oliguric group was lower than in the non-oliguric group. The risk factors for oliguria were non living related donor, intraoperative urine volume lower than 500ml and postoperative hypotension. In conclusion, renal transplantation from non living related donor needs to be proceeded with caution; the maintenance of intraoperative urine volume and the prevention of postoperative hypotension are essential for better graft outcome.

PIN修復物의 維持力과 應力分散에 關한 力學的 및 光彈性學的 硏究

吳源萬(Won Mann Oh),柳善烈(Sun Youl Ryu) 대한치과의사협회 1988 대한치과의사협회지 Vol.26 No.10

The Effectiveness of Gelfoam Technique before Percutaneous Vertebroplasy: Is It Helpful for Prevention of Cement Leakage? A Prospective Randomized Control Study

Jae-Sang Oh,Jae-Won Doh,Jai-Joon Shim,Kyeong-Seok Lee,Seok-Mann Yoon,Hack-Gun Bae 대한척추신경외과학회 2016 Neurospine Vol.13 No.2

Objective: Preinjection gelfoam embolization during percutaneous vertebroplasty (PVP) has been thought alternative technique to prevent the leakage of bone cement. The goal of this study was to evaluate whether the gelfoam techniques are useful to reduce bone cement leakage. Methods: Total 100 PVPs of osteoporotic spine compression fractures were performed by 1 spine surgeon who experienced more than 500 PVP cases under prospective control study. Operation was done in T-L junction (T10-L2) fractures with bitranspedicular approach. Preinjection gelfoam PVP was done in the 50 levels. As control group, PVP without gelfoam was done in the 50 levels. We did not perform preoperative venography. We inserted normal saline-mixed gelfoam to the anterior third of vertebral body via PVP needle, and then 3mL of polymethylmetacrylate (PMMA) was injected. We prospectively evaluated the incidence and leakage pattern of PMMA by postoperative computed tomography. Results: Between gelfoam and control groups, there were 11 leaks (22%) versus 12 leaks (26%). The mean operation time was 7.00 minutes versus 6.30 minutes. In gelfoam group, there were 6 spinal canal leaks, 4 paravertebral venous leaks, and 1 soft tissue leaks. In control group, there were 4 spinal canal leaks, 8 paravertebral venous leaks, and 1 disc space leak. In spite of cement leakage, there was no symptomatic case in both groups. Statistically, gelfoam technique was not related to decrease the incidence of leakage (p=0.64). Conclusion: Our prospective study showed that it did not significantly decrease cement leakage when vertebroplasty is performed by experienced spine surgeon.

비등온 TGA에 의한 개질NR고무복합재료의 열분해 Kinetics에 관한 해석

오정석(Jeong Seok Oh),이준만(Joon Mann Lee),안원술(Won Sool Ahn) 한국고분자학회 2009 폴리머 Vol.33 No.5