Machining accuracy of CAD/CAM ceramic crowns fabricated with repeated machining using the same diamond bur.
The purpose of this study was to investigate the effect of repeated machining up to 51 times using the same diamond bur on machining accuracy of inner and outer surfaces of CAD/CAM (computer-aided designing and computer-aided manufacturing) machined ceramic crowns. The surface topography of machined crowns was examined using photographs. It was found that machining accuracy was not affected by the number of machining times. In all measuring points, the inner surface was machined to a dimension larger than the die model (i.e., increased gap), whereas the outer surface was machined to a dimension smaller than the crown model (i.e., smaller crown). Photo observation showed that cervical contour was machined in a clear, rounded form from 1st to 11th crowns.
Tomita
Sachiko
S
Department of Crown and Bridge, School of Dentistry at Tokyo, The Nippon Dental University, Tokyo, Japan.
Shin-Ya
Akiyoshi
A
Gomi
Harunori
H
Matsuda
Tetsuji
T
Katagiri
Shingo
S
Shin-Ya
Akikazu
A
Suzuki
Hitosi
H
Yara
Atsushi
A
Ogura
Hideo
H
Hotta
Yasuhiro
Y
Miyazaki
Takashi
T
Sakamoto
Yuuki
Y
D000704:Analysis of Variance; D017076:Computer-Aided Design / Q000295:instrumentation*; D003442:Crowns; D003762:Dental Instruments; D003775:Dental Polishing / Q000295:instrumentation / Q000379:methods; D003776:Dental Porcelain; D017267:Dental Prosthesis Design / Q000295:instrumentation*; D018130:Diamond; D017743:Equipment Reuse; D008855:Microscopy, Electron, Scanning; D023861:Photography, Dental; D015203:Reproducibility of Results; D013499:Surface Properties
D003776:Dental Porcelain; D018130:Diamond