Clinical applications of glass-ceramics in dentistry

Abstract

Glass-ceramics featuring special properties can be used as a basis to develop biomaterials. It is generally differentiated between highly durable biomaterials for restorative dental applications and bioactive glass-ceramics for medical use, for example, bone replacements. In detail, this paper presents one biomaterial from each of these two groups of materials. In respect to the restorative dental biomaterials, the authors give an overview of the most important glass-ceramics for clinical applications. Leucite, leucite-apatite, lithium disilicate and apatite containing glass-ceramics represent biomaterials for these applications. In detail, the authors report on nucleation and crystallization mechanisms and properties of leucite-apatite glass-ceramics. The mechanism of apatite nucleation is characterized by a heterogeneous process. Primary crystal phases of alpha - and beta -NaCaPO4 were determined. Rhenanite glass-ceramics represent biomaterials with high surface reactivity in simulated body fluid, SBF, and exhibit reactive behaviour in tests with bone cells. Cell adhesion phenomena and cell growth were observed. Suitable colonization and proliferation and differentiation of cells as a preliminary stage in the development of a material for bone regeneration applications was established. The authors conclude that the processes of heterogeneous nucleation and crystallization are important for controlling the required reactions in both biomaterial groups.

Dental ceramics: a review of new materials and processing methods

“…The adequate mechanical properties of these materials reflect in the good longevity of such dental restorations. 34 The good aesthetic quality is another factor that greatly contributes to the attractiveness of glass-ceramics to clinicians 35,36,37 .…”

Próteses Livres de Metal: Revisão de Literatura

“…A cerâmica vítrea reforçada por 40% a 50% de leucita, apesar de ser muito utilizada devido sua precisão oclusal, mas ainda apresenta algumas falhas, em que sua média de resistência flexural de 110 Mpa a tornam inadequadas para confecção de próteses fixas totalmente cerâmicas, tendo seu uso indicado apenas para confecção de restaurações unitárias 6,13 . As IPS Empress são pastilhas pré ceramizadas fabricadas por um sistema de termo-injeção.…”

“…Inicialmente, é feito um molde, em que será injetada a porcelana, após ser aquecida, reduzindo sua porosidade devido ao preenchimento de espaços vazios, que podem enfraquecer o material. Já as IPS Empress CAD apresentam a mesma composição, porém ao invés de serem utilizadas no sistema de cerâmica injetada são usinadas pelo método CAD/CAM 13 . As porcelanas reforçadas por leucita são passíveis de condicionamento por apresentarem baixo conteúdo de alumina e serem baseadas em sílica.…”

“…Os sistemas cerâmicos à base de dissilicato de lítio são basicamente compostos por uma subestrutura de vidrocerâmica à base de dissilicato de lítio 60% e recobertos por fluorapatita, por serem baseadas em vidros bioativos podem ser utilizadas como cerâmica de recobrimento, devido sua união com os óxidos de zircônio 13 . Reforçado por cristais de dissilicato de lítio, o Sistema IPS Empress II (Ivoclar North América, Amherst, NY, EUA) apresenta resistência flexural de 300 -400 MPa e, também, utiliza da técnica da cera perdida para processar a porcelana 13 .…”

Experimental and theoretical approaches on thermal and structural properties of Zn doped BSCCO glass ceramics

“…Some of these applications include superconductivity, biomedical applications, applications requiring high dielectric constant, material connections and substrates for electronics [5,6]. Moreover, the glass-ceramic * E-mail: atasci@kastamonu.edu.tr materials are used in aerospace and aviation industry, electronics industry, material coating technology, production of superconducting materials and even in medicine [7,8]. Glass ceramics, having low thermal expansion and high transparency to the dedicated wavelengths can be used as windows for laser applications [9].…”