Selected characteristics of an Ormocer and a conventional hybrid resin composite.

Abstract

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 600mN 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 mm3; Wd(amelogen) = 0.032 +/- 0.00075 mm3). However, Admira demonstrated the highest surface roughness value compared to Amelogen, with plasma arc 5 s (0.65 +/- 0.023 microm). Amelogen was found to have the lowest surface roughness value with conventional 40 s (0.45 +/- 0.012 microm).

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.

• Authors: Dilek Arslantunali Tagtekin, Funda Caliskan Yanikoglu, Funda Ozturk Bozkurt, Burcu Kologlu, Haydar Sur
• Journal: Dental materials : official publication of the Academy of Dental Materials (Dent Mater) Vol. 20 Issue 5 Pg. 487-97 (Jun 2004) ISSN: 0109-5641 [Print] England
• PMID: 15081556 (Publication Type: Comparative Study, Evaluation Study, Journal Article)
• Copyright: Copyright 2003 Academy of Dental Materials

Chemical References

• Composite Resins
• Methacrylates
• Organically Modified Ceramics
• Silanes
• Siloxanes
• admira
• amelogen
• Xenon

Topics

• Analysis of Variance
• Ceramics (radiation effects)
• Composite Resins (radiation effects)
• Dental Restoration Wear
• Dental Restoration, Permanent
• Dental Stress Analysis
• Hardness
• Light
• Materials Testing
• Methacrylates (radiation effects)
• Microscopy, Electron, Scanning
• Organically Modified Ceramics
• Silanes (radiation effects)
• Siloxanes (radiation effects)
• Statistics, Nonparametric
• Surface Properties (radiation effects)
• Xenon