Therapeutic ultrasound to stimulate osteoconduction; A placebo controlled single blind study using e-PTFE membranes in rats.

To decrease healing time of bone defects covered with osteoconductive membranes, an attempt was made to stimulate the osteoconductive process with therapeutic ultrasound. In 72 rats, a circular mandibular defect was created and covered on both sides with an e-PTFE membrane. A control group, an ultrasound treatment group and a placebo treatment group were studied. At 2 and 4 weeks, the osteoconduction was expressed as the percentage of defect closure using digitized microradiographs. At 2 weeks, there was no significant difference in the percentage of defect closure between the groups. At 4 weeks, there was significantly more bone defect closure in the placebo group (77.9%) as compared to the control group (59.3%). Membrane ultrasound attenuation measurements indicated that the membrane blocks most of the applied ultrasound. In conclusion, low intensity pulsed ultrasound does not appear to significantly stimulate osteoconduction into a bone defect in the rat mandible that is covered by an e-PTFE membrane.