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...

The objectives of this study were to compare the polymerization shrinkage of three orthodontic adhesives. In addition we wanted to determine the effectiveness of the high-intensity quartz tungsten halogen (HQTH) in curing orthodontic adhesives on polymerization shrinkage with that of the quartz tungsten halogen (QTH). A total of 120 glass ring molds were prepared using a low-speed saw. The inte...

The aim of this in vitro study was to compare the photoactivation effects of QTH (Quartz-Tungsten-Halogen) and LED (Light-Emitting Diode) on the SBS (Shear Bond Strength) of orthodontic brackets at different debond times. Seventy-two bovine lower incisors were randomly divided into two groups according to the photoactivation system used (QTH or LED). The enamel surfaces were conditioned with Tr...

OBJECTIVE The aim of this study was to compare the cytotoxic effects of various resin-based core materials that were cured with three light curing units (LCUs) in different modes on L-929 mouse fibroblast cells over 24 h and 72 h periods. STUDY DESIGN Eighty-four cylindrical discs (2 mm in thickness and 6 mm in diameter) of each material (Rebilda, Voco; Build-It FR, Pentron; Clearfil DC Core,...

BACKGROUND The purpose of this study was to evaluate the effects of light intensity and curing cycles of QTH and LED lights on the microleakage of Class V composite restorations. MATERIALS AND METHODS Eighty freshly extracted human maxillary premolars were used for this study. Standardized Class V cavities were prepared and they were restored with microhybrid resin composite. According to the...

OBJECTIVES The purpose of this study was to explore the effects dual-cure resin cements on nerve conduction. METHODS Panavia F, RelyX ARC, and Variolink II polymerized either by light-emitting diode (LED) or quartz tungsten halogen (QTH) were used in the study (n=10). The conductance of sciatic nerves of 50 rats were measured before and after contact with the specimens for 1 h. RESULTS The ...

OBJECTIVE This study evaluated the surface hardness of a resin cement (RelyX ARC) photoactivated through indirect composite resin (Cristobal) disks of different thicknesses using either a light-emitting diode (LED) or quartz tungsten halogen (QTH) light source. MATERIAL AND METHODS Eighteen resin cement specimens were prepared and divided into 6 groups according to the type of curing unit and...