THE EFFECTS OF VARIOUS CURING LIGHT SOURCES ON THE MICROHARDNESS OF LIGHT-ACTIVATED RESTORATIVE MATERIALS |
Nam-Ki Choi, Kyu-HO Yang, Seon-Mi Kim, Choong-Ho Choi |
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다양한 광원에 의한 광중합형 수복물질의 미세경도에 관한 연구 |
최남기, 양규호, 김선미, 최충호 |
전남대학교 치과대학 소아치과학교실 |
Correspondence:
Nam-Ki Choi, |
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Abstract |
The aim of this study is to evaluate the effects of blue light emitting diode (LED) Light Curing Units (FreeLight 2, L.E.Demetron I, Ultra-Lume 5) on the microhardness of three resin composites (Z250, Point 4, Dyract AP) and to determine their optimal curing time. Samples were made using acrylic molds (2.0mm×3mm) of each composite. All samples were prepared over a Mylar strip placed on a flat glass surface. After composite placement on the molds, the top surface was covered with another Mylar strip and a glass slab was gently pressed over it. The times of irradiation were as follows: Elipar TriLight, 40 s; Elipar FreeLight 2. L.E.Demetron I, and Ultra-Lume 5, 10s, 20s, 40s, respectively. Mean hardness values were calculated at the top and bottom for each group. ANOVA and Sheffe's test were used to evaluate the statistical significance of the results. Results showed that FreeLight 2, Ultra-Lume 5, and L.E.Demetron I were able to polymerize point 4 in 20 seconds to a degree equal to that of the halogen control at 40 seconds. FreeLight 2 and L.E.Demetron I were able to polymerize Z250 in 10 seconds to a degree equal to that of the halogen control at 20 seconds. FreeLight 2 and L.E.Demetron I were able to polymerize Dyract AP in 10 seconds to a degree equal to that of the halogen control at 40 seconds. The commercially available LED curing lights used in this study showed an adequate microhardness with less than half of the exposure time of a halogen curing unit. |
Key Words:
Composite resin, Halogen curing light, Light emitting diode, Microhardness |
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