Development of Powder Jet Deposition Technique and New Treatment for Discolored Teeth

Abstract

The powder jet deposition (PJD) process is for creation of a hydroxyapatite (HA) layer on human teeth. To develop the PJD device, the layer-forming properties have improved. Created HA layers with a new handpiece-type PJD device demonstrate excellent material properties in vitro. Titanium dioxide (TiO 2 ) is known to cause whitening because of the selective reflection of the light. Therefore, we assessed the possibility of using the creation of TiO 2 -HA layers with the new PJD device as a new treatment for discolored teeth. In this study, the microstructural and mechanical properties of TiO 2 -HA layers were evaluated under the same conditions of the previous study. These properties were evaluated before and after 500 cycles of thermal cycling (5-55 °C). Furthermore, the CIE L * a * b * color system was used for color measurement and ⊿E * values for color differences were calculated. The maximum thickness of the TiO 2 -HA layers was about 60 μm. There were no significant differences in thickness, hardness, or bonding strength before and after thermal cycling. The layers showed an increased L * parameter and a decreased b * parameter, and the color difference ⊿E * was approximately 6.7 units. Creation of TiO 2 -HA layers by PJD might be a valuable new treatment for discolored teeth.

A novel treatment based on powder jet deposition technique for dentin hypersensitivity: a randomized controlled trial

“…To solve these problems, we focused on the powder jet deposition (PJD) technique [ 22 – 25 ] as a new method for treating DH. PJD is a method whereby a thin layer of hydroxyapatite (HAP) is formed on the material surface by injecting fine HAP particles at high speed.…”

Antibacterial tooth surface created by laser-assisted pseudo-biomineralization in a supersaturated solution

“…There are many reports on techniques for the production of an artificially mineralized tooth surface [13][14][15][16][17][18][19][20][21][22][23][24][25]. However, each of them has its own strengths and weaknesses, and there is thus a demand for a more practical technique.…”

“…Various techniques have been proposed to create an artificially mineralized tooth surface [13][14][15][16][17][18][19][20][21][22][23][24][25]. These techniques include physical coating techniques such as pulsed laser deposition [13], powder jet deposition [14], and apatite sheet adhesion [15], and chemical techniques based on pseudo-biomineralization [16][17][18][19][20][21][22][23]. In general, physical techniques are weak in the coating adhesion and integration with a tooth surface, whereas chemical techniques are time-consuming.…”