Zirconia ceramic fixed partial dentures after cyclic fatigue tests and clinical evaluation: a systematic review

ABSTRACT

Zirconia fixed prosthetic dentures are extensively used for replacing missing teeth. The primary objective of this systematic review was to gather and present the results of all in vitro studies and clinical trials conducted on zirconia fixed prosthetic dentures. This review concentrated exclusively on bilayered zirconia and monolithic fixed prosthetic dentures. As such this paper can act as a guideline for more comparable future experimental work on zirconia ceramics. Future studies must use a more systematic approach such as the uniform use of abutment material, material for simulating periodontal support, data about fracture strength before and after fatigue, number of cycles, information about position and size of the indenter. The new digital techniques with long-term follow-up are desirable in further clinical studies.     

纳米载银磷酸锆的有机改性及其对3D打印的义齿基托复合材料性能的影响

以γ甲基丙烯酰氧基丙基三甲氧基硅烷偶联剂(MPS)对纳米载银磷酸锆(6S-NP3)进行表面改性,再通过溶液聚合在其表面接枝甲基丙烯酸甲酯(MMA),得到有机改性纳米载银磷酸锆(P-6S-NP3)。将P-6S-NP3与义齿基托树脂混合,通过3D打印制备了义齿基托复合材料。使用傅里叶变换红外光谱仪(FT-IR)和扫描电镜(SEM)对改性前后6S-NP3的结构和形貌进行了表征,考察了6S-NP3和P-6S-NP3在义齿基托复合材料中的分散情况,测试了改性前后6S-NP3的水接触角、粒径分布,以及义齿基托复合材料的机械性能和抑菌性能。结果表明,MPS和MMA已成功接枝到6S-NP3表面,改性后的6S-NP3平均粒径降低,疏水性增强,在义齿基托复合材料中的分散性更好。采用P-6S-NP3制备的义齿基托复合材料的机械性能与对大肠杆菌和金黄色葡萄球菌的抑菌效果明显提高。     

Ce-Y(Ca)-TZP陶瓷及Ce-TZP/Al2O3复相陶瓷的研究与应用进展

氧化铈稳定的四方氧化锆多晶陶瓷(Ce-TZP)具有良好的抗低温老化性和很高的断裂韧性(K_IC>20 MPa·m^1/2),但是弯曲强度较低(500 MPa左右)。如何在保留Ce-TZP陶瓷的抗低温老化性和高断裂韧性的同时,提高其强度,是本领域研究人员共同关心的问题。大量研究表明,通过添加其他固溶离子(如Y³⁺)达到共稳定效果和引入第二相(如Al₂O₃)获得细晶Ce-TZP基的复相陶瓷,可以显著提高材料的断裂强度,综合改善其力学性能。本文对CeO₂与其他氧化物共稳定的ZrO₂陶瓷及Ce-TZP/Al₂O₃复相陶瓷的研究进展进行了综述,并以义齿种植和增材制造为例介绍了其应用现状。     

Antimicrobial Activity of Ozone against Pathogenic Oral Microorganisms on Different Denture Base Resins

ABSTRACT

The present study aimed to evaluate the antimicrobial effect of gaseous ozone against specific oral pathogens on denture base resins. 1080 round samples were prepared (10mm-diameter, 2mm-thickness). Candida albicans, Streptococcus mutans, Streptococcus gordonii, and Aggregatibacter actinomycetemcomitans, polyamide-Deflex, heat-cured polymethyl-methacrylate (PMMA)-QC-20, and cold-cured-PMMA-Meliodent. The doses and durations: 25, 50 and 100µg/ml, 5, 10, 20, 30 minutes. For Cell viability (CV) MTT was used. 100µg/ml was most effective dose for C. albicans, S .gordonii, and A. actinomycetemcomitans were in heat-cured-PMMA and polyamide for S.mutans. For polyamide, lowest CV was 43% in S.mutans and A.actinomycetemcomitans. CV of heat-cure and cold-cure PMMA were 31% and 32% in S.gordonii, respectively. CV was similar for all resins and durations in S.mutans and A.actinomycetemcomitans and for polyamide for C.albicans and for heat-cure PMMA for S.gordonii. 30-min ozone application killed 80% of all microorganisms in all resins except for C.albicans in polyamide (65% cell death) and cold-cure PMMA (57% cell death). Optimal dose/duration combination was 100 µg/ml-10 min. Gaseous ozone can be considered as an effective cleansing agent for denture base resins.     

Preparation and lab evaluation of a new denture adhesive

To develop a new kind of denture adhesive (DA), then to evaluate its mechanical and chemical properties, polyethylene oxide, methyl cellulose, sodium alginate, and cellulose ether, were viewed as four main factors, which would affect bonding load of DA, while two levels of each component were differentiated. Following table L12(211), twelve different formulae were designed by orthogonal design and bonding load values were recorded. According to bonding load of each formula, the optimized formula was selected out as this new adhesive material, Comfort-DA II. The changing of bonding load values of Comfort-DA II marinating in artificial saliva were measured, and an existing product, Protefix and Comfort-DA, were used as controls. Following initial load readings, samples and controls were measured from 1- to 12- hour intervals, respectively. Comfort-DA II was diluted at 1.0%, 2.0%, 3.3%, 5.0%, and 10.0% concentrations, and pH values were measured at 1-, 2-, 3-, 4-, 5-, 6-, and 8-hour intervals. Comfort-DA II presented as a pale-yellow paste. Group 6 gained the highest bonding load value of [193.8 (4.2)] N. The mean bonding load of Comfort-DA II was statistically different to Comfort-DA (p = 0.004) and Protefix (p = 0.006). Comfort-DA II exhibited a progressive increase in pH value over time and was slightly alkaline. Comfort-DA II showed significantly elevated mechanical and chemical properties, comparing to Comfort-DA. The results also indicate that orthogonal design may be an efficacious way to develop new dental materials.     

牙种植体系统对种植体周骨吸收影响的临床评价

我国的口腔种植学随着瑞典Branenmrk教授骨整合理论与国际上一些种植体系统的引进而逐渐发展起来,研究主要集中在种植体组织界面、生物力学及种植材料学方面。和传统义齿相比,种植义齿优点明显,被誉为人类的第三副牙齿,受到普遍欢迎。本研究收集种植病例的直接数字化全景片进行测量分析,研究种植体周牙槽骨吸收的情况,以评价种植体系统对骨吸收的影响。实验结果表明,不同的种植体系统对骨吸收的影响没有差异,同一种植体近中、远中也没有差异。本文对实验的测量方法进行了讨论,认为实验结果较为准确地反映了实际情况,并分析了种植体周骨丧失的呵能原因及对策。     

Y-TZP陶瓷义齿高速铣削特性研究

针对义齿制作材料氧化锆陶瓷的高速铣削性能展开研究。介绍了实验中使用的预烧结Y-TZP陶瓷属性;研究Y-TZP陶瓷义齿铣削加工时铣削力对刀具变形的影响并建立变形模型,然后利用有限元分析获得铣刀受力状态下应力、应变的计算结果;最后,对铣削加工过程中铣刀及工件的颤振特性进行有限元模态分析,从而对无共振的工况起到指导作用。     

Light cured fluoride filled denture‐coating materials

Light cured denture‐coating materials were prepared by formulating an acrylate monomer with a photoinitiator system (camphorquinone and dimethylaminoethyl methacrylate) using one of three base monomers [bisphenol A glycerolate diacrylate (Bis‐GDA), glycerol 1,3‐diglycerolate diacrylate (GDA), and diurethane dimethacrylate (DU‐DMA)] each with four diluents [triethylene glycol dimethacrylate (TEGDMA), di(ethylene glycol) methyl ether methacrylate, 2‐hydroxyethyl methacrylate (HEMA), and methacrylic acid (MAA)] at a fixed 1 : 1 molar ratio of base monomer to diluent. The twelve formulations were then evaluated for their surface hardness and water sorption as coating materials. The DU‐DMA/MAA, DU‐DMA/HEMA, Bis‐GDA/HEMA, and GDA/MAA based coatings provided a high level of both surface hardness and water sorption properties. When sodium fluoride (NaF) or calcium fluoride (CaF₂) was incorporated into those formulations, the fluoride ion release rate from all four NaF containing coating materials was extremely high in the first week, decreasing sharply in the second week and then decreasing in the later 2 weeks. In contrast, the CaF₂ containing coating materials showed a slower sustained rate of fluoride ion release over the 4‐week test period, with the DU‐DMA/HEMA based coating having a fluoride ion release pattern that meets the requirements for dental use. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

舌侧集中和解剖式双侧平衡咀嚼能力的对比研究

目的比较舌侧集中和解剖式双侧平衡这2种型总义齿患者之间咀嚼能力的差异。方法以问卷的形式,采用VAS量化义齿咀嚼面包、豆腐干、胡萝卜、苹果、硬香肠、牛肉干和蛋炒饭7种不同食物的能力。在10例无牙颌患者依次戴用舌侧集中和解剖式双侧平衡总义齿8周后,比较2种型总义齿患者之间咀嚼能力（VAS评分）的差异。结果在咀嚼胡萝卜和苹果这2种食物时,舌侧集中总义齿VAS评分高于解剖式双侧平衡总义齿（均P〈0.05）;对其余食物,2种型总义齿VAS评分差异无统计学意义（均P〉0.05）。结论舌侧集中总义齿患者在咀嚼较脆、较硬食物时比解剖式双侧平衡具有优越性。     

老年人全口义齿修复临床分析

目的探讨老年人修复全口义齿的临床特点。方法对192例老年人全口义齿修复的临床特征进行回顾性分析。结论对重新修复全口义齿的老年患者,采取适当的措施可以达到满意修复效果。