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。     

数字化印模对可摘局部义齿临床适合性的影响

目的: 探讨口内数字化印模制取方法对可摘局部义齿临床适合性的影响。方法:选择Kennedy第三类或第四类牙列缺损患者47例,采用硅橡胶印模灌制超硬石膏(传统模型组)和3shape Trios口内扫描仪制取数字化印模结合3D打印树脂模型(数字化模型组)两种方法为每一例患者制作两副铸造可摘局部义齿,检查义齿初戴过程中固位体、大连接体和基托与口内软硬组织的适合性和咬合的准确性并评分,对各项计分结果行χ²检验。结果:数字化模型组制作的可摘局部义齿固位体的适合性和咬合准确性优于传统模型组,差异有统计学意义(P<0.05);两组可摘局部义齿大连接体和基托的适合性差异无统计学意义(P>0.05)。结论:数字化印模结合3D打印树脂模型可提高可摘局部义齿与天然牙的适合性及义齿初戴时咬合的准确性。     

数字化印模技术在可摘局部义齿中的应用现状

可摘局部义齿具有强度高、价格低、适应证广、创伤小及可修理等特点,是治疗牙列缺损的重要手段之一。随着人口老龄化日趋凸显,可摘局部义齿在未来仍将是一种常用的修复方式。可摘局部义齿的制作离不开精确的印模技术,传统可摘局部义齿印模制取过程中存在诸多不足,如就诊次数多、耗时长、制作过程复杂、污染高、浪费多、效率低、质量不易控制等。然而,数字化印模的出现为可摘局部义齿印模的制取提供了新的技术支持,数字化印模技术具有高精度、舒适性、高效、缩短治疗时间以及个性化设计等优势,有助于提高可摘局部义齿修复的效果和患者的满意度。数字化印模技术作为全程数字化可摘局部义齿修复诊疗的前提和基础,其对口腔模型重建的精度直接影响最终义齿修复效果。目前,数字化印模技术已广泛运用于口腔修复领域,本文将对数字化印模技术在可摘局部义齿中的应用现状进行综述,以期进一步指导临床应用。     

数字化印模技术在可摘局部义齿中的应用及其准确度的影响因素

数字化印模技术已经是临床较为常用的印模方式之一,并被广泛应用于牙列缺损的可摘局部义齿修复领域。该文介绍了可摘局部义齿修复中数字化印模技术的应用,并对数字化口内印模技术准确度的相关影响因素进行综述分析,以期为临床应用提供指导。     

可摘局部义齿

弹性义齿与传统可摘局部义齿对牙周情况影响的比较,套筒冠-卡环联合同位在可摘义齿中的应用,第七届国际口腔磁性附着体专题研讨会纪要[编者按]     

可摘局部义齿

观测器在可摘局部义齿修复中的临床应用调查；He支托的设计对隐形义齿咬合力的影响；铸造支架与隐形义齿联合修复的临床应用；     

A self-locking posterior attachment for removable tooth-supported partial dentures

• 1.A positive-locking posterior attachment for tooth-supported partial dentures has been described.
• 2.This attachment is limited in its application by the length of span of the pontics to be supplied and by the vertical length required in the most anterior pontic.
• 3.Where indicated, it reduces the number of attachments dependent upon either friction or resiliency of metal retainers.
     

Provisional removable partial and complete prostheses

The incorporation of the use of provisional removable complete and partial prostheses is an extremely valuable diagnostic and therapeutic modality in the comprehensive rehabilitation of the partially and fully edentulous patient. There is no question that the use of this restoration addresses many of the chief complaints of patients in a timely fashion and, in so doing, builds a high degree of confidence in the dentist by the patient. The evaluation of the provisional restorations and their subsequent refinement results in a higher quality, more predictable definitive restoration. Experience has demonstrated that postinsertion problems are reduced with the definitive prosthesis following successful therapy with the provisional restoration. The provisional prosthesis is also valuable as a "spare" denture after insertion of the definitive prosthesis. The role of the provisional removable prosthesis is readily understood and accepted by most patients, and the appropriate use of these restorations in prosthetic dentistry is an indication of a high-quality, highly individualized, and service-oriented dental practice.     

Quality of written communication and master impressions for fabrication of removable partial prostheses in the Kingdom of Bahrain

The aim of this study was to examine the quality of written instructions and choice of impression trays and materials for removable partial dentures (RPDs) in the Kingdom of Bahrain. All six private dental laboratories in Bahrain were contacted and invited to participate in the study. Five laboratories participated, and submitted written instructions received by them for fabrication of both acrylic (A-RPDs) and cobalt-chromium (CC-RPDs) RPDs. These were examined for evidence of selected design variables. Types of impression trays and materials used were also recorded. One hundred and thirty-one written instructions were examined. Eleven percent (n = 14) were for CC-RPDs, 89% (n = 117) for A-RPDs. All treatments were provided on a private basis. Fifty-seven percent (n =1 8) of CC-RPD instructions requested the technician to design the prosthesis, 43% (n = 6) contained a diagram and 43% (n = 6) mentioned all design variables. Seventy-nine percent (n = 92) of A-RPDs requested the technician to design the denture, and only 1% (n = 1) mentioned all design variables. Alginate impression material was most commonly used for master impressions (83% of impressions (n = 109); 85% (n = 99) of A-RPDs, and 71% (n = 10) of CC-RPDs). Master casts were poured after a minimum of 24 h. Acrylic custom trays were used in 14% (n = 19) of cases (43% (n = 6) of CC-RPDs; 13% (n = 15) of A-RPDs). The quality of written instructions to dental laboratories for the fabrication of RPDs was found to be inadequate in Kingdom of Bahrain. There was widespread use of inappropriate impression trays and materials.     

Use of CAD/CAM technology to fabricate a removable partial denture framework

This article reports on the first patient-fitted chromium cobalt removable partial denture framework produced by computer-assisted design, computer-assisted manufacture and rapid prototype technologies. Once the dental cast was scanned, virtual surveying and design of the framework on a 3-dimensional computer model was accomplished. A rapid prototype machine was used for direct fabrication of the alloy framework. Traditional finishing techniques were applied, the framework was assessed by a clinician in a conventional manner, fitted to the patient, and judged to be satisfactory by both the patient and clinician.