Table 2.
Reported irradiation parameters of recent (2014–2015) relevant literature in LLLT/photobiomodulation
| Author/ref. | Method for light measurement | Light source | Dose | Conclusion |
|---|---|---|---|---|
| Low and level and light and therapy | ||||
| Wang et al. [34] | No info | Source, LED; wavelength, 660 nm; power, –; frequency, –; beam area, – | Irradiance, 3.5 mW/cm2; time, 6–24 min; energy, –; radiant exposure, 0–20 J/cm2 | 660 nm LED accelerated palatal wound healing, potentially via reducing reactive oxygen species production, facilitating angiogenesis and promoting provisional matrix and wound reorganisation. |
| Park et al. [36] | No info | Source, LED array; wavelength, 660 nm; power, –; frequency, –; beam area, – | Irradiance, 50 mW/cm2; time, 10 min/day; 20 days; energy, –; radiant exposure, 30 J/cm2 | LLLT was a effective biostimulator of adipose derived stem cells in vascular regeneration |
| Moneib et al. [40] | No info | Source, erbium glass laser; wavelength, 1550 nm; power, –; frequency, –; beam area, – | Irradiance, –; time, –; energy, 30–40 mJ; radiant exposure, – | Treatment of active acne with 1550 nm erbium glass laser is effective. |
| Kansal et al. [43] | No info | Source, GaAs; wavelength, 904 nm; power, 12 mW; frequency, –; beam area, – | Irradiance, –; time, 10 s × 10 irradiations × 10 days; energy, –; radiant exposure, 4.2 J/cm2 | No evidence of pathological changes in radiograph following LLLT. |
| Park et al. [45] | No info | Source, LED; wavelength, 660 nm; power, –; frequency, –; beam area, – | Irradiance, 50 mW/cm2; time, 10 min/day; 20 days; energy, –; radiant exposure, 30 J/cm2 | LLLT is an effective biostimulator of spheroid human adipose derived mesenchymal stem cells in tissue regeneration. |
| Imaoka et al. [48] | No info | Source, SuperLizer; wavelength, –; power, –; frequency, –; beam area, – | Irradiance, –; time, 20 min; energy, radiant exposure, 7.64 J/cm2 | The reduction of proinflammatory cytokine, IL-20 by LLLT suggests laser irradiation will be useful for rheumatoid arthritis therapy. |
| Lim et al. [49] | No info | Source, LED; wavelength, 635 nm; power, –; frequency, CW; beam area, – | Irradiance, 5 mW/cm2; time, 1 h; energy, –; radiant exposure, – | Direct and indirect exposure with 635 nm light can inhibit activation of pro-inflammatory mediators and may be clinically useful as an anti-inflammatory tool. |
| Asai et al. [50] | No info | Source, LED; wavelength, 630 nm; power, –; frequency, –; beam area, – | Irradiance, 20 mW/cm2; time, –; energy, –; radiant exposure, 0.5–3 J/cm2 | Low-level red LED light can enhance MC3T3-E1 cell proliferation and osteogenic differentiation when the cells are cultured for a relatively long time. |
| Bavrina et al. [54] | No info | Source, –; wavelength, 356–530 nm; power, –; frequency, –; beam area, – | Irradiance, –; time, 15 min; energy, radiant exposure, – | Exposure to low-intensity incoherent red light after exposure to ionising radiation led to a decrease in the level of oxidative modification of protein and LPO products and diminished cellular manifestation of radiation sickness. |
| Ko et al. [55] | No info | Source, laser/LED; wavelength, 635 nm; power, 6 mW; frequency, –; beam area, – | Irradiance, –; time, 5 min (total); energy, –; radiant exposure, – | The use of low-level laser emitting toothbrush is a safe and effective treatment option for the management of dentine hypersensitivity. |
| Jun et al. [58] | No info | Source, Nd/YAG and Er/YAG; wavelength, 532 and 1064 nm; power, –; frequency, 2 and 10 Hz; spot size, 2 and 8 mm | Irradiance, –; time, –; energy, –; radiant exposure, 1.2–1.4 J/cm2 | Combined therapy and Q-switched Nd/YAG alone were effective in reducing light solar lentigines. |
| Hiratsuka et al. [61] | No info | Source, –; wavelength, –; power, –; frequency, –; beam area, – | Irradiance, 63–333 μW/cm2; time, –; energy, –; radiant exposure, 2.76–36.13 J cm−2 day−1 | Artificial light phototherapy suppressed dextran sulphate sodium-induced colitis in mice by suppression of pro-inflammatory cytokines and promotion of anti-inflammatory cytokines. |
| Felici et al. [62] | No info | Source, laser; wavelength, 1100–1800 nm; power, –; frequency, –; spot size, 10 × 15 or 10 × 30 mm | Irradiance, –; time, 4–10 s; energy, 34–50 J; radiant exposure, 5–65 J/cm2 | The use of infrared radiation represents a valid alternative to surgical lifting but cannot replace it. |
| Gold et al. [63] | No info | Source, LED array; wavelength, 405–460 nm; power, –; frequency, –; beam area, – | Irradiance, –; time, 10 min/zone; energy, –; radiant exposure: | The Silk’n Blue device is a safe efficacious at home device for the treatment of mild to moderate inflammatory acne vulgaris. |
| Fioramonti et al. [64] | No info | Source, laser; wavelength, 500–1200 nm; power, –; frequency, 2.5 ms; beam area, – | Irradiance, –; time, –; energy, –; radiant exposure, 30–35 J/cm2 | Intense pulsed light therapy is a safe and effective treatment for telangiectsias and striae rubra, also in the complex clinical condition of Behҁet’s disease. |
| Wang et al. [67] | No info | Source, LED; wavelength, 660 nm; power, –; frequency, –; spot area, – | Irradiance, 3.5 mW/cm2; time, 6–24 min; energy, –; radiant exposure, 5–20 J/cm2 | LED light irradiation at 660 nm accelerated palatal wound healing, potentially via reducing reactive oxygen species production, facilitating angiogenesis and promoting provisional matrix and wound reorgainisation. |
| Wang et al. [69] | No info | Source, GaAlAs laser; wavelength, 808 nm; power, 170 mW; frequency, –; spot area, 3.8 cm2 | Irradiance, 44.7 mW/cm2; time, 67.2–335.6 s; energy, –; radiant exposure, 3–15 J/cm2 × 20 | Results suggest that 808 nm LLLT at a low energy density (3 J/cm2) and 8 J/cm2 is capable of enhancing sciatic nerve regeneration following a crush injury. |
| Pinheiro et al. [70] | No info | Source, diode laser and LED; wavelength, 780 nm (laser), 850 nm (LED); power, 70 mW (laser), 150 mW (LED); frequency, –; spot area, 0.4 cm2 (laser) and 0.5 cm2 (LED) | Irradiance, –; time, –; energy, –; radiant exposure, 20 J/cm2 (140 J/cm2 total) | The use of biphasic synthetic micro-granular HA + Beta − TCP graft improved the repair of bone defects, associated or not with laser or LED light. |
| Tsai et al. [71] | Power meter (Thorlabs, USA) to measure power densities | Source, GaAlAs; wavelength, 810 nm; power, –; frequency, CW; beam area, – | Irradiance, 20 mW/cm2; time, –; energy, –; radiant exposure, 1.5 J/cm2 | LLLT moderately increased the uptake of mono-l-aspartyl chlorine(e6) and cellular ATP levels. |
| Gavish et al. [72] | LaserMate power-meter (coherent, Auburn group, Holland) | Source, diode laser; wavelength, 780 nm; power, –; frequency, –; beam area, – | Irradiance, 4 mW/cm2; time, 9mins; energy, –; radiant exposure, 2.16 J/cm2 | LLLT prevented de novo development of abdominal aortic aneurysms (AAA) and also arrested further progression of pre-induced AAA and its associated deterioration in the biochemical integrity of the aortic wall. |
| Dungel et al. [73] | USB2000 spectrometer (Ocean Optics, FL) | Source, LED; wavelength, 470 nm and 629 nm; power, –; frequency, –; beam area, – | Irradiance, 50 mW/cm2; time, 10 min; energy, –; radiant exposure, 30 J/cm2 | LED treatment of ischemia challenged tissue improved early wound healing by enhancing angiogenesis irrespective of wavelength. |
| Taflinski et al. [74] | Measured at Philips Research using a integrating sphere (Ulbricht) | Source, LED array; wavelength, 420 nm; power, –; frequency, –; beam area, – | Irradiance, 50 mW/cm2; time, –; energy, –; radiant exposure, 0–90 J/cm2 | Observed effects are promising for a clinical use of blue light in the treatment or prevention of myofibroblast-mediated pathological condition such as tissue fibrosis and scleroderma or hypertrophic scarring. |
| Lanzafame et al. [77] | Ophir Nova Power meter (Model 30A-P-R-SH; Ophir Spiricon, UT) | Source, lasers and LEDs; wavelength, 655 nm; power, 5 mW; frequency, –; beam area, – | Irradiance, –; time, 25 min × 60; energy, 2.9 J/session; radiant exposure, 67 J/cm2 | LLLT of the scalp at 655 nm significantly improved hair counts in women with androgenetic alopecia. |
| Tedford et al. [80] | Power Meter (OptoTest OP710-Si), thermal-based power detector with meter (ophir LD40-150, Ophir Nova), Optical power and wavelength detector (ILX lightwave OHM-6810B) and amplified photodiode (Thorlabs PDA10A) | Source, laser diode; wavelength, 660, 808 and 940 nm; power, 50 mW–70 W; frequency, PW and CW, –; beam diameter, 30 mm | Irradiance, –; time, –; energy, –; radiant exposure, – | The 808-nm wavelength light demonstrated superior CNS tissue penetration. |
| Photobiomodulation | ||||
| Freire et al. [85] | No info | Source, laser (GaInPAl; 660 nm) and LED (670 nm); wavelength, 660 and 670 nm; power, 40 mW (laser), 150 mW (LED); frequency, CW; beam area, 4 mm2 (laser) and 0.5 cm2 (LED) | Irradiance, –; time, 30 s (laser) and 16 s (LED); energy, 16 J; radiant exposure, 4.8 J/cm2 (laser) and 4 J/cm2 (LED) | The best results were obtained from the preventive laser and LED photobiomodulation groups; both groups were effective in diminishing the oral mucositis lesions. |
| Larkin-Kaiser et al. [89] | No info | Source, laser; wavelength, 800 and 970 nm; power, 3 W; frequency, –; beam area, – | Irradiance, –; time, 4 min; energy, 360 J; radiant exposure, – | Applied to skeletal muscle before resistance exercise, NIR light therapy effectively attenuated strength loss. |
| de Carvalho et al. [90] | No info | Source, GaAlAs (660 nm, laser) and InGaAlP (630 nm, LED); wavelength, 660 and 630 nm; power, 40 mW (laser) and 150 mW (LED); frequency, CW; beam area, 4 mm2 (laser) and 0.8 cm (LED) spot | Irradiance, –; time, –; energy, –; radiant exposure, 4.8 J/cm2 | Laser and LED photobiomodulation were effective in accelerating the healing of formocresol-induced oral ulcers in both clinical and histological aspects. |
| Ban Frangez et al. [92] | No info | Source, LED; wavelength, 470, 625, 660 and 850 nm; power, –; frequency, kHz range; beam area, – | Irradiance, 2.16–8.23 mW/cm2; time, 3 min; energy, –; radiant exposure, – | Photobiomodulation using LED improved the sperm motility in asthenozoospermia regardless of wavelength. |
| Ramalho et al. [93] | No info | Source, InGaAlP laser; wavelength, 660 nm; power, 50 mW; frequency, –; spot area, 0.028 cm2 | Irradiance, –; time, –; energy, –; radiant exposure, 3.57 J/cm2 | Low- and high-power lasers can contribute positively to all steps of the indirect restorative treatment period. |
| Turrioni et al. [94] | No info | Source, LED (InGaN); wavelength, 450, 630 and 840 nm; power, –; frequency, –; beam area, – | Irradiance, 88 mW/cm2; time, 1 min 20 s and 8 min 40 s; energy, –; radiant exposure, 4 and 25 J/cm2 | The infrared LED irradiation at an energy density of 4 J/cm2 and red LED at an energy density of 25 J/cm2 were the most effective parameters for transdentinal photobiomodulation of cultured ondontoblast-like cell. |
| Barbosa et al. [95] | No info | Source, –; wavelength, 670 nm; power, –; frequency, –; beam area, – | Irradiance, –; time, 3 min; energy, –; radiant exposure, 9 J/cm2 | Morphological image analysis was used to quantify the extent of vaso-obliteration in oxygen-induced retinopathic vascular growth, the preventive effect (by photobiomodulation) of exposure during tissue development to near-infrared light (670 nm) and the lack of adverse effects due to exposure to NIR light. |
| Tang et al. [97] | No info | Source, –; wavelength, 670 nm; power, –; frequency, –; beam area, – | Irradiance, –; time, 160 s/day (2–9 months); energy, –; radiant exposure, 25 J/cm2 | Photobiomodulation potentially offers a non-invasive and cost effective therapeutic option for patients with non-centre-involving diabetic macular oedema. |
| Ekizer et al. [98] | No info | Source, LED; wavelength, 618 nm; power, –; frequency, –; beam area, – | Irradiance, 20 mW/cm2; time, 20 min (200 min total); energy, –; radiant exposure, – | Photobiomodulation therapy has the potential of accelerating orthodontic tooth movement and inhibitory effects on orthodontically induced resorptive activity. |
| Di Marco et al. [100] | Calibrated sensor (Quantum devices, Barnfield, Wisconsin) | Source, –; wavelength, 670 nm; power, –; frequency, –; spot area, – | Irradiance, –; time, 3 min; energy, –; radiant exposure, 4–4.5 J/cm2 | Detailed analysis suggests that there is a negative interaction between photobiomodulation and saffron when given simultaneously, with a consequent reduction of neuroprotection. |
| Pitzchke et al. [102] | Integrating sphere (LMS-200, 20-in. diameter, Labsphere, USA) and Power meter (detector 818P-010-12, driver 1918-R, Spectra Physics Newport) | Source, laser diode; wavelength, 671 and 808 nm; power, 0.8 W at 671 nm and 1 W at 808 nm; frequency, –; spot area, 1 cm2 | Irradiance, –; time, –; energy, –; radiant exposure, – | Objective was to refine a possible treatment option for PD patients and validate the practicalities of light delivery and light dosimetry. The study demonstrates the possibility to illuminate deep brain tissues transcranially, transsphenoidally and via different application routes. |