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, ...

T o simulate the bluish-white fluorescence of natural teeth under ultraviolet light,‘-’ dental manufacturers use fluorophors of proprietary composition. Uranium oxides were often used in the past in combination with cerium to impart a realistic fluorescence to dental porcelain.* Uranium is no longer used as a result of increased awareness of possible radiation effects on oral tissues.‘.” Fluore...

Pulpal temperature changes induced by modern high powered light emitting diodes (LEDs) are of concern when used to cure composite resins. This study showed an increase in pulp chamber temperature with an increase in power density for all light cure units (LCU) when used to bulk cure composite resin. Amongst the three LEDs tested, the Elipar Freelight-2 recorded the highest temperature changes. ...

The aim of this study was to assess polymerization ability of three light-curing units by evaluating the influence of the light source, curing regimen and permeant (water or ethanol) on sorption, solubility and amount of residual monomers of a dental adhesive. Specimens of Adper Single Bond 2 were fabricated using a stainless steel circular matrix (8 mm x 1 mm). One quartz-tungsten-halogen (QTH...

This paper examines the effects of some key operating parameters of UV sources on the curing of various UV inks, coatings and adhesives. The effects of peak UV wavelength and peak intensity are quantitatively evaluated using FT-IR. The data are helpful in guiding both formulators, raw material suppliers and end users to better understand the impact of the UV sources, especially UV LED sources, ...

Te ch ni ca l P ap er UV-LED Overview Part II — Curing Systems By Jennifer Heathcote This article is the second installment in a three-part series designed to consolidate key principles and technical information regarding the science and engineering behind ultraviolet light-emitting diodes (UV-LEDs). If you have not yet read “Part I— Operation and Measurement” in the July/August 2010 issue, you...

Ultraviolet light emitting diodes (UV-LEDs) have attracted great interest in recent years. They can be used to polymerize coatings, such as those used for prefinished wood flooring. In this project, two lamps were compared for their suitability to be used on a wood flooring finishing line: a UV-microwave and a UV-LED lamp. Low heat emission was found for the UV-LED lamp compared to the UV-micro...