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目的探讨IPS Empress 2可铸玻璃陶瓷嵌体修复后牙牙体缺损的临床疗效。方法对沈阳市和平区牙病防治所2010年6月至2012年6月接受治疗的后牙牙体缺损患者30例（48颗患牙）,采用IPS Empress 2可铸玻璃陶瓷嵌体修复,随访观察6个月至2年,参照改良的美国公共卫生服务（USPHS）评价标准对修复体的边缘适合性、外形、颜色匹配、继发龋发生以及磨损与折裂情况进行评价。结果 IPS Empress可铸玻璃陶瓷嵌体具有良好的边缘适应性及外形,色泽稳定,强度较高,未发现继发龋。结论 IPS Empress 2可铸玻璃陶瓷嵌体是一种修复后牙牙体缺损效果较好的修复体。     

Revision Total Hip Arthroplasty for Ceramic Head Fracture : A Long-Term Follow-Up

The results of revision total hip arthroplasty (THA) for ceramic head fracture have generally been disappointing, largely due to third body wear after incomplete synovectomy. We have followed 8 patients who sustained ceramic head fractures and were subsequently revised to a metal-on-polyethylene articulation. There were no revisions for osteolysis or aseptic loosening at a mean follow-up of 10.5 years. The yearly wear rates of each of 5 of these THAs after revision were compared with 6 matched metal-on-polyethylene THAs; there were no significant differences in wear rates. Greater than 10-year survivorship with a metal-on-polyethylene bearing couple is possible after revision THA for a ceramic head fracture if a complete and thorough synovectomy can be performed. Our technique of synovectomy will be described.     

Manufacture and Cytotoxicity of a Lead-free Piezoelectric Ceramic as a Bone Substitutc Consolidation of Porous Lithium Sodium Potassium Niobate by Cold Isostatic Pressing

Aim The piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated. Methodology Cold isostatic pressing （CIP） was applied to fabricate porous lithium sodium potassium niobate （Li0.06Na0.5K0.44） NbO3 specimens using a pore-forming method. The morphologies of the CIP-processed specimens were characterized and compared to those of specimens made by from conventional pressing procedures. The effects of the ceramic on the attachment and proliferation of osteoblasts isolated from the cranium of 1-day-old Sprague- Dawley rats were examined by a scanning electron microscopy （SEM） and metbylthiazol tetrazolium （MTT） assay. Results The results showed that CIP enhanced piezoelectricity and biological performance of the niobate specimen, and also promoted an extracellular matrix-like topography of it. In vitro studies showed that the CIP-enhanced material had positive effects on the attachment and proliferation of osteoblasts. Conclusion Niobate ceramic generated by CIP shows a promise for being a piezoelectric composite bone substitute.     

Alumina‐reinforced zirconia implants: survival rate and fracture strength in a masticatory simulation trial

Background: Alumina‐toughened zirconia (ATZ) is a possible alternative material to titanium for oral implants. No data are available on the fracture strength of ATZ oral implants. Purpose: The purpose of this study was to examine one‐piece implants made of ATZ ceramic under artificial loading conditions and to compare the fracture strength of these implants with implants fabricated from tetragonal zirconium dioxide poylcrystal (TZP)‐A. Materials and methods: A total of 72 implants, 48 ATZ implants (groups A and B) and 24 TZP‐A implants (group C), were investigated. A chamfer preparation at the implant heads was performed on all implants of groups B and C. Eight implants of each group underwent 1.2 or five million thermomechanical loading cycles in the chewing simulator (load value: 98 N). Further eight implants of each group were not cyclic loaded. Finally, the fracture strength of all implants was determined using a universal testing machine. Results: No implant fractured during loading in the chewing simulator. All implants were placed in the universal testing machine to evaluate fracture strength. The mean fracture strength values±standard deviations for the implants without artificial loading were 1734±165 N (ATZ, no preparation), 1220±85 N (ATZ, with preparation), and 578±49 N (TZP‐A, with preparation); 1489±190 N (ATZ, no preparation), 1064±121 N (ATZ, with preparation), and 607±57 N (TZP‐A, with preparation) with 1.2 million loading cycles; and 1358±187 N (ATZ, no preparation), 1098±97 N (ATZ, with preparation), and 516±45 N (TZP‐A, with preparation) with five million cycles. The ATZ implants showed significantly higher mean fracture strengths compared with the TZP‐A implants. Modification of the implant head using diamond burs and increased loading time also led to a significant decrease in fracture strength. Conclusions: The ATZ implants showed an increased mechanical stability compared with the TZP‐A. Modification of the implant head resulted in a decrease in fracture strength. However, within the limits of this in vitro investigation it can be concluded that ATZ implants will withstand functional loading over an estimated period of 20 years. To cite this article:
Kohal R‐J, Wolkewitz M, Mueller C. Alumina‐reinforced zirconia implants: survival rate and fracture strength in a masticatory simulation trial.
Clin. Oral Impl. Res. 21 , 2010; 1345–1352.
doi: 10.1111/j.1600‐0501.2010.01954.x     

羟基磷灰石复合体在牙周骨缺损中的应用

骨形成蛋白（bone morphogenetic protein，BMP）作为一种高效骨诱导物质，对促进骨缺损的修复具有显著的效果。以羟基磷灰（hydroxylapatite，HA）微粒，胶原（collagen，Co）与牛骨形成蛋白（bBMP）合成的一种具有高生物诱导活性的新型复合人工骨材料即HA-bBMP-Co，可用于牙周病所致骨缺损的修复。我科用此种生物材料已治疗完成46例共46牙，并与经牙周基础治疗的患牙进行比较，经临床观察，疗效满意，现报道如下。     

人工骨异烟肼体外及家兔体内释放度研究

 目的：了解蜂蜡为阻滞剂包裹的异烟肼-人工骨(INH-PHA-wax)与未包裹蜂蜡的异烟肼-人工骨(INH-PHA)体外及家兔体内的释放度。方法：用RP-HPLC在不同时间分别测定体外及植入家兔体内的包裹或未包裹蜂蜡的异烟肼-人工骨中异烟肼的浓度。结果：包裹15%蜂蜡INH-PHA-wax,体外20 d释药66%;包裹25%蜂蜡INH-PHA-wax,20 d释药22%;未包裹蜂蜡INH-PHA,6 d释药97%。包裹25%蜂蜡INH-PHA-wax植入家兔体内，可持续释药达240 d,而未包裹蜂蜡INH-PHA持续释药仅60 d。结论：INH-PHA-wax可有效地控制药物的释放，对治疗骨结核可能是一有效植入式缓释剂。     

烧结温度对牙科氧化锆陶瓷部分物理机械性能的影响

目的研究烧结温度对氧化锆陶瓷的机械性能及可加工性能的影响。方法纳米级氧化锆(ZrO2)粉体,由3mol%氧化钇(Y2O3)稳定,经干压成型,于800℃～1300℃之间,间隔50℃烧结,测试不同烧结温度瓷块的密度、硬度和断裂韧性并测算可加工性能。结果800℃～1300℃温度范围内,随着烧结温度的提高,氧化锆陶瓷的密度、硬度和断裂韧性均呈现逐步上升趋势。在所设定的温度范围内,纳米3mol%,Y2O3-ZrO2粉体在1200℃基本完成烧结(>99%理论密度),当烧结温度为900℃时瓷块的可加工指数达到最高,显著优于其它各温度段(P<0.05)。结论纳米氧化锆粉体能在较低的烧结温度达到完全致密;通过对3mol%Y2O3-ZrO2粉体烧结温度的控制可以调节氧化锆瓷块的机械性能和可加工性,降低加工成本满足牙科CAD/CAM加工所需材料的要求。     

正常妊娠和妊高征胎盘血管三维铸型形态研究

目的:建立正常妊娠和妊高征胎盘血管的三维铸型模型,探讨正常妊娠和妊高征胎盘血管的三维分布结构特征和临床价值。方法:采用改良的血管铸型方法,通过胎盘脐动、静脉灌注血管铸型材料,铸建20例正常胎盘,48例异常胎盘血管模型。结果:①人胎盘血管三维结构模型中,正常胎盘血管分支分为5-7级,胎盘动静脉系统容积为152.5mL±45.3mL,末梢动静脉分支数比值为1:2;②重度妊高征胎盘血管系统容积为102.8mL±36.1mL（P<0.01）,末稍动静脉分支数比值2:3或1:1（P<0.05）;③特殊胎盘的血管结构均有特殊性。结论:建立胎盘血管三维铸型,有利于直观了解正常和异常胎盘血管系统的结构,它不仅可作为教研模型,而且对深入探讨胎盘功能也有一定价值。     

Cerebral cast angiography as an aid to medicolegal autopsies in cases of death after adult cardiac surgery

Due to an increase in age of the patient population in cardiac surgery, cerebral complications are increasing in frequency, also as a cause of death. In order to reveal cerebral pathology associated with a fatal outcome after cardiac surgery, we re-evaluated the cast angiographs and medico-legal autopsy documents of 144 adult cardiac surgery subjects over a 7-year period. Special attention was paid to the ability of post-mortem cast angiography to aid in diagnosing cerebral pathology. The autopsy detected new ischemic cerebral lesions in 29 (20%) cases, of which 22 (15.3%) were recent infarcts, and 7 were cases of anoxic brain damage. Of the recent cerebral infarcts, 12 were associated with cerebral artery thrombosis, 4 showed multiple lesions, and the remaining 6 were small single infarcts. In addition, one subject had an intracerebral hemorrhage and 72 (50%) cerebral edema. By cast angiography, the leakage of contrast medium in the case of intracerebral hemorrhage and stenoses of intracranial and cervical arteries could be well demonstrated and also revealed 17 (77%) of the 22 recent cerebral infarcts. It was found to be suitable for detecting recent brain infarcts associated with main cerebral artery thrombosis, with a sensitivity of 92% (11 out of 12 cases), but was less sensitive in showing small recent infarcts with a sensitivity of 60% (6 out of 10 cases) and inferior for the older ones where none of the 6 cases were detected. Filling defects caused by cerebral edema were difficult to differentiate from technical errors and were encountered in 7 (4.8%) cases. A significant predictor for the 29 recent ischemic brain lesions was perioperative hypotension. The immediate cause of death was most often of cardiac (83%) and cerebral (14%) origin. In 14 cases, cerebral damage was considered to be an additional cause of death. The use of cerebral post-mortem cast angiography should be recommended, especially for its excellent ability to visualize intravascular pathology such as arterial stenoses and thromboses, with a 92% sensitivity in showing new main cerebral artery thromboses, before likely distortion of the vascular anatomy by dissection. Received: 18 January 2000 / Accepted: 26 April 2000