Statement of problem
The marginal adaptation of metal ceramic crowns is affected by firing cycles for veneering porcelain application. The effect of multiple firings on the marginal integrity of pressable ceramic core crowns is unknown.
The purpose of this in vitro study was to evaluate the effect of repeated firing cycles on the marginal discrepancy of veneered (layered) pressable ceramic anterior crowns with 2 different finish line configurations.
Material and Methods
Forty pressable ceramic single anterior complete crowns were fabricated from 2 systems (IPS Empress Esthetic and IPS e.max Press) with 2 finish line designs (shoulder, chamfer) on epoxy resin dies. Specimens were divided into 4 groups of 10, and measurements were made after pressing (control) and after 5 veneer firing stages: 1) wash, 2) first incisal, 3) second incisal, 4) characterization and glazing, and 5) corrective. The change in vertical marginal discrepancy was measured with a light microscope at 4 locations: facial (F), mesial (M), lingual (L), and distal (D) surfaces. One-way ANOVA (α-=.05) was used to evaluate the marginal change. A Student-Newman-Keuls test was also used for comparison among the groups.
There were no significant changes in the vertical marginal integrity related to ceramic type and marginal location and their interactions. However, there was a significant marginal integrity change during the characterization and glazing firing stage. (P<.05)
The marginal gap increased for both systems during veneer application and decreased during the characterization and glazing firing cycle. The total marginal fit change after 5 firings was 0.33 μm for IPS e.max Press, and 0.27 μm for IPS Empress Esthetic.
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Journal of Prosthetic Dentistry
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- Current ceramic materials and systems with clinical recommendations: A systematic review.J Prosthet Dent. 2007; 98: 389-404
- The effect of cement thickness on the fracture strength of all-ceramic crowns.Aust Dent J. 1995; 40: 17-21
- Marginal fit changes during porcelain firing cycles.J Prosthet Dent. 1995; 73: 49-54
- Thermal cycling distortion of metal ceramics: part I–metal collar width.J Prosthet Dent. 1992; 67: 603-608
- Distortion related to margin design in porcelain-fused-to-metal restorations.J Prosthet Dent. 1980; 43: 149-155
- Evaluation of the marginal integrity of ceramometal restorations: part I.J Prosthet Dent. 1981; 46: 59-65
- Marginal distortion of the porcelain-bonded-to-metal complete crown: an SEM study.J Prosthet Dent. 1982; 47: 146-153
- The effect of repeated firings and strength on marginal distortion in two ceramometal systems.J Prosthet Dent. 1981; 45: 502-506
- The effect of repeated firings on the margins of nonprecious ceramometals.J Prosthet Dent. 1984; 51: 628-630
- Distortion of ceramometal fixed partial dentures during the firing cycle.J Prosthet Dent. 1981; 45: 507-514
- Influence of firing cycles on the margin distortion of 3 all-ceramic crown systems.J Prosthet Dent. 2005; 93: 346-355
- Influence of porcelain-firing procedures on the marginal distortion of electroformed metal-ceramic restorations.Quintessence Int. 2007; 38: E583-E588
- Biaxial flexural strength, elastic moduli, and x-ray diffraction characterization if three pressable all-ceramic materials.J Prosthet Dent. 2003; 89: 374-380
- Comparison of two heat-pressed all-ceramic dental materials.Dent Mater. 2000; 16: 389-395
- Marginal fit of leucite-glass pressable ceramic restorations and ceramic-pressed-to-metal restorations.J Prosthet Dent. 2005; 93: 143-147
- Heat-pressed ceramics: technology and strength.Int J Prosthodont. 1992; 5: 9-16
- Leucite crystallization during processing of a heat-pressed dental ceramic.Int J Prosthodont. 1996; 9: 261-265
- The effect of ceramic thickness and number of firings on the color of ceramic systems: An in vitro study.J Prosthet Dent. 2007; 97: 25-31
Supported by a 2008 Stanley D. Tylman Research Grant and the Baylor College of Dentistry Research Fund. First place award winner 2010 Tylman Award Program.
© 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.