The polymerization rate and the degree of conversion of composite resins by different light sources.
10.5395/JKACD.2004.29.4.386
- Author:
Joo Hee RYOO
1
;
In Bog LEE
;
Hyun Mee YOO
;
Mi Ja KIM
;
Chang In SEOK
;
Hyuk Choon KWON
Author Information
1. Department of Conservative Dentistry, College of Dentistry, Seoul National University, Korea. dentphd@hanmail.net
- Publication Type:Original Article
- Keywords:
LED light curing units;
DSC;
Heat of cure;
Maximum rate of heat output;
Peak heat flow time;
Degree of conversion;
Depth of cure
- MeSH:
Composite Resins*;
Hot Temperature;
Kinetics;
Polymerization*;
Polymers*;
Spectroscopy, Fourier Transform Infrared
- From:Journal of Korean Academy of Conservative Dentistry
2004;29(4):386-398
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVES: The purpose of this study was to observe the reaction kinetics and the degree of polymerization of composite resins when cured by different light sources and to evaluate the effectiveness of the blue Light Emitting Diode Light Curing Units (LED LCUs) compared with conventional halogen LCUs. MATERIALS AND METHODS: First, thermal analysis was performed by a differential scanning calorimeter (DSC). The LED LCU (Elipar Freelight, 320 mW/cm2) and the conventional halogen LCU (XL3000, 400 mW/cm2) were used in this study for curing three composite resins (SureFil, Z-250 and AEliteFLO). Second, the degree of conversion was obtained in the composite resins cured according to the above curing mode with a FTIR. Third, the measurements of depth of cure were carried out in accordance with ISO 4049 standards. Statistical analysis was performed by two-way ANOVA test at 95% levels of confidence and Duncan's procedure for multiple comparisons. RESULTS: The heat of cure was not statistically different among the LCUs (p > 0.05). The composites cured by the LED (Exp) LCUs were statistically more slowly polymerized than by the halogen LCU and the LED (Std) LCU (p < 0.05). The composite resin groups cured by the LED (Exp) LCUs had significantly greater degree of conversion value than by the halogen LCU and the LED (Std) LCU (p = 0.0002). The composite resin groups cured by the LED (Std) LCUs showed significantly greater depth of cure value than by the halogen LCU and the LED (Exp) LCU (p < 0.05).
