Journal of Dental Research, Vol 75, 1491-1496, Copyright © 1996 by International & American Associations for Dental Research Online Journals
Trial production of titanium orthodontic brackets fabricated by metal injection molding (MIM) with sintering
T. Deguchi, M. Ito, A. Obata, Y. Koh, T. Yamagishi and Y. Oshida
Department of Orthodontics, Matsumoto Dental College, Nagano, Japan.
Safety and esthetics are two indispensable factors to consider when
fabricating orthodontic brackets. However, these factors are not easily
achieved when conventional techniques (including forging and casting) are
used in the mass production of titanium brackets, albeit the brackets
exhibit excellent biocompatibility. In the present study, orthodontic
brackets were manufactured by metal powder injection molding with
sintering. Brackets with three different base designs were made and
subjected to compression shear tests for evaluation of their bonding
strength to enamel substrate. The shapes given to the dimple of the base
were spherical, oval, and grooved. The maximum shear forces for each type
were 11.1 kgf, 7.6 kgf, and 18.5 kgf, respectively. The bonding strengths
of the titanium bracket were equivalent to those obtained with conventional
stainless steel brackets. Moreover, uniform distribution of Vickers
hardness values (average, 240 +/- 40 Hv) measured at three locations
indicated that the titanium bracket was uniformly sintered. Accordingly,
titanium brackets thus fabricated exhibit a potential for clinical
application.
