Direct Esthetic Restorations Based on Translucency and Opacity of Composite Resins

Light dynamics is a relevant phenomenon with respect to esthetic restorations, as incorrect analysis of the optical behavior of natural dentition may lead to potential clinical failures. The nature of incident light plays a major role in determining the amount of light transmission or reflection, and how an object is perceived depends on the nature of the light source. Natural teeth demonstrate translucency, opalescence, and fluorescence, all of which must be replicated by restorative materials in order to achieve clinical success. Translucency is the intermediary between complete opacity and complete transparency, making its analysis highly subjective. In nature, the translucency of dental enamel varies from tooth to tooth, and from individual to individual. Therefore, four important factors must be considered when appraising translucency. Presence or absence of color, thickness of the enamel, degree of translucency, and surface texture are essential components when determining translucency. State-of-the-art resin composites provide varying shades and opacities that deliver a more faithful reproduction of the chromaticity and translucency/opacity of enamel and dentin. This enables the attainment of individualized and customized composite restorations. The objective of this article is to provide a review of the phenomena of translucency and opacity in the natural dentition and composite resins, under the scope of optics, and to describe how to implement these concepts in the clinical setting.CLINICAL SIGNIFICANCEChoosing composite resins, based on optical properties alone, in order to mimic the properties of natural tooth structures, does not necessarily provide a satisfactory esthetic outcome. In many instances, failure ensues from incorrect analysis of the optical behaviors of the natural dentition as well as the improper use of restorative materials. Therefore, it is necessary to implement a technique that enables a restorative material to be utilized to its full potential to correctly replicate the natural teeth.(J Esthet Restor Dent 23:73-88, 2011)

Sistemas cerámicos puros parte 1: una evolución basada en la composicíon

The continuing advances in technology, dental materials and equipment have contributed significantly to improve the level of esthetic dentistry today. Among these innovations, development of pure ceramic restorations has evolved to give different alternatives. Dental ceramics have presented a rapidly technological changing to improve mechanical and optical properties. Currently there are several systems of metal free ceramics with excellent mechanical and optical properties, for making crowns and plurals. These modern systems are presented with various compositions and different preparation techniques, making these more versatile. Within this perspective, the dental market offers a huge range of new indirect and metal-free materials for prostheses, providing new options, plus also new questions to decide among the available alternatives. The aim of this review is take a view of the different ceramic systems in terms of its composition and different techniques of production.Los continuos avances en la tecnología, materiales dentales y equipamientos han contribuido significativamente con el nivel que la Odontología estética está logrando hoy. Entre estas innovaciones, el desarrollo de restauraciones de cerámica pura ha evolucionado aportando diferentes alternativas. Las cerámicas han presentado una rápida evolución desde el punto de vista tecnológico con el objetivo de mejorar las propiedades mecánicas y ópticas. En la actualidad existen varios sistemas de cerámicas libres de metal con propiedades mecánicas y ópticas excelentes, para la confección de coronas unitarias y plurales. Estos sistemas modernos se presentan con variadas composiciones y diferentes técnicas de confección, haciendo de estos más versátiles. Dentro de esta perspectiva, el mercado odontológico ofrece una gama enorme de nuevos materiales indirectos y sistemas libres de metal para la confección de prótesis, lo que proporciona nuevas opciones, más también nuevas interrogantes para decidir entre las alternativas disponibles. En este contexto esta revisión de la literatura tiene como objetivo abordar los diferentes sistemas cerámicos del punto de vista de su composición y sus diferentes técnicas de obtención

Sistemas cerámicos puros parte 2: materiales, propiedades ópticas y consideraciones clínicas

While dentistry continues to advance, the aesthetic techniques have evolved in proceedings more effective, functional and biocompatible. Meanwhile, cosmetic dentistry has become a bit more complex and technically difficult. With improvement of the properties (physical and optical) of the ceramics and the establishment of a working protocol, ceramic restorations have become increasingly popular. Currently there are several ceramic systems have excellent optical properties such as opalescence, fluorescence, translucency, chromaticity, which allow the restoration to mimic the tooth structure. From the physical point of view has restored biomechanical integrity and strengthening the remaining tooth structure. All this has led the profession to experience the use of new ceramic systems ranging from conventional feldspathic ceramics to modem ceramic reinforced, injected or computer-aid made. The material selection should be based on clinical need, aesthetic and functional requirements, restoration site, prosthetic design and laboratory techniques. In this article we will deal with the characteristics of the materials, their optical properties and clinical considerations for proper selection.Mientras la odontología continúa avanzando, las técnicas estéticas han evolucionado en procedimientos más efectivos, funcionales y biocompatibles. Al mismo tiempo, la odontología estética se ha tornado un poco más compleja y técnicamente dificultosa. Con la mejoría de las propiedades (físicas y ópticas) de las cerámicas y el establecimiento de un protocolo de trabajo, las restauraciones cerámicas se han tornado cada día más populares. Actualmente existen diversos sistemas cerámicos que poseen excelentes propiedades ópticas como opalescencia, fluorescencia, translucidez, cromaticidad, que permiten mimetizar la restauración a la estructura dentaria. Desde el punto de vista físico se ha logrado devolver integridad biomecánica y estructural reforzando al remanente dentario. Todo esto ha llevado a la profesión a experimentar el uso de nuevos sistemas cerámicos que van desde las convencionales cerámicas feldespáticas hasta las modernas cerámicas reforzadas, inyectadas o confeccionadas con auxilio de computadoras. Su selección debe estar basada en la necesidad clínica, exigencias estéticas y funcionales, localización de la restauración, diseño protético y técnicas de laboratorio. Durante este artículo estarán abordadas las características de los materiales, sus propiedades ópticas y consideraciones clínicas para una correcta selección

Efeito da intensidade de fontes de luz e barreiras de cerâmica na microdureza de cimento resinoso dual

ResumoIntroduçãoO cimento resinoso dual é o principal material para cimentação de cerâmicas. Contudo, fatores, como fonte de luz, podem influenciar no desempenho do cimento.ObjetivoAvaliar a influência de duas fontes de luz de diferentes intensidades sobre a microdureza de um cimento resinoso quando fotoativado sob diferentes cerâmicas.Material e métodoForam fotoativados 40 espécimes de cimento resinoso dual (10 mm × 1,0 mm) por meio de duas fontes de luz LED, com intensidades de 1.000 mW/cm² e 800 mW/cm² durante 40 segundos, sob cerâmicas (15 mm × 2 mm) à base de zircônia, espinélio MgAl2O4 e dissilicato de lítio. No grupo controle, foi utilizada uma placa de vidro de mesma dimensão. As amostras tiveram a superfície regularizada com lixa d`água (600 e 1200). Após armazenagem a seco no escuro (24 h), foram realizadas as medidas de microdureza Vickers (HMV Shimadzu - 50g/10 segundos). Os dados foram submetidos à Anova fatorial e ao teste de Tukey com nível de significância de 5%.ResultadoO cimento polimerizado apresentou valor médio de microdureza e desvio padrão para o grupo controle de 43,9±1,5 e 43,4±1,3, para as intensidades de 1.000 mW/cm2 e 800 mW/cm2, respectivamente. O menor valor de microdureza do cimento foi observado para a cerâmica à base de espinélio MgAl2O4, polimerizado a 800 mW/cm², com valor de 34,3±3,3.ConclusãoO tipo de cerâmica e a intensidade da fonte de luz influenciam na microdureza do cimento. A intensidade de 1.000 mW/cm2 sobre as cerâmicas à base de zircônia e espinélio MgAl2O4 resultaram na melhor combinação de valores de dureza do cimento.</sec