IADR Abstract Archives
Use of (Meth)Acrylamide as Alternative Monomers in Adhesive Systems
Objectives: Methacrylamide monomers are able to resist hydrolysis and enzymatic attack. This study evaluated polymerization kinetics, water stability and bond strength of adhesives based on (meth)acrylamides.
Methods: 60 wt% BisGMA was mixed with 40 wt% of: HEMA (2-Hydroxyethyl methacrylate), HEA (2-Hydroxyethyl acrylate), HEMAM (N-(2-Hydroxyethyl)methacrylamide), HEAM (N-Hydroxyethyl acrylamide), and newly synthesized HEMMA (N-(2-Hydroxyethyl)methyl-methacrylamide), or HEM (N-(2-Hydroxyethyl)methyl-acrylamide). Ethanol was added at 40 vol% for the microtensile bond strength (MTBS) tests. 0.2 wt% DMPA, 0.4 wt% DPI-PF6, and 0.1 wt% BHT were added as initiators/inhibitor. Adper Single Bond Plus and Clearfil SE Bond were the commercial controls. Degree of conversion (DC) was followed in near-IR. Water sorption/solubility (WS/SL) were tested (ISO 4049). Sound human dentin was used as the bonded substrate for MTBS, tested at 24 hr or 3 weeks. Data were analyzed with one-way ANOVA/Tukey's test (95%).
Results: Results are presented in the table. DC was higher for the acryl versions of each monomer and decreased as follows: methacrylate (HEA>HEMA)>secondary methacrylamide (HEAM>HEMAM)>tertiary methacrylamide (HEM>HEMMA). The DC reached by HEMMA suggests no co-polymerization with BisGMA. HEM presented the lowest WS/SL, followed by HEMA/HEA. Other monomers presented twice the WS/SL, which influenced the MTBS at 3 weeks. All but HEAM/HEMMA materials presented values similar to methacrylate controls.
Conclusions: Experimental adhesive formulated with a tertiary acrylamide monomer was able to resist bond degradation over a short storage time. Secondary (meth)acrylamides led to high water sorption and loss of MTBS comparable to that of conventional (meth)acrylates. NIH-NIDCR/1U01-DE02756.
Methods: 60 wt% BisGMA was mixed with 40 wt% of: HEMA (2-Hydroxyethyl methacrylate), HEA (2-Hydroxyethyl acrylate), HEMAM (N-(2-Hydroxyethyl)methacrylamide), HEAM (N-Hydroxyethyl acrylamide), and newly synthesized HEMMA (N-(2-Hydroxyethyl)methyl-methacrylamide), or HEM (N-(2-Hydroxyethyl)methyl-acrylamide). Ethanol was added at 40 vol% for the microtensile bond strength (MTBS) tests. 0.2 wt% DMPA, 0.4 wt% DPI-PF6, and 0.1 wt% BHT were added as initiators/inhibitor. Adper Single Bond Plus and Clearfil SE Bond were the commercial controls. Degree of conversion (DC) was followed in near-IR. Water sorption/solubility (WS/SL) were tested (ISO 4049). Sound human dentin was used as the bonded substrate for MTBS, tested at 24 hr or 3 weeks. Data were analyzed with one-way ANOVA/Tukey's test (95%).
Results: Results are presented in the table. DC was higher for the acryl versions of each monomer and decreased as follows: methacrylate (HEA>HEMA)>secondary methacrylamide (HEAM>HEMAM)>tertiary methacrylamide (HEM>HEMMA). The DC reached by HEMMA suggests no co-polymerization with BisGMA. HEM presented the lowest WS/SL, followed by HEMA/HEA. Other monomers presented twice the WS/SL, which influenced the MTBS at 3 weeks. All but HEAM/HEMMA materials presented values similar to methacrylate controls.
Conclusions: Experimental adhesive formulated with a tertiary acrylamide monomer was able to resist bond degradation over a short storage time. Secondary (meth)acrylamides led to high water sorption and loss of MTBS comparable to that of conventional (meth)acrylates. NIH-NIDCR/1U01-DE02756.