Histomorphometrical and clinical evaluation of the effects of decortication procedure using er:Yag laser on tooth movement in rats

The aim of this study was to histomorphometrically and clinically evaluate the effect of decortication procedure, which has been prepared transmucousally with the use of Er:YAG laser, on tooth movement.28 Sprague-Dawley rats were used for this purpose. The upper first molar teeth were mesialized with the use of a Sentalloy closed coil spring that was placed between the upper first molars and the incisor teeth. Rats were seperated into experimental and control groups. Each group consisted of one week and two weeks follow-ups. Total experimental time was 2 weeks. Experimental groups were treated with an Er:YAG laser right after the appliance insertion. Three decortication points were prepared on the mesial, palatal and buccal sides of the first upper molar teeth. The power of the laser applied was 1 watt and the duration was 8 seconds. Tooth displacements were measured on model casts which were prepared from impressions of the upper jaw taken before placement of the appliance, on day 7 and day 14. At the end of the experiment, upper jaws of the sacrified rats were dissected and prepared for histological examination.The histological evaluation revealed that alveolar bone volume and total volume between the roots of upper first and second molar teeth of the experimental groups were statistically higher than the control groups on day 7 (p<0,001, p<0,001) and day 14 (p<0,001, p<0,05).The clinical evaluation revealed statistical difference between the tooth movement measurements of the experimental groups and the control groups on day 7 (p<0,05) and day 14 (p<0,05). There was a significant increase in the tooth movement measurements of the experimental groups compared with the control groups.In our study decortication procedure, which is known to accelerate orthodontic tooth movement, was applied with a different and novel method. The results suggested that decortication procedure which is applied transmucousally with the use of an Er:YAG laser, contributed favorably during bone remodeling and accelerated tooth movement consequently.