A critical analysis of the degree of conversion of resin-based luting cements

Authors

  • Jaime Dutra Noronha Filho Federal Fluminense University; School of Dentistry; Department of Restorative Dentistry
  • Natasha Lamego Brandão Federal Fluminense University; School of Dentistry; Department of Restorative Dentistry
  • Laiza Tatiana Poskus Federal Fluminense University; School of Dentistry; Department of Restorative Dentistry
  • José Guilherme Antunes Guimarães Federal Fluminense University; School of Dentistry; Department of Restorative Dentistry
  • Eduardo Moreira da Silva Federal Fluminense University; School of Dentistry; Department of Restorative Dentistry

DOI:

https://doi.org/10.1590/S1678-77572010000500003

Keywords:

Resin cements, Cure

Abstract

OBJECTIVE: This study analyzed the degree of conversion (DC%) of four resin-based cements (All Ceram, Enforce, Rely X ARC and Variolink II) activated by two modes (chemical and dual), and evaluated the decrease of DC% in the dual mode promoted by the interposition of a 2.0-mm-thick IPS Empress 2 disc. MATERIAL AND METHODS: In the chemical activation, the resin-based cements were prepared by mixing equal amounts of base and catalyst pastes. In the dual activation, after mixing, the cements were light-activated at 650 mW/cm² for 40 s. In a third group, the cements were light-activated through a 2.0-mm-thick IPS Empress 2 disc. The DC% was evaluated in a FT-IR spectrometer equipped with an attenuated total reflectance crystal (ATR). The data were analyzed by two-way ANOVA and Tukey's HSD test. RESULTS: For all resin-based cements, the DC% was significantly higher with dual activation, followed by dual activation through IPS Empress 2, and chemical activation (p<0.05). Irrespective of the activation mode, Rely X presented the highest DC% (p<0.05). Chemically activated Variolink and All Ceram showed the worst results (p<0.05). The DC% decreased significantly when activation was performed through a 2.0-mm-thick IPS Empress 2 disc (p<0.05). CONCLUSION: The results of the present study suggest that resin-based cements could present low DC% when the materials are dually activated through 2.0 mm of reinforced ceramic materials with translucency equal to or less than that of IPS-Empress 2.

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Published

2010-10-01

Issue

Section

Original Articles

How to Cite

A critical analysis of the degree of conversion of resin-based luting cements . (2010). Journal of Applied Oral Science, 18(5), 442-446. https://doi.org/10.1590/S1678-77572010000500003