Fusion of inorganic materials to enamel and porcelain surfaces with Nd:YAG laser

Akinori Nagasawa, DDS, PhD,(a) Hiroyasu Koizumi, DDS, PhD,(b),(c) Daisuke Nakayama, DDS,(b) Hiromasa Kazama, DDS,(b) Hideo Matsumura, DDS, PhD,(b),(c) and Koji Nishikawa, DDS(d)

(a)Department of Bio-Medical Engineering, School of High-Technology for Human Welfare, Tokai University, Numazu, (b)Department of Fixed Prosthodontics, and (c)Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Tokyo, and (d)Private Practice, Saitama, Japan

Purpose: The aim of this study was to examine condition concerning fusion of inorganic material to enamel and porcelain surfaces by means of Nd:YAG laser.
Materials and Methods: Iron oxide was added to dental porcelain material in a range from 0.6 to 5.0% by weight. Slurry was placed on the human enamel and dental porcelain surfaces and Nd:YAG laser was exposed with varying energy and exposure time periods.
Results: Melting of material occurred with the following irradiation condition; 40 W for 4 s for 0.6% iron oxide, 20 W for 2 s for 2.5% and 5% iron oxide. Fusion of the material occurred with specific conditions. However, degeneration or degradation of tooth substrate also was detected with high energy and extended exposure period.
Conclusion: It was possible to fuse an inorganic substance to enamel surface using Nd-YAG laser. Further investigation is required about materials, type of laser, and irradiation condition. (Int Chin J Dent 2009; 9: 19-22.)

Key Words: ceramics, enamel, fusion, iron oxide, laser, porcelain.