双侧唇腭裂新生儿数字化模型与硬石膏模型的比较

目的： 比较双侧唇腭裂新生儿口内扫描数字化模型和硅橡胶制取灌注的超硬石膏模型的可靠性和稳定性。方法： 收集19例双侧唇腭裂新生儿病例,分别制取口内扫描数字化模型和硅橡胶取模超硬石膏灌注模型,对上颌牙槽骨长度、上颌牙槽骨宽度、腭裂宽度及上颌中线偏斜量等指标进行测量。采用SPSS 24.0软件包对测量结果进行统计学分析。结果： 2种方法上颌牙槽骨长度、上颌牙槽骨宽度、腭裂宽度及上颌中线偏斜量3次测量间均无统计学差异（P>0.05）,2种方法的测量值无统计学差异（P>0.05）。结论： 双侧唇腭裂新生儿口内扫描获取的数字化模型与硅橡胶取模超硬石膏灌注获取的石膏模型各测量项目之间无显著差异。口内数字化扫描操作过程简便,可以提高诊疗效率,新生儿承受痛苦少,风险小,可广泛用于唇腭裂患儿的研究、诊断分析及临床治疗。     

Novel fully digital workflow for removable partial denture fabrication

PurposeThis technical procedure report introduces a newly developed method for removable partial denture (RPD) fabrication using computer-aided design and computer-aided manufacturing (CAD/CAM) and rapid prototyping (RP) technologies.MethodsFull-arch digital impressions of the partially edentulous jaw were made by an IOS or the conventional method. The denture framework, artificial teeth, and denture base were designed by commercially available CAD software. Each of the denture components including connectors, clasps, and artificial teeth and the denture bases were fabricated separately by the CAM machine or the three-dimensional (3D) printer, and then assembled using an adhesive material.ConclusionsRPDs were successfully fabricated using fully digital workflow and delivered to the patient, and no clinical complications were reported. Within the limitations of this report, the newly developed RPD fabrication techniques have the potential to change clinical and laboratory workflow from analog to digital.     

Precision of maxillo-mandibular registration with intraoral scanners in vitro

PurposeTo compare the precision of maxillo-mandibular registration and resulting full arch occlusion produced by three intraoral scanners in vitro.MethodsSix dental models (groups A–F) were scanned five times with intraoral scanners (CEREC, TRIOS, PLANMECA), producing both full arch and two buccal maxillo-mandibular scans. Total surface area of contact points (defined as regions within 0.1 mm and all mesh penetrations) was measured, and the distances between four pairs of key points were compared, each two in the posterior and anterior.ResultsTotal surface area of contact points varied significantly among scanners across all groups. CEREC produced the smallest contact surface areas (5.7–25.3 mm²), while PLANMECA tended to produce the largest areas in each group (22.2–60.2 mm²). Precision of scanners, as measured by the 95% CI range, varied from 0.1–0.9 mm for posterior key points. For anterior key points the 95% CI range was smaller, particularly when multiple posterior teeth were still present (0.04–0.42 mm). With progressive loss of posterior units (groups D–F), differences in the anterior occlusion among scanners became significant in five out of six groups (D–F left canines and D, F right canines, p < 0.05).ConclusionsMaxillo-mandibular registrations from three intraoral scanners created significantly different surface areas of occlusal contact. Posterior occlusions revealed lower precision for all scanners than anterior. CEREC tended towards incorrect posterior open bites, whilst TRIOS was most consistent in reproducing occluding units.     

Full arch precision of six intraoral scanners in vitro

PurposeIntraoral scanners may offer an alternative to traditional impressions. That intraoral scanners produce precise scans is essential. Popular methods used to evaluate precision tend to rely on mean distance deviation between repeated scans. Mean value measurements may underestimate errors resulting in misleading conclusions and clinical decisions. This study investigated the precision of six intraoral scanners using the traditional method of measuring mean error, and a proposed method considering only the most extreme and clinically relevant aspects of a scan.MethodsAn edentulous model was scanned five times using six intraoral scanners. The repeated scans were aligned, uniformly trimmed and mean surface deviation measured across all 20 scan combinations within each scanner group. All scan combinations were then measured by arranging scan vertices from greatest to smallest unsigned distance from its compared scan and measuring the median value within the 1% of most greatly deviating points. Traditional mean deviation results and upper-bound deviations were compared.ResultsThe upper-bound deviation within a scan reported errors up to two times greater than those found when measuring global mean distances. Results revealed clinically relevant errors of more than 0.3 mm in scans produced by the Planmeca and Dentalwings scanners, findings not seen when measuring mean distance error of the complete scan.ConclusionsUpper-bound deviation of a cropped scan may provide a clinically useful metric for scanner precision. The Aadva, 3Shape, CEREC and TDS produced scans potentially appropriate for clinical use while Planmeca and Dentalwings produced deviations greater than 0.3 mm when measuring the upper-bound deviation.     

Electrowetting-on-dielectric (EWOD): Current perspectives and applications in ensuring food safety

Digital microfluidic (DMF) platforms have contributed immensely to the development of multifunctional lab-on-chip systems for performing complete sets of biological and analytical assays. Electrowetting-on-dielectric (EWOD) technology, due to its outstanding flexibility and integrability, has emerged as a promising candidate for such lab-on-chip applications. Triggered by an electrical stimulus, EWOD devices allow precise manipulation of single droplets along the designed electrode arrays without employing external pumps and valves, thereby enhancing the miniaturization and portability of the system towards transcending important laboratory assays in resource-limited settings. In recent years, the simple fabrication process and reprogrammable architecture of EWOD chips have led to their widespread applications in food safety analysis. Various EWOD devices have been developed for the quantitative monitoring of analytes such as food-borne pathogens, heavy metal ions, vitamins, and antioxidants, which are significant in food samples. In this paper, we reviewed the advances and developments in the design of EWOD systems for performing versatile functions starting from sample preparation to sample detection, enabling rapid and high-throughput food analysis.     

107例数字减影血管造影受检者所受辐射剂量分析

目的 统计血管造影受检者每次检查所受辐射剂量值及影响辐射剂量的相关因素,为分析、评估放射诊疗风险提供数据参考。方法 收集107例受检者检查时在线记录的全部辐射剂量值及其与剂量相关的技术参数值,按照检查区域头部、腹部和心脏进行分类,统计每例受检者的总透视时间、透视累积剂量面积乘积(DAP)、透视累积皮肤入射剂量(ESD),计算透视剂量率;统计每例受检者的造影曝光次数、造影曝光时间、采集帧频率,以及造影累积剂量面积乘积和造影累积皮肤入射剂量;统计每例受检者的透视加造影的总累积剂量面积乘积和总累积皮肤入射剂量。对所有数据分门别类进行相应的对比分析。结果 冠状动脉造影+介入,ESD为(22 285.5±18 682.7)μGy·m²,DAP为(2 942.1±2 557.3)mGy;头部血管造影DAP为(25 929.6±8 302.7)μGy ·m²,DAP为(1 288.8±682.3)mGy;腹部血管造影,DAP为(12 129.7±10 646.1)μGy·m²,ESD为(730.1±584.7)mGy。结论 血管造影受检者所受总累积剂量,冠状动脉造影相对最高,其次是头部血管造影,腹部血管造影相对较低。     

髋关节数字化断层融合摄影的低剂量研究

目的 探讨髋关节数字化断层融合(DTS)摄影中最佳剂量比的设定,以最大程度地减少患者接受的辐射剂量.方法 90例行髋关节数字化断层融合摄影的患者,以随机数字表法,分别以6、7、8倍的剂量比组进行DTS检查,使用单因素方差分析比较不同剂量比设定下所得的图像质量和辐射剂量.结果 3组的表面吸收剂量(ESD)、剂量面积乘积(DAP)、图像质量评分分别为[(3.76±1.89)mGy、(18.41±11.71)dGy ·cm²、3.03±0.24]、[(5.24±2.76)mGy、(26.99±13.34)dGy ·cm²)、3.60±0.11]、[(6.39±1.75)mGy、(36.96±22.49)dGy ·cm²、3.64±0.09],各组间差异有统计学意义(F=10.94、9.45、139.26, P<0.05),通过3组间两两比较,ESD值和DAP值均是6倍剂量比组<7倍剂量比组<8倍剂量比组.6倍剂量比组的图像质量评分低于其他两组,7倍剂量比组和8倍剂量比组的图像质量评分差异无统计学意义.结论 剂量比是决定DTS检查辐射剂量的重要参数,髋关节DTS检查的剂量比设置为7时,可实现低曝光剂量和高图像质量的平衡,以最大限度地保护患者免受不必要的辐射损害.     

直接数字X线摄影在尘肺病诊断中的应用价值

目的 探讨直接数字X线摄影(DR)在尘肺病诊断中的应用价值.方法 对随机抽取的298例接尘对象分批组织同期分别摄高仟伏和DR胸片,先由6名具有尘肺病诊断资质的医师随机均分甲、乙两组分别进行诊断,然后甲、乙两组合并阅片,使分组诊断不一致的结果得到统一.对DR和高仟伏两种胸片统一后诊断的胸片质量、小阴影的形态和大小、总体密集度、小阴影分布肺区数、尘肺分期等结果进行分析比较.结果 DR胸片质量等级集中在优片(97.99％),高仟伏胸片集中在良片(93.63％);DR胸片和高仟伏胸片小阴影的形态和大小、小阴影总体密集度、尘肺分期经一致性检验Kappa值分别为0.642、0.406、0.436,符合率分别为88.26％(263/298)、67.79％(202/298)、65.77％(196/298);小阴影分布肺区数在下肺区DR胸片明显多于高仟伏胸片.结论 DR胸片质量明显优于高仟伏胸片,可用于尘肺病的诊断.     

2014版ICSH血液分析仪评价指南介绍(下)

介绍了2014年国际血液学标准化委员会(ICSH)关于血液分析仪的性能评价指南。该指南从仪器的进样模式、批内精密度、批间精密度、携带污染、线性、标本稳定性、参考区间、准确性和可比性等方面对厂商提出了具体确认、评价的方法和要求,并推荐对流式细胞术和/或数字成像技术的白细胞分类计数、有核红细胞计数和未成熟粒细胞计数采用流式细胞免疫表型参考方法进行评价。每个临床实验室在仪器用于患者标本检测前,应对上述性能进行部分确认或转移。