Effects of Low-Intensity Pulsed Ultrasound on Dental Implant Osseointegration: A Preliminary Report

OBJECTIVES The aim of this pilot study was to evaluate the effects of low intensity pulsed ultrasound (LIPU) on dental implant osseointegration in a rabbit model using mechanical-histomorphometric methods and resonance-frequency analysis (RFA). METHODS Twelve skeletally mature, male New Zealand rabbits (3.4 kg+/-0.5) were included in the study. A total number of 24 implants were placed bilaterally into the tibiae of the subjects. The right tibia of each rabbit received LIPU application (20 min/day) while the left side received sham treatment. The study was carried on for six weeks and the rabbits were sacrificed in 7 days intervals (two rabbits for each week). The rabbits were categorized in the early or late osseointegration period according to their sacrification date. Comparisons between the groups were made using statistical analysis of histomorphometric analysis, resonance frequency analysis and mechanical tests. RESULTS The histomorphometry parameters showed that the bone area and the bone volume values have significantly increased in the early osseointegration period and the bone-implant contact values have significantly increased in the late osseointegration period in the LIPU treated subjects when compared to the control group. RFA scores had mild increase in the LIPU group. However the difference was not statistically significant. Mechanical test results suggest an increased mechanical stability in the LIPU group as well. CONCLUSIONS Results of this pilot study indicate that low intensity pulsed ultrasound may have positive effects on osseointegration and stability of dental implants.