| 0588 Micro-Raman Spectroscopy of Resin Penetration into Caries-affected Dentin | ||
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M. MIYAZAKI1, J. HIGAKI1, K. IWASAKI1, H. ONOSE1, and B.K. MOORE2, 1 Nihon University School of Dentistry, Tokyo, Japan, 2 Indiana University School of Dentistry, Indianapolis, USA Objectives: The purpose of this study was to investigate the pattern of resin penetration into caries affected dentin using a micro-Raman spectroscopic system (System 2000, Renishaw). Methods: Mac Bond II (Tokuyama Dental) and Single Bond (3M ESPE) were employed. Extracted human molars with coronal carious lesions were used in this study. Caries affected dentin was obtained using the combined criteria of visual inspection and staining with a caries detector solution. Sound dentin without staining the solution was obtained as a control. Resin composites were bonded to caries affected dentin and sound dentin with the two-step bonding systems. After 24 h storage in water, specimens were sectioned through the bonded interface, then polished with diamond pastes down to 1.0 mm particle size. Raman spectra were successively recorded along a line perpendicular to the dentin/resin interface with a He-Ne laser of a focal size of 0.6 mm. Raman spectra were successively recorded along a line perpendicular to the dentin-adhesive interface in steps of 0.2 mm on a computer controlled X-Y stage. The relative amounts of hydroxyapatite (960 cm-1), adhesive resin (640 cm-1), and organic substrate (1450 cm-1), in the dentin-adhesive bonding area were calculated. Results: The Raman spectra scanned across the resin-dentin interface of sound and caries-affected dentin showed transitional changes in the hydroxyapatite and resin components, indicating that the minerals removed by the acids were gradually replaced by resin. Evidence of poor saturation of the adhesive resin in the deepest portion of demineralized dentin was more pronounced for the caries affected dentin compared to those of sound dentin. Conclusions: From the results of this study, a gradient in resin infiltration into the demineralized dentin was detected and the resin infiltration of sound dentin was more evident than that of caries-affected dentin. Supported by Nihon University Individual Research Grant for 2002, #02-111. | ||
| Seq #82 - Adhesive Interface Microstructure 3:45 PM-5:00 PM, Thursday, 13 March 2003 Henry B. Gonzalez Convention Center Exhibit Hall C | ||
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