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Precision of Fit of Two Margin Designs for Metal‐Ceramic Crowns
Author(s) -
Limkangwalmongkol Penwadee,
Chiche Gerard J.,
Blatz Markus B.
Publication year - 2007
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/j.1532-849x.2007.00186.x
Subject(s) - margin (machine learning) , crown (dentistry) , gingival margin , enhanced data rates for gsm evolution , materials science , premolar , dentistry , butt joint , ceramic , dental porcelain , composite material , medicine , engineering , molar , metallurgy , computer science , telecommunications , machine learning
Statement of Problem : Although metal‐ceramic restorations are widely used, there is a lack of information about how the fit is affected by margin designs.Purpose : This study measured and compared the precision of fit of metal‐ceramic crowns with two margin designs.Material and Methods : Thirty‐two extracted human premolar teeth were prepared for complete‐coverage restorations with an internally rounded shoulder preparation. Impressions were made from all teeth, and master dies were poured with improved stone type V. MC crowns were fabricated with a porcelain‐butt margin on the buccal aspect (n = 32) and a feather‐edge metal margin on the lingual aspect (n = 32), which served as a control group. Precision of fit was measured three times at the mid‐buccal and mid‐lingual margins of each crown with a profilometer. The data were statistically analyzed with the paired t ‐test (α < .05).Results : Mean marginal gap size of porcelain‐butt margins was 27.93 μm (±15.84) and of feather‐edge metal margins 42.43 μm (±24.12). The marginal gap size of feather‐edge metal margins was statistically significantly greater than that of porcelain‐butt margins (p = 0.0045).Conclusion : The marginal fit of porcelain‐butt margins was significantly better than that of feather‐edge metal margins.Clinical Implications: Porcelain‐butt margins in this study had a better marginal fit than feather‐edge metal margins, and thus have given clinicians evidence to prefer the use of porcelain‐butt margins.