Table 1.
Key data pertaining to the included studies.
| Authors/study design | Type/number of samples | Type of light | Intensity of radiation (mW/cm2) | Parameters evaluated | Type of assay/test/equipment |
|---|---|---|---|---|---|
| Lee et al. (in-vitro, experimental) | Twenty-Four female C57BL/6 Mice divided into four groups – red, green, blue and untouched (UT) |
Red (630 ± 8) Green (525 ± 2) Blue (410 ± 10) |
48.8 59.5 29.2 |
Tear volume, Tear film breakup time (TBUT), Interferon (INF)-γ, Interleukin (IL)-1β, IL-6, Tumor necrosis factor (TNF)-α, Malondialdehyde (MDA), CD4 + CCR5 + T cells | Corneal Fluorescein staining, multiplex immunobead assay, enzyme linked immunosorbent Assay (ELISA), Flow cytometry, 2′7′-diachloroflouroscein diacetate (DCF-DA) assay, terminal de-oxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) staining |
| Chang et al. (in-vitro, experimental) | 45 male mice 36 – exposed 9 – controls |
Dim red light (>600 nm) Blue LED light (410 ± 10) |
Not specified | Osteopontin (OPN) | TUNEL assay, Western blotting, Immunohistochemistry, immunogold electron microscopy |
| Price et al. (in-vitro experimental) | Human teeth model | Sapphire Plus Plasma Arc LCU (Den-Mat, Lompoc CA) | Not specified | Effect of dental loupes – five types used Three loupes of 3.5× magnification (Design for Vision, Carl Zeiss, Quality Aspirator) and two 2.5× magnification (Design for Vision, Quality Aspirator) |
6-in integrating sphere (Labsphere, North Sutton, NH) connected to a fiber optic spectrometer (USB 4000, Ocean Optics, Dunedin, FL) |
| Rassaei et al. (in-vitro experimental) | Bovine superfused retina | Blue LED LCU (Delma Medical Instrument, Guangzhou, Guangdong, China) 420–480 nm |
>1000 (1200 lx for isolated retina) |
a and b waves used as indicators of retinal damage | Electroretinogram (ERG) |
| Labrie et al. (in-vitro experimental) | Extracted human maxillary teeth |
PAC: Sapphire (Den-Mat Santa Maria, CA) LED:
QTH: Optilux 501 (Kerr Corporation Orange, CA) |
826 ± 2 325 ± 1 740 ± 2 630 ± 5 |
Weighted blue light and effective ultraviolet (UV) irradiances received by the eye | A laboratory-grade light detector (3.9-mm diameter CC3-UV probe, Ocean Optics, Dunedin, FL) attached by a 1-mm fibre optic cable to a fibre optic spectroradiometer (USB 4000, Ocean Optics), with a spectral range of 300–890 nm, fully covering the spectral emission from the LCU |
| McCusker et al. (in-vitro experimental) | 8 different orthodontic brackets Ceramics Clarity, Clarity SL (3 M Unitek), Encore (Ortho Technology) Stainless Steel Victory (3 M Unitek), Microarch, Mini Ovation (GAC International), TOC Bracket (TOC) Composite Tiger (TOC) |
11 LCUs 1 Plasma Arc Apollo 95E(460–490 nm) 2 Halogens Cromalux (400–500 nm) CU80 (380–510 nm) 8 LEDs DEMIOrtho (420–465 nm) Elipar Freelight2 (430–480 nm) Fusion (385–430 nm) Mini LED (420–480 nm) Mini LED2 (420–480 nm) Ortholux (430–480 nm) Smartlite (450–490 nm) Starlite (440–480 nm) |
1600 650–800 600 1100-1330 1000 1500 1250 2000 1600 950 100 |
Weighted irradiance and safe exposure times | Integrated spectroradiometer (DMc150-MDE, Bentham Instruments Ltd. UK) |
| Jiangmei et al. (in-vitro experimental) | Female Sprague-Dawley rats | Blue light (400–480 nm) | 0.64 | Cell death following blue light exposure | TUNEL, gel electrophoresis |
| Eriksen et al. (in-vivo experimental) | Not specified | 12 dental LCUs | Not specified | Total irradiance(E), Effective UV irradiance (Eeff)), UV--A irradiance (EUVA), blue light radiance (Lb), Thermal hazard radiance (LR) and the Luminance (LV) | Spectroradiometer |