Influence of power density and primer application on polymerization of dual‐cured resin cements monitored by ultrasonic measurement

Abstract

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.

Effect of High-Irradiance Light-Curing on Micromechanical Properties of Resin Cements

“…The relative insensitivity of RelyX Unicem 2 is supported by studies on degree of conversion and hardness of RelyX ARC, an etch-and-rinse adhesive resin cement from the same manufacturer that also proved generally insensitive to changes in radiant exposure [22, 23]. Likewise, the relatively high sensitivity of Panavia F2.0 to changes in radiant exposure is in harmony with previous findings [17, 24]. These results may be caused by differences in the photoinitiator system indicating poorer efficiency for the latter material.…”

Effect of Pre-reacted Glass-ionomer Filler Extraction Solution on Demineralization of Bovine Enamel

“…16 Measurements were taken before the test, and then on days 1-7, 14, 21, and 28. The equipment was initially calibrated using a standard procedure with 304 stainless steel calibration blocks (2211M, Panametrics) with thicknesses of 2.5, 5.0, 7.5, 10.0, and 12.5 mm.…”

Intra- and inter-brand accuracy of four dental radiometers

“…Additionally, although general guidelines for assessing the substantial equivalence of medical/ dental devices, e.g., 510(K), exist [17], no standard methodology is specified by licensing agencies when determining equivalence of dental radiometers, as is the case for pharmaceutical bioequivalence [18]. Consequently, although many dental manufacturers, researchers and clinicians have used dental radiometers to measure the irradiance from curing lights [2,3,5,6,[19][20][21][22][23][24], the actual irradiance delivered to the specimens may be in question.…”