Comparative effectiveness of intraoral vs. combined intraoral/extraoral photobiomodulation for oral chemotoxicity prophylaxis: a pilot study

Introduction
Conventional chemotherapy frequently induces debilitating oral side effects, including muco­sitis, xerostomia, and dysgeusia, which significantly impair patients’ quality of life and treatment adherence. Photobiomodulation (PBM) has emerged as a promising therapeutic strategy for mitigating chemotherapy-induced oral toxicities. However, inconsistent irradiation parameters and absence of standardized protocols hinder its widespread clinical adoption.

Objectives
This pilot study evaluated the impact of PBM on oral health through comparative analysis of sole intraoral 635 nm wavelength delivery versus a dual-modality approach incorporating both intraoral 635 nm and extraoral 980 nm near-infrared irradiation.

Material and methods
This study enrolled 45 participants stratified into three demographically and clinically matched cohorts. Intervention groups were structured as follows: group 1 received standard oral care, group 2 added intraoral PBM (635 nm diode laser), and group 3 combined intraoral (635 nm) and extraoral (980 nm) PBM, with oral health outcomes assessed using the validated Oral Assessment Guide developed by Eilers (1988).

Results
Both laser-treated groups showed significant preventive advantages (p < 0.001) at one week and two weeks follow-ups compared with the control group. These protective effects were observed in swallowing, lips, tongue, mucosa, saliva, and gums. The clinical outcomes demonstrated comparable efficacy between the intraoral red laser and combined intraoral/extraoral infrared laser treatment modalities, except in swallowing, where the combined laser approach was superior.

Conclusions
PBM therapy, whether intraoral alone or combined intraoral and extraoral, effectively reduces chemotherapy-induced oral complications. The combined laser protocol demonstrated enhanced benefits in swallowing-related outcomes, emphasizing its potential as a valuable adjunctive therapy.