牙尖斜度对套筒冠义齿基牙位移的影响

目的:探讨人工牙牙尖斜度对单侧游离端套筒冠义齿基牙位移的影响。方法:建立肯氏II类塑料模型,制作不同牙尖斜度的套筒冠义齿,在食片介在的咬合状态下垂直加载29.4、49、68.6N时,测量基牙位移值,通过计算求出各方向的位移、扭转量,最后进行统计分析。结果:解剖式人工牙与25°半解剖式人工牙相比,两基牙在颊舌向及垂直向位移差异有统计意义(P<0.05);解剖式人工牙与12°半解剖式人工牙相比,基牙在各方向的位移、倾斜、扭转差异均有统计意义(P<0.05);无尖人工牙与25°半解剖人工牙相比,除近远中向外,基牙的位移、倾斜、扭转差异均有统计意义(P<0.05);无尖人工牙与12°半解剖人工牙相比,基牙水平扭转程度差异无统计意义(P>0.05)。随负荷力增加,基牙位移量、倾斜角度、水平扭转角度也随之增加,各组之间差异有统计意义(P<0.05)。结论:套筒冠义齿修复下颌牙列单侧游离端缺损时,减小人工牙牙尖斜度,基牙在各轴向的位移、倾斜、扭转程度随之减小;基牙的位移量与负荷力大小有关。     

应用CEREC3 CAD/CAM对上颌隐裂磨牙牙尖斜度的研究

目的：通过隐裂磨牙牙尖斜度的测量,从牙体解剖结构上探讨磨牙隐裂的病因。方法：选取隐裂组、对照组磨牙模型,应用CEREC3 CAD/CAM测量出各自的牙尖高度、牙尖斜嵴的长度及牙尖之间的距离,利用三角函数计算出牙尖斜度及近中颊舌斜面夹角、远中颊舌斜面夹角。结果：在近中颊尖斜度、近中舌尖斜度、远中颊尖斜度、远中舌尖斜度方面隐裂组比对照组大;在近中颊舌斜面夹角、远中颊舌斜面夹角大小方面隐裂组比对照组小,经成组t检验,有显著差异（P〈0.05）。结论：牙体解剖学因素与牙隐裂发病关系密切,牙尖斜度的大小是磨牙隐裂重要病因之一,牙尖斜度越大,牙尖斜面夹角越小,隐裂发生的可能性越大。     

老年人可摘局部义齿修复对基牙的影响

目的:分析研究老年人可摘局部义齿修复后对基牙的影响,探讨其原因及预防措施。方法:对95例牙列缺失后的老年人行冷弯卡环固位式可摘局部义齿修复,记录和比较戴可摘局部义齿后基牙和非基牙的龋坏率和缺失率,用χ2检验分析其结果有无差异,并对影响基牙的原因进行分析。结果:戴用可摘局部义齿5a后,基牙的患龋率(17.38%)显著高于非基牙(7.10%);因牙折、牙周病松动及龋坏无法保留而拔除的基牙缺失率(27.01%)也显著高于非基牙(7.79%)(P<0.01)。结论:冷弯卡环固位可摘局部义齿修复后在一定程度上可增加老年人基牙的患龋率和缺失率。     

The effect of various clasping systems on the mobility of abutment teeth for distal-extension removable partial dentures.

Three clasping systems were placed in five patients, and measurements of abutment tooth mobility were made. These data were compared to previously established baselines and statistically analyzed. The findings of the study are: 1. There was no difference in abutment tooth mobility during the 4-week test period with each of the three clasping systems. The important factor may have been the fit of the distal-extension denture base over the residual ridge, which provides the stability to prevent increases in abutment mobility. 2. Any mobility increases were in a buccal direction only, or toward the flexible retentive clasp arm. There was never any change in lingual mobility. 3. All five patients chose the I-bar retainer as the design of choice due to its increased resistance to dislodgment. Periodic recall of distal-extension removable partial denture patients is mandatory to ensure proper stress distribution and prevent increases in abutment tooth mobility.     

可摘局部义齿基牙楔状缺损充填修复的疗效评价

目的：比较应用GCFujiIXGP玻璃离子水门汀、Dyract复合材料及银汞合金三种材料对可摘局部义齿基牙颈部楔状缺损的临床修复疗效。方法：79例186颗楔状缺损可摘局部义齿基牙,缺损部位分别用GCFujiIXGP玻璃离子水门汀、Dyract复合材料及银汞合金修复,修复2年后用改良的USPHS系统评价修复体的疗效。结果：银汞合金修复效果好于另外两组。结论：银汞合金适合修复可摘局部义齿基牙的楔状缺损。     

Management of bruxism-induced complications in removable partial denture wearers using specially designed dentures: a clinical report

In patients with a limited number of remaining teeth, bruxism force can be destructive for both the remaining teeth and periodontal structures. This paper reports the successful management of four such patients with severe sleep bruxism, using conventional removable partial dentures and specially designed, splint-like removable partial dentures called a night denture. The night denture was fabricated in two different designs, which depended upon the pattern of the remaining tooth contacts. The patients were followed up for 2-6 years using a night denture in either of the two designs. Within the limitations of these four reports of clinical cases, the night denture appeared to be effective in managing the problems related to sleep bruxism.     

Basis of the algorithm of patient conducting using removable dentures in case of partial teeth loss

Paper is devoted to the actual problem in stomatology - removable dentures influence upon the intensity of prosthetic bed relief changes. Study of prosthetic bed relief in patients who for 2 years had used plate removable and clasp dental prostheses was done. The most pronounced prosthetic bed relief changes were seen under plate type of prostheses with prolonged defects the least - in patients with plate type of prostheses with short defects. In cases of end defects under clasp dental prostheses changes of prosthetic bed relief exceeded relief changes under plate type of prostheses during all terms of use. Based upon the received data algorithm of patient conducting during different terms of use by plate removable and clasp dental prostheses.     

上颌全口义齿基托多因素三维有限元分析

目的：研究不同腭穹隆形状时,人工牙排列位置、牙尖斜度对上颌全口义齿基托应力分布状况的影响,为上颌全口义齿修复的优化设计提供理论依据。方法：应用三维有限元应力分析法,研究在不同腭穹隆形状时,人工牙排列位置、牙尖斜度对上颌全口义齿基托应力分布状况的影响。结果：各种载荷条件(三种腭穹隆形状、五种人工牙排列位置)下,随着牙尖斜度的增加,基托的应力增大。后牙颊向偏离牙槽嵴顶,前牙唇向偏离牙槽嵴时,基托应力集中区的强度均发生变化。三种腭穹隆形状时,基托应力集中强度依次为：腭穹隆低平、腭穹隆适中、高腭穹隆。结论：牙尖斜度、腭穹隆形状和人工牙的排列位置对上颌全口义齿基托的应力集中状况有明显的影响作用。提示临床行全口义齿修复时,应考虑患者腭穹隆形状,选择适当牙尖斜度的人工牙,特别是腭穹隆低平患者。     

Influence of interocclusal distance of mandibular unilateral distal extension removable partial denture on masticatory function]

The purpose of this study was to elucidate the influence on masticatory function when the mandibular unilateral distal extension removable partial denture changed the interocclusal distance. The experiments, crushability, the sense of mastication, and the masticatory strokes until swallowing, were conducted, on four subjects, using the denture with the apparatus that enabled to change the interocclusal distance. The results were as follows: The particle size distribution showed that the ratio of small particle (diameter 2.5-4.5 mm) decreased, while that of large particle (more than 5.0 mm) increased, on three of four subjects, and the value of crushability diminished. A reduction of the value of crushability when the interocclusal distance was extended more than 800 microns was found. As for the other subject, no change was recognized on the particle size distribution under experimental condition, and the value of crushability showed no significant change.     

Longitudinal study on forces transmitted from denture base to retainers of lower distal-extension removable partial dentures with conus crown telescopic system

The purpose of this study was to perform longitudinal measurement of forces transmitted from the denture base to retainers of lower distal-extension removable partial dentures with a conus crown telescopic system. The experimental denture was embedded with a force-detecting unit which could detect a change in lateral and vertical forces transmitted from denture base to retainers at the same time. Forces were measured during chewing of food on several separate occasions from the insertion of new dentures to about 3 months after. Max.ver (maximal mean value of vertical force) and Max.lat (maximal mean value of lateral force) were calculated from the peak level of all strokes of chewing of food at the minimum of the interocclusal distance.
The results are summarized as follows:

• (i)

  There were no significant changes of Max.ver and Max.lat;
• (ii)

  There were no significant differences of Max.ver between subjects the value of which was about 20 N;
• (iii)

  There were significant differences of Max.lat between subjects the value of which was less than 15 N.

     

The effect of removable partial dentures on the oral function in shortened dental arches*

In this study the effect of free-end removable partial dentures (RPD) on oral function was investigated by comparing subjects with shortened dental arches (SDA, n=55) and a group of subjects with SDA and RPD (n=25). In addition, a group of subjects were selected who had worn an RPD in the past (n=19). All subjects had a remaining natural dentition consisting of an intact front region and three to five occlusal units (OU) in the posterior area. On the whole, subjects with RPD had less natural OU compared with subjects without RPD. However, this is also true for those who had worn an RPD in the past. The oral functions of subjects with SDA did not differ significantly when compared with subjects with SDA and RPD. Significantly more subjects who had an RPD in the past reported a limited mobility of the mandible, an impaired chewing capacity and chewing with the front teeth. They also reported more aesthetic complaints due to missing posterior teeth. It is concluded that within the populations investigated in this study oral function is not evidently improved by the insertion of a free-end RPD.     

成都市老年人可摘局部义齿戴用情况和修复效果调查

目的了解可摘局部义齿（RPD）戴用者戴用义齿后口腔卫生知识的知晓情况、义齿戴用的满意度、义齿对口腔软硬组织的影响,以针对性地进行口腔健康教育,为RPD的制作提供建议。方法对成都市307名戴用RPD的老年人进行问卷式调查并对其行统计学分析。结果 307名被调查者中有良好的口腔清洁习惯和正确刷牙方法者比例较高,但了解定期洁治术和使用牙线者仅分别为10.1%和2.9%。现有义齿使用的平均年限为6.94年,93.8%的人认为义齿应坏了才需更换,每3～6个月定期复查者仅有1.0%。87.6%以上被调查者对RPD满意。基牙龋坏率14.5%。组织面清洁情况依次与吸烟、食物嵌塞、睡前是否取下义齿、洁牙、刷牙习惯、义齿使用年限和清洗义齿方法相关。结论 RPD能取得较好的修复效果,戴用者口腔保健意识和复诊意识应加强。     

Detection of improvement in the masticatory function from old to new removable partial dentures using mixing ability test

The aim of this study was to determine the sensitivity of the Mixing Ability Test to detect improvement of masticatory function in subjects on transition from old to new removable partial dentures. Thirty-two subjects (seven males, 25 females, mean age 65.0 years) with distal extension partially edentulous area in mandible and/or maxilla participated in the study. The following reasons were presented for replacing the old removable partial dentures with new ones: fracture and/or poor fitness of retainers, extraction of abutment teeth, poor fitness of denture base, severe wear of artificial teeth and request for metal base dentures. Masticatory function with old and new removable partial dentures after an adaptation period (mean 27.4 weeks) was evaluated by the Mixing Ability Test. Subjects were asked to masticate five two-coloured wax cubes with each removable partial denture. Mixing Ability Index was obtained from the colour mixture and shape of the masticated cubes. Wilcoxon signed-rank test was used to test the difference of Mixing Ability Indexes between old and new removable partial dentures. The mixing ability indexes with new removable partial dentures (mean+/- s.d.: 0.70+/- 0.68) was significantly higher (P<0.001) than those with old removable partial dentures (-0.11+/-1.13). The results suggest that the Mixing Ability Test was capable of detecting improvement in masticatory function with new removable partial dentures.     

充填方式对种植义齿固定螺丝孔粘接强度及密封性的影响研究

 目的　研究不同充填方式封闭种植义齿固定螺丝孔对粘接强度及密封性的影响。方法　制作上颌第一前磨牙种植螺丝固位氧化锆冠试件80件，按照粘接前是否喷砂预处理、充填树脂种类、充填深度随机均分为8组，分别置于墨水溶液7 d，万能材料实验机上对螺丝孔内树脂充填体进行推出测试，记录树脂充填体脱粘接时的瞬间载荷，并取出树脂充填体，显微镜下观察记录并比较充填体染色的范围。结果    是否喷砂及树脂种类对粘接强度的影响均具有统计学意义（P < 0.01）；充填体厚度会显著影响粘接断裂载荷大小（P < 0.01），但对粘接强度的影响无统计学意义（P = 0.09）。喷砂后使用3 mm流动树脂充填微渗漏最少，不喷砂使用2 mm膏状树脂微渗漏最严重，是否喷砂、树脂种类及充填体厚度均对微渗漏有显著影响（P < 0.05）。结论    固定螺丝孔表面喷砂处理可增加粘接强度，减少微渗漏。流动树脂封闭种植义齿固定螺丝孔可获得相似的密封性及高于普通膏状树脂的粘接强度。在一定范围内，增加充填体厚度有助于提高固定螺丝孔封闭树脂的咬合承受力并减少微渗漏。     

Longitudinal study on torque transmitted from denture base to an abutment tooth of lower distal-extension removable partial dentures with conus crown telescopic system

The purpose of this study was to make a longitudinal analysis of torque transmitted to a direct abutment tooth of a lower distal-extension removable partial dentures constructed with the conus crown telescopic system. Torque around the vertical and lateral axes of the tooth were measured during chewing of food at the time of insertion of the new dentures to about three months after. The maximal mean value of torque ( Max.MT ) was calculated from the peak level of all chewing strokes at the minimum of the interocclusal distance. The integration values of torque (I) and time (T) from initiation of chewing to swallowing were obtained, then the average value of torque ( Ave.T ) was calculated ( Ave.T = I/T).
The results are summarized as follows: (a) There were no remarkable changes of Max.MT around the both axes; (b) Max.MT around the lateral axis was 7-47 × 10^-3kgm (mean: 25X10^-3kgm) (1kgm = 9.8Nm) in the downward direction and Ave.T around the lateral axis was 6.14 × 10^-3kgmss^-1 (mean: 10 × 10^-3kgm ss^-1) in the downward direction; (c) There were marked differences of Max.MT and Ave.T around the vertical axis between subjects. Max.MT around the vertical axis was less than 24 × 10^-3 kgm and Ave. T around the vertical axis was less than 6 × 10^-3 kgm ss^-1.     

上海市静安区老年人可摘局部义齿戴用及基牙健康状况的初步调查

目的 初步调查上海市静安区老年患者可摘局部义齿的戴用和基牙健康状况,有针对性地为老年患者提供基牙健康维护建议,提高基牙(余留牙)的存留率。方法 参照第四次全国口腔健康流行病学调查方法,对静安区340名60岁及以上老年人进行口腔检查和问卷调查,采用SPSS 21.0软件包进行数据分析。结果 可摘局部义齿肯氏Ⅲ类基牙的龋均明显低于肯氏Ⅰ类、Ⅱ类和Ⅳ类(P<0.05)。有饭后漱口和清洗义齿习惯的老年患者,其基牙患龋率、软垢指数和牙周探诊深度显著低于没有饭后清洁习惯的老年患者。有夜间佩戴义齿习惯的老年患者,基牙牙周方面的损害较夜间取下义齿的老年患者明显,差异有统计学意义(P<0.05)。可摘局部义齿戴用时间超过3年以上更易影响基牙健康(P<0.05)。结论 在社区口腔健康教育工作中,应指导老年患者掌握正确的可摘局部义齿使用方法和口腔清洁方式,养成定期复查习惯,提高基牙(余留牙)的留存率。