Piezoelectric properties of human dentin and some influencing factors

Objectives The present study focused on the piezoelectricity of human dentin. The effects of moisture content and orientation of tubules were investigated. Methods Fresh human dentin was cut with two surfaces generally parallel to the occlusal surface. The potentials generated by specimens were detected, as the compression loads were respectively parallel and vertical to the tubules. Moreover, specimens were dried and rehydrated; piezoelectric coefficients d33 of dentin with different moisture content were measured horizontally to, and vertically to, the tubules. Results The results showed that piezoelectricity of dentin increased with increasing moisture content. Furthermore, greater piezoelectricity was detected parallel to the tubules than vertical to the tubules. Significances This study indicated that the piezoelectric properties of dentin were significantly affected by both humidity and orientation of the tubules. Both structural and free water in dentin is attributed to its piezoelectric properties.