Recent advances in etched cast restorations

This article described the etched cast restoration. The advantages, disadvantages, indications, contraindications, and technique were discussed. The rationale for modifications in the original framework design and tooth preparation was also presented; some unique advantages over traditional fixed prosthodontics are provided. A retentive framework with maximum coverage is recommended until research expands and simplifies the technique.     

全瓷修复材料和方法的分化

全瓷修复材料包括玻璃基质陶瓷、玻璃渗透氧化物陶瓷、致密氧化铝陶瓷和氧化锆陶瓷4类,全瓷修复方法包括全冠、贴面、瓷粘接修复等。不同的材料和方法搭配,获得的治疗效果差异明显。确定最适宜的搭配形式,可以明显降低临床选择治疗方案的难度。对于活髓牙修复,最佳治疗方案是采用玻璃基质陶瓷材料,进行瓷贴面或瓷粘接修复;死髓前牙一般不采...     

Cements and adhesives for all-ceramic restorations

Dental cements are designed to retain restorations, prefabricated or cast posts and cores, and appliances in a stable, and long-lasting position in the oral environment. Resin-based cements were developed to overcome drawbacks of nonresinous materials, including low strength, high solubility, and opacity. Successful cementation of esthetic restorations depends on appropriate treatment to the tooth substrate and intaglio surface of the restoration, which in turn, depends on the ceramic characteristics. A reliable resin cementation procedure can only be achieved if the operator is aware of the mechanisms involved to perform the cementation and material properties. This article addresses current knowledge of resin cementation concepts, exploring the bonding mechanisms that influence long-term clinical success of all-ceramic systems.     

Bonding-cementation of all-ceramic restorations

The objective of this article is to synthesize the current scientific data relating to the bonding of ceramic restorations in order to present a reliable and reproductive clinical method for the general practitioner. The different ceramic treatments are explained with a distinction between those which can be etched and the others. A precise check list is suggested for the conditioning of dental tissues and ceramic surfaces.     

全瓷修复的牙体预备

多种全瓷系统可用来进行全冠、固定桥、嵌体、贴面等几乎所有类型的固定修复。全瓷修复的基牙预备牙体预备应兼顾牙齿健康,功能,美观三方面的要求。不同类型的修复体对聚合度、轴面预备形式、边缘线的位置及形式和宽度等都有特定的要求。     

直接盖髓应用材料的研究进展

直接盖髓术和活髓切断术的远期效果与盖髓材料的种类关系密切。直接盖髓材料的种类繁多,除临床上常用的氢氧化钙和三氧化矿物凝聚体（MTA）外,各种新的盖髓材料不断涌现。以硅酸钙类材料为代表的盖髓剂性能优良,受到学者们的广泛关注。此外,具有促再生和矿化作用的釉基质蛋白衍生物Emdogain以及其他具有修复功能的材料,也有望应用于盖髓。     

牙科粘接材料抗菌改性的研究进展

细菌、螺旋体、真菌、支原体等多种微生物在口腔内不同部位共栖、竞争和拮抗,形成口腔微生态系.正常情况下,口腔微生物之间、微生物与宿主口腔处于生态平衡状态.但体内外环境等因素的改变可导致一些细菌增殖过盛,使正常的口腔微生物失去生理性平衡,引起龋病、牙周病等口腔疾患.     

Factors to achieve aesthetics in all-ceramic restorations

The demand for aesthetic restorations has increased during the last years. Dental ceramics are a successful alternative for some cases because of aesthetics and biocompatibility. Therefore, the aim of this literature review was to present the factors necessary to fabricate all-ceramic restorations with aesthetics similar to natural dentition. A search of English-language peer-review literature was completed using MEDLINE database from 1975 to 2009 including the keywords "aesthetic," "metal-free crown," "all-ceramic," and "color." It was observed that several factors influence aesthetics of all-ceramic restorations. Color scale, light source during color evaluation, characteristic of core material, color of supporting tooth, presence of root post, and type of cement are clinical factors that may influence color of the restorations. Laboratorial factors as technique for ceramic condensation, thickness, temperature, and number of firing cycles also influence the result of these crowns. Although several clinical and laboratorial factors influence aesthetics of all-ceramic restorations, the aesthetic success and longevity of these restorations depend on the integration with surrounding periodontal tissue.     

全瓷修复体修复后可能出现的问题分析

随着齿科陶瓷材料性能的不断改进，全瓷修复体已经成为现在固定修复中一种重要的修复方式。如何提高全瓷修复体在临床上的修复效果，避免修复失败是口腔全瓷修复中的一个重点。本文就在临床修复过程中，全瓷修复体初戴后可能出现的问题及其预防方法作一综述。     

全瓷基台的研究进展

近年来,随着物质生活水平的提高和种植义齿学的飞速发展,口腔临床医生和患者对修复美学有着越来越高的要求.传统的钛基台在牙龈较薄或种植体肩部位置过高的患者会有不同程度金属颜色的暴露而影响美观,而全瓷基台因其具有良好的美学性能更受口腔修复医生和患者的欢迎.本文综述了全瓷基台的种类及制作方式、优点、机械性能和在临床种植修复中的应用.尽管全瓷基台受价格和机械强度的影响尚未成为种植修复常规的选择,但随着材料和技术的进步,相信其应用将越来越广.     

Graded structures for damage resistant and aesthetic all-ceramic restorations

ObjectivesClinical studies revealed several performance deficiencies with alumina- and zirconia-based all-ceramic restorations: fracture; poor aesthetic properties of ceramic cores (particularly zirconia cores); and difficulty in achieving a strong ceramic–resin-based cement bond. We aim to address these issues by developing a functionally graded glass/zirconia/glass (G/Z/G) structure with improved damage resistance, aesthetics, and cementation properties.MethodsUsing a glass powder composition developed in our laboratory and a commercial fine zirconia powder, we have successfully fabricated functionally graded G/Z/G structures. The microstructures of G/Z/G were examined utilizing a scanning electron microscopy (SEM). The crystalline phases present in G/Z/G were identified by X-ray diffraction (XRD). Young's modulus and hardness of G/Z/G were derived from nanoindentations. Critical loads for cementation radial fracture in G/Z/G plates (20 mm × 20 mm, 1.5 or 0.4 mm thick) bonded to polycarbonate substrates were determined by loading with a spherical indenter. Parallel studies were conducted on homogeneous yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) controls.ResultsThe G/Z/G structure consists of an outer surface aesthetic glass layer, a graded glass–Y-TZP layer, and a dense Y-TZP interior. The Young's modulus and hardness increase from surface to interior following power-law relations. For G/Z/G plates of 1.5 and 0.4 mm thick, critical loads for cementation radial fracture were 1990 ± 107 N (mean ± S.D., n = 6) and 227 ± 20 N (mean ± S.D., n = 6), respectively, which were ～30 and 50% higher than those for their monolithic Y-TZP counterparts (1388 ± 90 N for 1.5 mm and 113 ± 10 N for 0.4 mm thick; mean ± S.D., n = 6 for each thickness). A 1-sample t-test revealed significant difference (p < 0.001) in critical loads for radial fracture of G/Z/G and homogeneous Y-TZP for both specimen thicknesses.SignificanceOur results indicate that functionally graded G/Z/G structures exhibit improved damage resistance, aesthetics, and potentially cementation properties compared to homogeneous Y-TZP.