可摘局部义齿卡环疲劳的影响因素

研究卡环疲劳的影响因素对确保卡环功能的正常发挥以及延长卡环的使用寿命具有重要意义。本文从卡环的制作材料、组织结构、应力分布、形态、尺寸和使用环境等方面对卡环疲劳的影响因素作一综述。     

可摘局部义齿不锈钢丝卡环的设计

可摘局部义齿不锈钢丝卡环的设计河北医学院口腔医院（０５００１７）陈树国，孟令强，郭红言河北医学院附属二院口腔矫形科廉云敏可摘局部义齿是牙列缺损后进行修复的一种重要手段。其固位体主要为卡环。卡环的设计直接影响着义齿的固位和稳定，目前我国多采用不锈钢丝弯...     

可摘局部义齿卡环对基牙的影响

目的 研究可摘局部义齿卡环对基牙牙体牙周及义齿的修复效果的影响。方法 采用社会调查和门诊连续随访的形式,对被卡环损伤了的３９７颗基牙（１４６名患者的１７９件义齿）进行了调查分析。结果 基牙损伤与年龄、义齿使用时间、义齿类型及义齿质量有关。结论 戴牙时间越长,基牙发生损伤越重。主要原因是基牙与卡环的摩擦过多或卡环位置不当。     

E型卡环在可摘局部义齿中的应用

作者１９９５年９月至１９９７年１２月采用ＥＱＵＩＰＯＩＳＥ卡环（力平衡卡环）即Ｅ型卡环可摘局部义齿修复患者３５例，功能、美观效果均令人满意。一、卡环的设计制作及适应症１．卡环的设计：Ｅ型卡环由邻间隙板、牙合支托及舌侧卡环组成（见图１）。图１Ｅ型卡环的...     

用于可摘局部义齿的一种特殊卡环

双侧后牙缺失 ,牙槽骨严重萎缩的病例 ,按常规设计弯制卡环 ,其稳定性差 ,且易变形、折断 ;设计常规铸造卡环 ,唇颊黏膜常有不适感 ,且折断后修理较困难。为此 ,笔者在尖牙上设计了宽臂铸造卡环 (图 1) ,上缘与导线一致 ,下缘与龈缘平齐 ,内面不进入倒凹区。由于卡臂很宽 ,与基牙之间的摩擦力和制锁作用可获得很好的固位效果 ,而且稳定性好 ,不易变形 ,不易滞留食物残渣 ,光滑的平面使唇颊黏膜感觉舒适。当然 ,由于对基牙覆盖的面积较大 ,易继发龈炎和龋齿 ,应嘱患者加强口腔清洁。图 1　尖牙宽臂铸造卡环用于可摘局部义齿的一种特殊卡环@王…     

隐形卡环在铸造支架式可摘局部义齿中的应用

目的：探讨隐形卡环在支架式可摘局部义齿中的临床应用效果。方法：55例患者制作83件隐形卡环支架式可摘局部义齿修复体,观察义齿的使用效果。结果：除1件修复体因咬合过紧致牙面脱落、一件修复体基牙脱落外。其余修复体使用效果良好,无基牙及牙周组织破坏。结论：只要选择合适的适应症,采用隐形卡环支架式可摘局部义齿修复可取得良好的临床疗效。     

前牙舌面翼板无卡环式可摘局部义齿

为了观察一种新的前牙缺失修复体的修复效果，作者设计一种舌面金属翼板无卡环式局部可摘义齿，人造牙材料可以是树脂或烤瓷临床应用１２例患者，结果表明该修复体美观，舒适，卫生，固位力强，牙体磨除少，有时还可同时修复缺失的后牙舌尖及防止食物嵌塞。作者认为该法可作为一种前牙缺失的美容设计，但必须掌握适应证。     

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]     

可摘局部义齿修复效果的调查

目的：研究可摘局部义齿的治疗结果并探讨与患者满意度有关的因素。方法：通过患者满意度的调查和临床检查，对63例戴可摘局部义齿5年以上的患者的治疗效果进行评价。结果：70％以上的患者对可摘局部义齿满意，约1／5的义齿需要修理，约1／3的修复体与基牙的龋患有关。结论：绝大多数患者戴可摘局部义齿5年后仍可使用修复体。     

纯钛义齿支架表面抛光的临床研究

目的：探索纯钛义齿支架的表面抛光方法，确保义齿有良好稳定的抛光效果，且不影响义齿支架的精度。方法：为78例患者制作105件纯钛可摘义齿，分三组，每组35件，分别为未酸洗，酸洗，酸洗并组织面适量均匀打磨抛光，分别测定义齿戴入时的抛光亮度与义齿与口腔组织的贴合程度和半年后义齿的抛光度。结果：三组之间的义齿与组织的贴合度无显著性差异（P＞0．05），第二，三组义齿的表面抛光度明显好于未酸洗组即第一组（P＜0．001），组织面抛光的亮度第三组明显好于未抛光第二组（P＜0．001），结论：酸洗和组织面的均匀适量打磨抛光可提高纯钛可摘义齿的表面亮度而不影响其精度。     

Impact of removable partial denture prosthesis on chewing efficiency

Removable partial denture prostheses are still being used for anatomic, medical and economic reasons. However, the impact on chewing parameters is poorly described.

Objectives

The objective of this study was to estimate the impact of removable partial denture prosthesis on masticatory parameters.

Material and Methods

Nineteen removable partial denture prosthesis (RPDP) wearers participated in the study. Among them, 10 subjects were Kennedy Class III partially edentulous and 9 with posterior edentulism (Class I). All presented a complete and full dentate opposing arch. The subjects chewed samples of carrots and peanuts with and without their prosthesis. The granulometry of the expectorated boluses from carrot and peanuts was characterized by median particle size (D50), determined at the natural point of swallowing. Number of chewing cycles (CC), chewing time (CT) and chewing frequency (CF=CC/CT) were video recorded.

Results

With RPDP, the mean D50 values for carrot and peanuts were lower [Repeated Model Procedures (RMP), F=15, p<0.001] regardless of the type of Kennedy Class. For each food, mean CC, CT and CF values recorded decreased (RMP, F=18, F=9, and F=20 respectively, p<0.01). With or without RPD, the boluses'' granulometry values were above the masticatory normative index (MNI) determined as 4,000 µm.

Conclusion

RPDP rehabilitation improves the ability to reduce the bolus particle size, but does not reestablish fully the masticatory function.

Clinical relevance

This study encourages the clinical improvement of oral rehabilitation procedure.     

In vitro evaluation of a removable partial denture framework using multi-directionally forged titanium

PURPOSEThis study evaluated the availability of multi-directionally forged (MDF) titanium (Ti) as a component of removable partial dentures (RPDs). MDF-Ti remarkably improved the mechanical properties of RPDs due to its ultrafine-grained structure.MATERIALS AND METHODSThe wear resistance, plaque adhesion, and machinability of MDF-Ti were tested. As controls, commercially pure (CP) titanium was used for wear, plaque adhesion, and machinability tests. For wear resistance, the volume losses of the titanium teeth before and after wear tests were evaluated. Plaque adhesion was evaluated by the assay of Streptococcus mutans. In the machinability test, samples were cut and ground by a steel fissure bur and carborundum (SiC) point. An unpaired t-test was employed for the analysis of the significant differences between MDF-Ti and the control in the results for each test.RESULTSWear resistance and plaque adherence of MDF-Ti similar to those of CP-Ti (P>.05) were indicated. MDF-Ti exhibited significantly larger volume loss than CP-Ti in all conditions except 100/30,000 g/rpm in machinability tests (P<.05).CONCLUSIONAlthough the wear resistance and plaque adherence of MDF-Ti were comparable to those of controls, MDF-Ti showed better machinability than did CP-Ti. MDF-Ti could be used as a framework material for RPDs.     

铸造与冷弯卡环基牙菌斑致龋菌分析

目的 初步探讨可摘局部义齿卡环对基牙健康的影响。方法 对铸造、冷弯卡环可摘局部义齿初截一周前后,基牙菌斑中的主要致龋菌进行分析比较。结果 铸造卡环组初戴一周后,基牙菌斑中粘性放线菌与变形链球菌的百分比分别上升了２．３％和３．８％;冷弯卡环组初戴一周后,上述细菌百分比分别上升了５．９％和３．３％,二者间差异有显著性;铸造卡环组粘性放线菌上升的百分比显著低于冷弯卡环组。结论 可摘局部义齿卡环会增加基牙     

可摘局部义龄基牙健康状况的研究

目的 对比患者不同的口腔卫生习惯,不同的义齿设计,不同的义齿材料等,以分析可摘局部义齿（removable partial dentures,RPDs)对口腔微生态的影响。方法 在患者戴入RPDs3年后,用龋病,牙周病常用指数及口腔卫生指数来检查基牙健康状况,用X^2检验分析它们之间的结果有无差异。结果 患者的口腔卫生习惯,义齿的不同设计均与基牙健康密切相关,而两种不同材料的义齿对基牙的损坏无显著性差异。结论 RPDs基牙的健康与多因素有关,而口腔卫生状况是决定RPDs口腔微生态的重要因素。     

可摘局部义齿支架三维CAD方法的初步研究

目的:通过对KennedyⅡ类2亚类可摘局部义齿支架的三维计算机辅助设计,探索其CAD方法。方法:采用基于点云及曲线曲面的混合建模技术,按照临床设计原则,在牙列缺损三维重建模型上对卡环、支托、舌杆及加强网等支架部件分别构建其组织面、磨光面等,完成支架的三维设计。结果:初步建立了可摘局部义齿支架的三维计算机辅助设计方法,得到了个性化的局部义齿支架的三维几何模型。结论:混合建模技术可以实现可摘局部义齿支架的三维计算机辅助设计。     

磁性附着体在可摘局部义齿修复中的应用

目的：评价磁性附着体在可摘局部义齿修复中的临床效果。方法：为25例患者采用磁性附着体可摘局部义齿修复,追踪随访,通过对口内、X线的检查和修复体的戴用情况评估患者的满意度。结果：对戴用义齿后进行1-4年的随访,20例对义齿的美观性、稳固性、咀嚼功能及牙周健康均感到满意,5例出现牙龈炎和牙槽骨吸收。结论：磁性附着体可摘局部义齿是一种美观、经济、固位好,且对基牙具有保护的修复方式。     

可摘局部义齿支架几何模型的设计

目的:利用国产CAD/CAM软件系统,通过对可摘局部义齿支架的计算机辅助设计,探索开发适用于口腔修复专业义齿设计与数控加工制作的国产软件系统。方法:投影光栅测量法获取下颌KennedyⅡ类2亚类牙列缺损石膏模型的点云数据,在国产CAD/CAM系统中,进行数据精简,并在此点云数据基础上,确立观测线和就位道。按照临床设计原则,分别构建卡环、支托、舌杆、加强网等支架各部件的组织面与磨光面,包括舌杆的半梨形截面、加强网的内外终止线和组织终止点等特征性结构的构建,完成支架的三维几何模型计算机辅助设计。结果:成功建立了可摘局部义齿支架的几何模型。该模型可视性强,便于修改,支架与牙颌模型密合良好。模型的输出数据文件格式为STL,这种通用的传输格式有利于后续的计算机辅助制作。结论:基于国产CAD/CAM软件系统进行可摘局部义齿支架几何模型的设计是可行的。     

Longitudinal clinical evaluation of undercut areas and rest seats of abutment teeth in removable partial denture treatment

Purpose: Adequate preparation of abutment teeth for removable partial denture (RPD) rest seats allows appropriate masticatory force transmission, retention, and stability of supporting structures. It follows that careful preparation will be important for the longevity of the rehabilitation. The present study aimed to clinically evaluate rest seats and undercut areas of abutment teeth in RPD wearers after 2 years of use. Materials and Methods: A total of 193 occlusal, incisal, and cingulum rest seats were evaluated in terms of shape, rest adaptation, wear, caries, fractures, and surface type (enamel, composite resin, or amalgam). Two hundred and fourteen undercut areas were evaluated in terms of surface type (enamel or restoration) and integrity. This study was approved by the Research Ethics Committee of the Federal University of Rio Grande do Norte, resolution 196/1996, protocol number 11/05. Results: Intact preparations accounted for 92.2% of the total. Application of the Pearson test (p= 0.289) found no statistically significant differences among the materials on which the rest seats were prepared. For the undercut areas, 20.7% of those obtained on restorative material were nonintact. In addition, Fisher's exact test showed a statistically significant difference (p= 0.001) in surface type; enamel surfaces were shown to be 14 times more stable than restored surfaces. Conclusions: The results of this study suggest that rest seats are stable, regardless of the material on which they are prepared. Retentive areas were shown to be more stable when they were located in enamel.     

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.