Experimental Studies On Osteoblast-compatibility Of Piezoelectric Ceramic

After the loss of teeth, resorption of residual ridge (RRR) will be going on. This may result in the osseous loss and the shape change of the alveolar ridge, and influence the denture repair. In prosthodontics, it becomes a problem to be urgently solved. Considering the piezoelectricity of the bone, we try to put piezoelectric ceramic into polymethylmethacrylate (PMMA) and expect the low electricity of this new type of denture material can inhibit or limit the RRR. The study aims to evaluate the effects of Bi_0.5Na_0.5TiO₃-based (BNT) and (Li_xNa_yK_1-x-y NbO₃-based (NKN) lead-free piezoelectric ceramic on the proliferation and differentiation of osteoblast.In this study, primary osteoblast of rat was cultured using cranium and was identified through HE staining, ALP staining, immunohistochemical staining of type I collage and alizarin red staining of calcifying nodi. A conventional ceramic fabrication method was employed to prepare the BNT-based ceramic and NKN-based ceramic, after that, their electric properties were investigated. Using NKN and BNT as tests, PMMA and blank as controls, cell morphologies around these materials were observed by phase contrast microscope .Cell viability was evaluated by MTT assay at 1, 3, 5, 7,9 days and differentiated cell function was assessed by measuring alkaline phosphatase (ALP) activity at 1,4,7,10 days. The results show that:1. Cultured cells and the preparation of BNT,NKN and PMMA can be used for further experiments.2. At the same condition, BNT have a better osteoblast spreading degree than the other three groups after 6 hours; Compared to the NKN and PMMA, BNT showed a higher optical density (OD) at 1,3,5,7,9 days (P<0.05) and a higher ALP activity at 1,7,10 days (P <0.05); Compared to the blank, the OD of BNT was higher at 1,3,5,7 days (P<0.05) and the ALP activity higher at 7,10 days(P<0.05) .Based on these findings, we can draw a conclusion: BNT have a good role in promoting cell adhesion, proliferation and differentiation and have a better osteoblast-compatibility than NKN and PMMA.