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Dynamic Fatigue Behavior of Dental Porcelain Modified by Surface Deposition of a YSZ Thin Film
Author(s) -
Teixeira Erica C.,
Piascik Jeffrey R.,
Stoner Brian R.,
Thompson Jeffrey Y.
Publication year - 2008
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.2008.00340.x
Subject(s) - materials science , yttria stabilized zirconia , flexural strength , cubic zirconia , composite material , abrasive , dental porcelain , bending , ceramic
Abstract Purpose: The objective of this study was to evaluate the basic fatigue parameters of a dental porcelain modified by deposition of a yttria‐stabilized zirconia (YSZ) thin film and to compare the data to that of an unmodified control. Methods: Two hundred bars (2 × 2 × 15 mm 3 ) were cut from ProCAD blocks. Specimens were wet‐polished with 1200‐grit SiC abrasive. One surface of each bar was sandblasted with 50 μm Al 2 O 3 abrasive (50 psi). Half the specimens were further modified through deposition of a 3‐μm YSZ thin film on the sandblasted surface. Depositions were performed using an radio frequency magnetron sputter system (working pressure of 15 mT, 150°C, 30:1 Ar:O 2 gas ratio). Specimens were tested at different stressing rates: 5.0, 0.1, and 0.01 MPa/s (n = 25/group) in deionized water (37°C), and inert strength was determined in air (25°C, 70 MPa/s). All strength measurements were carried out by three‐point bending (span = 10 mm) in a servo‐electric test system. Results: The mean flexural strength values (MPa) and standard deviation for the uncoated sandblasted group were: 98.6 (5.5), 90.7 (5.9), and 84.2 (8.5), and for the sandblasted + YSZ thin film group: 125 (9.4), 119.3 (7.8), and 102.8 (7.0), for the highest to the lowest stressing rates, respectively. The fatigue parameters n and lnB were calculated by linear regression of dynamic fatigue data. For the uncoated group, n = 38 and lnB = 4.7 MPa 2 /s, and for the coated group, n = 33 and lnB = 10.8 MPa 2 /s. Weibull analysis was also performed showing that the characteristic parameter (σ o ) was 113.3 and 125.7 MPa for the uncoated and coated group, respectively. Conclusions: There was an increase in strength for specimens modified by application of a YSZ thin film. It is hypothesized that thin‐film application modifies flaws or residual surface stress states.