Selected characteristics of an Ormocer and a conventional hybrid resin composite
Objectives. The objective of this in vitro study was to evaluate surface roughness, hardness and wear resistance of an Ormocer (Admira), polymerized by a plasma arc system. A secondary objective was to investigate two placement technique bulk or incremental layers. Methods. Blocks from Admira and Am...
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Published in | Dental materials Vol. 20; no. 5; pp. 487 - 497 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
England
Elsevier Ltd
01.06.2004
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Subjects | |
Online Access | Get full text |
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Summary: | Objectives. The objective of this in vitro study was to evaluate surface roughness, hardness and wear resistance of an Ormocer (Admira), polymerized by a plasma arc system. A secondary objective was to investigate two placement technique bulk or incremental layers.
Methods. Blocks from Admira and Amelogen (a microhybrid composite) were prepared in cylinders, 3 mm in diameter, and 2 and 5 mm in thickness (bulk or incrementally placed) and polymerized by a plasma arc and a conventional light system. Surface roughness measurements were taken by a Surface Profilometer on the top of the specimens. Vickers hardness measurements, with a load of 600
mN were taken on the top and bottom of 2 mm and top, intermediate and bottom of 5 mm thick specimens. For the wear test, specimes (8 mm in diameter and 2 mm in thickness) of Admira, Amelogen and amalgam were tested in a ball-on design, by circular movements of the antagonist (alumina ball; diameter 10 mm) under 10 N load. For the statistical evaluation of the results of surface roughness, microhardness and wear test; a paired samples
t-test and Kruskal-Wallis analysis of variance test, were performed.
Results. Admira showed highest hardness values in all polymerization types at the top surface and this was statistically significant (
p<0.05). These highest hardness values were obtained with conventional polymerization (81.84±1.167 VHN). Meanwhile, the wear resistance of Admira was found to be higher than Amelogen (Wd
admira=0.024±0.00149 mm
3; Wd
amelogen=0.032±0.00075 mm
3). However, Admira demonstrated the highest surface roughness value compared to Amelogen, with plasma arc 5 s (0.65±0.023 μm). Amelogen was found to have the lowest surface roughness value with conventional 40 s (0.45±0.012 μm).
Significance. The results indicated that Ormocer, which was developed by Ormocer technology, demonstrated higher microhardness and wear resistance when compared to a hybrid composite; however, the polishability of Ormocer needs further investigation. Also the selection of visible light activated composite resins exhibited higher surface microhardness values when polymerized with conventional rather than with plasma arc. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0109-5641 1879-0097 |
DOI: | 10.1016/j.dental.2003.06.004 |