基于增材制造的口腔全瓷修复成型工艺研究进展与展望

全瓷修复相比金属和烤瓷修复具有明显优势,临床应用广泛。以等材制造和减材制造为代表,全瓷固定义齿的传统成型工艺发展较为成熟,但仍有许多不足之处。随着科技的快速进步,增材制造技术的出现正在改变口腔修复领域的传统制造模式,已有很多学者尝试将其用于加工全瓷固定义齿。本文将简要阐述全瓷修复成型工艺的技术现状和增材制造技术的原理及优势,着重论述基于口腔修复用陶瓷材料的增材制造技术分类及工艺探索的相关进展。     

Ceramic on ceramic hip arthroplasty in fused hips

Background:Most literature in the field of total hip arthroplasty (THA) for fused hips, until date has reported the results of using metal on polyethylene and ceramic on polyethylene bearings. Results of THA using ceramic on ceramic (CoC) bearings in fused hips have not been published in literature. This study reports the results of cementless THA using CoC articulation perfomed in fused hips.Results:Mean Harris hip score improved from 42.4 to 84.2 and mean leg lengthening of 36.6 mm was achieved. In the average 5.4 years (range 2.8-9.1 years) followup there were no cases with osteolysis around acetabular cup and femoral stem. In this study, there was no case of ceramic fracture. There was one case of squeaking.Conclusion:This study suggests that cementless THA performed for fused hips with CoC bearings can provide good early clinical results.     

Combination therapy with intra‐articular injection of mesenchymal stem cells and articulated joint distraction for repair of a chronic osteochondral defect in the rabbit

The present study investigated intra‐articular injection of bone‐marrow‐derived mesenchymal stem cells (MSCs) combined with articulated joint distraction as treatment for osteochondral defects. Large osteochondral defects were created in the weight‐bearing area of the medial femoral condyle in rabbit knees. Four weeks after defect creation, rabbits were divided into six groups: control group, MSC group, distraction group, distraction + MSC group, temporary distraction group, and temporary distraction + MSC group. Groups with MSC received intra‐articular injection of MSCs. Groups with distraction underwent articulated distraction arthroplasty. Groups with temporary distraction discontinued the distraction after 4 weeks. The rabbits were euthanized at 4, 8, and 12 weeks after treatment except temporary distraction groups which were euthanized at only 12 weeks. Histological scores in the distraction + MSC group were significantly better than in the control, MSC group or distraction group at 4 and 8 weeks, but showed no further improvement. At 12 weeks, the temporary distraction + MSC group showed the best results, demonstrating hyaline cartilage repair with regeneration of the osteochondral junction. In conclusion, joint distraction with intra‐articular injection of MSCs promotes early cartilage repair, and compressive loading of the repair tissue after temporary distraction stimulates articular cartilage regeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1466–1473, 2015.     

An Efficient and Cost‐Effective Technique to Construct an Intraoral Central Bearing Tracing Device

Intraoral central bearing tracing has been shown to be a predictable way of recording and verifying centric relation position for patients. Existing tracing devices are challenging to use due to several significant clinical limitations. In comparison to commercially available counterparts, this article presents a technique that simplifies instrumentation and clinical steps to make an intraoral tracer for making centric relation records, determining occlusal vertical dimension, and detecting deflective occlusal contacts in edentulous patients.     

The effect of orthodontic bands or tubes upon periodontal status during the initial phase of orthodontic treatment

Introduction

Orthodontic bands cause periodontal inflammation. In theory, the use of a buccal tube (bond) instead of a band should prevent or minimize periodontal changes because the bonds are positioned away from the gingival margins.

Objective

The primary aim of this study was to investigate the periodontal status of orthodontic bands compared with bonds in the first three months of orthodontic treatment.

Materials and methods

Twenty-four orthodontic patients (mean age = 12.6 years) were enrolled in this Randomized Controlled Trial (RCT). Using the cross-mouth technique, bands and bonds were used in opposite quadrants. Periodontal parameters including the presence or absence of Bleeding On Probing (BOP) and Probing Depths (PDs) were taken at the start and three months into treatment.

Results

Bands caused a statistically significant change in the Bleeding On Probing (BOP) (P = 0.001 and 0.021) and bonds displayed a statistically insignificant change in the Bleeding On Probing (BOP) (P = 0.125 and 1.00) for the upper and lower arch. The difference in Probing Depths (PDs) between bands and bonds was also statistically significant (P = 0.001).

Conclusion

Molar bands are associated with greater periodontal inflammation compared with molar bonds in the first three months of fixed orthodontic treatment.     

鹅去氧胆酸浙贝乙素酯对H22荷瘤小鼠抑瘤作用*

目的研究新型化合物鹅去氧胆酸浙贝乙素酯(CDCA-Ver)对H22荷瘤小鼠体内肿瘤细胞生长和免疫器官的影响。方法采用鼠系肝癌细胞H22造荷瘤模型,将H22荷瘤小鼠40只,采用随机数字表法随机分成4组,每组10只,分别为模型对照组、环磷酰胺(CTX)组、CDCA-Ver腹腔注射组和CDCA-Ver静脉注射组。模型对照组按每日10 mL·kg-1无菌0.9%氯化钠溶液腹腔注射1次,CTX组按每日20 mg·kg-1剂量腹腔注射1次,CDCA-Ver腹腔注射组每日按20 mg·kg-1剂量腹腔注射1次,CDCA-Ver静脉注射组每日按20 mg·kg-1剂量小鼠尾静脉注射1次。接种24 h后给药,给药量为0.1 mL·(10 g)-1,连续给药10 d。以CTX为阳性对照药,考察CDCA-Ver(静脉注射和腹腔注射)对荷瘤小鼠肿瘤的生长抑制作用,评价CDCA-Ver对荷瘤小鼠的免疫脏器指数(胸腺指数和脾指数)的影响,采用组织病理学切片法研究CDCA-Ver对荷瘤小鼠瘤块组织病理学形态的影响。结果CDCA-Ver静脉注射和腹腔注射两种给药方式对荷瘤小鼠的肿瘤生长均具有良好的抑制作用,腹腔注射20 mg·kg-1剂量CDCA-Ver抑瘤率达48.3%,与模型对照组比较差异有统计学意义(P＜0.05),与CTX组作用相当。与模型对照组相比,CDCA-Ver腹腔注射组脾指数和胸腺指数没有显著变化(P＞0.05),而CTX组脾指数和胸腺指数均显著降低(P＜0.01),表明CDCA-Ver发挥体内抗肿瘤作用不会降低荷瘤小鼠的免疫功能。组织病理学结果也证实CDCA-Ver具有体内抗肿瘤作用。结论CDCA-Ver对H22荷瘤小鼠肿瘤生长具有明显的抑制作用。     

不同材料固定义齿修复后牙连续缺损的效果及对口腔生物膜的影响

目的 研究不同材质义齿与修复材料对口腔生物膜的影响。方法 选择自2018年5月～2019年5月我院收治的120例2颗后牙连续缺损患者进行研究。将选取的120例牙体缺损患者平均分为三组,分别通过二氧化锆全瓷冠、钴铬合金烤瓷冠和银钯合金烤瓷冠进行修复。修复后三组患者均通过构建口腔生物膜体外模型对口腔生物膜形成情况进行分析;通过涂布等平板计数法对口腔生物膜平板菌落计数和口腔生物膜变形链球菌代谢产物进行分析。结果 三组患者口腔生物膜的形成、平板菌落计数和变形链球菌代谢产物的终pH值和ΔpH之间存在显著差异。其中二氧化锆组患者生物膜形成量较其他两组患者多,而平板菌落计数和变形链球菌代谢产物的pH值变化较小,三个指标的变化规律一致。结论 不同材质义齿与修复材料对口腔生物膜的影响不同。二氧化锆对患者口腔生物膜影响效果较其他两种材质与修复材料好,可进行临床推广。     

A Novel Framework to Eliminate the Effects of Casting Distortion when Fabricating a Fixed,Detachable Screw‐Retained Prosthesis

The ideal fixed, detachable framework sits passively on the implants and does not introduce any stress. Several techniques in the literature compensate for an ill‐fitting framework. These techniques require extra visits, chairtime, and laboratory time and only mitigate the stress; the stress is not eliminated. A framework is presented here that eliminates the stress transmitted to the implants by encircling the abutment cylinders and not directly incorporating them into the framework. Furthermore, the framework mitigates the stress from the polymerization distortion of acrylic when processing the acrylic onto the prosthesis.     

基于MRI的成人正常膝关节软骨形态学测量

目的：了解正常膝关节软骨分布及股骨髁承重区的软骨厚度特点,为膝关节病变早期诊断和动态观察提供依据。方法：选取100名成人志愿者,男、女各50名,年龄20—30岁,平均25．3岁,膝关节均行MRI扫描。应用MIMICS软件对图像进行处理,在矢状位窗面上测量膝关节各部位软骨最大厚度。选择膝关节正常运动时的承重区,测量承重区域软骨的最大厚度并与其他区域进行比较。基于MRI图像行膝关节软骨三维重建,观察膝关节软骨的三维形态特征。结果：膝关节各部位的最大软骨厚度如下。胫骨外侧平台3．19mm,胫骨内侧平台3．07mm,股骨外侧髁2．93mm,股骨内侧髁3．19mm,股骨滑车软骨3．57mm,髌软骨3．75mm。不同性别与左右侧之间的软骨厚度差异无统计学意义（P〉0．05）。胫股关节承重区软骨厚度大于其他区域,有统计学差异（P〈0．05）。结论：成人正常膝关节各区域软骨厚度不同,胫股关节承重区软骨厚度大于非承重区域。基于MRI可以准确地测量膝关节各部软骨的厚度及重建膝关节软骨的三维形态。