Influence of power density and primer application on polymerization of dual-cured resin cements monitored by ultrasonic measurement.
We used ultrasonic measurements to monitor the influence of power density and primer application on the polymerization reaction of dual-cured resin cements. The ultrasonic equipment comprised a pulser-receiver, transducers, and an oscilloscope. Resin cements were mixed and inserted into a transparent mould, and specimens were placed on the sample stage, onto which the primer, if used, was also applied. Power densities of 0 (no irradiation), 200, or 600 mW cm(-2) were used for curing. The transit time through the cement disk was divided by the specimen thickness to obtain the longitudinal sound velocity. When resin cements were light-irradiated, each curve displayed an initial plateau of approximately 1,500 m s(-1), which rapidly increased to a second plateau of 2,300-2,900 m s(-1). The rate of sound velocity increase was retarded when the cements were light-irradiated at lower power densities, and increased when the primer was applied. The polymerization behaviour of dual-cured resin cements was therefore shown to be affected by the power density of the curing unit and the application of self-etching primer.
Takubo
Chikako
C
Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.
Yasuda
Genta
G
Murayama
Ryosuke
R
Ogura
Yukari
Y
Tonegawa
Motoka
M
Kurokawa
Hiroyasu
H
Miyazaki
Masashi
M
D055117:Curing Lights, Dental / Q000145:classification*; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry / Q000528:radiation effects; D009991:Oscillometry / Q000295:instrumentation; D055668:Photochemical Processes; D011108:Polymers / Q000737:chemistry / Q000528:radiation effects; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects*; D055116:Self-Curing of Dental Resins / Q000295:instrumentation / Q000379:methods*; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014159:Transducers; D014465:Ultrasonics
C500742:ED Primer II; D008689:Methacrylates; C438843:Panavia-Fluoro; D011108:Polymers; D019279:Resin Cements; C530542:clearfil esthetic cement