The influence of temperature and curing light units on the microhardness of composite resin
Wu, X.-X.; Yang, H.-O.
Shanghai Kou Qiang Yi Xue 19(1): 104-106
2010
ISSN/ISBN: 1006-7248 PMID: 20300705 Document Number: 647000
To investigate the effect of different temperature and different light curing units on the hardness of composite resin. Specimens were fabricated from Clearfil AP-X composite resin (Kuraray,Japan)and stored at three different temperature(5degrees centigrade,23degrees centigrade,40degrees centigrade).Then they were cured by a quartz tungsten halogen Translux CL or a second generation LED Elipar FreeLight2. The microhardness of the top and bottom surfaces of the specimens were determined using a digital microhardness tester. Statistical analyses were performed using the two-way ANOVA by SPSS 17.0 software package. Whether cured by QTH or LED, the specimens stored at 40degrees centigrade had higher top and bottom hardness value than that stored at the other temperatures(P<0.01). The LED light produced a significantly better hardness on top and bottom surfaces of specimens stored at the three different temperatures(P<0.01). The use of pre-warmed composite resins might help to increase the composite resin hardness. Second generation LED is more efficient than halogen light unit.