钛合金铸造支架可摘局部义齿临床疗效观察

目的 观察用钛合金铸造金属支架进行可摘局部义齿修复的临床疗效.方法 2003～2006年制作45件钛合金铸造支架可摘局部义齿,戴入后追踪观察2年,了解义齿使用情况及基牙健康状况. 1年后将其与48件钴铬合金支架及塑料基托义齿的修复效果对比.结果 1年后钛合金支架义齿功能良好率为93.3%,基牙健康状况良好;不良症状明显低于钴铬合金支架及塑料基托义齿.结论 钛合金铸造支架可摘局部义齿具有良好的功能,适合于治疗义齿的临床应用.     

钴铬合金铸造支架可摘局部义齿的临床疗效：附1032件义齿？…

目的：观察钴铬合金铸造支架可摘义齿的临床疗效。方法；随访１９８８年～１９９６年间８６８例戴用钴铬合金铸造支架可摘义齿计１０３２件的患者，以义齿功能和基牙健康状况作为评价指标。结果：１年～２年义齿功能良好率为９７．６％，基牙健康率为９７．３％，３年～４年义齿功能良好率为９４．２％，基牙健康率为６８．１％，５年～８年义齿功能良好率为８６．５％，基牙健康率为４８．２％。结论：钴铬合金铸造支架可摘局部义齿     

钴铬合金铸造支架可摘局部义齿的临床疗效(附1032件义齿的临床分析)

目的：观察钴铬合金铸造支架可摘义齿的临床疗效。方法：随访１９８８年～１９９６年间８６８例戴用钴铬合金铸造支架可摘义齿计１０３２件的患者，以义齿功能和基牙健康状况作为评价指标。结果：１年～２年义齿功能良好率为９７．６％，基牙健康率为９７．３％；３年～４年义齿功能良好率为９４．２％，基牙健康率为６８．１％；５年～８年义齿功能良好率为８６．５％，基牙健康率为４８．２％。结论：钴铬合金铸造支架可摘局部义齿具有良好修复效果。     

两种支架义齿合金材料临床应用的效果评价

目的:评估维他灵(Vitallium)2000铸造支架义齿临床应用的效果。方法:150例行可摘局部义齿修复的患者随机分为两组,实验组75例采用Vitallium 2000铸造支架义齿修复,对照组75例采用传统钴铬合金铸造支架修复,通过比较两组患者的满意度,评估Vitallium 2000铸造支架义齿的临床修复效果。结果:Vitallium 2000支架义齿与钴铬合金支架相比起来,患者在美观性、舒适度、语言功能方面的满意度较高(P<0.05)。结论:与传统的钴铬合金铸造支架义齿相比,Vitallium 2000铸造支架义齿临床修复效果较好。     

纯钛支架义齿与钴铬合金支架义齿修复效果的比较

目的评估纯钛铸造支架义齿的临床应用效果。方法为168例肯氏Ⅰ、Ⅱ类牙列缺损的患者制作71例纯钛支架义齿和97例钴铬合金支架义齿,通过比较两组患者临床试戴情况、初戴义齿适应期的调改情况、义齿性口炎的发生情况以及满意度,评估纯钛铸造支架义齿的临床修复效果。结果纯钛支架义齿比钴铬合金支架义齿就位顺利、调改少、患者满意度高,并且义齿性口炎的发生率低。结论纯钛铸造支架义齿与传统的钴铬合金铸造支架义齿相比临床修复效果好。     

纯钛铸造支架可摘局部义齿的临床应用对比研究

目的：对比研究纯钛铸造支架、钴铬合金支架、塑料基托可摘局部义齿修复的临床疗效。方法：选择90件肯氏I类设计修复义齿,分别用三种义齿修复方法,戴用后半年～2年进行临床观察。结果：钝钛铸造支架叮摘局部义齿质量轻,佩戴舒适,咀嚼功能良好。结论：纯钛铸造支架可摘局部义齿可获得良好的临床效果。     

改良冷弯卡环与铸造支架联合应用修复牙列缺损的疗效观察

目的观察改良冷弯卡环联合铸造支架可摘局部义齿修复的临床效果。方法使用成品不锈钢圆丝锻制,配合扁丝弯制钳弯制成半圆形卡环臂、圆形卡环肩部及连接体、扁圆过度卡环体的改良冷弯卡环,与钴铬铸造支托、基托联合应用修复牙列缺损。并对90件改良冷弯卡环联合铸造支架可摘局部义齿戴入后追踪观察2年,了解义齿使用情况和基牙健康状况,并将其与钴铬合金支架义齿、传统冷弯卡环塑料基托义齿的修复效果对比。结果 2年后改良冷弯卡环联合铸造支架义齿基牙状况良好,不良症状明显低于其他两组义齿。结论改良冷弯卡环联合铸造支架可摘局部义齿具有良好的功能,可以获得良好的修复效果。     

数字化可摘局部义齿支架设计优化方法研究

目的 基于数字化可摘局部义齿支架构建三维有限元模型,分析不同建模策略对支架及口腔软硬组织受力的影响,探讨数字化支架优化设计的方法。方法 选择牙列完整、牙周组织健康的成年志愿者1名,在锥形束计算机断层扫描和口外石膏模型扫描的基础上,通过3Shape Dental System软件设计可摘局部义齿支架,利用Mimics、Geomagic Studio和HyperMesh软件对上颌肯氏Ⅱ类牙列缺损模型和可摘局部义齿模型进行三维建模,分别构建简化组和对照组(包含牙齿和牙周膜)三维有限元模型。使用Abaqus/CAE有限元分析软件,分析垂直和斜向45°载荷下两组模型的支架受力情况。结果 简化组模型与对照组模型支架的应力分布规律基本相同,应力值差异无统计学意义。其中垂直载荷下,两组模型均在支架小连接体处出现应力集中,支架远端下沉,最大应力值分别为44.39、51.05 MPa,最大位移值分别为49.05、38.29 μm;斜向载荷时,支架大连接体出现高应力区,Ⅰ杆直角转折处应力集中,最大应力值分别为324.58、303.11 MPa,最大位移值分别为291.86、298.02 μm。结论 采用适当简化模型的方法能够提高建模效率,同时计算结果具有较好的可信度,能够为临床数字化可摘局部义齿支架的优化设计提供参考。     

可摘局部义齿铸造支架铸型CAD/CAM技术的临床初步应用研究

目的通过对临床KennedyⅠ类上颌牙列缺损患者进行可摘局部义齿支架的计算机辅助设计与制作,为进一步开发适用于口腔临床的可摘局部义齿CAD/CAM技术奠定基础。方法选择临床病例KennedyⅠ类患者,常规牙体制备、模型观测、模型处理,投影光栅测量法获取工作模型以及对颌模型三维数据。在CATIA等软件中,按照临床设计要求分别完成卡环、支托、腭杆、加强网等支架部件的三维建模,最终连接为支架数字化模型,再将保存为三角网格数据STL格式的支架数据导入快速成型设备中,加工获得树脂铸型,常规包埋、铸造获得钴铬合金支架,在临床上进行口内试戴。结果初步完成1例临床病例可摘局部义齿铸造支架的CAD/CAM。结论运用工程软件,计算机辅助设计以及快速成型技术可以初步设计、制造出适用于口腔临床的可摘局部义齿铸造支架。     

减少高熔合金铸造支架收缩变形的有关方法

钴铬合金支架式可摘局部义齿在国内已开展多年,较之普通钢丝胶连义齿有许多优点.但钴铬合金铸造支架铸后收缩问题始终困扰着临床工作者,特别是初学者.在目前的专业书籍中没有详细论述减少铸后收缩,特别是在蜡型制作方面的具体方法、要求和原则.现将笔者对铸件收缩问题的认识体会以及一些对抗或减少收缩的方法总结如下.     

3D打印钴铬合金和铸造钴铬合金的理化性能和生物相容性的比较

目的 比较3D打印和传统铸造钴铬合金的理化性能及生物学影响.方法 实验组和对照组分别用3D打印技术中的选择性激光熔融(SLM)和传统铸造技术,制作钴铬合金试件各10个,采用洛氏硬度计HR-150A和金相显微镜对两组分别进行洛氏硬度测定和金相观察,并在自腐蚀电位下对金属试件进行极化曲线测定.在无菌环境下制备试件的浸提液,...     

Accuracy of CAD-CAM systems for removable partial denture framework fabrication: A systematic review

Statement of problemRemovable partial dentures (RPDs) are traditionally made by casting, a complex, error-prone, and time-consuming process. Computer-aided design and computer-aided manufacturing (CAD-CAM) RPD systems may simplify the clinical steps and minimize errors; however, the accuracy of CAD-CAM RPD systems is unclear.PurposeThe purpose of this systematic review was to determine whether CAD-CAM systems are accurate for the manufacturing of RPD frameworks.Material and methodsA literature search was conducted through Medline-PubMed, Scopus, Lilacs, Web of Science, and Cochrane Library databases using specific keywords for articles published up to November 2019. Three reviewers obtained data and compared the results. All studies evaluated the framework accuracy or fit of prostheses fabricated with conventional and digital techniques.ResultsA total of 7 articles, 2 clinical studies, and 5 in vitro studies that complied with the inclusion criteria were evaluated. One in vitro study compared indirect (extraoral) and direct (intraoral) scanning for partially edentulous ridges and shows that digital scans were better than conventional impressions in terms of trueness. In the other studies included, although the frameworks analyzed had clinically acceptable discrepancies (<311 μm), the material influenced the fit. Polyetheretherketone (PEEK) showed better fit than traditional metal cast RPDs. Co-Cr alloy RPDs produced by rapid prototyping exhibited the highest discrepancies when produced by sintering laser melting.ConclusionsThe results show that the digital technique for RPD frameworks is accurate. In the studies included, the analyzed frameworks had clinically acceptable gaps, but the results were heterogeneous among studies because the articles used different measurement methods with small sample sizes. Few studies discussed the long-term clinical performance. The digital technique for RPD frameworks was accurate because the misfits and mismatches found in in vitro and clinical studies were within the acceptable clinical limit for RPDs.     

激光选区熔化成形钴铬合金及钛合金金瓷结合强度的研究

目的　比较激光选区熔化（selective laser melting,SLM）技术与传统方法制作的钴铬合金（Co-Cr）和钛合金（Ti6Al4V）在金瓷结合性能方面的差异。方法　分别采用传统方法（铸造法和锻造法）和SLM技术制作4组直径10 mm、厚1 mm的圆形片状试件,每组各10个,分别记为铸造Co-Cr（CC）组、锻造Ti6Al4V（DT）组、SLM Co-Cr（SC）组、SLM Ti6Al4V（ST）组。流水下打磨抛光试件,氧化铝喷砂剂喷砂后,激光扫描共聚焦显微镜（CLSM）检测试件表面粗糙度。室温下干燥后分别烧结瓷粉,采用剪切强度测试法测定各组的金瓷结合强度,并进行统计学分析。体视显微镜观察瓷层断裂模式。场发射扫描电镜（FE-SEM）对金瓷结合界面形貌进行分析。结果　各组试件表面粗糙度未见明显差异（P > 0.05）。CC组和SC组的剪切强度无明显差异,分别为（25.949 ± 2.708）MPa和（26.707 ± 1.559）MPa,均显著高于DT组［（18.259 ± 1.882）MPa］和ST组［（21.504 ± 3.019）MPa］（P < 0.05）,其中DT组低于ST组（P < 0.05）。各组剪切强度测试后金瓷断裂模式均为混合断裂。FE-SEM下观察显示SC组和CC组金瓷界面结合紧密,DT组和ST组金瓷界面偶见气孔和裂隙。结论　SLM技术制作的Co-Cr金瓷结合强度与传统铸造法相当,SLM技术制作的Ti6Al4V金瓷结合强度明显高于传统锻造法。SLM技术作为一种新型的激光3D打印技术,在口腔修复学领域有极大的应用潜力。     

CAD/CAM切削技术在可摘局部义齿支架制作中的应用

目的探讨计算机辅助设计与制作（CAD/CAM）切削技术在可摘局部义齿（RPD）支架制作中的临床应用效果。 方法选取2017年9月至2018年6月南京市口腔医院修复科就诊的Kennedy Ⅰ类牙列缺损患者共26例，采用随机数字表法分为传统方法组和CAD/CAM组，每组13例。常规制取精细印模，其中CAD/CAM组通过扫描石膏模型获取三维数据，CAD RPD支架形态，CAM切削生成支架树脂铸型，常规包埋铸造完成RPD金属支架。传统方法组以常规方法制作支架蜡型，包埋铸造完成RPD支架。临床试戴，比较两种金属支架就位情况，与口内软硬组织的密合度。采用秩和检验的独立样本Mann-Whitney检验进行统计分析。 结果传统方法组制作的RPD支架9例就位顺利，4例经少量调磨就位，而CAD/CAM组制作的RPD支架10例顺利就位，3例经少量调磨就位。两组RPD支架均无大量调磨仍无法就位的现象发生，就位情况间差异无统计学意义（U = 78.0，P = 0.5）。2组患者中均有12例支架密合，1例支架存在≤3处不密合部位的现象，密合情况之间差异无统计学意义（U = 84.5，P = 0.760）。 结论CAD/CAM切削支架蜡型制作的RPD金属支架修复效果可以达到临床要求。     

Process parameter optimization for removable partial denture frameworks manufactured by selective laser melting

Statement of problemSelective laser melting (SLM), an additive manufacturing technology, is expected to replace the traditional lost-wax casting process used in producing removable partial denture (RPD) frameworks. However, studies comparing the accuracy of RPD frameworks and the effects of process parameters are lacking.PurposeThe purpose of this in vitro study was to optimize SLM process parameters and use a quantitative analysis method to improve the accuracy of 3D-printed RPD frameworks.Material and methodsThe orientation and support structure of Kennedy Class II RPDs were designed in various ways by using 2 different software programs, CAMbridge and Magics. The optimum melt-pool parameters, including laser power, scan speed, hatch distance, and layer thickness, were determined empirically before manufacturing 12 RPD frameworks with 4 different process designs by using SLM (n=3). The accuracy of the RPD frameworks was determined by 3D scanning and comparing the 3D scan data with the original standard tessellation language (STL) RPD design with the best-fit algorithm of the Geomagic software program.ResultsOptimum melt-pool parameters were found with the function of density, surface roughness, and productivity (P=180 W, v=1200 mm/s, h=60 μm, t=30 μm). RPD frameworks fabricated by the optimized process parameters (167 ±105 μm) showed significantly better (P<.05) mean ±standard deviation accuracy than the 3 other groups of RPD frameworks manufactured by using the nonoptimized process parameters (180 ±121 μm to 222 ±136 μm). The best accuracy was found with the transverse orientation and interconnected support structure.ConclusionsWith the optimized design of process parameters, clinically acceptable RPD frameworks were produced. The accuracy of RPD frameworks fabricated by using SLM varied according to the design of the process parameters, indicating that SLM technology can replace the traditional lost-wax casting process.     

Comparative study of two commercially pure titanium casting methods

The interest in using titanium to fabricate removable partial denture (RPD) frameworks has increased, but there are few studies evaluating the effects of casting methods on clasp behavior.

Objective

This study compared the occurrence of porosities and the retentive force of commercially pure titanium (CP Ti) and cobalt-chromium (Co-Cr) removable partial denture circumferential clasps cast by induction/centrifugation and plasma/vacuum-pressure.

Material and Methods

72 frameworks were cast from CP Ti (n=36) and Co-Cr alloy (n=36; control group). For each material, 18 frameworks were casted by electromagnetic induction and injected by centrifugation, whereas the other 18 were casted by plasma and injected by vacuum-pressure. For each casting method, three subgroups (n=6) were formed: 0.25 mm, 0.50 mm, and 0.75 mm undercuts. The specimens were radiographed and subjected to an insertion/removal test simulating 5 years of framework use. Data were analyzed by ANOVA and Tukey''s to compare materials and cast methods (α=0.05).

Results

Three of 18 specimens of the induction/centrifugation group and 9 of 18 specimens of plasma/vacuum-pressure cast presented porosities, but only 1 and 7 specimens, respectively, were rejected for simulation test. For Co-Cr alloy, no defects were found. Comparing the casting methods, statistically significant differences (p<0.05) were observed only for the Co-Cr alloy with 0.25 mm and 0.50 mm undercuts. Significant differences were found for the 0.25 mm and 0.75 mm undercuts dependent on the material used. For the 0.50 mm undercut, significant differences were found when the materials were induction casted.

Conclusion

Although both casting methods produced satisfactory CP Ti RPD frameworks, the occurrence of porosities was greater in the plasma/vacuum-pressure than in the induction/centrifugation method, the latter resulting in higher clasp rigidity, generating higher retention force values.     

制作方法对钴铬合金金瓷结合性能的影响

目的 比较铸造钴铬合金与选区激光熔化（SLM）钴铬合金金瓷结合强度的差异。方法 用铸造法和SLM技术制作钴铬合金试件各10个,在中间1/3区域熔附瓷粉,采用剪切力试验测试金瓷结合强度并观察断裂类型。采用SPSS 13.0软件中的t检验对结果进行统计学分析。结果铸造组、SLM组剪切力分别为（33.11±4.98）、（30.94±5.98） MPa,二者间差异无统计学意义（P>0.05）。样本的断裂类型为复合断裂。结论 SLM钴铬合金修复体精密度较高,其金瓷结合强度与铸造钴铬合金相近。     

可摘局部义齿支架的计算机辅助设计与快速制造

目的 自主开发可摘局部义齿支架三维设计软件及选择性激光熔融制造(selective laser melting,SLM)设备,探讨应用其进行可摘局部义齿支架设计并直接成形金属支架的方法 .方法 使用层析扫描仪获得两个牙列缺损模型的三维点云数据.使用自主开发的可摘局部义齿支架三维设计软件进行模型观测及可摘局部义齿支架(牙合)支托、卡环、舌杆、金属加强网、上颌大连接体等组件的设计.组件设计路线:首先确定组织面轮廓,利用轮廓线内的点云数据生成组织面.根据各个组件的特点,设定抛光面截面形态,结合轮廓线生成抛光面.各组件完成后,用小连接体连成完整支架.将完成的支架数据导入SLM设备中,直接成形金属支架.结果 应用自主开发的可摘局部义齿支架三维设计软件及SLM设备,成功进行了两个可摘局部义齿金属支架的计算机辅助设计及快速制造,在模型上试戴后目测金属支架适合性良好.结论 自主开发的具有完全自主知识产权的可摘局部义齿支架计算机辅助设计与辅助制作系统,可为可摘局部义齿金属支架的制作提供一种新的方法.     

激光选区熔化钛合金可摘局部义齿支架的临床应用

目的探讨激光选区熔化(selective laser melting,SLM)钛合金可摘局部义齿支架应用于临床时的效果。方法选取本院就诊的牙列缺损患者共20例,按照制作可摘局部义齿钛合金支架的方法不同而分为2组,SLM组与铸造组。对支架的成功率、就位率、义齿的咀嚼效率以及义齿性口炎发生率分别进行比较。结果数据使用SPSS20.0进行统计分析。结果 SLM组支架的成功率为100.00%,高于铸造组支架的成功率90.00%(P<0.001)。SLM组支架的就位率低于铸造组支架的就位率(P<0.05)。SLM组义齿的咀嚼效率高于铸造组义齿的咀嚼效率(0.783±0.030 vs. 0.699±0.037,P<0.001)。SLM组义齿使用一年的义齿性口炎发生率(10.00%)明显低于铸造组义齿的义齿性口炎发生率(30.00%)(P<0.001)。结论利用SLM制作可摘局部义齿支架在咀嚼效率与降低义齿性口炎发生率优于传统铸造法,可以满足临床使用要求,但跨度大的支架精度有待提高。     

Using Intraoral Scanning Technology for Three‐Dimensional Printing of Kennedy Class I Removable Partial Denture Metal Framework: A Clinical Report

Removable partial dentures (RPDs) are used to restore missing teeth and are traditionally fabricated using the lost‐wax casting technique. The casting process is arduous, time‐consuming, and requires a skilled technician. The development of intraoral scanning and 3D printing technology has made rapid prototyping of the RPD more achievable. This article reports a completed case of direct fabrication of a maxillary RPD metal framework (Kennedy Class I) using intraoral scanning and 3D printing techniques. Acceptable fit and satisfactory clinical outcome were demonstrated. Intraoral scanning and 3D printing for fabrication of the RPD metal framework is a useful alternative to conventional impression and casting techniques, especially for patients suffering from nasal obstruction or intolerance.