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.
Purpose
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.
Results
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)
Conclusions
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 accessOne-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 DentistryAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- 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
Article info
Footnotes
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.
Identification
Copyright
© 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.
