Setting behaviour of luting cements monitored by an ultrasonic method.
The purpose of this study was to monitor the setting behaviour and elastic modulus of luting cements using an ultrasonic device. The ultrasonic equipment comprised a pulser-receiver, transducers and an oscilloscope. The transit time through the cement disk was multiplied by the thickness of the specimen, and the sonic velocity within the material was then calculated. The sonic velocities of the longitudinal and shear waves were used to determine the elastic modulus. Analysis of variance and the Tukey HSD test were used to compare the elastic moduli of the set cements. In the earliest stages of the setting process, most of the ultrasound energy was absorbed by the cements and the sound waves were relatively weak. As the cements hardened, the sound velocities increased and this tendency differed among the luting cements used. The mean elastic moduli of the specimens ranged from 2.9 to 9.9 GPa after 15 min, from 14.4 to 20.3 GPa after 24 h and from 12.1 to 15.9 GPa after 1 month. The setting processes of the luting cements were thus clearly defined by using the present ultrasonic method.
Tsubota
Keishi
K
Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.
Mori
Kentarou
K
Yasuda
Genta
G
Kawamoto
Ryo
R
Yoshida
Takeshi
T
Yamaguchi
Kanako
K
Kurokawa
Hiroyasu
H
Miyazaki
Masashi
M
D000042:Absorption; D003188:Composite Resins / Q000737:chemistry; D003738:Dental Cements / Q000737:chemistry*; D004548:Elasticity; D005899:Glass Ionomer Cements / Q000737:chemistry; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D009991:Oscillometry / Q000295:instrumentation; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014159:Transducers; D014465:Ultrasonics; D014867:Water / Q000737:chemistry
D003188:Composite Resins; D003738:Dental Cements; D005899:Glass Ionomer Cements; C503682:Ionotite F; D019279:Resin Cements; C084550:Vitremer; C400934:fuji-lute; D014867:Water