Quantifying light energy from 450 nm, 650 nm, 810 nm, and 980 nm wavelength lasers delivered through dental hard tissue

Abstract

Purpose The energy available to treat the dental pulp after transmittance through overlying structures is clinically important for determining photobiological effects. This ex vivo study aimed to quantify laser energy delivery though the dental crown to the pulp from an initial energy of 5 J using four common laser wavelengths (λ = 450, 650, 810, and 980 nm). Material and methods A total of 30 extracted healthy human teeth (anterior n = 10; premolar n = 10; molar n = 10) were longitudinally sectioned (Project Number: 2021/421, University of Sydney, NSW, Australia). Each sample was methodically exposed in random order to the four wavelengths. Each wavelength was operated at the same power (0.50 W) for 10 s to deliver 5.0 J with a total energy delivery of 10 J/cm2. Laser light was delivered with an 8-mm-diameter fiber bundle probe directed perpendicularly to the buccal cervical-third of the crown. The transmitted energy was measured twice and averaged using a periodically pre-calibrated power meter in blinded conditions. Data were analyzed using a general linear model with logarithmic transformation. Results Wavelength and tooth thickness were significant predictors of optical transmittance (P < 0.05) while tooth type was significant only for the 450 nm wavelength. The average attenuation coefficients (µ) were 2.55, 2.45, 1.87, and 5.42 cm−1 (± 10%) for the 980, 810, 650, and 450 nm groups, respectively. Conclusion Clinicians should recognize that significant attenuation occurs during laser energy delivery to the pulp, influenced by the wavelength, thickness, and tooth type. Our findings support the potential for laser energy delivery to the pulp for photobiomodulation applications.

Effectiveness of Diode Laser in Intraoral Soft Tissue Surgeries - An Evaluative Study

“…At a temperature above 60°C, enzymes, cytokines and other bioactive molecules are instantly denatured due to photocoagulation. [ 4 22 23 ] Laser damage to erythrocytes attracts a population of platelets which encourage intraluminal thrombosis, further decreasing the blood loss. This explains why the laser wound had minimal blood loss in comparison to the scalpel, and this is especially important in our study because lasers provide excellent haemostasis.…”

“…[ 1 2 3 ] A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. [ 4 ] Its effects on the biological tissue depend on the wavelength of the monochromatic light that can be reflected, scattered or absorbed. [ 5 ] The advantages of laser are precise and rapid tissue dissection, a bloodless field due to sealing of blood vessels, so it reduces the surgical site morbidity and lessens the post-operative inflammatory sequelae such as pain, swelling and post-operative infection; hence, it offers excellent patient acceptance.…”