Effect of defocused infrared diode laser on salivary flow rate and some salivary parameters of rats

Clin Oral Investig. 2008 Mar;12(1):25-30. doi: 10.1007/s00784-007-0135-y. Epub 2007 Jul 12.


This study aims to investigate whether infrared diode low-level laser therapy (LLLT) increased salivary flow rate and altered pH value, protein concentration, and peroxidase and amylase activities in saliva of rats. Wistar rats were used and divided into three groups. Experimental groups (A and B) had their parotid, submandibular and sublingual glands submitted to diode laser, 808-nm wavelength, on two consecutive days. The dose results were 4 and 8 J/cm(2), respectively. A red guide light was used to visualize the irradiated area. Group C was irradiated only with red pilot beam and served as control. The saliva samples were collected after each irradiation step (first and second collection days) and 1 week after the first irradiation (seventh day). Statistical analysis was performed, and differences were observed according to different days of salivary collection. The results showed that salivary flow rate for groups A and B was higher on the seventh day if it is compared to data obtained for the first day (p < 0.05). LLLT applications on salivary glands are a therapy procedure that requires further studies.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amylases / radiation effects
  • Animals
  • Hydrogen-Ion Concentration
  • Lasers, Semiconductor / therapeutic use*
  • Low-Level Light Therapy / methods*
  • Male
  • Parotid Gland / metabolism
  • Parotid Gland / radiation effects
  • Peroxidase / radiation effects
  • Radiation Dosage
  • Rats
  • Rats, Wistar
  • Saliva / metabolism
  • Saliva / radiation effects*
  • Salivary Glands / metabolism
  • Salivary Glands / radiation effects*
  • Salivary Proteins and Peptides / radiation effects
  • Secretory Rate / radiation effects
  • Spectrophotometry
  • Sublingual Gland / metabolism
  • Sublingual Gland / radiation effects
  • Submandibular Gland / metabolism
  • Submandibular Gland / radiation effects


  • Salivary Proteins and Peptides
  • Peroxidase
  • Amylases