Original scientific paper
Flexural Strength of E - glass Fiber Reinforced Dental Polymer and Dental High Impact Strength Resin
Denis VOJVODIĆ
; School of Dental Medicine, University of Zagreb, Zagreb, Croatia
Franjo MATEJIČEK
; School of Engineering in Slavonski Brod, J. J. Strossmayer University, Osijek, Croatia
Zdravko SCHAUPERL
; School of Engineering and Naval Constructions, University of Zagreb, Croatia
Ketij MEHULIĆ
; School of Dental Medicine, University of Zagreb, Zagreb, Croatia
Ivana BAGIĆ-ČUKOVIĆ
; School of Dental Medicine, University of Zagreb, Zagreb, Croatia
Sanja ŠEGOVIĆ
; School of Dental Medicine, University of Zagreb, Zagreb, Croatia
Abstract
Fractures of denture base polymer material are one of the most frequent reasons for repair of removable dentures. Therefore, there is a continuous effort to strengthen them, and polymer materials of high resistance to fracture are being developed. The aim of this study was to determine the flexural strength of denture base polymers (pressure-heat polymerizing and auto polymerizing) reinforced with E -glass fibers and high impact strength resin (injectional polymerization) material using the “short beam” method. Specimens were tested after polymerization and after artificial ageing performed by storage at 37 ºC temperature during 28 days and thermocycling. Microscopic examination was performed to determine the quality of bonding between glass fibers and matrix. The study showed significantly higher values of flexural strength (130.1-163.88 MPa) of glass fiber reinforced specimens compared to the un-reinforced specimens (91.77 – 122.75 MPa) – control group, matching those of high impact strength resin (145.67 MPa). Between the groups of samples tested after polymerization and storage in water at 37 ºC during 28 days there was no statistically significant difference in flexural strength values while samples tested after thermocycling unexpectedly revealed significantly higher values. Fiber reinforced materials and high impact strength resin revealed similar results of flexural strength both being acceptable for clinical use. Obtained results suggest that the increase of temperature (during thermocycling) had the effect of prolonged polymerization which resulted in a decrease of residual monomer volume, enhancing polymer mechanical properties.
Keywords
Dental materials; Flexural strength; Polymers
Hrčak ID:
40626
URI
Publication date:
29.8.2008.
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