Er:YAG Laser-Roughened Enamel Promotes Osteoblastic Differentiation

Objective: The aim of this study was to test whether Er:YAG laser-etched enamel of human teeth could act as a biologically active scaffold for tissue regeneration. Background data: Hydroxylapatite (HA) with rough surface created by acid etching treatment has been used as a scaffold for tissue engineering. However, whether tooth HA can be a scaffold for osteoblastic cell seeding is still unclear. Materials and methods: Enamel samples from human teeth were pretreated with an Er:YAG laser to create a rough surface. Then the surface of the laser-treated enamel was examined using a surface roughness profilometer and a scanning electron microscope. In addition, static water contact angles of the Er:YAG laser-treated enamel samples were measured using goniometry. To observe the effects of cell behavior on an Er:YAG laser-roughened enamel surface, we cultured MG63 osteoblast-like cells on the surface-modified enamel samples. Alkaline phosphatase activity, a marker of cell proliferation and differentiation, was monitored and compared with that in untreated control and acid-etched enamel samples. Results: Er:YAG laser treatment significantly improved the surface roughness of the enamel samples. Furthermore, MG63 osteoblast-like cells cultured on the Er:YAG laser-roughened enamel surface expressed more alkaline phosphatase activity and exhibited greater degrees of cellular differentiation than did cells that had been cultured on untreated enamel samples. Conclusions: These results demonstrate that Er:YAG laser-roughened enamel promotes osteoblastic differentiation. This finding suggests that Er:YAG laser-roughened enamel surfaces can potentially serve as a scaffold for tissue engineering.