TY - JOUR
T1 - Effects of ethanol addition on the water sorption/solubility and percent conversion of comonomers in model dental adhesives
AU - Malacarne-Zanon, Juliana
AU - Pashley, David H.
AU - Agee, Kelli A.
AU - Foulger, Stephen
AU - Alves, Marcelo Corrêa
AU - Breschi, Lorenzo
AU - Cadenaro, Milena
AU - Garcia, Fernanda P.
AU - Carrilho, Marcela R.
N1 - Funding Information:
The editorial assistance of Ms. Michelle Barnes and the scientific advices of Dr. Frederick Rueggeberg are greatly appreciated. BISCO Inc. is thanked for formulating the experimental resins. This manuscript is in partial fulfillment of requirements for the PhD degree for Juliana Malacarne-Zanon, Piracicaba School of Dentistry, University of Campinas, Brazil. This study was supported by grants from CAPES (P.I. Juliana Malacarne-Zanon), FAPESP (# 07/54618-4 -P.I. Marcela Carrilho). CNPq (#300615/2007-8 and 473164/2007-8 - P.I. Marcela Carrilho) and from NIDCR (# R01-DE-014911 - P.I. David Pashley).
PY - 2009/10
Y1 - 2009/10
N2 - Objectives: This study evaluated the kinetics of water uptake and percent conversion in neat versus ethanol-solvated resins that were formulated to be used as dental bonding agents. Methods: Five methacrylate-based resins of known and increasing hydrophilicities (R1, R2, R3, R4 and R5) were used as reference materials. Resins were evaluated as neat bonding agents (100% resin) or they were solvated with absolute ethanol (95% resin/5% ethanol or 85% resin/15% ethanol). Specimens were prepared by dispensing the uncured resin into a circular mold (5.8 mm × 0.8 mm). Photo-activation was performed for 80 s. The water sorption/diffusion/solubility was gravimetrically evaluated, while the degree of conversion (DC) was calculated by Fourier-transform infrared spectroscopy. Results: Water sorption increased with the hydrophilicity of the resin blends. In general, the solvated resins exhibited significantly higher water sorption, solubility and water diffusion coefficients when compared to their corresponding neat versions (p < 0.05). The only exception was resin R1, the least hydrophilic resin, in which neat and solvated versions exhibited similar water sorption (p > 0.05). Addition of ethanol increased the DC of all resins tested, especially of the least hydrophilic, R1 and R2 (p < 0.05). Despite the increased DC of ethanol-solvated methacrylate-based resins, it occurs at the expense of an increase in their water sorption/diffusion and solubility values. Significance: Negative effects of residual ethanol on water sorption/solubility appeared to be greater as the hydrophilicity of the resin blends increased. That is, the use of less hydrophilic resins in dental adhesives may create more reliable and durable bonds to dentin.
AB - Objectives: This study evaluated the kinetics of water uptake and percent conversion in neat versus ethanol-solvated resins that were formulated to be used as dental bonding agents. Methods: Five methacrylate-based resins of known and increasing hydrophilicities (R1, R2, R3, R4 and R5) were used as reference materials. Resins were evaluated as neat bonding agents (100% resin) or they were solvated with absolute ethanol (95% resin/5% ethanol or 85% resin/15% ethanol). Specimens were prepared by dispensing the uncured resin into a circular mold (5.8 mm × 0.8 mm). Photo-activation was performed for 80 s. The water sorption/diffusion/solubility was gravimetrically evaluated, while the degree of conversion (DC) was calculated by Fourier-transform infrared spectroscopy. Results: Water sorption increased with the hydrophilicity of the resin blends. In general, the solvated resins exhibited significantly higher water sorption, solubility and water diffusion coefficients when compared to their corresponding neat versions (p < 0.05). The only exception was resin R1, the least hydrophilic resin, in which neat and solvated versions exhibited similar water sorption (p > 0.05). Addition of ethanol increased the DC of all resins tested, especially of the least hydrophilic, R1 and R2 (p < 0.05). Despite the increased DC of ethanol-solvated methacrylate-based resins, it occurs at the expense of an increase in their water sorption/diffusion and solubility values. Significance: Negative effects of residual ethanol on water sorption/solubility appeared to be greater as the hydrophilicity of the resin blends increased. That is, the use of less hydrophilic resins in dental adhesives may create more reliable and durable bonds to dentin.
KW - Dental adhesives
KW - Percent conversion
KW - Residual ethanol
KW - Water sorption/solubility
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U2 - 10.1016/j.dental.2009.03.015
DO - 10.1016/j.dental.2009.03.015
M3 - Article
C2 - 19592083
AN - SCOPUS:68949101452
SN - 0109-5641
VL - 25
SP - 1275
EP - 1284
JO - Dental Materials
JF - Dental Materials
IS - 10
ER -