| 3239 Dentin proteoglycans within the hybrid layer | ||
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L. BRESCHI1, P.S. SUPPA2, S. CHERSONI3, F. TAY4, D.H. PASHLEY5, and C. PRATI2, 1University of Trieste, Bologna, Italy, 2University of Bologna, Italy, 3School of Dentistry, University of Bologna, Italy, 4University of Hong Kong, China, 5Medical College of Georgia, Augusta, USA Dentin proteoglycans are fundamental constituents of the dentin organic matrix stabilizing the collagen fibrils network. Objectives:The aim of this study was to evaluate the proteoglycans distribution within the hybrid layer created by different adhesive systems under high resolution SEM. Methods: Human dentin disks obtained by recently extracted molars were prepared with a low speed diamond saw and treated with: (1) Single Bond, (2) Clearfil SE Bond, (3) Xeno III. Adhesive systems were applied as per manufactures' instructions followed by a 1 mm thick layer of composite resin that was light-cured. The adhesive surface and hybrid layers were exposed by cross-sectioning the bonded disks with a slow-speed diamond saw. The interfaces were submitted to immunohistochemical analysis using primary monoclonal anti- chondroitin-4 and 6-sulfate antibody and a secondary antibody conjugated with 15 nm colloidal gold particles. After fixation and dehydrated in ascending ethanol, specimens were mounted on SEM stubs. Observations were carried out under a high resolution SEM (JEOL 890). Results: The SEM analysis revealed the proteoglycans distribution within the HL: intense labeling of the peritubular dentin areas were clearly observable. Proteoglycans appeared both as fibrous and globular structures associated with collagen fibrils. Areas of close relationships between proteoglycans and adhesive agent were also found. Conclusions: Due to the high affinity of proteoglycans for water, chondroitin sulfate associated to collagen fibrils can be considered water reservoirs of the dentin matrix. The identification and selective distribution of proteoglycans within the hybrid layer may influence adhesive interfaces. How much this bound water contributes to water movement within adhesive interfaces remains to be determined. Supported, in part, by NIDCR DE014911. | ||
| Seq #344 - Prosthodontic Polymers 10:15 AM-11:30 AM, Saturday, 13 March 2004 Hawaii Convention Center Exhibit Hall 1-2 | ||
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Back to the Dental Materials: VI - Polymer Materials-Mechanical Properties and Degradation Program
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