Laser Photobiomodulation: What Are the Ideal Parameters for Each Type of Laser Used in Dental Practice to Promote Fibroblast Proliferation and Differentiation? A Systematic Review

Laser photobiomodulation (LPMB) is a non-invasive therapy that relies on the use of low-power lasers. The literature supports the positive effect of LPBM on tissue regeneration, since it reduces the timing of the inflammatory phase, promoting the proliferative phase of the process. From a purely clinical point of view, the breadth of lasers currently available for dental use makes it difficult to identify unambiguous parameters that can guarantee the best regenerative effect. Therefore, the aim of the present systematic review is to identify the best irradiation parameters for each type of dental laser that can provide the best effects on fibroblast proliferation and differentiation. The literature was searched through the following electronic databases: Medline, Scopus, Web of Science, Springer, and Cochrane, while respecting the PRISMA 2020 guidelines. In vitro studies conducted on human fibroblast cells, drafted in English between 2004 and 2025, were included. A total of 17 papers assessing the effects of diode lasers at different wavelengths (445 nm, 635 nm, 650 nm, 660 nm, 670 nm, 685 nm, 810 nm, 830 nm, 915 nm, 940 nm), CO2 lasers (10.6 µm), and Er:YAG lasers (2940 nm) were included. What can be concluded from the present review is that, for the same wavelength, the wide variability in the results obtained from each study makes it complicated to identify unambiguous parameters for each laser device that can guarantee the best effect on fibroblast proliferation and differentiation.