This study investigated the characteristics of output light from different types of light curing units, and their effects on polymerization of light-activated composite resin. Three quartz-tungsten-halogen lamps, one plasma arc lamp, and one LED light curing unit were used. Intensity distribution of light emitted from the light guide tip was measured at 1.0-mm intervals across the guide tip. Di...

This study aimed to analyze the microhardness (KHN) and diametral tensile strength (DTS) of two hybrid resin composites (TPH Spectrum and Filtek Z250). To this end, the composites were polymerized with six laboratory photo-curing units (LPUs) and the results compared with an alternative polymerization method using conventional halogen light source in conjunction with additional polymerization i...

BACKGROUND The use of external sources of energy may accelerate the setting rate of glass ionomer cements (GICs) allowing better initial mechanical properties. AIM To investigate the influence of ultrasound and halogen light on the microleakage and hardness of enamel adjacent to GIC restorations, after artificial caries challenge. DESIGN Cavities were prepared in 60 primary canines, restore...

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...

Polymerisation characteristics of conventional units for curing composite resins are insufficient considering handling feasibilities particularly in the premolar and molar region. There is also hazardous ocular effect of near ultra-violet part of visible spectra. Sodium high pressure lamp technology has been applied to develop a new high pressure zinc lamp, which is for the first time used for ...

background and aims. newer curing units such as plasma arc can polymerize the sealants in much shorter curing times. the aim of this study was to compare the effect of two different curing units on the micro-leakage of a fissure sealant material. materials and methods. sixty two extracted premolars without caries were randomly divided into two groups of 31 samples. occlusal surfaces of all teet...

OBJECTIVE To evaluate the shear bond strength of orthodontic brackets bonded to bovine enamel using a new curing appliance composed of an LED cluster. DESIGN In vitro, laboratory study. MATERIALS AND METHODS Standard edgewise maxillary central incisor metal brackets (0.022'' slot) were bonded to 60 bovine incisors which were arranged in a parabola, simulating the dental arch. The arches wer...

We apply terahertz (THz) time-domain spectroscopy for monitoring the curing process of three different light-curing dental composites. Exact knowledge of the sample thickness is required for a precise determination of the THz dielectric parameters, as the materials exhibit shrinkage when they are cured. We find very small but significant changes of the THz refractive index and absorption coeffi...

BACKGROUND The authors aimed to determine whether electrical dental devices would interfere with the function of cardiac pacemakers or implantable cardioverter defibrillators (ICDs) in humans. METHODS The authors exposed asymptomatic nonpacemaker-dependent patients to commonly used electrical dental equipment (for example, battery-operated curing lights, ultrasonic baths, ultrasonic scalers, ...