Abstract
Objective This study aimed to perform the beam profile of dental light-curing units (LCUs)
using mirrorless and smartphone cameras and correlate it to a camera-based laser beam
profiling system.
Materials and Methods Three LCUs were evaluated (Radii Plus; Bluephase G2; and VALO Cordless). The spectral
power of the LCUs was measured by using a spectrophotometer. The light emitted from
the LCUs was projected onto a glass diffuser, and the images were recorded by using
a mirrorless camera (NEX-F3), a smartphone (iPhone) and a camera-based beam profiler.
Bandpass optical-filters were used, and for each LCU, the total spectral power output
was integrated to calibrate the images. Statistical analysis was performed by digital
image correlation (pixel by pixel) using Pearson’s correlation (α = 0.05; β = 0.2).
Results The beam profile images showed nonuniform radiant emittance and spectral emission
distributions across all the LCUs light tip. A strong correlation was found among
cameras (Pearson’s r = 0.91 ± 0.03 with 95% confidence interval [CI]: 0.88–0.94 for
the NEX-F3 and Pearson’s r = 0.88 ± 0.04 with 95% CI: 0.84–0.92 for the iPhone).
Conclusion The standard Ophir beam profile system presented the most accurate distribution,
but the mirrorless and smartphone cameras presented a strong correlation in the irradiance
distribution of the beam profile images. Alternative cameras can be used to perform
light beam profile of dental LCUs, but caution is needed as the type of sensor, image
bit depth, and image processing are important to obtain accurate results.
Keywords
beam profile - light curing units - spectrophotometric analysis - digital cameras
