An Alternative Method for Incorporating Fiber Meshes in Complete Upper Dentures

The most commonly used material for constructing complete dentures is polymethyl methacrylate (PMMA). However, the strength characteristics of PMMA, such as impact strength and fatigue strength, are poor, and fracturing of PMMA dentures is a common problem in prosthodontic practice. Reinforcing PMMA with various materials, such as carbon fibers, glass fibers (fiberglass), and ultrahigh modulus polyethylene fibers, has been suggested to strengthen the denture-base material. A common problem encountered when packing the resin on these specimens is fiber slippage beyond the denture edges. The present study proposes an alternative method of incorporating fiber meshes into complete dentures, whereby a thin filament of self-polymerizing resin at the perimeter of the fiber mesh is produced, giving a clear and stable shape to the mesh that fits the upper jaw cast. During placement of the shaped mesh on the cast, a positive-negative relationship is created between the mesh and cast, which immobilizes the mesh during the incorporation process.

The Evaluation of the Dietary Habits Influence on the Microhardness of Gingiva-Coloured Composite and Acrylic Denture Base Materials

Purpose: The study investigated the impact of dietary habits, specifically soda, milk kefir, water kefir, almond milk, and distilled water (control) consumption, on the microhardness of gingiva-coloured composite and acrylic denture bases. Methods: Materials included gingiva-coloured composite (Fusion Universal G1), acrylic (Imicryl), and subdivided Procryla group. Subgroups comprised 15 and 30-minute heat polymerized (Pro15, Pro30), and 1 wt% (Pro1Z) and 3 wt% (Pro3Z) zirconium added groups. Immersed in beverages for 1, 7, and 14 days, pH and microhardness were assessed. SEM examined random samples. Statistical analysis used repeated measures ANOVA, and post hoc tests (p Results: The gingiva-coloured composites displayed noteworthy time-associated microhardness changes (p 0.05). Despite variable pH levels in beverages, no substantial group interaction effects were observed (p > 0.05). Initial microhardness rankings shifted after a 14-day immersion. Conclusions: Gingiva-coloured composite exhibited the highest microhardness pre- and post-immersion, followed by Procryla30 and Imicryl groups. .

Clinical performance of removable partial dentures: A retrospective clinical study

Removable partial dentures (RPDs) (conventional and implant-supported) treatment is considered a viable option to replace missing teeth as inexpensively as possible, but it has limitations. Objectives: This study reports the effect of gender and location (maxilla vs. mandible) on the clinical performance of removable partial dentures (RPDs). Materials and Methods: A total of 100 Patients who had RPDs delivered between 1990-1995 were evaluated. A 4-point scoring system was used to assess seventeen criteria. These criteria include acceptance, stability, support, retention, adaptation, occlusion, integrity, and design of the pros-theses, rest and rest seat preparation, occlusal wear, esthetics, phonetics, tissue condition, mobility of abutments, gingival and plaque indices. The data were analyzed using Kruskal-Wallis and Mann-Whitney U non-parametric statistical tests. Results: The results showed that acceptance of RPDs was rated the lowest. Other reasons for failure were poor retention, lack of integrity of the prostheses and inadequate adaptation. Retention and design of major connectors attributed to Mandibular RPD failure. Success rate of 75% was observed in male compared with 67.2% for female. Maxillary RPDs showed a higher success rate (78%) compared with the mandibular (70.1%). No significant statistical difference in Alpha scores between female and male patients and between maxillary and mandibular RPDs (p < 0.05). Conclusions: The clinical performance of RPDs showed a higher success rate in male patients compared to female patients and the maxillary RPDs showed a higher success rate compared to mandibular.

Swallowing threshold parameters of subjects with complete dentures and overdentures

Aim: To compare the chewing process and swallowing threshold parameters of subjects with complete dentures and overdentures with data obtained from subjects with complete natural dentitions. Metho-dology: The chewing process in terms of swallowing threshold parameters of four groups of subjects with complete dentures (all females) was quantified by sieving particles after chewing of an artificial test ‘food’ and compared with that of subjects with com-plete natural dentitions as a reference group (33 sub-jects). All subjects (except those of the reference group) had a complete denture in the upper jaw. Regarding the lower jaw two groups with complete dentures (with high (24 subjects), respectively low mandible (12 subjects)) and two groups with overdentures (implant-retained (22 subjects), respectively natural root supported (19 subjects)) were composed. Results: The ‘overdenture-implants’ group needed significantly more chewing cycles and time (mean: 45 cycles in 32 seconds) until ‘swallowing’ compared to the group with complete natural dentitions (mean: 26 cycles in 19 seconds until ‘swallowing’). Also the ‘complete denture-low mandible’ group needed sig-nificantly more cycles and time (mean: 52 cycles in 44 seconds) until ‘swallowing’ than the complete dentition group. In the ‘overdenture-natural roots’ group these outcomes (33 cycles in 24 seconds) were not significantly different compared with the complete dentition group. The ‘complete denture-high mandi-ble’ group (32 cycles in 26 seconds) needed not sig-nificantly more cycles until ‘swallowing’, however time until ‘swallowing’ was significantly longer com-pared to the complete dentition group. All denture groups had significantly larger mean particle sizes when ‘swallowing’ (sizes in the order of 3 mm) than the natural dentition group (about 2 mm). Conclusion: Despite efforts to compensate for a reduced chewing efficiency, subjects with complete dentures (including overdentures) had 50% larger median particle sizes when ‘swallowing’ compared to subjects with complete natural dentitions.

Treatment of Elderly Bedridden Patients with Removable Dentures to Promote Their Daily Physical Activities: A Case-Control Study

Bedridden patients remain in bed for various reasons, such as chronic illness, old age, and disability, and they cannot perform self-care activities completely or partially. The provision of care for bedridden patients is a major issue in the aging population. Effective rehabilitation is associated with several factors such as cooperation between the patient and the medical staff, selection of effective facilities, and the financial burden. The objective of this study was to evaluate the effect on the activities of daily living (ADL) of occlusion restoration using removable dentures in bedridden older people. This case-control study comprised 32 bedridden older patients who were divided into two groups as follows: denture (n = 18) and no-denture (n = 14). No rehabilitation was provided to any of the patients. The patients were evaluated 3 months after placing the denture, and the ADLs were compared between the two groups. Of the 18 bedridden patients who received removable dentures, 55.6% demonstrated improvements in the ADLs, and the effects persisted for at least 3 months. No improvement in the ADL was observed in the no-denture group. The results of this study suggested that adequate occlusal support can improve the ADL of the elderly. Thus, it is important to take care of oral health early in life in order to maintain oral health, which could help prevent the decrease in the ADL during the later stages of life.

Biomechanical Analysis of Implant Assisted-Overdentures with Variations in the Attachments Systems

The aim of this study was to assess the stress patterns on the peri-implant zone and residual alveolar ridge in different overdenture attachment system designs by the photoelasticity method. Four attachments systems were tested: O-ring, ERA, Bar-clip, and Bar-clip/O-ring association. The prostheses were loaded with 100 N in five pre-determined points and the photoelastic model was evaluated by a circular polariscope. The anterior load, O-ring, and ERA showed better stress distribution in relation to the bars systems, which presented stress levels surrounding implants. The molar load, Bar-clip/O-ring association, presented the biggest stress concentration on the peri-implant region in relation to the others. When the second molar was loaded, there was a concentration of stress in the alveolar ridge in all situations analyzed. Within the limitation of this “in vitro” study, it could be concluded that there were biomechanical differences among the attachments systems analyzed, principally between isolated and the bars systems. The O-ring showed better stress distribution and the Bar-clip/O-ring showed higher stress concentration.

舌侧金属加强杆种植覆盖义齿的三维有限元分析

目的 通过三维有限元分析探讨舌侧金属加强结构义齿基托设计对无牙下颌种植修复义齿的生物力学影响,为无牙颌修复治疗提供参考。方法 构建舌侧金属加强结构与无加强结构两种义齿基托设计的2颗种植体支持Locator式覆盖义齿三维有限元模型,分别对后牙中央窝垂直施加150 N载荷、斜向施加150 N载荷以及对前牙垂直施加150 N载荷,模拟正中咬合、左右侧方咀嚼以及前牙切割食物时两种模型各组织的受力情况。结果 后牙及前牙垂直向加载时,两种义齿基托设计模型各组织的应力分布较为接近,所受最大应力差别在0~0.16 MPa之间;偏侧咀嚼时,未添加金属加强杆的义齿基托、种植体和黏骨膜应力集中范围,以及种植体、种植体周围骨最大受力明显大于添加金属加强杆模型,所受最大应力差别在0.59~2.99 MPa之间。结论 在义齿基托舌侧添加金属加强杆,可以起到应力分散的作用,或可在一定程度上减小骨吸收及基托折断的风险。

传统性修复和吸附性修复全口义齿的效果比较

目的:比较传统义齿和吸附性义齿哪种修复效果更好,找到合适的修复方式。方法:选取2022年1月至2023年1月佳木斯大学附属口腔医院收治的50例无牙颌牙槽骨吸收呈Ⅲ-Ⅳ的患者,随机采用传统修复方式和吸附性义齿修复方式,通过问卷调查数据论证。结果:3个月和半年后,对20例传统修复方式和30例吸附性义齿修复方式患者的适应性调查(包括颌位关系、固位、疼痛点、咀嚼效率、发音、美观),吸附性义齿适应性显著提高,存在统计学意义(P<0.05)。结论:吸附性义齿修复方式的疗效较传统性修复好,值得推广。

WEGO种植体系统边缘骨吸收情况的临床观察

目的:探讨手术和负载对WEGO种植系统边缘骨吸收(MBL)的影响,评价WEGO种植系统的临床可靠性。方法:回顾性分析行WEGO种植系统单颗单冠修复病人61例,比较骨整合期和负载期种植体MBL情况,收集病人年龄、性别、种植牙位(前磨牙/磨牙)、种植体长度/直径、种植体愈合方式等资料,分析骨整合期和负载期种植体MBL的影响因素。结果:种植体植入时边缘骨水平(0.59±0.08)mm,经过≥3个月的骨整合期,种植体MBL为(-0.18±0.09)mm,经过≥10个月的负载期,种植体MBL为(-0.04±0.03)mm,骨整合期和负载期MBL差异有统计学意义(P<0.01)。不同牙位和种植体直径病人骨整合期种植体MBL差异均有统计学意义(P<0.01和P<0.05);不同种植体长度病人负载期种植体MBL间差异有统计学意义(P<0.05)。结论:WEGO种植系统临床使用可靠性较高,骨整合期和负载期种植体MBL存在差异,牙位、种植体直径和种植体长度与WEGO种植体MBL有关。

无牙颌患者种植固定义齿饰面材料研究及应用进展

目前无牙颌患者种植固定义齿常用饰面材料包括丙烯酸树脂、聚合瓷、陶瓷、氧化锆等,不同材料的理化性质、临床表现各不相同。临床上固定义齿饰面材料的选择与患者口腔修复空间及软硬组织状况、力、生活习惯、口腔副功能、对颌牙材料及患者期望有关。无牙颌患者种植固定义齿相关的常见机械并发症为饰面材料的折裂/崩瓷及磨损,可通过咬合调整、修复体设计加工以及合适的修复材料选择予以规避。本文就常用无牙颌患者种植固定义齿饰面材料的特点、选择与设计要点、临床常见修复体材料相关并发症的病因及处理展开综述,以期为临床无牙颌患者种植固定义齿饰面材料的选择提供参考。

不同金属材质假牙对舌癌放疗患者肿瘤靶区的剂量学参数影响

目的探讨舌癌放疗患者植入的不同金属材质假牙对肿瘤靶区(GTV)的剂量学影响。方法建立由组织补偿膜、牙齿和标准固体水组成的模体,获取镍铬合金、二氧化锆和钴铬合金3种金属假牙组成的模体CT图像。在假牙后方设置不同深度、半径为1.9 cm的GTV,并设计单射束开野照射计划和容积旋转调强放疗(VMAT)计划。计算CT下不同假牙的靶区剂量分布,分析不同假牙对靶区剂量学参数的影响。结果与正常牙齿比较,镍铬合金、二氧化锆和钴铬合金3种金属假牙引起的最大剂量(D_(max))和平均剂量(D_(mean))计算偏差均<3%,其中二氧化锆假牙对靶区剂量影响最大。当GTV深度为5.9 cm时,金属假牙导致的靶区剂量偏差最大。结论金属假牙产生的CT伪影可影响舌癌放疗的靶区剂量。当GTV离金属假牙较近时,需要考虑拔除假牙或使用伪影修正算法对定位CT图像进行伪影修正。

老年可摘义齿佩戴者口腔健康相关生活质量的影响因素分析

目的分析老年可摘义齿佩戴者口腔健康相关生活质量(oral health-related quality of life,OHRQoL)的影响因素及相互关系。方法选取牙列缺损/牙列缺失患者86名作为义齿佩戴组,行可摘义齿修复且义齿远端至少延伸到第一磨牙。选择天然牙列保留至第一磨牙的无可摘义齿患者72名作为对照组。采用Eichner分类法记录上下颌之间的咬合单位和咬合支持数量,口腔健康影响程度量表(Oral Health Impact Profile,OHIP)评价OHRQoL,接触定位法确定主要咬合区,双侧第一磨牙作为测量部位评估最大咬合力,粘性凝胶法评估咀嚼效率,食物接受度问卷评估咀嚼能力。结果义齿佩戴组的OHIP评分以及心理不适和生理能力受限两个分量表的评分高于对照组(P<0.05)。OHIP评分与余留牙数、咬合支持数量、最大咬合力和咀嚼能力呈显著负相关。下颌余留牙数、咬合支持数量、下颌主要咬合区是否为天然牙以及咀嚼能力是OHIP评分的显著影响因素。结论老年可摘义齿佩戴者口腔健康相关生活质量与余留牙咬合关系和主要咬合区存在相关性,其中保留下颌第一磨牙是一个关键影响因素。

肯氏Ⅰ、Ⅱ类牙列缺损数字化印模及模型在可摘局部义齿中的应用

目的评估肯氏Ⅰ、Ⅱ类牙列缺损数字化印模及树脂模型技术在可摘局部义齿(RPD)中的应用效果。方法选择肯氏Ⅰ、Ⅱ类牙列缺损患者,按照义齿制作流程分组:数字化印模/树脂模型/钴铬合金铸造支架组(A组)、数字化印模/树脂模型/激光打印钛支架组(B组)、藻酸盐印模/石膏模型/钴铬合金铸造支架组(C组)、藻酸盐印模/石膏模型/激光打印钛支架组(D组),每组40例。对最终完成的RPD在口内就位情况进行检查,评估指标包括卡环固位力、连接体和基托在口内的密合度、咬合准确度,各项指标评估分值使用Kruskal-Wallis秩和检验进行分析。结果4组RPD各项指标的评分值差异无统计学意义。结论利用数字化印模及树脂模型完成的铸造钴铬合金和激光打印钛支架式RPD能够满足肯氏Ⅰ、Ⅱ类牙列缺损患者的临床修复要求。

个别托盘预留空间厚度与牙槽嵴低平无牙颌义齿修复效果的关系

目的探究个别托盘不同预留空间厚度与牙槽嵴低平无牙颌义齿修复的关系。方法选择2020年3月至2023年3月期间于我院就诊的75例牙槽嵴低平无牙颌患者,采用随机数字表法将患者分为A组(n=25)、B组(n=25)和C组(n=25),3组分别按无预留空间(0 mm),预留空间(1.5 mm)和(2 mm)制作个别托盘并行全口义齿修复。对比3组患者的一般资料、修复有效率、VAS评分、TMD及PES评分,并分析3组患者修复后的满意程度评分。采用广义估计方程模型评价3组患者各项指标的改善情况。结果3组在终印与组织面的偏差值、复诊次数以及压痛位点之间存在显著差异,B组<C组<A组(P<0.05)。B组患者的总有效率高于A组和C组(P<0.05)。术后3个月,3组患者的VAS评分无明显差异,B组患者的TMD评分显著低于A组和C组,PES评分显著高于A组和C组(P<0.05)。比较3组患者对固位效果、稳定性、咀嚼功能、舒适度的满意度,B组患者的满意度明显高于A组和C组(P<0.05)。经广义估计方程分析可见:B组在TMD评分、PES评分、固位效果、稳定性、咀嚼功能、舒适度方面的改善情况优于A组和C组,C组在各方面的改善情况优于A组。结论个别托盘预留空间为1.5 mm时制作终义齿组织面与粘膜形态适合性较好、复诊次数和压痛位点较少、修复效果较好、患者的满意度较高。

BPS吸附性义齿在全口牙列缺失患者中的临床应用

目的探讨吸附性义齿在牙槽嵴牙列缺失患者中的临床应用效果。方法选取2017年1月至2022年1月连云港市中医院口腔科收治的全口牙列缺失、牙槽嵴重度吸收、牙槽嵴不对称吸收等复杂情况的牙列缺失患者100例,按照信封法将其分为对照组(传统总义齿,n=50)和研究组(吸附性义齿,n=50)。统计并比较两组治疗前后咀嚼功能[咬合力占最大咬合力百分比(MABF/MMF)、咬合时间(OT)、左右侧咬合力平衡度(BFDB)、口香糖咀嚼物各像素点色调值标准化后的标准差(SDHue)]、吞咽及语言功能、治疗总满意度。结果治疗后,两组MABF/MMF较治疗前增高,OT、BFDB、SDHue较治疗前下降,且研究组MABF/MMF高于对照组,OT、BFDB、SDHue低于对照组,差异有统计学意义(P<0.05)。研究组吞咽及语言功能评分高于对照组,差异有统计学意义(P<0.05)。研究组治疗总满意度高于对照组,差异有统计学意义(P<0.05)。结论吸附性义齿修复复杂牙槽嵴情况的牙列缺失,可有效恢复患者咀嚼、吞咽及语言功能,并且患者的满意度较高。

分体式颌位关系记录托盘的设计与应用

现有的颌位关系记录托盘为上下一体式设计,在临床使用过程中无法准确获取上颌平面、上唇下约1 mm的位置、上唇支撑度等重要信息。从而使得数字化颌托(或诊断义齿)准确性欠佳,为后继进行准确边缘整塑印模及最终颌位关系记录与转移带来困难。该文介绍了一种分体式颌位关系记录托盘的设计、临床使用方法及要点。其能够准确获取上颌平面、上唇下约1 mm的位置、上唇支撑度等重要信息,为后继进行准确的颌位关系记录与转移提供参考,也为利用口内扫描获取数字化印模后,基于采用分体式颌位关系记录托盘获取的平面、上唇下约1 mm的位置、上唇支撑度等信息直接制作全口义齿奠定基础。

正中关系的临床决策

正中关系(CR)最初应用于无牙颌的全口义齿修复,后来逐渐应用于有牙颌的临床诊疗。关于CR在有牙颌中的应用,一方面对其合理性有不少质疑,如在颞下颌关节紊乱病治疗中,CR是否应作为诊疗核心?咬合重建修复治疗中,CR是否应作为建颌位?正畸治疗中,CR是否应作为目标颌位?但另一方面,CR的各种临床运用却是客观存在的。根据现有认知,本文汇总整理了争议不大的几种主要临床场景的适用条件,初步提出了CR临床应用时的决策树,供临床参考。

生物功能修复系统应用于无牙颌患者的疗效分析

目的 评价内蒙古地区应用生物功能修复系统制作全口义齿的临床效果。方法 2019年7月至2023年6月来包头医学院第一附属医院就诊的无牙颌患者72例纳入研究,随机分为对照组(n=36)和实验组(n=36),对照组选用传统全口义齿修复,实验组选用生物功能义齿修复系统制作。两组患者分别进行咀嚼效率评价、口腔健康相关生活质量评估以及义齿压痛特征性分析。结果 (1)咀嚼效率实验组高于对照组,差异具有统计学意义(t=6.774, P <0.01)。(2)实验组义齿在戴用舒适度、吸附效果、黏膜疼痛、溃烂和复诊的频次等方面都明显优于传统方法制作的全口义齿,差异具有统计学意义(P <0.05);义齿在戴用恶心、味觉异常、口齿不清和精神心理因素方面无明显区别,差异无统计学意义(P> 0.05)。(3)对疼痛特性分析显示,实验组黏膜出现中重度压痛的人数(6例)明显少于对照组义齿(16例),且以无痛或轻度居多。结论 生物功能义齿修复系统应用于全口义齿方面临床效果显著,是一种更舒适的义齿修复新方法。

可摘局部旧义齿改造全口义齿修复牙列缺失一例

传统全口义齿是口腔修复中一种较为常规的无牙颌修复方式。但其流程繁琐,过程复杂[1]。临床中会遇到患者已行可摘局部义齿修复,佩戴时间不足5年,局部义齿使用情况良好,但就诊时余留牙缺失,需要镶佩全口义齿。为简化操作流程,降低技术敏感性,提高患者对新义齿的适应性及满意度,考虑采用复制义齿技术进行全口义齿修复。本文报告一例下颌牙列缺失病例,通过改造旧可摘局部义齿,利用组织调整剂(tissue conditioner,TC)制取动态印模,最终通过复制义齿为患者制作了一副全新的下颌全口义齿,并取得了满意的临床效果。

无牙颌患者人格特征对面部美学满意度的影响

目的探讨人格特征在无牙颌患者自我面部美学评价中的作用,为提升患者全口义齿修复后的美学满意度提供借鉴。方法随机选取行全口义齿修复治疗的无牙颌患者22例,在治疗前,艾森克人格问卷(EPQ)N量表被用于评估患者的情绪稳定性。在治疗前和治疗后3个月,面部美学评分问卷和三维摄影测量系统(3dMD)被分别应用于评估患者对面部外观的满意度及颌面软组织的变化。此外,利用N量表评分、面部美学测量指标和面部美学评分,建立多重线性回归模型。结果治疗后,患者面中部与面下部的比例与面型正常人群的差值缩小了(3.85±2.63)%,鼻唇角与正常人群的差值缩小了(6.66±5.39)°。多重线性回归模型结果显示:N量表评分及治疗前后面部比例与正常面型差值的变化值均可影响患者正面美学满意度,而N量表评分及鼻唇角与正常面型差值的变化值均可影响患者侧面美学满意度。纳入模型的两个自变量(N量表评分和颌面软组织变化)对于正面和侧面美学满意度的影响均具有统计学意义(P<0.001)。其中,N量表评分增加时,患者正面和侧面美学满意度均下降(B<0)。结论人格特征可影响无牙颌患者面部美学满意度,故在全口义齿修复治疗中应为不同人格的患者制定合理的诊疗方案,从而达到提高患者面部美学满意度的目标。