Low-level laser therapy for xerostomia in primary Sjögren's syndrome: a randomized trial

To evaluate the effectiveness of low-level laser therapy (LLLT) in the treatment of xerostomia in primary Sjögren's syndrome (SS), a randomized clinical trial of patients with dry mouth symptoms associated with primary SS receiving care at a university hospital was conducted. Sixty-six patients were randomly assigned with a 1:1 allocation ratio to receive LLLT (laser group, n = 33) or placebo treatment (placebo group, n = 33). Patients in the laser group received LLLT twice a week for 6 weeks, for a total of 12 treatment sessions. Laser irradiation was performed with an aluminum-gallium-arsenide laser diode at a wavelength of 808 nm, 100-mW output power, and energy density of 4.0 J/cm² per irradiation point per session. Placebo treatment was performed following the same protocol used for irradiated patients and using the same laser device to mimic a real irradiation, but with no active laser emission and the tip of the laser probe covered with aluminum foil. The outcomes of interest were xerostomia inventory scores, salivary flow rate, salivary beta-2 microglobulin levels, and salivary sodium and chlorine concentrations. Patients in both groups showed no improvement in xerostomia. Likewise, there was no significant improvement in xerostomia inventory scores (p = 0.301) or salivary flow rate (p = 0.643) in either group. There was no difference in salivary beta-2 microglobulin levels, sodium concentration, and chlorine concentration before and after intervention or between the two groups. The LLLT protocol used in this study effected no improvement in xerostomia or salivary flow rate in patients with primary SS. ClinicalTrials.gov Identifier: NCT02066896.