某陶瓷洁具厂粉尘综合治理的效果分析

目的掌握某陶瓷洁具生产企业工作场所中粉尘的职业病危害特点和对粉尘职业病危害综合治理的效果,为该行业的粉尘职业病危害治理提供经验参考。方法分析工作场所降尘的游离二氧化硅含量,分别在治理前和治理后检测原料制备、喷釉、洗改坯和修坯岗位的空气中总粉尘和呼吸性粉尘的时间加权平均浓度。结果粉尘作业场所降尘的游离二氧化硅含量的范围在22.59%～48.46%之间,治理后工作场所中的总粉尘和呼吸性粉尘浓度大幅降低(P0.05),检测点合格率由5.4%上升到93.4%(P0.05)。结论该陶瓷洁具厂针对粉尘职业危害的综合治理效果良好,相关措施实用有效,值得推广。     

Surface-modified nanocrystalline ceramics for drug delivery applications

Drug delivery systems comprised of various types of carriers have long been the object of pharmacological investigation. The search has been stimulated by the belief that carriers will lead to reduced drug toxicity, dosage requirements, enhanced cellular targeting and improved shelf-life. Among the carriers investigated are complex polymeric carbohydrates, synthetic proteins and liposomal structures. For the past four years, we have been experimenting with a radically new class of carriers comprised of surface-modified nanocrystalline ceramics. While the ceramics provide the structural stability of a largely immutable solid, the surface modification creates a glassy molecular stabilization film to which pharmacological agents may be bound non-covalently from an aqueous phase with minimal structural denaturation. As a consequence of maintained structural integrity and owing to concentration effects afforded by the surfaces of the nanocrystalline materials, drug activity following surface immobilization is preserved. We have used successfully surface-modified nanocrystalline ceramics to deliver viral antigens for the purpose of evoking an immune response, oxygenated haemoglobin for cell respiration and insulin for carbohydrate metabolism. The theoretical principles, technical details and experimental results are reviewed. Surface-modified nanocrystalline materials offer an exciting new approach to the well-recognized challenges of drug delivery. Biomaterials (1994) 15, 1201–1207     

多孔碳酸钙陶瓷修复骨缺损的实验研究

目的 探讨多孔碳酸钙陶瓷修复骨缺损的可行性。方法 取20只新西兰大白兔，采用兔桡骨干1．5cm缺损的动物模型并植入多孔CaCO3陶瓷，分别于术后2、4、8、12及16周处死后取材，行大体、X线、扫描电镜和组织切片观察。结果 植入材料4周扫描电镜显示材料的骨结合紧密、且无纤维组织界面；组织学观察12周植入材料内有较多板层骨生成、植入材料被吸收，骨缺损得到修复。结论 多孔CaCO3陶瓷具有良好的生物相容性和降解率，是一种替代自体骨修复骨缺损较理想材料。     

The processing of hydroxyapatite-based rolled sections

Hydroxyapatite can be tape-cast into a thin flexible sheet which can be formed into suitable shape before firing. X-ray analysis of fired samples showed the undesirable presence of β-whitlockite retained in some of them.     

氧化铝全陶界面在中青年患者全髋关节置换术中的临床中期结果

目的回顾分析第三代氧化铝陶瓷全髋关节置换在中青年患者中的中期临床疗效。方法回顾性收集2001年5月至2006年5月,本组98例行全陶人工髋关节置换术患者的临床资料,共获得有效随访患者82例,共89例髋,其中男43例（48髋）,女39例（41髋）,平均年龄47.6岁,平均随访时间101.9个月（66~120个月）,对有效随访的患者均进行临床和影像学检查评估疗效。结果患者术前Harris评分（49.8±8.0）分（36~65分）,术后末次随访（92.3±2.6）分（86~97分）（P〈0.05）。术后随访均未见假体破裂,未发生假体周围感染,无翻修病例。1例术后出现脱位,1例出现关节异响现象,均在非手术治疗后消失。术后影像学均无可观察到的磨损和骨溶解,无明显异位骨化,无假体松动。结论本研究结果显示,第三代氧化铝全陶髋关节假体用于中青年患者初次全髋关节置换术,中期临床随访结果满意,是一种良好的手术选择。     

Microshear bond strength of dual-cure resin cement in zirconia after different cleaning techniques: an in vitro study

PURPOSEThis study aimed to compare the microshear bond strength (µSBS) of dual-cure resin cement in CAD-CAM zirconia after different cleaning techniques.MATERIALS AND METHODSFifty discs of zirconia-based ceramic from Ivoclar Vivadent were embedded in acrylic resin. The discs were divided into five groups according to the cleaning methods used: Group 1: drying with spraying + sandblasting with Al₂O₃; Group 2: washed with water and dried with spraying + sandblasting with Al₂O₃; Group 3: washed with distilled water and dried with spraying + sandblasting with Al₂O₃ + zirconium oxide (Ivoclean); Group 4: washed with distilled water and dried with spraying + sandblasting with Al₂O₃ + potassium hydroxide (Zirclean); and Group 5: washed with distilled water and dried with spraying + sandblasting with Al₂O₃ + 1% NaClO. All of the groups were contaminated with artificial saliva for 1 minute and then cleaned. Statistical analyses were performed using ANOVA and Tukey''s tests. RESULTSThere were statistically significant differences among all groups for µSBS (P < .05). The group treated with zirconium oxide (Group 3) showed the highest µSBS (18.75 ± 0.23 MPa).CONCLUSIONWhen applied to zirconia, the cleaning methods affected the bonding with resin cement differently.     

生物陶瓷在骨科的应用

生物陶瓷具有良好生物相容性 ,在骨科中广泛应用。通过控制其制备过程可改变生物陶瓷的理化性能以达到不同的应用目的。本文对生物陶瓷在骨科的临床应用作一介绍     

Flexural properties of three lithium disilicate materials: An in vitro evaluation

ObjectiveThe goal of this study was to investigate the flexural strength, Young’s modulus and Weibull modulus of two heat-pressed and one CAD/CAM processed lithium disilicate (LD) ceramics.Material and methodsA total of 45 specimens with dimensions 16 × 4 × 1.2 ± 0.2 mm were fabricated out of three LD ceramics. For heat-pressed LD specimens, acrylate polymer blocks were cut and divided into two groups (n = 15 per group); a GC LiSi Press LD group (LP) and an IPS e.max Press group (EP). Specimens for each group were pressed corresponding to the manufacturer’s recommendations. For the CAD-CAM Group (EC), IPS e.max CAD blocks were cut to obtain specimens (n = 15) to the desired dimensions. Flexural strength and Young’s modulus tests were executed using a universal testing machine. A one-way ANOVA and post-hoc Tuckey’s tests were applied to analyze the results (p ≤ 0.05).ResultsRegarding flexural strength, the EC group showed higher statistically substantial difference than the EP and LP groups (p = 0.001), while there was no pronounced difference between the EP and LP groups (p = 0.065). For Young’s modulus test, all the three tested groups had no statistically substantial difference (p = 0.798).ConclusionThe IPS e.max CAD group had higher mechanical performance than the IPS e.max Press and GC LiSi Press groups.     

对比切削与胶态成型工艺制作的氧化锆陶瓷的透光性与遮色效果

目的：利用切削素烧瓷块法与三维（three dimensional,3D）胶态成型法制作遮色效果不同的3种氧化锆陶瓷,对比其在不同厚度下的透光性及对异色离体牙的遮色效果,为临床口腔修复提供材料选择依据。方法：制备90片直径14 mm的A2色氧化锆圆盘试件,分成3组（n=30）：（1）CZ组,采用计算机辅助设计（computer aided design,CAD）/计算机辅助制造（computer aided manufacturing,CAM）切削素烧瓷块法;（2）NZW组,采用3D胶态成型法,试件内表面无多孔遮色层;（3）NZY组,采用3D胶态成型法,试件内表面有多孔遮色层。3组试件根据厚度0.6 mm、1.0 mm、1.5 mm再分成3个亚组（n=10）。选用因牙周病拔除的中、重度异色前牙10颗,唇面打磨成大于 6 mm2×6 mm2的平面。暗盒中用Crystaleye比色仪在黑、白背景下分别测量9组试件的色度值（CIE1976 L*a*b*）,计算透光性［半透性参数（translucency parameter, TP）］。将每组试件与牙齿唇面依次粘接并测量色度值。选标准比色片A2中1/3色度值作为对照,计算试件粘接后同对照色的色差ΔE。以One-way ANOVA和Bonferroni法对数据进行统计分析。结果:（1）3组氧化锆试件在0.6 mm、1.0 mm、1.5 mm 厚度下的TP值分别为：CZ组14.09、12.31和10.45,NZW组19.84、16.54和12.44,NZY组14.81、13.16和11.92。每组试件的3个亚组间透光性均显示为0.6 mm组>1.0 mm组>1.5 mm组,厚度相同的亚组间透光性均显示为NZW组>NZY组>CZ组。（2）3组氧化锆试件粘接后在0.6 mm、1.0 mm、1.5 mm厚度下与对照色的色差ΔE分别为：CZ组10.77、9.94和8.50,NZW组6.84、5.89和5.29,NZY组4.16、3.92和3.67。每组试件的3个亚组间色差值均显示为0.6 mm组>1.0 mm组>1.5 mm组,厚度相同的亚组间色差值均显示为CZ组>NZW组>NZY组。结论：3种氧化锆试件在厚度相同的情况下,透光性均为3D胶态成型技术制作的内表面无遮色处理组试件最好,而遮色效果均为3D胶态成型技术制作的内表面有遮色处理组试件最好,且其厚度在0.6 mm时即可获得较好的遮色效果。