Effect of ultrasound on bone differentiation in human PDL fibroblasts

Effect of low intensity pulsed ultrasound on collagen type-1, osteocalcin, alkaline phosphotase, osteopontin in human periodontal ligament fibroblasts

Abstract

Objective: Low intensity pulsed ultrasound (LIPUS) has been demonstrated to accelerate bone growth during fracture healing and distraction osteogenesis. This study was to evaluate the effect of LIPUS on the alteration of the expressions of osteogenesis related genes in periodontal ligament fibroblasts (PDLFs) using the polymerase chain reaction (PCR) method.

Method: PDLFs were pre-cultured for eight days in the presence of differentiation media and then exposed to LIPUS for 7 days each 15-min. 6 passages of PDLFs were used in this study. RT-PCR was used to determine the effect of LIPUS on expression of several genes associated with bone differentiation markers in PDLFs.

Result: The expression of the genes was increased compared to controls. Increases in both gene expressions and bone nodule formation were greatest at 7 days after last LIPUS exposure, implying that there may be a time dependence for the stimulus of bone differentiation markers in PDLFs.

Conclusion: LIPUS treatment could accelerate the differentiation of the PDLFs into osteoblasts or cementoblasts. In the future, attempts to stimulate bone defect healing and periodontal tissue remodelling using LIPUS may focus on the use of other treatment protocols.