Quantitative micro-Raman assessment of dentine demineralization, adhesive penetration, and degree of conversion of three dentine bonding systems.
Unreacted monomers in adhesive systems may cause a reduction in material properties, an increase in the long-term instability of the restoration, and pulpal irritation. The degree of dentine demineralization, adhesive penetration, and the degree of conversion (DC) across the dentine-adhesive interface of self-etch adhesives were measured using micro-Raman spectroscopy. Two-step, self-etch AdheSE, one-step self-etch AdheSE One, and etch-and-rinse Excite (control) (Ivoclar Vivadent AG, Schaan, Liechtenstein) were studied. Nine human molars were allocated to three groups and a flat dentine surface was prepared. A smear layer was produced by grinding dentine with 600-grit silicone-carbide discs under water. After application and polymerization of the adhesive, teeth were sectioned to produce four 1-mm-thick slices per tooth for micro-Raman spectroscopy. There were statistically significant differences in the depth of dentine demineralization between all adhesives. The depth and degree of demineralization decreased in the order: Excite>AdheSE>AdheSE One. The mean +/- standard deviation (SD) values for DC within the adhesive layer were 85.2 +/- 2.9% (Excite), 81.4 +/- 4.2% (AdheSE), and 54.3 +/- 10.1% (AdheSE One), and within the hybrid layer were 55.2 +/- 22.5% (Excite), 65.1 +/- 16.9% (AdheSE), and 42.0 +/- 16.2% (AdheSE One). All systems showed a discrepancy between dentine demineralization and adhesive penetration. A significant amount of unreacted monomers were associated with all systems but particularly with the etch-and-rinse system.
Santini
Ario
A
Postgraduate Dental Institute, University of Edinburgh, Edinburgh, UK. ariosantini@hotmail.com
Miletic
Vesna
V
D000180:Acrylic Resins; D000704:Analysis of Variance; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D003804:Dentin; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents; D006801:Humans; D008689:Methacrylates; D044367:Phase Transition; D019279:Resin Cements; D016369:Smear Layer; D013059:Spectrum Analysis, Raman / Q000379:methods; D018709:Statistics, Nonparametric
D000180:Acrylic Resins; C489662:AdheSE cement; D017220:Dentin-Bonding Agents; C420130:Excite cement; D008689:Methacrylates; D019279:Resin Cements