Abstract
Purpose: Low intensity pulsed ultrasound stimulation (LIPUS) has been clinically applied to promote bone fracture healing in the orthopedic field. Thus, it is likely that LIPUS also stimulates bone regeneration in bone defects in the cranial-maxillofacial area. However, this has not been clearly proved. Furthermore, optimal time point and period of the application after the surgery has not been reported. The purpose of the present study was to evaluate the effect of LIPUS on bone regeneration in the rat parietal bone defects especially focusing on time and period of the application. Materials and Methods: Eighteen Wistar rats (14 weeks old) were divided into 6 groups: 5 experimental groups and a control group. Bone defect of 5 mm diameter was prepared on each side of the parietal bone and customized gelatin membranes were placed over the bone defects. LIPUS (160 mW/cm2, 15 min/day) was applied to the defect area with an active transducer externally in the experimental groups according to the schedules of the applications: Group 1 (day 6 - 12), group 2 (day 13 - 19), group 3 (day 20 - 26), group 4 (day 6 - 19) and group 5 (day 6 - 26). All the animals were sacrificed at 28 days. The defects were analyzed with micro CT and then histologically. Results: In Group 1, new bone formation was significantly promoted and the newly-formed bone was thick and matured compared to the one of the control group. In other experimental groups there were tendencies of stimulation of new bone formation; however, they were not statistically significant. Discussion and Conclusion: The present study demonstrated that amount of new bone formation in the bone defect depended on the time and period of LIPUS application. It has been suggested that application of LIPUS at an early healing period, the second week after the surgery, effectively accelerated new bone formation.
Highlights
Prosthetic treatment with dental implants has already been recognized as an effective modality for substituting lacking teeth and its long term prognosis is predictable
It has been reported that application of low-intensity pulsed ultrasound stimulation (LIPUS) promotes fracture healing and LIPUS has been clinically applied in the orthopaedic field [2,3], where positive effects of LIPUS on fracture healing of long bone were clearly concluded to reduce the time frame of clinical and radiographic healing by 38% [4]; effects of LIPUS on bone regeneration of flat bones in the cranial-maxillofacial area have not been abundantly documented promotion of reossification ratio in rat noncritical-sized parietal bone defects by LIPUS or by low magnitude and high frequency mechanical stimuli has been recently reported [5,6] and some clinicians have already performed LIPUS for bone augmentations in this area
It has been established that LIPUS stimulates bone regeneration in orthopedic field
Summary
Prosthetic treatment with dental implants has already been recognized as an effective modality for substituting lacking teeth and its long term prognosis is predictable. This modality needs bone to stabilize the implants; bone augmentation is often required in bone reduction cases [1]. Several bone augmentation techniques have been developed and clinically applied. Effects of LIPUS on bone regeneration in the cranial-maxillofacial should be carefully evaluated in animal experiments prior to its clinical trials
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
