功能重衬印模技术修复下颌游离端牙列缺损的临床研究

[摘要] 目的 探讨用功能重衬印模技术修复下颌游离端牙列缺损患者的效果。方法 在解剖式印模上常规制作义齿,利用印模膏对义齿游离端组织面进行功能重衬。结果 88.89%的患者用功能重衬印模技术制作的义齿疗效良好。结论 功能重衬印模方法 可作为游离端牙列缺损修复的一种良好选择。     

数字印模技术在下颌游离端可摘局部义齿制作中的应用

[摘要] 目的 探讨使用模拟压力数字模型进行游离端可摘局部义齿制作技术的应用。方法 对21个研究对象采用2种不同方法制作义齿。实验组使用3shape口腔数字印模仪扫描患者口腔软硬组织形态及咬合关系,生成数字模型,与患者CBCT数据一同导入义齿设计软件。依据余留牙位置将CBCT影像与数字模型进行拟合对齐，获得骨形态与对应粘膜厚度信息。对数字模型进行虚拟磨除或缓冲操作，生成模拟压力数字模型，在此模型上设计义齿支架，3D打印支架，最后排牙充胶完成义齿制作。对照组采用模型置换技术获得压力印模模型完成义齿制作。通过测试对比两组义齿临床效果，并对两种方式取得的工作模型游离端上对应的63个位点粘膜形态差异进行测量分析。结果21个研究对象，实验组粘膜压痛比例4.76%明显低于对照组23.81%。模拟压力数字模型与压力印模模型对应的63个位点粘膜差异性分析显示，近基牙端牙槽嵴顶软组织变形，实验组与对照组没有显著性差异，P＝0.11；远基牙端实验组软组织形变显著大于对照组，P＜0.05；下颌隆突区实验组比对照组有更多缓冲空间，形态存在显著性差异，P＜0.05。结论 将数字化印模与CBCT数据拟合进行个性化数字模型修整，可以选择性调整粘膜压力分布，有效缓解游离端可摘局部义齿游离端不均匀下沉及压痛，临床效果满意。     

游离端可摘局部义齿修复的印模技术

游离端缺失可摘局部义齿修复的印模技术有其特殊性，并对义齿功能的发挥起着重要的作用。本文对于游离端缺牙的特点和存在的问题进行了分析，结合近年来的进展对于功能重衬法、模型置换印模技术、双重印模法以及选择性压力印模法逐一进行了介绍，分析了各种不同的印模法的优缺点和适应范围。     

隐形义齿与铸造支架联合修复双端游离缺失的临床探讨

目的：探讨采用隐形义齿与铸造支架联合修复双端游离缺失的临床效果。方法：采用弹性树脂做基托和唇（颊）侧固位体,缺失区和支托采用铸造支架,制作修复件27件,修复双端游离缺失23例。患者戴用1年后进行临床观察。结果：弹性树脂与铸造支架联合义齿的美观舒适感、食物嵌塞、基牙情况等较传统活动义齿均有明显改善。结论：弹性树脂与铸造支架联合义齿修复双端游离缺失是一种解决游离端缺失修复的好方法。     

余留牙缺失后原铸造可摘局部义齿的焊接修复

目的研究原有铸造可摘局部义齿(RPD)修复的患者,在余留牙缺失后,直接在原支架义齿上修复失牙的一种方法。方法将原RPD放入患者口内,取印模,磷酸盐高温包埋粉灌注模型,用氩弧焊在失牙区焊接固位装置。若基牙缺失,则另选基牙,常规牙体制备,脱模制作固位体,并与原RPD支架焊接在一起,再修复缺失牙。对义齿进行2～3年随访及复诊观察。结果18件RPD义齿,经氩弧焊焊接固位装置,修复缺失余留牙,随访发现1件焊接处断裂,1件再修复义齿脱落,总失败率11.11%,余者完好。结论氩弧焊接固位装置,修复RPD余留牙缺失,是一种可行有效的方法。     

牙列游离端缺损可摘局部义齿数字化制作流程初探

探讨牙列游离端缺失可摘局部义齿的数字化制作流程。选择2021年11月至2022年12月于第四军医大学口腔医学院口腔修复科就诊的牙列游离端缺损患者12例, 男性7例, 女性5例, 年龄(59±3)岁。采用口内扫描技术获取牙列、牙槽嵴及颌位关系的三维模型, 常规设计制作并试戴可摘局部义齿金属支架。金属支架就位于口内, 再次口内扫描获取牙列、牙槽嵴及金属支架的复合模型, 采用虚拟模型置换游离端牙槽嵴数字化印模的方法获取游离端修正模型。在游离端修正模型上设计栓体栓道式树脂基托及人工牙列三维模型, 并采用数字化切削技术制作基托及人工牙列树脂模型, 利用栓体栓道精准就位基托及人工牙列, 并用注塑树脂粘合金属支架、树脂基托及人工牙列, 打磨抛光后完成可摘局部义齿的制作。临床试戴后与设计数据对比, 结果显示在人工牙列、树脂基托与就位栓体连接杆的连接处以及人工牙列与树脂基托连接处存在0.4～1.0mm的误差, 面误差为0.03～0.10mm。12例患者戴用义齿后, 仅2例患者因压痛而复诊调磨, 其余病例未见任何不适。本项研究使用的可摘局部义齿数字化制作流程可基本解决游离端修正模型的数字化制取以及树脂基托...     

不同印模法对KennedyⅡ类牙列缺损修复时牙槽骨吸收的影响

目的：运用锥形束CT（cone beam CT,CBCT）评价解剖性印模法和功能性印模法修复下颌KennedyⅡ类牙列缺损患者牙槽骨吸收情况。方法选择下颌KennedyⅡ类牙列缺损患者16例,随机分为功能组和解剖组,每组8例。功能组采用功能性印模,解剖组采用解剖性印模。戴义齿前、正常使用义齿6个月后用CBCT分别测量末端基牙近中、远中牙槽骨及远中游离端剩余牙槽骨骨高度,并计算戴牙前、后的高度差值。结果正常使用义齿6个月后,解剖组末端基牙近中（t=0.742,P＜0.05）、远中牙槽骨高度差值（t=5.727,P＜0.05）明显高于功能组;功能组和解剖组的游离端剩余牙槽骨高度差值差异无统计学意义（P＞0.05）。结论应用功能性印模制作的可摘局部义齿有减少末端基牙近远中牙槽骨骨吸收的趋势,短期内对游离端剩余牙槽骨骨吸收影响不明显。     

组织调节剂在无牙颌功能性印模中的临床研究

目的：将组织调节剂的重衬义齿技术应用于无牙颌功能性印模技术中,评价其对下颌牙槽嵴严重吸收的无牙颌病例临床修复效果的影响。方法：选择36例下颌牙槽骨广泛吸收的无牙颌老年患者,其主诉为经反复修改后的原义齿仍然有压痛（17名）和易脱位（34名）,要求重做义齿。印模时在义齿蜡型暂时基托组织面涂布组织调节剂,嘱患者作正中咬合,并以主动方式完成印模边缘整塑,修整后再在组织面用藻酸盐印模料取模,以此作终印模。结果：36例患者戴用重新制作的义齿后咀嚼疼痛得到解决,义齿固位显著提高。结论：将组织调节剂重衬义齿技术应用于功能性印模中,能预防性地避免印模不准确造成的咀嚼疼痛和固位不佳等问题。     

张口受限患者的数字化修复1例及文献回顾

目的 探讨因系统性硬皮病导致的特殊张口受限（小口畸形）患者取模困难时准确得到其口内模型的方法。方法 本研究遵循医学伦理,并获得患者知情同意。对1例肯氏Ⅰ类下颌牙列缺损的硬皮病张口受限患者应用以数字化技术为主导,结合传统印模方式的分段印模方案。根据其本身的左、右下颌牙列制作个别托盘后进行分段式取模,同时口内扫描取得上、下颌软硬组织形态数据。在获得各部分模型后,对下颌模型进行扫描和数字对齐,形成最终的牙列模型,并借助CAD/CAM技术设计制作最终的可摘局部义齿,同时结合文献对张口受限患者可摘局部义齿修复诊疗进行回顾分析。结果 义齿固位良好,获得了良好的修复效果,患者对该义齿的咀嚼效率等功能行使均满意。文献复习结果表明,数字化技术结合传统印模方法,利用计算机进行拟合可以准确地得到患者口内模型,为后续修复做好基础工作。然而患者下颌牙列前段无牙时该流程误差可能较大,仍需要进一步完善。结论 以数字化技术为主导,结合传统印模方式的分段印模方案用于修复张口受限患者的牙列缺损效果良好,患者就医体验、满意度高,值得临床推广。     

总义齿修复中应用闭口式印模法的体会

制作总义齿时,本着一切以口腔内具体情况为依据的基本原则,我们采用了闭口式印模法[1](也称二次印模法),取得满意效果,现报道如下。2003年1月至2005年6月,我科总义齿修复的患者共68例,其中男性39例,女性29例,年龄45-76岁。初次修复总义齿者47例,原有全口假牙再次修复全口义齿者21例。随机分成A、B两组,每组34例。操作方法:常规制作总义齿所需全部器械和材料。对A组病人,应用传统方法先取印模、制作蜡基托、蜡堤、转移咬合关系、上牙合架、排牙、调牙合、试戴,再回到石膏模型上装盒、热处理等;对B组患者,应用闭口式印模法,也是先取模、制作…     

The altered cast impression technique revisited

BACKGROUND: The altered cast impression technique of fabricating removable partial dentures, originally described more than 60 years ago, improves the residual-ridge-to-dentition relationship of the prosthesis. This potentially increases patient satisfaction while preserving the remaining supporting structures. LITERATURE REVIEWED: This article reviews research that evaluated abutment tooth movement as a result of the relationship of the denture base to the residual ridge, revealing that improved fit reduced tooth movement. Load distribution studies have shown that a well-fitting denture base distributes stresses favorably to the supporting bone and abutment teeth. Other studies showing that increased residual ridge coverage coupled with a well-fitting denture base reduces stress per unit area, potentially preserving the remaining supporting structures. CASE DESCRIPTION: The article describes a patient who had a unilateral distal extension removable partial denture that was fabricated after the failure of a 20-year-old partial denture due to extensive dental decay. The prosthesis was fabricated over the course of four appointments, and the prosthesis was delivered on the fifth appointment. The patient, who wears the prosthesis daily, expressed comfort and ease of use at a one-year recall examination. CLINICAL IMPLICATIONS: Distal extension edentulism can affect a patient's ability to function as a dentate person. A well-made removable partial denture that has appropriate extensions, borders and ridge-to-dentition relationship will benefit the partially edentulous patient by providing increased comfort and improved dental function.     

Prefabricated custom impression trays for the altered cast technique

Removable partial prosthodontic treatment requires multiple patient appointments with intermediate laboratory steps. A technique is described that allows the removable partial denture framework try-in and the impression for the altered cast to be efficiently completed in a single appointment. The method uses prefabricated custom impression trays that are readily attached to the framework after the try-in.     

Clinical outcome of the altered cast impression procedure compared with use of a one-piece cast

STATEMENT OF THE PROBLEM: An altered cast impression procedure to improve the support of distal extension removable partial dentures is widely taught, but not often used in dental practice. PURPOSE: The purpose of this study was to determine the efficacy of an altered cast compared to a one-piece cast with regard to base support, abutment health, and patient comfort over time. MATERIAL AND METHODS: Seventy-two patients receiving a mandibular bilateral distal extension removable partial denture were assigned randomly for treatment using either a one-piece or an altered cast. All impressions and associated laboratory procedures were made by one investigator. A second investigator evaluated extension, support, and adaptation of the denture bases by observation of border length and lifting of the indirect retainer from its seat. The space between the soft tissues and the base when the framework was related to the teeth was measured cross-sectionally at half the length of the denture base. Mobility, gingival index, and sulcus depths at 6 locations around each abutment tooth were recorded at insertion and again 1 year later. Chi-square tests were used to evaluate differences between the treatment groups (alpha=.05). RESULTS: There was 0.15 mm less space between the ridge crest and base in the altered cast group (P<.01), and underextension of the base occurred only in the one-piece cast group (P=.01). At insertion, no tissue-ward movement was observed in 85% of the prostheses when anterior-posterior rotation was attempted. Fifteen subjects (21%) were lost to recall at 1 year, but they were distributed equally between the 2 groups. Of the remaining 57 prostheses, 42% exhibited decreased base support and 33% had increased gingival inflammation; the deepest probing depth decreased in 61%, mobility decreased or remained the same in 80% of the direct abutments, and 88% of the subjects were satisfied. None of these findings were related to the impression procedure. CONCLUSION: The altered cast impression procedure does not offer significant advantages over the one-piece cast, provided the standards used in this study are met. These include a completely extended impression, use of magnification to adjust and ensure complete seating of the framework, and coverage of the retromolar pad and buccal shelf by the base.     

Repair with a surveyed cast clasp while patient retains the partial denture

A technique is described that allows a removable partial denture with a broken clasp or a removable partial denture in which an abutment has been extracted to be restored by the reattachment of a new cast clasp component or a complete surveyed clasp assembly. The technique is applicable to most clasp designs and can include attachment to the acrylic denture base or the metal major connector. The technique is distinguished from other repair techniques by (1) providing a cast clasp replacement, (2) allowing the patient to retain the prosthesis during the repair, (3) generating a precisely formed surveyed clasp assembly by the laboratory, and (4) including an efficient transfer mechanism for the precision clasp created in the laboratory to be attached to the removable partial denture in the dental office. A two-step impression procedure is used to ensure proper relation of the partial denture to the abutments. (J Prosthet Dent 1997;77:624-9.)     

激光选区熔化技术制作纯钛可摘义齿支架的可行性研究

目的    探讨激光选区熔化技术制作牙科纯钛义齿支架的可行性,并评价不同打印支撑方向对纯钛支架适合性、力学性能和显微结构的影响。方法    采用激光三维金属打印机按照垂直支撑和横向支撑方向各打印制作15个哑铃状拉伸试件,经真空热处理后,测试其力学性能,并使用激光共聚焦显微镜观察拉伸试件的内部组织结构。用3shape D2000扫描仪对一个上颌无牙颌和一个下颌牙列缺损标准模型进行扫描,建立通用的模型设计文件。采用3shape相应的可摘义齿设计软件包设计义齿支架的数字化模型,按照拉伸试件相同条件,各打印6个纯钛义齿支架,经热处理后在标准模型上检查支架的就位情况,用X线检测纯钛支架内部的气孔。结果   打印支撑方向对拉伸试件的力学性能有显著影响,横向支撑打印试件的弹性模量、屈服强度、极限拉伸强度高于垂直支撑打印试件,但试件的延伸率结果则相反,且各个机械性能数值之间的差异均有统计学意义（均P < 0.05）。纯钛义齿支架在上下颌标准模型上的适合性良好,常规X线检测未发现钛试件内有气孔存在,但2种支撑方向打印的纯钛试件组织致密性都欠佳,内部存在散在气孔。结论   激光选区熔化技术制作的纯钛可摘义齿支架适合性良好,机械性能够满足临床要求,但打印支撑设计显著影响试件的力学性能和显微结构。     

选择性激光熔覆(SLM)钛合金可摘局部义齿支架的适合性研究

目的:评价选择性激光熔覆(SLM)技术制作的钛合金可摘局部义齿的适合性.方法:用选择性激光熔覆(SLM)技术制作7 个肯氏Ⅲ类Ti-6Al-4V可摘局部义齿支架,采用光学扫描仪分别扫描通过"印模法"得到的粘附有硅橡胶薄膜的石膏模型,以及去除该薄膜的石膏模型的光学印模,导入Geomagic Qualify软件,通过3D比较功能分析支架大连接体组织面与模型之间的间隙,对其适合性进行评价.结果:钛合金支架与模型之间的总体3D偏差值为(0.221 9±0.07) mm.结论:SLM技术制作的钛合金可摘局部义齿支架的适合性基本满足临床要求.     

Using Silicone Impression Material and Acrylic Resin to Fabricate Remount Casts for Removable Partial Dentures

A technique is described for fabrication of a remount cast for a removable partial denture. This procedure consists of filling the occlusal/incisal third with acrylic resin and injecting polyvinylsiloxane impression material into the irreversible hydrocolloid impression. This technique provides a simple method for making a remount cast and enables the clinician to remove and easily place the partial denture on the cast during occlusal refinement procedures without damage to the removable partial denture or the remount cast.     

Fabrication of a removable partial denture combining conventional and digital techniques

This article describes a combined conventional and digital workflow for fabricating removable partial dentures (RPDs). After scanning the dental cast and RPD framework assembly, artificial teeth and denture base regions were designed using computer-aided design software. The artificial teeth and denture base assembly was milled as a single structure by using a wax disk and then placed on the RPD framework. The artificial teeth were additionally milled from a polymethyl methacrylate disk. Conventional procedures were followed for denture investment until the wax elimination procedure, after which the assembly was replaced with the artificial teeth in the cope of the flasks, and the denture resin material was injected to process the RPD. This technique enabled the RPD to be fabricated in the same form as the design state.     

Abstracts from the Table Clinic Session of the Annual Session of the American College of Prosthodontists October 28, 2004

Yung-tsung Hsu , DDS MS Assistant Professor   UAB School of Dentistry
For a removable prosthesis, the best way to perform occlusal equilibration is to remount the prosthesis on the articulator. To remount a removable partial denture, a remount cast must be fabricated. Many techniques have been presented in the literature, including fabrication with stone, occlusal registration material, or silicone impression material. This presentation will compare several different techniques for making remount casts for removable partial dentures. A new technique of using the silicone impression material with acrylic resin and dental stone will also be demonstrated.     

Index to reposition the metal framework accurately on the altered cast.

The relieved portion of a master cast below the major connector of a cast removable partial denture framework can be filled with dental stone to act as a third point of reference when the framework is reseated in an altered cast procedure. With this simple procedure, an index is formed that will allow accurate repositioning of the metal framework on the altered cast.