Abstract
Powder jet deposition (PJD) is a coating process through the use of high speed particle impact. The authors have proposed a new dental treatment method by using this process with hydroxyapatite (HA) powder, which accomplishes cavity protection, caries prevention, and tooth color improvement. The coating principle of PJD is accumulation of chemical bonds among impacted particles. Hence it is estimated that the fractured HA particle crystal architecture affects the deposition property. In this study, PJD coating experiments were conducted with two kinds of HA particles. It is found that the mechanical strength of the formed films depends on the density of the chemical bonds among the crystal grain boundaries in the films and HA particles suited for PJD can be designed with the control of the powder thermal treatment condition.
