The objective of the study was to develop a biocompatible composite system which was composed of TZP-ceramic (tetragonal zirconia polycrystals, ZrO2 stabilized with 3 mol % Y2O3) and two glass-ceramics of the SiO2-Li2O-ZrO2-P2O5 type. The metal-free composite system would satisfy the translucency, the biocompatibility and the strength requirements of dentistry. The two glass-ceramics of the SiO2-Li2O-ZrO2-P2O5 type with a content of 15 and 20 wt % ZrO2 respectively, were chemically and physically adapted to TZP-ceramic. The glass-ceramics were used as a dentin buildup material. The TZP-ceramic had the function of a root post. The shape of the post was cylindrical with a conical tip. The composite system was easy to process through viscous flow of the glass-ceramic at 900 and 1000 degrees C, respectively. The microstructure and the mechanical properties of two glass-ceramics of the SiO2-Li2O-ZrO2-P2O5 type were examined therefore.