Adherence of Streptococcus mutans to uncoated and saliva-coated glass-ceramics and composites

This study sought to investigate the surface roughness and the adherence of Streptococcus mutans (in the presence and absence of saliva) to ceramics and composites. The early dental biofilms formed in situ on the materials were illustrated, using scanning electron microscopy (SEM). Feldspathic and leucite/feldspathic ceramics and microhybrid and microfilled composites were evaluated. Human dental enamel was used as the control. Standardized specimens of the materials were produced and surface roughness was analyzed. The adhesion tests were carried out in 24-well plates and colony forming units (CFU/mL) were evaluated. Values of roughness (μm) and adherence (CFU/mL) were analyzed statistically. Of all the surfaces tested, enamel was the roughest. Leucite/feldspathic ceramics were rougher than the feldspathic ceramic, while composites were similar statistically. Enamel offered the highest level of adherence to uncoated and saliva-coated specimens, while the leucite/feldspathic ceramic demonstrated greater adherence than the feldspathic ceramic and the composites were similar statically. The rougher restorative materials increased the adherence of S, mutans on the material surfaces.

Stress distribution in ceramic restorations over natural tooth using finite element analysis. lithium disilicate x aluminum oxide material

Background: Data on stress distribution in tooth-restoration interface with different ceramic restorative materials are limited. The aim of this chapter was to assess the stress distribution in the interface of ceramic restorations with laminate veneer or full-coverage crown with two different materials (lithium dissilicate and densely sintered aluminum oxide) under different loading areas through finite element analysis. Materials and Methods: Six two-dimensional finite element models were fabricated with different restorations on natural tooth: laminate veneer (IPS Empress, IPS Empress Esthetic and Procera AllCeram) or full-coverage crown (IPS e.max Press and Procera AllCeram). Two different loading areas (L) (50N) were also determined: palatal surface at 45° in relation to the long axis of tooth (L1) and perpendicular to the incisal edge (L2). A model with higid natural tooth was used as control. von Mises equivalent stress (σ vM) and maximum principal stress (σ max) were obtained on Ansys software. Results: The presence of ceramic restoration increased σ vM and σ max in the adhesive interface, mainly for the aluminum oxide (Procera AllCeram system) restorations. The full-coverage crowns generated higher stress in the adhesive interface under L1 while the same result was observed for the laminate veneers under L2. Conclusions: Lithium dissilicate and densely sintered aluminum oxide restorations exhibit different behavior due to different mechanical properties and loading conditions. © 2011 Nova Science Publishers, Inc.

Effect of ceramic surface treatment on the shear bond strength of a resin cement to different ceramic systems

This study evaluated three surface treatments and their effects on the shear bond strength between a resin cement and one of three ceramics. The ceramic surfaces were evaluated with scanning electron microscopy (SEM ) as well. Specimens were treated with 50 μm aluminum oxide airborne particles, 10% hydrofluoric acid etching, or a combination of the two. Using a matrix with a center hole (5.0 mm × 3.0 mm), the ceramic bonding areas were filled with resin cement following treatment. The specimens were submitted to thermal cycling (1,000 cycles) and the shear bond strength was tested (0.5 mm/minute). The failure mode and the effect of surface treatment were analyzed under SEM . Data were submitted to ANOVA and a Tukey test (α = 0.05). Duceram Plus and IPS Empress 2 composite specimens produced similar shear bond strength results (p > 0.05), regardless of the treatment method used. Hydrofluoric acid decreased the shear bond strength of In-Ceram Alumina specimens. For all materials, surface treatments changed the morphological surface. All treatments influenced the shear bond strength and failure mode of the ceramic/resin cement composites.

Estudo dos procedimentos utilizados para obtenção de microrretenções na superfície interna da porcelana: avaliação por meio de testes de rugosimetria e microscopia eletrônica de varredura

Pós-graduação em Ciências Odontológicas - FOAR

Avaliação de tratamentos de superfície em diferentes sistemas cerâmicos e seu efeito na resistência de união a um cimento resinoso

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Resistência à flexão, resistência à tração diametral e dureza de sistemas cerâmicos para infra-estrutura

Pós-graduação em Reabilitação Oral - FOAR

Influência da interposição de diferentes cerâmicas no grau de conversão de agentes cimentantes resinosos

Pós-graduação em Odontologia - FOA

Análise da distribuição das tensões em restaurações cerâmicas sobre dente natural e implante por meio do método dos elementos finitos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da ciclagem mecânica na deflexão de cúspides de pré-molares restaurados pela técnica direta e indireta: estudo com strain gauge

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da adaptação marginal de restaurações cerâmicas inlay após a cimentação

Pós-graduação em Odontologia Restauradora - ICT

Avaliação da microdureza de quatro cimentos resinosos duais fotopolimerizados através da interposição de diferentes materiais: estudo in vitro

Pós-graduação em Odontologia Restauradora - ICT

Resistência de união cerâmica - agente cimentante. Teste de micro-tração e análise por microscopia eletrônica de varredura

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise da influência de diferentes tratamentos superficiais de sistemas cerâmicos na resistência de união adesiva

Pós-graduação em Ciências Odontológicas - FOAR

Estudo da influência das características químicas e microestruturais nas propriedades mecânicas de sistemas totalmante cerâmicos

Pós-graduação em Odontologia Restauradora - ICT

Avaliação in vitro da resistência adesiva ao cisalhamento entre a dentina bovina, cimentos resinosos e materiais restauradores indiretos, tratados ou não com jato de óxido de alumínio, ácido fluorídrico e silano

The purpose of this study was to evaluate in vitro the shear bond strenght to bovine dentin, during 24h and 30 days with the following variables: resin cements Enforce and Panavia F; aesthetics restorative materials Art Glass, IPS Empress 2 and Targis, with surface treatment with microetching with aluminium oxide, fluoridric acid and silane. Two hundred eighty eight sound bovine teeth from 3 years old animals constituted the samples after inclusion on polyester resin box. lnstron model 430 Universal Testing Machine, a crosshead speed 0,5 mm/min and load cells of 500 Kg, was used for shear bond strenght testing (MPa). The results were statistically analysed by ANOVA The best result was obtained with /PS Empress 2, microetched with aluminium oxide, fluoridric acid and silane, cemented with Panavia F and stored in distilled water, 3f'C during 30 days