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Stresses within porcelain veneers and the composite lute using different preparation designs
Author(s) -
Seymour Kevin G.,
Cherukara George P.,
Samarawickrama Dayananda Y.D.
Publication year - 2001
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.2001.00016.x
Subject(s) - chamfer (geometry) , ultimate tensile strength , materials science , veneer , composite number , compressive strength , bevel , composite material , enhanced data rates for gsm evolution , orthodontics , structural engineering , computer science , mathematics , medicine , engineering , geometry , telecommunications
Purpose The purpose of this study was to investigate compressive and tensile stresses in porcelain and composite at the labial marginal region of porcelain veneer restorations using chamfer, shoulder, or knife‐edge labial margin designs with labial window or incisal overlap incisal preparation designs. Methods Porcelain veneer models were constructed and loaded with (1) a 200‐N, 45° palatal load to simulate functional loading, and (2) a horizontal labial loading of 200 N to mimic trauma. Maximum tensile and compressive stresses were recorded within the labial marginal region of both porcelain and composite lute. Results Under the 45° palatal load, stresses within the palatal marginal porcelain were chiefly compressive, and stresses for the knife‐edge designs as much as 42% less than for shoulder designs. Incisal overlap preparations were generally associated with less compressive stress within both porcelain and composite than the window preparation. When a labial load was applied, tensile stresses were as much as 25 times greater for the chamfer and shoulder designs compared with the knife‐edge design. Labial loading also resulted in an increase in tensile stresses within the composite lute, and stresses were again lowest within the knife‐edge margin design. Conclusions Under the limitations of this study, using the incisal overlap preparation, porcelain veneers with knife‐edge labial margins could better sustain occlusal loading without fracture.