The purpose of the present study was to evaluate differences in the mechanism of periodontium remodeling of canine teeth of young adult dogs subjected to orthodontic forces with and without the use of ultrasound stimulation. Eight dogs of both sexes, of undefined breed, aged 1-2 years and weighing 10-15kg were delivered a 150g force by means of a superelastic spring mesially anchored to their first right upper molars and extending to their right upper canines. Four of these animals were also given ultrasound stimuli of 200µs 1.000Hz bursts on the region of dental movement for 20 minutes a day. The other four animals served as controls. One animal of each group was sacrificed on days 7, 14, 21, and 28 of the experiment. The dental arch halves involved were then removed and treated in Bouin solution, and sections for optical microscopy were stained in hematoxylin-eosin and Masson trichrome. Histological aspects were found to differ between groups: animals subjected to ultrasound stimuli responded with pronounced vascular and cellular remodeling of periodontal ligament and alveolar bone, and with an improved organization of collagen fibers and regularity of mineralized tissues. Results provide evidence that ultrasounds may be regarded as a tool for stimulation of the supporting periodontium, as their use helped enhance metabolism in the course of induced dental movements.
Ultrasound; Dental movement; Bone remodeling
