Objective To evaluate the potential repairing effects of low-intensity pulsed ultrasound（LIPUS） irradiation on acute horizontal alveolar bone defects at the mandibular pre -molar areas in Beagle dogs. Methods Horizontal alveolar bone defect models were established under enamelo-cemental junction 6 mm at the mandibular third and forth pre -molar buccal regions on both sides in 4 beagle dogs, and bilateral sides of each dog were randomly divided into two groups: Experimental groups with LIPUS irradiation（ISATA 30 mW·cm-2，20 min·d-1） and control groups without opening power source of LIPUS radiation. Dual energy X-ray bone densitometer was used to detect the bony density after an 8 weeks′ irradiation. Meanwhile, decalcified bone tissue sections were used to assess the histological effects of new alveolar bone. Results The results of new bony density detection in experimental group and control group were （0.605 3±0.056 6） g·cm-2, （0.604 7±0.055 2）g·cm-2, respectively, and there was no statistical significance between the differences of the two groups（P=0.983 9）. Hematoxylin-eosin staining of decalcified bone tissue sections demonstrated that there were more osteoblasts lining at the edge of new alveolar bone in the experimental groups than that scattered in the control groups, and Masson staining revealed that collagens in new alveolar bone stained bright red indicating higher maturity in the experimental groups, while in the control groups mainly stained blue with some virescent areas indicating lower maturity. Conclusion LIPUS irradiation on acute horizontal alveolar bone defects has potential repairing effects.
