The effect of low-energy laser on periodontal ligament and bone during orthodontic movement : an experimental study on rabbits

Abstract EN

The purpose of this study was to investigate whether a low-energy laser irradiation can accelerate orthodontic movement? A total of (30) male laboratory rabbits were used for this experiment.

And a total of (50 cN) of orthodontic force was applied by an open-coil spring to rabbit lower incisors to cause orthodontic movement by means of fixed orthodontic appliance.

A Galium-Aluminum-Arsenide (Ga-Al-As) diode laser of two types: (the continuous wave (CW) of (808nm) wavelength and (100mW) output power, and pulsed (PW) of (904nm) wavelength, (1000Hz) repetition rate, (6W) peak power and (100mW) average output power), were used to irradiate the area around the moved teeth at (3 and 10 minutes) of laser exposure time, the amount of orthodontic movement measured at three times interval (day 4, 7, and 10).

After 10 days of the experimental period, the biopsy was taken.

A histopathological based assessment method for periodontal ligament (PDL) and bone remodeling has been used.

The cellular proliferation stimulation estimated by silver staining of nucleolar organizer regions (Ag-NORs) method.

In the laser irradiation groups, the amount of orthodontic movement was significantly greater (1.6 fold) than that of the non-irradiation group at the end of the experiment.

The stimulation of cellular proliferation was significantly increased in the laser irradiation groups in comparison with the non-irradiation group (p<0.001) and this increase was duration of exposure-dependant.

These findings suggest that low-energy laser irradiation can accelerate orthodontic movement accompanied with enhanced cellularity of periodontal ligament and alveolar bone remodeling.

We suggest laser therapy may be of great therapeutic benefit to abbreviate the long orthodontic treatment period, which is burdensome for patients