History and Objectives: Increase in attention is paid for the use of various techniques such as ultrasound to improve connective tissue healing. The present research will study the effect of ultrasound therapy on bone regeneration in rabbits from histological point of view.

Materials and Methods: In an experimental study, 28 white male Dutch rabbits with 3 month of age and 1200gr weight underwent medical open partial osteomy of tibia bone under general anesthesia and sterile conditions. Rabbits were divided randomly into experimental and control groups. In each seven subgroup (5th, 7th, 9th, 13th, 15th, 20th and 27th days) were formed. The experimental group was treated with 1 w/cm² ultrasound pulse 2:8 with 1.5MHz frequency for 5 min for 7 days (As mentioned above) against control group. Measurements wee done in above mentioned time intervals after surgery. After the time intervals, animals were killed and tibia was examined for fracture macroscopically as well as microscopically.

Results: Histological findings (Light microscopy measurements indicated that healing process in experimental group was faster compared to control group in inflammation and proliferation phase (15th days after surgery). Healing process in experimental group was slower than control group in callus formation and remodeling phase (From 15th to 27th days after surgery).

Conclusion: Ultrasound therapy with 1.5MHz frequency accelerates bone healing in initial stage (Inflammation and proliferation) in rabbits.