Fotobiomodulação como tratamento de distúrbios de paladar e salivares em pacientes pós-COVID: uma revisão sistemática

Abstract

In 2019, a new type of coronavirus, SARS-CoV-2, the causative agent of COVID-19, was first detected in Wuhan, China. It soon became evident that SARS-CoV-2 infection produced a wide range of manifestations. Fever, cough, dyspnea, myalgia, and cardiomyopathy are among the most prevalent symptoms in the early stages of infection. Additionally, oral cavity manifestations, including salivary disorders (xerostomia and hyposalivation) as well as taste disorders (ageusia and dysgeusia), have been observed in these patients. Since then, researchers have been seeking therapeutic measures for the management and control of the secondary manifestations of this disease. Given this, the present study aimed to evaluate the effectiveness of photobiomodulation therapy (PBM) for taste and salivary secretion disorders in patients diagnosed in the post-COVID phase. Literature searches were conducted in five electronic databases: PubMed, Ovid (Medline), Scopus, Web of Science, and ProQuest, with the aid of the reference manager ‘Rayyan QCRI,’ using the following keywords: “COVID-19 syndrome AND Low-Level Light Therapy OR Photobiomodulation OR LLLT OR Low Power Laser Irradiation OR Low Level Laser Therapy AND Xerostomia OR Hyposalivation OR Dryness OR Taste disorders OR Ageusia OR Dysgeusia AND Salivary Glands.” A manual search for full articles was also conducted online using Google Scholar with the same strategy. After screening, eligibility criteria were applied, and relevant articles were included. The systematic review is limited to randomized or controlled clinical trials and pilot studies published in English or Spanish between 2018 and 2025. A total of four articles were included in the qualitative synthesis, addressing PBM as a treatment for taste disorders in post-COVID patients. The results indicate promising effects on taste disorders in these patients, with a response rate of approximately 70%. However, due to the innovative nature of the topic, a significant knowledge gap remains. Therefore, more long-term clinical trials are necessary to strengthen the evidence on the effects of PBM and COVID-19.