Effects of coronal substrates and water storage on the microhardness of a resin cement used for luting ceramic crowns

Authors

  • Luana Menezes de MENDONÇA University of São Paulo; Bauru School of Dentistry; Department of Prosthodontics
  • Luiz Fernando PEGORARO University of São Paulo; Bauru School of Dentistry; Department of Prosthodontics
  • Marcos Daniel Septímio LANZA University of São Paulo; Bauru School of Dentistry; Department of Prosthodontics
  • Thiago Amadei PEGORARO Sagrado Coração University; Department of Prosthodontics
  • Ricardo Marins de CARVALHO University of British Columbia; Faculty of Dentistry; Department of Oral Biological and Medical Sciences Division of Biomaterials; Frontier Clinical Research Centre

DOI:

https://doi.org/10.1590/1678-775720130455

Abstract

Composite resin and metallic posts are the materials most employed for reconstruction of teeth presenting partial or total destruction of crowns. Resin-based cements have been widely used for cementation of ceramic crowns. The success of cementation depends on the achievement of adequate cement curing. Objectives: To evaluate the microhardness of Variolink® II (Ivoclar Vivadent, Schaan, Liechtenstein), used for cementing ceramic crowns onto three different coronal substrate preparations (dentin, metal, and composite resin), after 7 days and 3 months of water storage. The evaluation was performed along the cement line in the cervical, medium and occlusal thirds on the buccal and lingual aspects, and on the occlusal surface. Material and Methods: Thirty molars were distributed in three groups (N=10) according to the type of coronal substrate: Group D- the prepared surfaces were kept in dentin; Groups M (metal) and R (resin)- the crowns were sectioned at the level of the cementoenamel junction and restored with metallic cast posts or resin build-up cores, respectively. The crowns were fabricated in ceramic IPS e.max® Press (Ivoclar Vivadent, Schaan, Liechtenstein) and luted with Variolink II. After 7 days of water storage, 5 specimens of each group were sectioned in buccolingual direction for microhardness measurements. The other specimens (N=5) were kept stored in deionized water at 37ºC for three months, followed by sectioning and microhardness measurements. Results: Data were first analyzed by three-way ANOVA that did not reveal significant differences between thirds and occlusal surface (p=0.231). Two-way ANOVA showed significant effect of substrates (p<0.001) and the Tukey test revealed that microhardness was significantly lower when crowns were cemented on resin cores and tested after 7 days of water storage (p=0.007). Conclusion: The type of material employed for coronal reconstruction of preparations for prosthetic purposes may influence the cement properties.

Downloads

Download data is not yet available.

Downloads

Published

2014-07-01

Issue

Section

Original Articles