Eick JD, Kotha SP, Chappelow CC, Kilway KV, Giese GJ, Glaros AG, Pinzino CS. Properties of silorane-based dental resins and composites containing a stress-reducing monomer.
Dent Mater 2007;
23:1011-7. [PMID:
17097138 DOI:
10.1016/j.dental.2006.09.002]
[Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Revised: 08/31/2006] [Accepted: 09/13/2006] [Indexed: 01/04/2023]
Abstract
OBJECTIVE
To evaluate properties of silorane-based resins and composites containing a stress reducing monomer.
METHODS
Resin mixtures and composites were formulated containing (a) a developmental stress reducing monomer [TOSU; Midwest Research Institute]; (b) Sil-Mix (3M-ESPE); (c) photo cationic initiator system. Standard BISGMA/TEGDMA resin (B/T) and composite (Filtek Z250) were used as controls. Polymerization volume change was measured using a NIST mercury dilatometer and polymerization stress using an Enduratec mechanical testing machine. Three point bend tests determined flexural elastic modulus, work of fracture, and ultimate strength (ADA 27; ISO 4049). Fracture toughness was measured using ASTM E399-90. Four groups of resins and composites were tested: Sil-Mix, methacrylate standard, and Sil-Mix with two addition levels of TOSU. An ANOVA was used and significant differences ranked using Student-Newman-Keuls test (alpha=0.05).
RESULTS
Polymerization stress values for resins containing TOSU were significantly less than the other materials. Polymerization shrinkage values for Sil-Mix formulations were significantly less than for B/T, but were not different from each other. TOSU-containing formulations generally had somewhat lower mechanical properties values than Sil-Mix or B/T. Polymerization stress values for Sil-Mix-based composites were significantly less as compared to Z250. The 1wt.% TOSU composite had the lowest stress. No difference between composite groups was noted for fracture toughness or work of fracture. For ultimate strength, the 5wt.% TOSU formulation differed significantly from Z250. All Sil-Mix formulations had elastic modulus values significantly different from Z250.
SIGNIFICANCE
The ability of TOSU to reduce polymerization stress without a proportional reduction in mechanical properties provides a basis for improvement of silorane-based composites.
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