To make a color tone similar to that of dentin of a tooth at a low cost without discoloration when baking, a dental ceramics material is produced by: mixing a pink coloring agent and a yellow coloring agent with zirconium oxide containing a stabilizer while having a mixing ratio of 0. One method migrates a subscriber’s communications device to a Global System for Mobile communications network. Thereafter an antenna transmits the second RF signal according to the communications protocol either by active transmission or modulated backscatter. A DC supply voltage is supplied to the driver via a current-limiting circuit. A controller operates the purification device by sensing an operative status of the purification device.