OBJECTIVE To evaluate the microhardness of resin-modified glass-ionomer cements (RMGICs) photoactivated with a blue light-emitting diode (LED) curing light. MATERIAL AND METHODS Thirty specimens were distributed in 3 groups: Fuji II LC Improved/GC (RM1), Vitremer/3M ESPE (RM2) and Filtek Z250/3M ESPE (RM3). Two commercial light-curing units were used to polymerize the materials: LED/Ultrablue...

AIM The purpose of this study was to investigate the effect of different temperatures on the efficacy of polymerization during the insertion of composite resin using different light curing units. METHODS AND MATERIALS A total of 45 disc-shaped specimens were fabricated from Z250 composite resin (3M/ESPE, St. Paul, MN, USA) with 15 each prepared at three different temperatures (refrigerated to...

OBJECTIVE To test the hypothesis that bonding with a blue light-emitting diode (LED) curing unit produces no more failures in adhesive-precoated (APC) orthodontic brackets than bonding carried out by a conventional halogen lamp. MATERIALS AND METHODS Sixty-five patients were selected for this randomized clinical trial, in which a total of 1152 stainless steel APC brackets were employed. In or...

Inadequate intensity of the polymerization light source can compromise the quality and longevity of dental composite restorations. In order to maintain optimal strength of polymerization devices, regular control of polymerization units is necessary. The aim of this study was to compare the accuracy of two radiometers in the measurement of light intensity of photopolymerization devices concernin...

OBJECTIVES The aim of this study was to compare the shear bond strength (SBS) of two different light sources under different thermal cycle frequencies. METHODS Ninety human premolar teeth were divided into six groups, in which three groups consisted of halogen groups - Group I was cured with halogen without thermocycle, Group II cured with halogen with 500 thermocycles, and Group III cured wi...

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...