Browse

Influence of instrument compliance and specimen thickness on the polymerization shrinkage stress measurement of light-cured composites

Cited 47 time in Web of Science Cited 48 time in Scopus
Authors
Lee, Sue Hyun; Chang, Juhea; Ferracane, Jack; Lee, In Bog
Issue Date
2007-09
Publisher
ELSEVIER SCI LTD
Citation
DENTAL MATERIALS, Vol.23, No.9, pp.1093-1100
Keywords
specimen geometrypolymerization shrinkage stresscompositescompliance
Abstract
objectives. The aim of our study was to investigate the effects of instrument compliance and specimen geometry on the polymerization shrinkage stress measurements of composites. Methods. A custom designed stress-strain analyzer was made using a linear variable differential transformer probe and a cantilever load cell. A sandblasted glass rod was fixed at the free end of the load cell, and another glass rod was located on a base plate. A composite was placed between the two rods and light cured. The end displacement of the load cell during polymerization was recorded for 10 min. A flowable (Filtek Flow), a universal hybrid (Z100), and a packable (P60) composite were studied. To investigate the effect of specimen geometry and instrument compliance, specimen thickness was varied between 0.5, 1.0, and 2.0 mm, and three load cells with maximum capacities of 20, 100, and 500 kgf were used. Ten maxillary premolars were prepared with two sizes of MOD cavities; the bucco-lingual widths and depths of the cavities were 1.5 mm x 2 mm and 3 mm x 2 mm, and the cusp compliance and deflection were measured before and during composite polymerization. Results. The measured polymerization stress decreased in the order of Filtek Flow, Z100, and P60 for all measurement conditions. As the specimen thickness was increased, the shrinkage stress per unit thickness (mm) decreased. The measured stress decreased with increasing instrument compliance. The cusp compliance (3.32 mu m/N) of the 3 mm x 2 mm cavities was similar to that of instrument with a 20 kgf load cell (3.34 mu m/N). Significance. For determining the most clinically relevant values for shrinkage stress of dental composites, the instrument compliance should closely match that of the tooth walls in the cavity geometry to be tested. (C) 2006 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
ISSN
0109-5641
Language
English
URI
https://hdl.handle.net/10371/80497
DOI
https://doi.org/10.1016/j.dental.2006.10.003
Files in This Item:
There are no files associated with this item.
Appears in Collections:
College of Dentistry/School of Dentistry (치과대학/치의학대학원)Dept. of Dentistry (치의학과)Journal Papers (저널논문_치의학과)
  • mendeley

Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse