Biophotonics is defined as the combination of biology and photonics (the physical science of the light). It is a general term for all techniques that deal with the interaction between biological tissues/cells and photons (light). Biophotonics offers a great variety of techniques that can facilitate the early detection of diseases and promote innovative theragnostic approaches. As the COVID-19 infection can be transmitted due to the face-to-face communication, droplets and aerosol inhalation and the exposure to saliva, blood, and other body fluids, as well as the handling of sharp instruments, dental practices are at increased risk of infection. In this paper, a literature review was performed to explore the application of Biophotonics approaches in Dentistry focusing on the COVID-19 pandemic and how they can contribute to avoid or minimize the risks of infection in a dental setting. For this, search-related papers were retrieved from PubMED, Scielo, Google Schoolar, and American Dental Association and Centers for Disease Control and Prevention databases. The body of evidence currently available showed that Biophotonics approaches can reduce microorganism load, decontaminate surfaces, air, tissues, and minimize the generation of aerosol and virus spreading by minimally invasive, time-saving, and alternative techniques in general. However, each clinical situation must be individually evaluated regarding the benefits and drawbacks of these approaches, but always pursuing less-invasive and less aerosol-generating procedures, especially during the COVID-19 pandemic.

Temporomandibular dysfunction (TMD) can be described as a set of clinical conditions that includes disorders of the temporomandibular joint (TMJ) and/or the masticatory muscles that has a multifactorial origin, like bruxism, sleep alteration, trauma, among others. There are several ways to treat TMD, such as: occlusal splints, physiotherapy, viscosupplementation, among others. The aim of this case report was to show the new possibility in the treatment of TMD by means of a combined therapy using low-level laser (LLL) and vacuum therapies in the recovery process of two patients with TMD. A simultaneous LLL under 660 and 808 nm, 600 mW of power divided into six lasers outputs around the tip was used synergistically with a vacuum device under negative pressure between 100 and 150 mbar. This case report included 2 patients and both of them were diagnosed with TMD according to the research diagnostic criteria for temporomandibular disorders (RDC/TMD). Patients were treated for LLLT and vacuum therapy at the same time. The treatment was applied to the left and right sides of the face on the masseter muscles, temporal muscles on the previous fibers and TMJs. Two sessions per week were performed totaling eight sessions. Oral opening, visual analogue scale (VAS) and OHRQoL (oral health-related quality of life) measurements were evaluated by the Oral Health Impact Profile (OHIP-14) at three moments: pre-treatment (T0), after the eight treatment sessions (T1) and 30 d after the end of treatment (T2). The obtained results showed the improvement of muscle pain and oral opening accompanied by improved quality of life of the volunteers treated with a percentage of 84% in patient 1 and 100% in patient 2. Combined therapies (LLL and vacuum therapies) may be a complementary or alternative treatment to control pain and decrease the recovery time of normality masticatory muscles.

The post-COVID-19 condition or ‘long COVID’ is a clinical and scientific challenge for society. In this regard, patients after COVID-19 recovery show a vast range of sequels including muscular, articular lesions, neurological, dermatological, and pulmonary issues. These clinical consequences are issues in the present and for the future. In this case, rehabilitation therapies based on photobiomodulation and combined therapies arise as excellent tools to solve it. Herein, we describe and discuss the perspectives on the use of light-based therapies such as photobiomodulation, photodynamic therapy and combined vacuum and laser therapy for rehabilitation of patients who present some sequelae of the COVID-19 infection. We did not intend to produce a comprehensive review; instead we highlight the most important and clinical protocols against these sequels. Moreover, the principles and mechanism of action of each light-based technique proposed were reported and discussed.

Background: tinnitus is a symptom with no specific cause known to date, and there are no associated pharmacogenomics of hearing disorders and no FDA-approved drugs for tinnitus treatment. The effectiveness of drug treatments is not reproducible on idiopathic patients and inexistent in refractory patients. Personalized treatments for these patients are a great clinical need. Our study investigated the outcome of potential alternative and complementary treatment modalities for idiopathic and refractory tinnitus patients. Methods: we were the first to evaluate the tinnitus handicap inventory (THI) score changes over the course of treatment up to 15 days after complete cessation of treatment for novel transmeatal low-level laser therapy (LLLT) modalities using light alone, as well as LLLT combined with vacuum therapy (VT), ultrasound (US), Ginkgo biloba (GB) and flunarizine dihydrochloride (FD), while also comparing all treatment outcomes with laser puncture (LP), FD alone and GB alone. Results: a positive treatment outcome (superior to a placebo effect) was achieved by using either LP or transmeatal LLLT, whereas short-term antagonistic effects of VT, US, GB and FD when combined with LLLT. For transmeatal LLLT, an improvement in the treatment outcome was observed by increasing the irradiation time from 6 min to 15 min (with 100-mW of applied laser power at 660 nm). Finally, a lasting therapeutic effect higher than the placebo was observed at 15 days after treatment upon combining LLLT with VT, GB or by using FD alone, by using the transmeatal LLLT alone or by using LP. Conclusions: LP and Transmeatal LLLT can be promising alternative treatments for idiopathic and refractory tinnitus patients. Future studies should investigate the long-term effects of LLLT in tinnitus patients, as well as the dosimetry and wavelength of transmeatal LLLT.