Low Level Laser Therapy Overview

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Questions and Answers

What wavelength is commonly used in Low-Level Laser Therapy (LLLT) for treating Alzheimer's disease?

630 nm

What is the suggested range of energy density, in J/cm², for cellular efficacy in LLLT?

3 to 10 J/cm²

According to the Bunsen Roscoe Reciprocity Law, what factors can determine the photochemical effect in LLLT?

The product of irradiance and time of exposure.

How does the treatment duration change with varying power densities while maintaining the same energy output in LLLT?

Increasing power density decreases treatment duration. Signup and view all the answers

What is the significance of choosing between pulsed or continuous power in LLLT?

It allows for flexibility in treatment protocols by intermittently interrupting the power. Signup and view all the answers

What role do mitochondria play in cellular function concerning oxidative stress?

Mitochondria regulate oxidative stress by managing reactive oxygen species and maintaining redox balance within the cell. Signup and view all the answers

Identify the primary photo-acceptor in mammalian cells and its significance in LLLT.

The primary photo-acceptor in mammalian cells is cytochrome c oxidase (COX), which is essential for absorbing light photons during low-level light therapy (LLLT). Signup and view all the answers

How does calcium metabolism in mitochondria influence apoptosis?

Calcium metabolism in mitochondria influences apoptosis by regulating mitochondrial membrane potential and the release of pro-apoptotic factors. Signup and view all the answers

Explain the interaction between light photons and mitochondria in PBM.

In photobiomodulation (PBM), light photons are absorbed by chromophores in the mitochondria, particularly cytochrome c oxidase, leading to enhanced cellular energy production. Signup and view all the answers

Discuss the importance of cytochrome c oxidase in relation to red-NIR wavelengths.

Cytochrome c oxidase is crucial because it is specifically responsive to the red-NIR wavelength range, facilitating energy production and cellular signaling. Signup and view all the answers

What is the range of treatment times for low-level laser therapy per point?

30 seconds to 1 minute. Signup and view all the answers

In complex cases like cervical or lumbar radiculopathy, how many points may be treated?

10 to 15 points. Signup and view all the answers

What anesthetic agents were used for the immobilization of animals in the radiation-induced OM study?

Ketamine and Xylazine. Signup and view all the answers

What radiation dose was delivered to induce severe oral mucositis in the experimental animals?

20 Gy. Signup and view all the answers

What type of linear accelerator was used for the irradiation in the protocol?

6 MV linear accelerator. Signup and view all the answers

What effect does low-level laser therapy have on tissue?

Photobiomodulation effect. Signup and view all the answers

What is the purpose of immobilization in the radiation-induced OM protocol?

To prevent movement during the procedure. Signup and view all the answers

How does the treatment approach vary between simple cases and complex dysfunctions in low-level laser therapy?

Simple cases may require treatment of as little as one point, while complex dysfunctions may need multiple points. Signup and view all the answers

What is the primary mechanism through which LLLT exerts its physiologic effects?

A photochemical reaction is responsible for the physiologic effects of LLLT. Signup and view all the answers

What two possible physiological outcomes can result from the application of LLLT?

Photobiostimulation and photobioinhibition. Signup and view all the answers

How does the dosage of LLLT affect its biological effects?

The dosage determines whether the effect is photobiostimulation or photobioinhibition. Signup and view all the answers

In the context of LLLT, describe the difference between photobiostimulation and photobioinhibition.

Photobiostimulation enhances cellular function, while photobioinhibition suppresses or inhibits it. Signup and view all the answers

What role does the photochemical reaction play in low-level laser therapy (LLLT)?

It mediates the physiological effects observed during LLLT. Signup and view all the answers

Why is it important to consider the dosage when utilizing LLLT in treatment?

Because the dosage dictates the type of physiological response (stimulation or inhibition). Signup and view all the answers

Can you explain how varying the dosage of LLLT could influence treatment results?

Varying dosages can lead to either beneficial effects (stimulation) or detrimental effects (inhibition). Signup and view all the answers

Study Notes

Low Level Laser Therapy (LLLT)

LLLT, also known as low level light therapy or photobiomodulation (PBM), is a low-intensity light therapy.
The effect is photochemical, not thermal.
Light triggers biochemical changes in cells, comparable to photosynthesis in plants.
Photons are absorbed by cellular photoreceptors, triggering chemical changes.
Mitochondria are cellular power plants.

History of LLLT

In 1903, Dr. Nils Finsen was awarded a Nobel Prize for using concentrated light radiation to treat diseases, especially lupus vulgaris.
In 1967, Mester et al. demonstrated "laser bio stimulation."
In 1999, Whelan et al. researched the medical applications of LEDs for use on the NASA space station.
Over 400 Phase III randomized, double-blind, placebo-controlled trials, along with over 4000 laboratory studies, have examined LLLT.

Mechanisms of LLLT

Mitochondria play an important role in regulating oxidative stress, calcium metabolism, and apoptosis.
In photobiomodulation (PBM), chromophores in mitochondria absorb light photons.
Cytochrome c oxidase (COX) is the primary photo-acceptor for the red-NIR wavelength range in mammalian cells.
Cellular signaling, nitric oxide (NO) dissociation, and increased ATP are also involved.
NO produced in mitochondria can inhibit respiration by binding to COX.
Other signaling molecules involved include ATP (adenosine triphosphate), ROS, and Ca.

Instrumentation

LLLT devices use lasers or LEDs.
Light sources vary in power (10mW-500mW).
Wavelengths range from 660nm to 905nm.
LEDs and SLDs are often used for superficial tissues like wounds.
Lasers are typically more effective for deep tissue treatment.

Treatment Parameters in LLLT

Wavelength (nm): 630nm is a common wavelength.
Power density (W/cm²): Various power densities are used, including 100mW/cm², 1W/cm², & 6W/cm².
Energy density (J/cm²): Studies show fluences ranging from 3 to 10 J/cm² are effective at a cellular level.
Optical properties of the tissue: Tissue properties influence light absorption and penetration.
Continuous or pulsed: Intensity can be continuous or pulsed, where energy delivered is periodically interrupted.
Treatment duration (sec or min): Treatment times per point typically range from 30 seconds to 1 minute, potentially up to 10-15 points for complex issues.

Radiation-Induced OM Protocol

Protocol: Animals are immobilized, given specific anesthetic doses, before irradiation using a linear accelerator.
Important fact: A dose of 20 Gy of radiation is used to induce severe oral mucositis in animals.

Summary

LLLT has a photobiomodulation (PBM) effect, a photochemical reaction in tissue.
The response (biostimulation or inhibition) can change based on the dose.
Cells with more mitochondria respond better to PBM.
In vivo studies may be ineffective due to under-dosing.
Irradiance and time of exposure are important considerations. Fluence, in J/cm², is more significant to the outcome than irradiance, mW/cm².

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Description

Explore the fundamentals of Low Level Laser Therapy (LLLT), also known as photobiomodulation. This quiz covers its history, mechanisms, and effects on cellular functions. Understand the role of light in biochemical processes and the significance of mitochondrial activity in therapy.