title: Microleakage of composite resin and amalgam core material under complete cast crowns.
abstract: Ninety extracted human teeth were used to compare the microleakage of composite resin over, amalgam core, and regular crown preparations under a complete cast gold crown cemented with zinc phosphate cement as determined by 2% fluorescein dye solution. Specimens were compared with and without aging after cementation in a thermal bath by cycling some of them between 4 degrees C and 60 degrees C in a 2% fluorescein dye bath and others in a similar bath held at 37 degrees C. Fluorescein dye (under ultraviolet light) demonstrated microleakage of the specimens between the crown-tooth interface and the core-tooth interface. There were no significant differences in the microleakage due to aging. The specimens held at 37 degrees C in the fluorescein dye bath showed no significant differences between the core preparations and the regular crown preparations. However, when specimens were thermally cycled between 4 degrees C and 60 degrees C, there were significant differences. With thermal cycling, the regular crown preparations were better able to resist microleakage at the crown-tooth interface than either the composite resin core or the amalgam core preparations. The results of this investigation seem to indicate a need for further evaluation of core build-ups under cemented complete gold crowns.
mesh_terms: D003188:Composite Resins; D003442:Crowns; D003723:Dental Amalgam; D001840:Dental Bonding; D003737:Dental Cavity Preparation; D003779:Denture Design; D005452:Fluoresceins; D006047:Gold Alloys; D006801:Humans; D011176:Post and Core Technique; D013499:Surface Properties; D013696:Temperature; D015036:Zinc Phosphate Cement
chemical_list: D003188:Composite Resins; D005452:Fluoresceins; D006047:Gold Alloys; D015036:Zinc Phosphate Cement; D003723:Dental Amalgam