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Title Marginal Accuracy Of Zirconia vs. Porcelain Fused To Metal
Clinical Question In a patient needing a restoration, does a milled zirconium crown have as accurate of a margin as a porcelain fused to metal crown?
Clinical Bottom Line In a patient needing a restoration, a milled zirconium crown does not offer as accurate of a marginal fit as a porcelain fused to metal crown, but, both were found to offer clinically acceptable marginal fits.
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 20875526Baig/2010Premolar dies prepared with champfers or shouldersLab Study
Key resultsThe author’s conclusions are as stated: “The overall mean (SD) marginal gap at the marginal opening for the crowns was 66.4 (42.2) μm for Cercon in office milled restoration, 36.6 (32.1) μm for IPS Empress II milled ceramic restoration, and 37.1 (22.3) μm for complete metal (control). Overall mean (SD) overhang was -15.2 (47.5) μm for Cercon, -22.1 (34.7) μm for IPS Empress II, and 30.9 (31.3) μm for complete metal (control). The ANOVA revealed significant effects by material and no significant effects by marginal configuration for marginal gap. There were significant differences in the marginal overhang values between the 2 margins, but no significant differences were found between the material groups for overhang. The Cercon milled in office system showed significantly larger (P<.05) marginal gaps than both the IPS Empress II and complete metal (control) crowns, but no significant differences were found in marginal overhang among the 3 material groups.”
#2) 21165185Pak/201020 Lava and 20 Digident Cad/Cam crownsLab Study
Key resultsThe author’s conclusions are as stated: “The means and standard deviations of the marginal fit were 61.52 +/- ; 2.88 μm for the Digident CAD/CAM zirconia ceramic crowns before porcelain veneering and 83.15 +/- ; 3.51 μm after porcelain veneering. Lava CAD/CAM zirconia ceramic crowns showed means and standard deviations of 62.22 +/- ; 1.78 μm before porcelain veneering and 82.03 +/- ; 1.85 μm after porcelain veneering. Both groups showed significant differences when analyzing the marginal gaps before and after porcelain veneering within each group. However, no significant differences were found when comparing the marginal gaps of each group before porcelain veneering and after porcelain veneering as well.”
#3) 19682215Holden/200930 restorations evaluated on typodontLab study
Key resultsThe author's conclusions are as stated: "The mean marginal opening was 72.2 +/- 5.9 micron for the Metal Ceramic Restorations, 49.0 +/- 5.9 micron for Pressed To Metal restoration, and 55.8 +/- 5.9 micron for Porcelain Ceramic Restoration. The post hoc tests showed that there was a statistical difference between the marginal adaptation of the PTM and MCR groups (p < 0.05). There was no significant difference in marginal adaptation between the PTM and the PCR groups, or the PCR and the MCR groups.The PTM group demonstrated a smaller mean marginal opening than the MCR group. The mean marginal openings of all three groups were within a clinically acceptable range."
Evidence Search Search porcelain fused to metal crown marginal fit Search dental zirconia marginal fit Search sirona cerec
Comments on
The Evidence
The studies included multiple lab studies in which similar standards were used. They each had a 100% completion rate.
Applicability These studies are very applicable to a wide range of dental specialties due to the importance of marginal fit and longevity of the crown.
Specialty/Discipline (Public Health) (General Dentistry) (Prosthodontics) (Restorative Dentistry)
Keywords Porcelain fused to metal crown, dental zirconia, marginal fit
ID# 831
Date of submission: 03/30/2011spacer
E-mail schaferb@livemail.uthscsa.edu
Author Brad Schafer
Co-author(s) e-mail
Faculty mentor/Co-author David Cox, DDS
Faculty mentor/Co-author e-mail CoxD@uthscsa.edu
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
post a rationale
None available
Comments on the CAT
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by Fawzi Hijazi, DDS, Dayo, Adeyinka Folashade, DDS (San Antonio, TX) on 11/16/2015
Current literature suggests that the marginal discrepancy value of the Zirconia-based crowns when compared to PFM crowns could be similar or even better. It is also worth mentioning that Zirconia based crowns are made using different manufacturing systems. Generally most systems provide a clinically acceptable marginal fit with variations among them. The current evidence does not allow for an accurate comparison between the various systems in terms of marginal fit and accuracy. The use of more advanced technology is recommended to precisely address the issue of crown marginal adaptation. PMID: 26340011 and 22946875.

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