Effects of low-level light therapy on xerostomia related to hyposalivation: a systematic review and meta-analysis of clinical trials.

Hyposalivation is a condition represented by a reduced salivary flow and may include symptoms such as mouth dryness (xerostomia), loss of taste, pain, dysphagia, and dysphonia, all of which greatly affect an individual's quality of life.The aim of the present study was to systematically review the effects of low-level light therapy irradiation (photobiomodulation) on salivary gland function in patients with hyposalivation.The main question of the systematic review was: "Does low-level light irradiation therapy of the salivary glands affect salivary flow rate or indicators of salivary function (ion and protein concentrations) in patients with xerostomia or hyposalivation?" The question was based on the PICO (participant, intervention, control, outcome) principle and followed the PRISMA guidelines. Databases were explored and papers published between the years 1997 and 2020 were reviewed for the following Mesh-term keywords and their corresponding entry terms in different combinations: "Low-level light therapy," "Xerostomia," "Saliva," "Salivary glands," "Salivation."The initial sample consisted of 220 articles. Of those, 47 articles were used for full-text analysis and 18 were used for a systematic review, 14 were used in meta-analysis. According to their individual quality, most articles were classified as high quality of evidence according to the GRADE score. Meta-analysis of the evidence observed increase of unstimulated salivary flow 0.51 SMD compared to placebo (95% CI: 0.16-0.86), I2 = 50%, p = 0.005.The findings of our review revealed evidence of a beneficial effect of photobiomodulation therapy on salivary gland function. The therapy alleviates xerostomia and hyposalivation. However, these effects are reported short term only and did not induce lasting effects of photobiomodulation therapy on patients' quality of life.

The impact of photobiomodulation of major salivary glands on caries risk.

Dental caries is a complex multifactorial chronic infectious disease guided by several risk or protective factors. Saliva has an important role in caries and the remineralization process. Caries risk assessment is defined as the probability of new caries lesion development or the existing lesion progression in a given time period. Caries diagnostics and risk factor assessment are followed by targeted elimination of risk factors and less conservative but abundant preventive therapeutic measures. The aim of our prospective randomized study was to elucidate on how photobiomodulation of major salivary glands with polychromatic light or LED light affects caries risk factors in high caries-risk patients. Thirty-six patients were assigned to one of the following three experimental groups: the first, irradiated with polarized polychromatic light (40 mW/cm2, wavelengths 480-3400 nm); the second, a continuous LED light (16 mW/cm2, wavelengths 625, 660, 850 nm); the third, same LED light in a pulsed mode. The fourth group was the control, for which a non-therapeutic visible light was used. Light was administered extra-orally bilaterally above the parotid and submandibular glands for 10 min and intra-orally above the sublingual glands for 5 min, 3 times a week, for 4 consecutive weeks. Each patient's caries risk was assessed according to Cariogram before and after therapy. Caries risk factors were determined from samples of saliva before therapy, two weeks after it commenced, at the end of therapy, and four weeks after the end of therapy. At the end of treatment, the following findings were obtained: In the group irradiated with polarized polychromatic light and in the group irradiated with continuous LED light, the Streptococcus mutans and Lactobacillus counts decreased and salivary buffering capacity increased (p < 0.05). In the group irradiated with pulsed LED light, Streptococcus mutans counts decreased and unstimulated salivary flow and salivary buffering capacity increased (p < 0.05). In all three experimental groups, caries risk was lower (p < 0.05). In the placebo control group, there were no statistically significant differences between parameters before and after therapy. We concluded that photobiomodulation of major salivary glands in high caries-risk patients can reduce the cariogenic bacteria in saliva and improve some salivary parameters, thus reducing caries risk.

Phototherapy with LED Shows Promising Results in Healing Chronic Wounds in Diabetes Mellitus Patients: A Prospective Randomized Double-Blind Study.

OBJECTIVE: The study examined the influence of phototherapy with light-emitting diodes (LEDs) on chronic diabetic wound healing. BACKGROUND: Chronic diabetic wounds are very difficult to treat due to underlying conditions such as angiopathy and neuropathy, resulting in slow healing rates. Conventional treatment options are often insufficient and do not provide satisfactory outcomes. Phototherapy with LED enhances the healing processes through mechanisms of energy exchange between incoming photons and their target, the main one being cytochrome-c oxidase in mitochondria. METHODS: A double-blind, randomized study included 60 patients with a chronic diabetic wound treated at the University Medical Center Ljubljana between October 1, 2012 and December 1, 2014. Patients were randomized into either an active group (LED group) or a control group (Co-group). The active group was treated with LED 2.4 J/cm2 (wavelengths 625, 660, 850 nm) three times a week for 8 weeks. The Co-group was treated with light that simulated LED. Healing was evaluated using the Falanga wound bed score and wound surface area. RESULTS: The average baseline wound surface before treatment was 1315 mm2 in the LED group and 1584 mm2 in the Co-group (p = 0.80). After 8 weeks, the mean surface in the LED group was 56% of the baseline surface and 65% in the Co-group (p > 0.05). Falanga score evaluation showed significantly faster wound bed healing in the LED group compared with the Co-group (p < 0.05). CONCLUSIONS: According to our results, LED significantly improves healing of chronic diabetic wounds and prepares the wound bed for further coverage options.

The effect of LED on blood microcirculation during chronic wound healing in diabetic and non-diabetic patients-a prospective, double-blind randomized study.

Chronic wounds, especially in diabetic patients, represent a challenging health issue. Since standard treatment protocols often do not provide satisfactory results, additional treatment methods-like phototherapy using low-level light therapy-are being investigated. The aim of our study was to evaluate the effect of phototherapy with light-emitting diodes on chronic wound treatment in diabetic and non-diabetic patients. Since a sufficient blood supply is mandatory for wound healing, the evaluation of microcirculation in the healthy skin at a wound's edge was the main outcome measure. Forty non-diabetic patients and 39 diabetics with lower limb chronic wounds who were referred to the University Medical Center Ljubljana between October 2012 and June 2014 were randomized to the treated and control groups. The treated group received phototherapy with LED 2.4 J/cm2 (wavelengths 625, 660, 850 nm) three times a week for 8 weeks, and the control group received phototherapy with broadband 580-900 nm and power density 0.72 J/cm2. Microcirculation was measured using laser Doppler. A significant increase in blood flow was noted in the treated group of diabetic and non-diabetic patients (p = 0.040 and p = 0.033), while there was no difference in the control groups. Additional Falanga wound bed score evaluation showed a significant improvement in both treated groups as compared to the control group. According to our results, phototherapy with LED was shown to be an effective additional treatment method for chronic wounds in diabetic and non-diabetic patients.

Photobiomodulation with light-emitting diodes improves sperm motility in men with asthenozoospermia.

Sperm motility is an important parameter of male fertility and depends on energy consumption. Photobiomodulation with light-emitting diode (LED) is known to stimulate respiratory chain in mitochondria of different mammalian cells. The aim of this research was to evaluate the effect of photobiomodulation with LED on sperm motility in infertile men with impaired sperm motility-asthenozoospermia. Thirty consecutive men with asthenozoospermia and normal sperm count who visited the infertility clinic of University Medial Centre Ljubljana between September 2011 and February 2012 were included in the study. Semen sample of each man was divided into five parts: one served as a non-treated (native) control and four parts were irradiated with LED of different wavelengths: (1) 850 nm, (2) 625, 660 and 850 nm, (3) 470 nm and (4) 625, 660 and 470 nm. The percentage of motile sperm and kinematic parameters were measured using a Sperm Class Analyser system following the WHO recommendations. In the non-treated semen samples, the average ratio of rapidly progressive sperms was 12% and of immotile sperm 73%. Treating with LED significantly increased the proportion of rapidly progressive sperm (mean differences were as follows: 2.83 (1.39-4.28), 3.33 (1.61-5.05), 4.50 (3.00-5.99) and 3.83 (2.31-5.36) for groups 1-4, respectively) and significantly decreased the ratio of immotile sperm (the mean differences and 95% CI were as follows: 3.50 (1.30-5.70), 4.33 (2.15-6.51), 5.83 (3.81-7.86) and 5.50 (2.98-8.02) for groups 1-4, respectively). All differences were highly statistically significant. This finding confirmed that photobiomodulation using LED improved the sperm motility in asthenozoospermia regardless of the wavelength.