Effect of LED and Argon Laser on Degree of Conversion and Temperature Rise of Hybrid and Low Shrinkage Composite Resins
Ayob Pahlevan, Masumeh Hasani Tabatabaei, Sakineh Arami, Sara Valizadeh*
Operative Dentist, Tehran University of Medical Science, North Amir-Abad, Tehran, Iran
Different light curing units are used for polymerization of composite resins. The aim of this study was to evaluate the degree of conversion (DC) and temperature rise in hybrid and low shrinkage composite resins cured by LED and Argon Laser curing lights.
Materials and Methods:
DC was measured using FTIR spectroscopy. For measuring temperature rise, composite resin samples were placed in Teflon molds and cured from the top. The thermocouple under samples recorded the temperature rise. After initial radiation and specimens reaching the ambient temperature, reirradiation was done and temperature was recorded again. Both temperature rise and DC data submitted to one-way ANOVA and Tukey-HSD tests (5% significance).
The obtained results revealed that DC was not significantly different between the understudy composite resins or curing units. Low shrinkage composite resin showed a significantly higher temperature rise than hybrid composite resin. Argon laser caused the lowest temperature rise among the curing units.
Energy density of light curing units was correlated with the DC. Type of composite resin and light curing unit had a significant effect on temperature rise due to polymerization and curing unit, respectively.
Keywords: Argon laser, DC, LED, Low shrinkage composite, Temperature rise.
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License (CC BY-NC 4.0) (https://creativecommons.org/licenses/by-nc/4.0/legalcode), which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
* Address correspondence to this author at the Tehran University of Medical Science, North Amir-Abad, Tehran, Iran; Tel: +989123488820; E-mail: firstname.lastname@example.org