The Potency of Low-Intensity Pulsed Ultrasound in a Rat Calvarial Guided Bone-Regeneration Model

Low-intensity pulsed ultrasound (LIPUS) is a biophysical intervention used to repair bone. LIPUS may reduce the healing time of bone defects covered with osteoconductive membranes. The purpose of this study was to identify the required characteristics of membranes used with LIPUS in guided bone-regeneration (GBR) procedures. Two bioabsorbable membranes (Bio-Mend (R), GC membrane), one non-bioabsorbable membrane (GORE-TEX (R)), and one titanium membrane (FRIOS (R) BoneShield) were evaluated with an oscilloscope in two settings: underwater and with an ultrasound gel. One side of the membrane was attached to the LIPUS transducer, and the other side was connected to the oscilloscope transducer. The commercial bioabsorbable and GORETEX (R) membranes transmitted only 7-16% of the 30- and 60-mW/cm(2) LIPUS waves with ultrasound gel or while underwater, whereas the titanium membrane transmitted 81-90% of these waves in both settings. Based on results of propagation analysis, we also examined the potency of LIPUS used with GBR in critical bone defects in vivo in a rat calvarium model. Two 5.0-mm defects were trephined in rat calvarium and covered with a GC membrane and FRIOS (R) BoneShield, respectively. Rats were exposed to LIPUS 30 min/day for 3 weeks. In vivo, more active bone regeneration was observed in defects covered with titanium membranes than in those covered with GC membrane in the combined use of LIPUS with GBR. These results suggest that titanium membranes perform better than other commercial membranes in the combined use of LIPUS with GBR.