Effect of Preheating on Micro-hardness of different Composite Resins

Authors

  • Thyab, Samer, A.1 , Al-Maroof, Ahmed, S.2 , Ali, Ahmed, H.2

Keywords:

Composite resins, Preheating, Vicker’s microhardness

Abstract

Aim: The aim of this study was to assess the effect of preheating on the surface microhardness of different

commercially available composite resins (G-aenial, Filtek Z350 and Tetric-N-Ceram).

Materials and Methods: Tubes of the composite resins were either kept at room temperature (24 ±10 C) or

preheated for 40 min in a commercially preheating device to 40 0 C, 50 0 C and 60 0C, respectively. From

composite resin tubes, a total of 120 disk-shaped specimens (40 specimens of each composite resin, 10

disks from each temperature setting) were prepared by inserting uncured preheated composite resin into

cylindrical nylon moulds (5 mm diameter × 2 mm height); before light polymerized for 40s with a light

emitting diode curing unit. The Vicker’s microhardness number (VHN) of each specimen was measured.

Two-way ANOVA and Tukey test were used to analyze the collected data at a significance level of 0.05.

Results: In comparison to the room temperature, there was a significant increase in the mean VHNs of each

composite resin by preheating to 40 0C, 50 0 C and 60 0 C, respectively (p<0.05). For G-aenial posterior, Filtek

Z350XT and Tetric-N-Ceram, at room temperature, the mean VHNs were 51± 4.3, 60.6± 3.7 and 76.6±1.4,

respectively with significant difference between G-aenial posterior and Tetric-N-Ceram (p<0.05), while

at 400C, the mean VHNs were 65.7±2.5, 86.8±2.3 and 88.4±1.8, respectively with significant differences

(p<0.05) between G-aenial posterior and the other two composites. At 500C, the mean VHNs were 109.4±0.9,

104.4±3.4 and 114±0.71, respectively with no significant difference between composite resins. At 600C, the

mean VHNs were 122±3.2, 129±3.4 and 136±2, respectively with significant difference between G-aenial

posterior and Tetric-N-Ceram (p<0.05).

Conclusions: Preheating significantly increased the surface microhardness of all tested composite resins

with the highest value observed for Tetric N-Ceram at 600C preheating temperature.

Author Biography

Thyab, Samer, A.1 , Al-Maroof, Ahmed, S.2 , Ali, Ahmed, H.2

1 M.Sc. (Baghdad), 2 Ph.D. (London), Department of Restorative and Aesthetic Dentistry, College of Dentistry,

University of Baghdad, Iraq.

Published

2020-07-30

How to Cite

Thyab, Samer, A.1 , Al-Maroof, Ahmed, S.2 , Ali, Ahmed, H.2. (2020). Effect of Preheating on Micro-hardness of different Composite Resins. Indian Journal of Forensic Medicine & Toxicology, 14(3), 1423-1427. Retrieved from http://medicopublication.com/index.php/ijfmt/article/view/10607