Date of Degree
MS (Master of Science)
Steven R. Armstrong
Ethanol‐wet bonding (EW) has been proved to effectively infiltrate hydrophobic monomers into the demineralized hydrophilic dentin matrix and create a more degradation‐resistant network when bonding to normal dentin. Caries-affected dentin (CAD) has consistently demonstrated lower bond strength than normal dentin.
Objective: To evaluate effect of EW on resin-CAD bond strength.
Methods: Seventy five human molars with occlusal caries were randomly divided into water-wet (WW) and EW groups. CAD was obtained using the combined criteria of visual examination, surface hardness to an excavator and carbide bur and staining with 1% acid red in propylene glycol dye solution (Caries detector, Kuraray). For EW, the etched and water rinsed dentin was subsequently rinsed with absolute ethanol for 15s x3 before primer application. Four bonding agents, Bis-GMA/TEGDMA (ER2), Bis-GMA/HEMA (ER3), Bis-GMA/2-MP/HEMA (ER5), and Adper Scotchbond Multi Purpose (SBMP) were applied followed by resin-based composite (Heliomolar, Ivoclar Vivadent) incrementally built-up. Specimens (549) with a square cross-sectional area of approximately 0.7 mm2 were formed. Specimens (one day: 263; 6 month: 276) were subjected to micro-tensile bond test. Data were analyzed by one two-way and three-way ANOVA, two-sample t-test, and the parametric Weibull regression models.
Result: There was a significant difference in the mean microtensile bond strength between WW and EW substrate condition for ER2 (p=0.0443). The mean microtensile bond strength with EW was significantly greater.
Conclusion: Unlike prior research using normal dentin, EW bonding had significant effect only on 6 month bond strength to CAD for ER2.
Copyright 2009 Tipapat Attathom