Effect of eugenol-containing and resin endodontic sealers on retention of prefabricated metal posts cemented with zinc phosphate and resin cements

PurposeThe aim of this study was to compare the effects of two endodontic sealers on the retention of posts cemented with zinc phosphate or resin cement.Materials and methodsCrowns of 72 mandibular premolars were removed at the cementoenamel junction. Root canals were prepared and specimens were randomly divided into two groups of 36. In each group, 12 specimens were obturated with gutta percha only; 12 specimens with gutta percha/ZOE sealer and 12 specimens with gutta percha/AH26. In the first group, 10 mm Post spaces were prepared with Peeso reamers size 4 and, size 5 stainless steel Paraposts were cemented in with zinc phosphate. In the second group, 10 mm Post spaces were prepared with Fiber Lux size 5.5 drills and size 5 Paraposts were cemented with Panavia F_2.0. After mounting in resin blocks, posts were pulled out by universal testing machine at 1 mm/min and results were analyzed by two-way ANOVA and Dunnett test.ResultsMean forces (in Newtons) required to remove posts cemented with zinc phosphate in canals obturated without sealer, with ZOE, and with AH26 sealers were 270 ± 83, 281 ± 128 and 266 ± 67, respectively; and for posts cemented with Panavia F_2.0 were 520 ± 290, 464 ± 212 and 229 ± 108, respectively. Statistical analysis showed that AH26 significantly reduced retention of posts cemented with Panavia F_2.0 (p < 0.05).ConclusionDifferent sealers had no significant effect on retention of posts cemented with zinc phosphate. However posts cemented with Panavia F_2.0 showed reduced retention in canals obturated with AH26.     

Maxillary cement retained implant supported monolithic zirconia prosthesis in a full mouth rehabilitation: a clinical report

This clinical report presents the reconstruction of a maxillary arch with a cement retained implant supported fixed prosthesis using a monolithic zirconia generated by CAD/CAM system on eight osseointegrated implants. The prosthesis was copy milled from an interim prosthesis minimizing occlusal adjustments on the definitive prosthesis at the time of delivery. Monolithic zirconia provides high esthetics and reduces the number of metal alloys used in the oral cavity.     

桩核黏接界面物理构象的实验研究

目的本实验用激光共聚焦显微镜观测根管内壁牙本质-黏接剂-桩黏接界面的物理构象,了解微观的结构和形态与宏观的固位力之间的关系。方法将18颗人上前牙于釉牙骨质界冠方2mm处截断,根充1周后用预成桩配套钻制备根管。确保预备的根管位于中央包埋牙根。包埋后将钛合金和玻璃纤维两种预成桩分别用磷酸锌水门汀(ZPC)、玻璃离子水门汀(GIC)、树脂类黏接剂黏接于根管内。用LSCM共聚焦显微镜观察截断面的牙本质-黏接剂-桩之间的界面,用随机软件测量黏接层的厚度。结果不同的黏接剂的黏接层厚度没有显著差异;牙根不同部位的黏接层厚度有显著差异,即根尖部<根中部<根颈部;纤维桩的黏接层厚度大于钛桩。结论不同黏接剂的黏接层厚度没有显著差异,不同部位及不同桩的黏接层厚度有显著差异。Parapost Cement黏接层均匀、连续、无孔隙,优于其他两种黏接剂。     

Sky型膨胀式椎体成形器治疗疼痛性骨质疏松性椎体压缩骨折

目的评价Sky型膨胀式椎体成形器治疗疼痛性骨质疏松性椎体压缩骨折的临床效果。方法对疼痛性骨质疏松性椎体压缩骨折患者35例（40椎）应用Sky型膨胀式椎体成形器对病椎进行扩张,并用骨水泥填充,采用视觉模拟量表（VAS）及Stauffer—Coventry（SC）评定术后疗效。结果本组病例手术均获得成功,椎管内硬膜外渗漏1例,椎间盘渗漏2例,椎弓根穿刺针道渗漏1例,均未引起严重的神经症状及肺栓塞等致命并发症,VAS由术前（7．6±0．6）降到术后（3．1±0．3）,随访6个月时为（2．1±0．4）,差异有统计学意义（P〈0．05）。临床效果SC评分：优21例,良11例,可3例,优良率91．4％（32／35例）。结论Sky型膨胀式椎体成形器手术创伤小、手术时间短,可迅速有效地缓解疼痛,远期疗效可靠,具有很好的临床应用价值。     

Effect of lavage and brush preparation on cement penetration and primary stability in tibial unicompartmental total knee arthroplasty: An experimental cadaver study

Background

Unicompartmental total knee arthroplasty (UKA) is a well-established treatment option for unicondylar osteoarthritis, and generally leads to better functional results than tricompartimental total knee arthroplasty (TKA). However, revision rates of UKAs are reported as being higher; a major reason for this is aseptic loosening of the tibial component due to implant–cement–bone interface fatigue. The objective of this study was to determine the effects of trabecular bone preparation, prior to implantation of tibial UKAs, on morphological and biomechanical outcomes in a cadaver study.

2008～2009年龙岩市某水泥厂职工健康检查结果分析

[目的]了解水泥厂职工的健康状况,为开展职业病防治工作提供依据。[方法]对370名水泥厂职工进行职业性健康检查,并对实验检查结果进行统计分析。[结果]370名受检者中,检出异常195人,异常率为52.70%。肝功异常128例,异常率为34.59%,血脂异常112例,异常率为30.27%。肝功及血脂异常率男女之间、一线工人和后勤工人之间差异有统计学意义（P〈0.05）。[结论]实验室检查结果显示,该厂半数以上的职工正处于亚健康状态或正罹患疾病,因此对职工定期进行健康体检,对疾病的早发现、早诊断及早治疗,保障职工身体健康,避免职业危害,促进安全生产至关重要。     

不同桩核系统固位力的比较研究

本试验比较研究了膨胀复合型螺纹桩、铸造桩、成品螺纹桩固位力的异同。以标准尺寸有机玻璃模拟上中切牙根27个,分成3组,分别制作膨胀复合型螺纹桩、成品螺纹桩和铸造桩,在INSTRON4302万能试验机进行拉伸测试,加载速度10 mm/min,至桩核松动或脱位,记录最大载荷。另测试平面和轴面粘结力,测算出桩核的粘结力及摩阻力大小。结果发现膨胀复合型螺纹桩固位力明显高于铸造桩和成品螺纹桩,差别有统计学意义(P<0.05),铸造桩固位力略高于成品螺纹桩固位力,但差别无统计学意义,(P>0.05)。通过该试验我们认为膨胀复合型螺纹桩的固位力学性能优于铸造桩和成品螺纹桩,是一种新型的具有良好力学性能的桩核修复方法。     

Inferior stability of a biodegradable cement plug

Introduction: Modern cementing technique demands high intramedullar cement pressure to create an optimum fixed cement support of the femoral stem. Pressure resistant, stable closure of the canal therefore is absolutely necessary. Biodegradable cement restrictors, if corresponding to above mentioned attributes, could be of immense advantage in case of potential revision surgery. Material and methods: A prospective, randomized trial was performed on a consecutive series of 130 patients who underwent primary cemented total hip arthroplasty due to hip arthrosis to compare a degradable cement restrictor and a non-degradable cement restrictor in their ability to resist distal migration during stem insertion. Results: The median cement plug length measured 27 mm (range −12 to 126 mm, 95% confidence interval (CI) 20–33 mm) in the biodegradable restrictor group and 15 mm (range 0–61 mm, 95% CI 12–18 mm) in the non-degradable restrictor group (P=0.003). A significant effect of the relationship between the difference of restrictor size and the diameter of the femoral canal on length of cement distal of the tip of the stem in between the two groups was evident (P=0.031). Conclusion: The results indicate insufficient intramedullary plug fixation of the degradable restrictor probably due to the elastic material properties which also may lead to inferior precision in restrictor size choice.     

髋动力加压钢板内固定治疗股骨粗隆间骨折

目的回顾分析用髋动力加压钢板(DHS)内固定治疗老年股骨粗隆间骨折的疗效,并探讨与疗效相关的有关因素。方法应用DHS内固定治疗52例股骨粗隆间骨折病人,47例得到随访。结果优28例,良15例,可2例,差2例。1例加压钉向上穿出股骨头出现髋内翻畸形,1例内固定螺钉断裂内固定失败,优良率91.4%。结论只要术中处理好几个关键问题,术后合理功能锻炼,DHS内固定是治疗老年股骨粗隆间骨折的理想方法。