BACKGROUND Light-emitting diode (LED) curing lights offer advantages over quartz-tungsten-halogen (QTH) lights, but the first-generation LED lights had some disadvantages. PURPOSE This study compared a second-generation LED light with a QTH light to determine which was better at photopolymerizing a variety of resin composites. METHODS The ability of a LED light used for 20 and 40 seconds to...

PURPOSE To compare the effect of reduced exposure times on the microhardness of resin composites cured with a "second-generation" light-emitting diode (LED) curing light and a quartz-tungsten-halogen (QTH) curing light. METHODS Ten composites were cured with a LED curing light for 50% of the manufacturers" recommended exposure time or a QTH light at the high power setting for 50% of the recom...

OBJECTIVES To compare curing performance of a second generation LED curing light with a high power tungsten quartz halogen (QTH). METHODS A hybrid composite resin (Filtek Z 250, 3M, USA) was used as test material and cured using a second generation LED light (Translux Power Blue™, Heraus Kulzer ,Germany) or a very high power QTH light unit (EMS, Switzerland). A two split aluminum mold was use...

If G is a finitely generated profinite group then the verbal subgroup Gq is open. In a d-generator finite group every product of qth powers is a product of f(d, q) qth powers. 20E20, 20F20.

The purpose of this study was to evaluate, in vitro, the color stability of three composite resins of two different shades (A3 and C3) cured with either a quartz tungsten halogen (QTH) or a light emitting diode (LED) source. Forty specimens (20 x 2 mm) were prepared for each composite (Tetric Ceram, Heliomolar and Esthet-X), being 20 for each shade. In each group, 10 specimens were light-cured ...

OBJECTIVE The objective of this study was to compare the conversion degree of six different composite materials (Filtek Z 250, Filtek P60, Spectrum TPH, Pertac II, Clearfil AP-X, and Clearfil Photo Posterior) using three different light sources (blue light-emitting diode [LED], plasma arc curing [PAC], and conventional halogen lamp [QTH]). METHODS Composites were placed in a 2 mm thick and 5 ...

OBJECTIVE To test the null hypothesis that when the equivalent total light energy is irradiated to three orthodontic adhesive resins, there is no difference between the microhardness and water sorption values regardless of the curing light sources. MATERIALS AND METHODS Samples were divided into six groups according to the combination of three orthodontic adhesives (Kurasper F, Light-Bond, Tr...