ABSTRACT
Objective: The aim of this study was to analyze mechanical and thermal stresses of hybrid ceramic and lithium disilicate based ceramic of CAD/CAM inlays using 3D Finite element analysis. Material and Methods:A three dimensions finite element model of permanent maxillary premolar designed according to standard anatomy with class II cavity preparation for inlay restored with two different ceramic materials: 1- Hybrid ceramic (Vita Enamic), 2- Lithium disilicate based ceramic (IPS e.max CAD). Totally six runs were performed on the model as: One loading case for each restorative material was tested in stress analysis; seven points of loading with 140N vertically applied at palatal cusp tip and cusp slop, marginal ridges and central fossa while the models base was fixed as a boundary condition in the two cases. Two thermal analysis cases were performed for each restoration material by applying 5ºC and 55ºC on the crown surface including the restoration surface. Results:The results of all structures were separated from the rest of the model to analyze the magnitude of stress in each component. For each group, maximum stresses on restorative materials, cement, enamel, and dentin were evaluated separately. Both ceramic materials generated similar stress distribution patterns for all groups when a total occlusal load of 140 N was applied. Conclusion: Thermal fluctuations of temperature have a great influence on the stresses induced on both restoration and tooth structure. IPS e.max CAD produced more favorable stresses on the tooth structure than Vita Enamic. (AU)
Objetivo: O objetivo deste estudo foi analisar o estresse mecânico e térmico de inlays de cerâmica hibrida e a base de dissilicato de lítio através da análise em 3D de elementos finitos. Material e Métodos: Foi realizado o design de um modelo de três dimensões em elementos finitos de um pré-molar superior de acordo com os padrões anatômicos de um preparo de cavidade classe II para restauração de inlay em dois tipos de cerâmicas diferentes: 1 Cerâmica hibrida (Vita Enamic), 2 Cerâmica a base de dissilicato de lítio (IPS e.max CAD). No total, seis execuções foram realizadas no modelo como: Uma carga para cada material restaurador foi testado para análise de tensão; sete pontos de carga com 140N foi aplicado verticalmente na ponta da cúspide palatina, saliência da cúspide, cristas marginais e fossa central enquanto a base do modelo foi fixada como uma condição de limite nos dois casos. Duas análises térmicas foram realizadas para cada material de restauração, aplicando 5ºC e 55ºC na superfície da coroa, incluindo a superfície da restauração. Resultados: Os resultados de todas as estruturas foram separados do resto do modelo para analisar a magnitude do estresse de cada componente. Para cada grupo, o máximo de estresse nos materiais restauradores, cemento, esmalte e dentina foram avaliados separadamente. Padrões similares de distribuição de estresse foram gerados em todos os grupos para ambos os materiais cerâmicos, quando a carga oclusal de 140 N foi aplicada. Conclusão: As variações térmicas de temperatura têm uma grande influência nas tensões induzidas na restauração e na estrutura dentária. IPS e.max CAD produziu tensões mais favoráveis na estrutura dentária do que o Vita Enamic (AU)
Subject(s)
Bicuspid , Finite Element Analysis , Dental Cavity Preparation , Dental Cementum , Dental Enamel , DentinABSTRACT
Introduction: the clinical success of a restoration is strongly associated with the quality and durability of the ceramic-cement resin interface. In order to obtain an adequate union between these materials of different nature surface treatments are used and achieve mechanical retention or chemical interaction. Objectives: to check if any method promotes a true chemical bond between lithium disilicate ceramics and resin cement. As well as determineif there is any treatment that reports bonding values comparable to hydrofluoric acid and silane (gold standard). Methods: a systematic literature review was developed based on the PRISMA strategy, where the databases were searched: Science Direct, Pubmed (MEDLINE), EMBASE, Springer Journal, SciELO with MeSH and free terms from 2005 to November 2016 for articles in English and Spanish on surface treatments for lithium disilicate. Results: from 58 publications selected a sample of 21 articles. Two articles reported high risk of bias. Conclusions: hydrofluoric acid and silane continue to be the method with the highest and most reliable adhesion values in the literature. Universal adhesives are an alternative to promote chemical adhesion additional to the silane. Diamond burs, Nd: YAG and Er: YAG laser are not recommended as surface treatments(AU)
Introducción: el éxito clínico de una restauración se asocia fuertemente a la calidad y duración de la interface cerámica-cemento resinoso. Para que exista una adecuada unión entre estos materiales de distinta naturaleza se emplean tratamientos de superficie para lograr una buena retención mecánica o interacción química. Objetivos: revisar si algún método promueve una verdadera adhesión química entre la cerámica de disilicato de litio y el cemento resinoso, así como determinar si existe algún tratamiento que reporte valores de unión comparables al ácido fluorhídrico y silano (patrón de oro). Métodos: se desarrolló una revisión sistemática de literatura basada en la estrategia PRISMA, donde se buscó en las bases de datos: Science Direct, Pubmed (MEDLINE), EMBASE, Springer Journal, SciELO con términos MeSH y libres desde el 2005 a noviembre de 2016 para artículos en inglés y español sobre tratamientos de superficie para disilicato de litio. Resultados: de 58 publicaciones, se seleccionó una muestra de 21 artículos. Dos artículos reportaron riesgo de sesgo alto. Conclusiones: el ácido fluorhídrico y silano continúan siendo el método con los valores de adhesión más altos y confiables de la literatura. Los adhesivos universales son una alternativa para promover adhesión química adicional al silano. Fresas diamantadas, laser Nd: YAG y Er:YAG no se recomienda como tratamientos de superficie(AU)
Subject(s)
Humans , Review Literature as Topic , Ceramics/adverse effects , Databases, Bibliographic/statistics & numerical data , Self-Curing of Dental Resins/methods , Hydrofluoric Acid/adverse effectsABSTRACT
Objective @#To investigate different Er:YAG laser power settings on the bonding properties of IPS e.max CAD ceramics. @*Methods@# 96 IPS e.max CAD ceramics blocks (5 mm × 5 mm × 5 mm) were prepared and randomly divided into 8 groups (n = 12), the untreated blocks served as the control, while one of the experimental groups was treated with 4.5% HF for 20 seconds, six remaining test group (C、D、E、F、G、H) were treated with different Er: YAG laser power settings: 100 mJ、200 mJ、300 mJ、400 mJ、500 mJ and 600 mJ. Morphology of the ceramic surface was observed by atomic force microscopy and its shear bond strength (SBS) was tested. @*Results @#Higher shear bond strength values were found in group C-H compared to group B, the highest is group F (24.12 ± 1.91) MPa. The difference was statistically significant. The atomic force microscope observation of the surface structure showed that the control group was smooth and flat, and the HF-like etching group formed a uniform needle-like convex structure. The laser group gradually formed a regularly arranged cylindrical convex structure, in which the surface of the G and H groups was damaged. @*Conclusion @#The Er: YAG laser power settings of 400 mJ can be used as an effective pretreatment method before bonding of IPS e.max CAD ceramic.
ABSTRACT
Objective@#To investigate different Er:YAG laser power settings on the bonding properties of IPS e.max CAD ceramics. @*Methods @# 96 IPS e.max CAD ceramics blocks (5 mm × 5 mm × 5 mm) were prepared and randomly divided into 8 groups (n = 12), the untreated blocks served as the control, while one of the experimental groups was treated with 4.5% HF for 20 seconds, six remaining test group (C、D、E、F、G、H) were treated with different Er: YAG laser power settings: 100 mJ、200 mJ、300 mJ、400 mJ、500 mJ and 600 mJ. Morphology of the ceramic surface was observed by atomic force microscopy and its shear bond strength (SBS) was tested. @*Results @#Higher shear bond strength values were found in group C-H compared to group B, the highest is group F (24.12 ± 1.91) MPa. The difference was statistically significant. The atomic force microscope observation of the surface structure showed that the control group was smooth and flat, and the HF-like etching group formed a uniform needle-like convex structure. The laser group gradually formed a regularly arranged cylindrical convex structure, in which the surface of the G and H groups was damaged. @*Conclusion@# The Er: YAG laser power settings of 400 mJ can be used as an effective pretreatment method before bonding of IPS e.max CAD ceramic.
ABSTRACT
Objetivo: comparar la adaptación marginal In Vitro de incrustaciones MOD con terminación en esmalte fabricadas con IPS e.max CAD (Computer Asisted Desing) y fabricadas en oro tipo III. Materiales y métodos: En este estudio experimental exploratorio se uso una muestra no probabilística de 15 premolares sanos por cada uno de los dos grupos; IPS e.max CAD y oro tipo III.A todos los premolares se les realizó cavidades MOD estandarizadas para los 2 grupos. Los dientes preparados fueron asignados aleatoriamente a cada grupo. Las incrustaciones del grupo IPS e.max CAD fueron elaboradas con el sistema CEREC 3 y las incrustaciones en oro fueron elaboradas por los investigadores. Se tomaron estereo microfotografías de todas las muestras sobre papel milimetrado, y las imágenes fueron analizadas mediante el programa ImageTool. Se tomaron tres medidas adaptación marginal en el área proximal mesial o distal de cada muestra, que fueron promediadas y reportadas en micras. Los datos fueron analizados mediante ANOVA y Test de Mann-Whitney. Resultados: el 98% del total de las incrustaciones en oro y el 47% del total de las incrustaciones de IPS e.max CAD presentaron una adaptación marginal < a 120 micras. El promedio de desadaptación marginal del grupo IPS e.max CAD fue 122.8 μ + 44.1, mientras que para el grupo oro fue de 75.3 μ+42,6 encontrándose diferencias estadísticamente significativas entre los dos. Conclusiones: El oro reporta mejor adaptación marginal en restauraciones inlays MOD que los sistemas maquinados como el sistema IPS e.max CAD.
Objective: To compare In Vitro, the marginal adaptation of MOD fillings with an enamel finish manufactured with IPS e.max CAD (Computer Assisted Design) and those manufactured with gold type III. Materials and methods: In this exploratory experimental study, a non-probabilistic sample of 15 healthy premolars for each of the two groups (IPS e.max CAD and gold type III) was used. Standardized MOD cavities were made in all the premolars for both groups. The prepared teeth were randomly assigned to each group. The IPS e.max CAD fillings were made using the CEREC 3 system and the gold fillings were made by the researchers. Stereo microphotographs of all the samples were taken on millimeter paper and the images were analyzed using the Image Tool software. Three marginal adaptation measurements in the mesial proximal or distal area were taken for every sample; they were averaged and reported in microns. The data was analyzed using ANOVA and the Mann-Whitney test. Results: 98% of all the gold fillings and 47% of all the IPS e.max CAD fillings showed a marginal adaptation of less than or equal to 120 microns. The marginal unfitness average for the IPD e.max CAD group was 122.8 + 44.1 μm, and for the gold fillings group it was 75.3 + 42.6 μm. There was a statistically significant differences between the groups. Conclusions: Gold reports a better marginal adaptation for inlay MOD fillings than manufactured systems like IPS e.max CAD system.