TY - JOUR
T1 - Effect of solvent type and content on monomer conversion of a model resin system as a thin film
AU - Holmes, Robert G.
AU - Rueggeberg, Frederick
AU - Callan, Richard S
AU - Caughman, Wyatt Franklin
AU - Chan, Daniel C.N.
AU - Pashley, David Henry
AU - Looney, Stephen Warwick
PY - 2007/12/1
Y1 - 2007/12/1
N2 - Objective: The purpose of this study was to examine the effect of solvent concentration on the degree of conversion of a model photo-activated resin formulation when placed as a thin film in ambient air. Methods: A photo-activated co-monomer mixture (ethoxylated bis-GMA/TEGDMA) (Bisco Inc.) was diluted into six concentrations (from 1.0 to 13.0 M) with either acetone or ethanol. A controlled volume of diluted, uncured resin was placed on the horizontal surface of an attenuated reflectance unit and the infrared (IR) spectrum obtained. A light emitting diode light-curing source (Bluephase, Ivoclar/Vivadent) then immediately irradiated the specimen for 10 s (n = 5). Five minutes after exposure, IR spectra of the cured material were obtained, and monomer conversions were calculated using standard methods that monitored changes in aliphatic-to-aromatic C{double bond, long}C absorbance ratios in the uncured and cured states. Results: In the acetone/model resin system, maximum conversion occurred with 2.5-5.0 M solvent. In the ethanol/model resin system, conversion peaked at 2.5 M solvent. Above 5.0 M solvent, conversion values declined rapidly for both solvents. A 13.0-M solution resulted in near 0% conversion for both solvents. At 2.5 and 5.0 M acetone, conversions exceeded those of equivalent concentrations of the ethanol-based system. Conclusions: For both an acetone- and ethanol-solvated model resin system, conversion did not immediately decrease with addition of solvent, but instead increased over that of the model resin alone. At higher solvent content (greater than 2.5 M ethanol and 5.0 M acetone), conversion rapidly declined, with ethanol causing less conversion at equal-molar solvent concentrations.
AB - Objective: The purpose of this study was to examine the effect of solvent concentration on the degree of conversion of a model photo-activated resin formulation when placed as a thin film in ambient air. Methods: A photo-activated co-monomer mixture (ethoxylated bis-GMA/TEGDMA) (Bisco Inc.) was diluted into six concentrations (from 1.0 to 13.0 M) with either acetone or ethanol. A controlled volume of diluted, uncured resin was placed on the horizontal surface of an attenuated reflectance unit and the infrared (IR) spectrum obtained. A light emitting diode light-curing source (Bluephase, Ivoclar/Vivadent) then immediately irradiated the specimen for 10 s (n = 5). Five minutes after exposure, IR spectra of the cured material were obtained, and monomer conversions were calculated using standard methods that monitored changes in aliphatic-to-aromatic C{double bond, long}C absorbance ratios in the uncured and cured states. Results: In the acetone/model resin system, maximum conversion occurred with 2.5-5.0 M solvent. In the ethanol/model resin system, conversion peaked at 2.5 M solvent. Above 5.0 M solvent, conversion values declined rapidly for both solvents. A 13.0-M solution resulted in near 0% conversion for both solvents. At 2.5 and 5.0 M acetone, conversions exceeded those of equivalent concentrations of the ethanol-based system. Conclusions: For both an acetone- and ethanol-solvated model resin system, conversion did not immediately decrease with addition of solvent, but instead increased over that of the model resin alone. At higher solvent content (greater than 2.5 M ethanol and 5.0 M acetone), conversion rapidly declined, with ethanol causing less conversion at equal-molar solvent concentrations.
KW - Acetone
KW - Ethanol
KW - Polymerization
KW - Solvent evaporation
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U2 - 10.1016/j.dental.2007.01.007
DO - 10.1016/j.dental.2007.01.007
M3 - Article
C2 - 17368744
AN - SCOPUS:35548936002
VL - 23
SP - 1506
EP - 1512
JO - Dental Materials
JF - Dental Materials
SN - 0109-5641
IS - 12
ER -