Photobiomodulation-induced orthodontic tooth movement.

Chiari S. Baloul S. Goguet-Surmenian E. Dyke T. Kantarci A.
Boston University Goldman School of Dental Medicine, Department of Periodontology and Oral Biology, Boston MA USA (pending publication)

Objective: The study has been designed to assess the effect of LED radiation versus NIR-Laser radiation phototherapy on the rate of the orthodontic tooth movement and the biological impact in the rat model.

Materials/Methods: Nineteen healthy adult CRL-CD male rats with a body weight of 350-400 g were used as experimental animals. The orthodontic appliances were placed to mesially move the left maxillary 1st molar. The test animals in phototherapy groups daily received LED or Laser applications while the stability of the orthodontic appliances were constantly checked under isoflurane anesthesia. All animals were constantly monitored for 21 days. Two different application times were selected to deliver the two different doses: 333 seconds (5 minutes and 33 seconds) or 1000 seconds (16 minutes and 40 seconds) and the photobiomodulation test groups were designated as LED-Short, Laser-Short, LED-Long, or Laser-Long accordingly. Animals in the LED-Short group, the device was applied for a cumulative energy dose of 10J/cm2; for the LED-Long group for 30J/cm2; for animals in the Laser-Short group for 10J/cm2; and for the Laser-Long group for 30J/cm2.

Results: The Faxitron analyses demonstrated that mesial movement of the first molar in three (LED-Long, Laser- Short, Laser-Long: 1.46 to 1.88 mm) of the four test groups with light application compared was significantly enhanced compared to the tooth movement (0.51±0.05 mm) alone (p

Conclusions: Both phototherapy methods have the potential of accelerating orthodontic tooth movement with an increase of bone remodeling in the interradicuar area. NIR-Laser irradiation and an increased application time per day lead to a more predictable tooth movement. LED application however provides a lower velocity compared to Laser application but the tooth movement can be considered of a higher quality, as indicated by the high bone regeneration and the bodily movement of the mesialized tooth and the less resorptive activity in the distance, in the third molar region. No negative effects due to light penetration could be found in any group.