The field-of-view (FOV) of a simple imaging system can be dramatically improved using a liquid crystal spatial light modulator (SLM). A SLM can be used to correct the off-axis aberrations that often limit the useful FOV of an imaging system giving near diffraction-limited performance at much larger field angles than would otherwise be possible. Foveated imaging refers to the variation in spatia...

The potential ocular hazards associated with the use of dental curing lights were evaluated. Recommendations are provided for precluding exposure of personnel to hazardous levels of optical radiation. Users should not stare directly into the dental curing lights at distances shorter than 25 cm (which would not be a likely event). Eye protectors which filter wavelengths below 500 nm may be desir...

OBJECTIVES The aim of this in vitro study was to evaluate the influence of different light curing units and modes on microleakage of flowable composite resins. METHODS Eighty Class V cavities were prepared in buccal and lingual surfaces of 40 extracted human premolars with cervical wall located in dentin and the occlusal wall in enamel. These teeth were randomly assigned into two groups (n=20...

PURPOSE To measure the amount of light energy that dental students actually deliver to a Class I preparation in a dental mannequin. MATERIALS AND METHODS Approval for the study was obtained from the Dalhousie University Health Sciences Research Ethics Board. Each of 20 third-year dental students light-cured a Class I preparation in tooth 27 in a mannequin head. A photodetector located at the ...

The aim of this study was to evaluate the influence of different light-curing units on the tensile bond strength and microhardness of a composite resin (Filtek Z250 - 3M/ESPE). Conventional halogen (Curing Light 2500 - 3M/ESPE; CL) and two blue light emitting diode curing units (Ultraled - Dabi/Atlante; UL; Ultrablue IS - DMC; UB3 and UB6) were selected for this study. Different light intensiti...

PURPOSE To prevent contamination of the light guide on a dental curing light, barriers such as disposable plastic wrap or covers may be used. This study compared the effect of 3 disposable barriers on the spectral output and power density from a curing light. The hypothesis was that none of the barriers would have a significant clinical effect on the spectral output or the power density from th...

A prospective clinical trial was carried out to compare argon laser-curing of a traditional light-activated composite resin with conventional visible light-curing in terms of bond failure rate and incidence of enamel decalcification. Forty-five patients with a total of 742 metal brackets bonded to the upper and/or lower teeth in a modified split-mouth design participated in the study. The adhes...

Dental chair lights have been known to rapidly polymerize lightcured composites beyond the point of workability. Often in our dental clinics we are advised to switch off the dental chair light while light curing of dental composites. The purpose of this study was to determine whether the dental chair light causes any effect on the degree of polymerization of light cured composites using the qua...