title: Effects of an internal escape channel on a castable ceramic crown.
abstract: This study evaluated the adaptation and strength of Dicor castable ceramic crowns cemented using an internal escape channel on the axial wall of the preparation. Twenty-eight crown wax patterns were made on 14 machined brass dies. The adaptation of the crowns was evaluated by measuring the combined height of the die and crown. The results revealed a significant difference in the mean and standard deviation of 16 +/- 13 micron in the experimental group and 85 +/- 31 microns in the control group. The differences between the force to fracture of 2155 +/- 1188 N and 1040 +/- 658 N, respectively, was also significant. The findings suggested that having an internal escape channel during cementation significantly improved the fit and strength of Dicor castable ceramic crowns. This technique would be particularly beneficial for cementation of posterior castable ceramics.
authors.affiliation: Prosthodontic Department, National Naval Dental Center, Naval Dental School, Bethesda, Md.
authors.forename: K M
authors.initials: KM
authors.lastname: Harrison
authors.forename: E J
authors.initials: EJ
authors.lastname: Billy
authors.forename: G B
authors.initials: GB
authors.lastname: Pelleu
mesh_terms: D002484:Cementation / Q000379:methods; D002516:Ceramics / Q000737:chemistry; D003442:Crowns; D003776:Dental Porcelain / Q000737:chemistry; D003799:Dental Stress Analysis; D003779:Denture Design / Q000295:instrumentation; D005069:Evaluation Studies as Topic; D006874:Hydrostatic Pressure; D013314:Stress, Mechanical; D013499:Surface Properties; D015036:Zinc Phosphate Cement
chemical_list: C047475:Dicor ceramic; D003776:Dental Porcelain; D015036:Zinc Phosphate Cement