| 摘要 |
There are several techniques that are recommended for removal of cement after cementation of castings, veneers, and all ceramic units. With the introduction of resin and resin ionomer cements and their inherent hardness after setting, removal of excess cement has become more difficult. To determine by means of an in vitro study whether the marginal integrity and seal of indirectly fabricated restorations cemented with a resin-based cement are affected by the technique of cement removal. Materials & Methods. Chamfer preparations were made on extracted human teeth. Impressions of the preparations were pour in die stone and wax patterns were fabricated and cast in gold using conventional laboratory techniques. A resin cement was used for cementation and 5 techniques (three castings per technique) were employed for removal of excess cement. After cementation the samples were immersed in methylene blue dye solution for 24 hours and sectioned. Dye leakage scores were determined with light microscopy and the sections further examined with a Field Emission Scanning Electron Microscope. Results: The group in which excess cement was removed with a pointed sable hair brush and, which had the margins finished with a brush dipped in a dentin bonding agent (brushed to contour), not only demonstrated the lowest leakage scores, but also had the most favorable contour of cement at the maternal interface. Clinical significance: The technique of cement removal when using resin based elements has an effect on the quality of the cement adaptation at the marginal interface.
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