Dental erosion (DE), defined as a pathological, chronic and irreversible dissolution of dental hard tissues caused by acids of a non-bacterial origin, 1 has been identified as a globally emerging oral health problem. 2 The estimated global prevalence of DE is 30% in adolescents, 25% in Australia. 3 Understanding of risk factors and early diagnosis are essential to prevent and manage DE. 4 When allowed to progress, it can lead to dentinal hypersensitivity, aesthetic concerns and loss of vertical dimension, all of which affect oral health-related quality of life. 3,5 Management of advanced DE often requires costly and invasive functional and aesthetic rehabilitation. 6 DE is multifactorial and is caused by a complex interaction between environmental factors and tooth enamel. 7 Dietary acids are not only considered the predominant factor, but also the easiest to control. 8-10 Such acids can arise from a number of sources including soft drinks, sports/energy

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.