Degree of Conversion and Mechanical Properties of Resin Cements Cured Through Different All-Ceramic Systems.

Camila De Carvalho Almança Lopes,Veridiana Resende Novais,Paulo Cézar Simamoto Júnior,André Luis Faria E Silva,Renata Borges Rodrigues,Carlos José Soares

doi:10.1590/0103-6440201300180

Camila De Carvalho Almança Lopes, Veridiana Resende Novais + Show 4 more

Open Access

https://doi.org/10.1590/0103-6440201300180

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Abstract

The aim of this study was to verify the degree of conversion (DC), Vickers microhardness (VH) and elastic modulus (E) of resin cements cured through different ceramic systems. One 1.5-mm-thick disc of each ceramic system (feldspathic, lithium dissilicate and zircônia veneered with feldspathic) was used. Three dual-cured (Allcem, Variolink II and RelyX U200) and one chemically-cured (Multilink) resin cements were activated through ceramic discs. For dual-cured resin cements was used a conventional halogen light-curing unit (Optilux 501 at 650 mW/cm2 for 120 s). Samples cured without the ceramic disc were used as control. The samples were stored at 37 °C for 24 h. ATR/FTIR spectrometry was used to evaluate the extent of polymerization in the samples (n=5). Micromechanical properties - VH and E - of the resin cements (n=5) were measured with a dynamic indentation test. Data were statistically analyzed with two-way ANOVA, Tukey's test and Pearson's correlation (α=0.05). DC was affected only by the type of resin cement (p=0.001). For VH, significant interaction was detected between resin cement and ceramic (p=0.045). The dual-cured resin cements showed no significant differences in mean values for E and significantly higher values than the chemically-cured resin cement. The degree of conversion and the mechanical properties of the evaluated resin cements depend on their activation mode and the type of ceramics used in 1.5 mm thickness. The dual-cured resin cements performed better than the chemically-cured resin cement in all studied properties.

Highlights

The interest in all-ceramic materials is on increase, since these materials have adequate physical and mechanical properties, excellent esthetic and biocompatibility that make them suitable for dental rehabilitation [1]
The aim of this study was to evaluate degree of conversion (DC), Vickers microhardness (VH) and elastic modulus (E) of resin cements cured under different ceramic systems
Preparation of Ceramic Discs Three all-ceramic materials were selected for this study: feldspathic glass-ceramic (Noritake EX 3; Kuraray, Miyoshi, Chugoku, Japan); low translucency lithium disilicate glassceramic (IPS e-max Press LT; Ivoclar Vivadent, Schaan, Liechtenstein) and polycrystalline zirconia ceramic (Lava All-Ceramic System; 3M ESPE, Seefeld, Bavaria, Germany)

Summary

Introduction

The interest in all-ceramic materials is on increase, since these materials have adequate physical and mechanical properties, excellent esthetic and biocompatibility that make them suitable for dental rehabilitation [1]. With the developments in adhesive dentistry, resin cements became attractive because of their low solubility, good esthetics, and proper bond strength to both tooth substrate and restorative materials [2]. These materials can be classified according to their activation modes, since the activation can be chemical, physical (by light) or combination of both (dual) [3]. It was shown that increased amount of residual monomers may cause pulp irritation and irreversible pulpitis [6]

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