J Adhes Dent 16 (2014), No. 3 16. June 2014
J Adhes Dent 16 (2014), No. 3 (16.06.2014)
Page 229-234, doi:10.3290/j.jad.a32034, PubMed:24847490
Effects of Prolonged Light Exposure Times on Water Sorption, Solubility and Cross-linking Density of Simplified Etch-and-Rinse Adhesives
Wambier, Letícia / Malaquias, Tamirez / Wambier, Denise Stadler / Patzlaff, Rafael T. / Bauer, José / Loguercio, Alessandro D. / Reis, Alessandra
Purpose: This study evaluated the effects of light exposure times on water sorption, solubility, and polymer cross-linking density of simplified etch-and-rinse adhesives.
Materials and Methods: Four commercial adhesives (XP Bond, Adper Single Bond 2, Tetric N-Bond, and Ambar) were selected, and resin disks 5 mm in diameter and 1.0 mm thick were prepared and light cured for 20, 40, or 80 s using an LED light-curing unit at 1200 mW/cm2. Water sorption and solubility were evaluated over a 28-day period. For polymer cross-linking density, additional specimens were prepared and their Knoop hardness measured before and after immersion in 100% ethanol. The data from each test were evaluated using a two-way ANOVA and Tukey's test (α = 0.05).
Results: The XP Bond adhesive showed higher water sorption (similar to Adper Single Bond 2) and solubility (p < 0.05) than did the other materials. Prolonged exposure times did not reduce the water sorption but did reduce the solubility of all tested materials (p < 0.05). For Ambar, the increase in the exposure time resulted in a significantly lower percent reduction in hardness.
Conclusion: Water sorption, solubility, and cross-linking density of the materials selected in this study seem to be mainly influenced by the adhesive composition. Prolonged light exposure times reduced the solubility of the materials.
Keywords: adhesives systems, water sorption, solubility, polymerization time