The effect of whole-body vibration on peri-implant bone healing in rats

Abstract

The aim of this study was to evaluate the effect of low-magnitude, high-frequency (LMHF) loading, applied by means of whole-body vibration (WBV), on peri-implant bone healing and implant osseointegration in rat tibiae. A custom-made titanium implant was inserted into the proximal metaphysis of the tibiae of 42 rats and left to heal for 3, 7, 14 or 25 days. Half of the animals received LMHF mechanical vibration for 5 days per week (test), whereas the others served as unloaded controls. The WBV consisted of 15 consecutive frequency steps (12, 20, 30, … to 150 Hz). Each of the 15 frequencies was applied for 2000 cycles, at an acceleration of 0.3 g. In the group with a 25-day healing period, PET images were taken at -1 (day before surgery), 3, 5, 7, 10, 14 and 21 days of loading, after an injection of [(18)F]sodium fluoride, a positron-emitting tracer. The ratio of the metabolic activity around the implants to that of a reference site (uptake ratio) was calculated as a measure of bone metabolism. Bone-to-implant contact (BIC) and peri-implant bone fraction (BF) were analysed for histomorphometrical measurement. The mean BIC and BF were significantly influenced by both the loading and the healing time (ANOVA, P<0.01). The PET images did not reveal any significant difference in uptake ratio between the test and the control implants. LMHF loading increased BIC and BF significantly. The results confirm the bone-stimulating potential of LMHF loading, through WBV, on peri-implant bone healing and osseointegration.