Polymerization stress, shrinkage and elastic modulus of current low-shrinkage restorative composites

Autor(es)

Cidreira Boaro, Leticia Cristina ^[1] ; Goncalves, Flavia ^[1] ; Guimaraes, Thayse Costa ^[1] ; Ferracane, Jack Liborio ^[2] ; Versluis, Antheunis ^[3] ; Braga, Roberto Ruggiero ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Dent Mat, BR-05508000 Sao Paulo - Brazil

^[2] Oregon Hlth & Sci Univ, Dept Restorat Dent, Div Biomat & Biomech, Portland, OR 97201 - USA

^[3] Univ Tennessee Hlth Sci Ctr, Dept Biosci Res, Coll Dent, Minneapolis, MN - USA

• Tipo de documento: Artigo Científico
• Fonte: Dental Materials; v. 26, n. 12, p. 1144-1150, DEC 2010.
• Citações Web of Science: 121

Resumo

Objective. To compare currently available low-shrinkage composites with others regarding polymerization stress, volumetric shrinkage (total and post-gel), shrinkage rate and elastic modulus. Methods. Seven BisGMA-based composites (Durafill/DU, Filtek Z250/FZ, Heliomolar/HM, Aelite LS Posterior/AP, Point 4/P4, Filtek Supreme/SU, ELS/EL), a silorane-based (Filtek LS, LS), a urethane-based (Venus Diamond, VD) and one based on a dimethacrylate-derivative of dimer acid (N'Durance, ND) were tested. Polymerization stress was determined in 1-mm high specimens inserted between two PMMA rods attached to a universal testing machine. Total volumetric shrinkage was measured using a mercury dilatometer. Maximum shrinkage rate was used as a parameter of the reaction speed. Post-gel shrinkage was measured using strain-gages. Elastic modulus was obtained by three-point bending. Data were submitted to one-way ANOVA/Tukey test (p = 0.05), except for elastic modulus (Kruskal-Wallis). Results. Composites ranked differently for total and post-gel shrinkage. Among the materials considered as ``low-shrinkage{''} by the respective manufacturers, LS, EL and VD presented low post-gel shrinkage, while AP and ND presented relatively high values. Polymerization stress showed a strong correlation with post-gel shrinkage except for LS, which presented high stress. Elastic modulus and shrinkage rate showed weak relationships with polymerization stress. Significance. Not all low-shrinkage composites demonstrated reduced polymerization shrinkage. Also, in order to effectively reduce polymerization stress, a low post-gel shrinkage must be associated to a relatively low elastic modulus. (C) 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 08/54456-7 - Validação do ensaio de polimerização através de correlações com testes de qualidade da interface de restaurações em compósito
• Beneficiário: Letícia Cristina Cidreira Boaro
• Modalidade de apoio: Bolsas no Brasil - Doutorado