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The purpose of this study was to confirm the formation of hybrid layer and resin tags in dentin tissue and the possibility of bonding between luting cements used for the prosthesis and the resinous surface coated with resin bonding agents to prevent the dentin hypersensitivity after abutment preparation. Some resin bonding agents, which may have the possibility of bonding with polyacrylic acid as a liquid ingredient of polycarboxylate and glass ionmer coments, were selected. All-Bond desenstizer containing NTG-GMA and BPDM, Scotch-Bond Multipurpose plus containing HEMA, and XR-bond cotaining organophosphate were selected as a coating agent. Dental cements were zinc phosphate, polycarboxylate, and glass ionomer cement. After the exposed dentin surface of premolars was ethced with 10% phosphoric acic and coated with resin bonding agents, the monophology of treated surfaces and the resin tags and hybrid layers on sectioned surfaces were observed by SEM. Shear bond strength between the resin bonding agents and 3 kinds of cements was measured 24 hours after bonding. On the debonded surfaces of the shear bond strength tested specimens, the cement tags and the bonding sites between the resin materials and cements were examined by SEM. Following conclusions were drawn : 1. Coating of dentin with resin bonding agents had no effect on the shear bond strength of zinc phosphate cement. 2. Both of polycarboxylate and glass ionomer cements showed the increased shear bond strength by the dentinal coating with Scotch-Bond Multipurpose plus containing HEMA. However, in the case of dentinal coating with some agents containing NTG-GMA and BPDM or organophosphate, polycarboxylate cement exhibited the lowered shear bond strength, and glass ionomer cement showed the unchanged shear bond strength. 3. Complete obstructions of dentinal tubules were observed on the dentin coasted with All-Bond desensitizer or XR-bond, but distinct shape of the orifices of dentinal tubules was observed consistently on the dentin coated with Scotch-Bond Multipurpose plus 4. The hybrid layer was thickest on the dentin coated with All-Bond desensitizer, and the length of resin tags was longest one the dentin coated with Scotch-Bond Multipurpose plus. 5. On the debonded specimens which had been bonded with polycarboxylate cement or glass ionomer cement after coating with Scotch-Bond Multipurpose plus, the cement tags and the bonding sites between the resinous surface and the cements could be examined.
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