Cyclic fatigue of sintered alloy and zirconia three units FPD frameworks supported by two dental implants
Date
2010
DOI
Authors
Nafash, Frederick
Version
OA Version
Citation
Abstract
Purpose: The objectives of this study were to investigate the effect of cyclic fatigue on the mechanical properties of three unit fixed partial denture frameworks made of sintered alloys or zirconia, to compare mechanical properties of a new version of a sintered alloy (Captek) to the older version, and to compare two zirconia systems for strength and effect of cyclic fatigue.
Material and Methods: This in-vitro study included four groups of implants supported fixed partial dentures, made from four different FPD framework materials/systems, including Original CAPTEK (PRECIOUS CHEMICALS LTD), CAPTEK NANO (PRECIOUS CHEMICALS LTD), LAVA zirconia (3M-ESPE), and CERCON zirconia (Dentsply). Four frameworks, of each of the studied materials, were loaded on the Instron machine, until catastrophic failure occurred. 40% of the breakage force (load bearing capacity) was calculated, to cyclic load the 9 remaining samples for 500,000 cycles. Frameworks then, were loaded on the Instron machine until the catastrophic failure occurred; in order to study the effect of fatigue on the restorative materials fabricating the frameworks.
Results: The obtained data were normalized for samples of all groups.
For Captek groups, One-way analysis of variance (ANOVA) was performed for Captek groups (P = 0.037) (table 27) Bonferroni multiple comparison post hoc test showed that there was significant difference between Captek (Original) and Captek Nano groups (p= 0.051) (table 28), before 500.000 fatigue cycles performed in dry environment.
For Zirconia groups, One-way analysis of variance (ANOVA) was performed for Zirconia groups(p = 0.003) (table 29). Bonferroni multiple comparison post hoc test showed that there was significant difference between Lava group after fatiguing for 500,000 cycles and the Cercon group after fatiguing for 500,000 cycles (p = 0.032) (table 30), when tests performed in dry environment. Relative modulus of elasticity was calculated for samples of all groups (table 13 → table 24).
For Captek groups, One-way analysis of variance (ANOVA) was performed for Captek groups (p = 0.001) (table 32). Bonferroni muptiple comparison post hoc test showed that there was significance difference between Captek (Original) group and Captek Nano group after fatiguing for 500,000 cycles (p= 0.001)(table 33), when tests performed in dry environment.
For Zirconia groups, One-way analysis of variance (ANOVA) was performed for Zirconia groups (p= 0.000) (table 34). Bonferroni multiple comparison post hoc test showed that there was significance difference between Lava group before fatiguing for 500,000 cycles and Lava group after fatiguing for 500,000 cycles (P = 0.036) (table 35). Also, Bonferroni multiple comparison post hoc test showed that there was significance difference between Lava group and Cercon group after fatiguing for 500,000 cycles (p = 0.014) (table 35).
Conclusion:
- Under static testing Captek Nano has a significantly higher yield-strength (approx. 30%) than Captek Original (P = 0.05).
- The overall effect of cyclic fatigue for the Captek groups was not significant (P = 0.37). However, there is significant difference (P = 0.032) in the cyclic fatigue effect between the two Captek groups.
- Captek Nano frameworks after cyclic fatigue are stiffer (p = 0.001) than Captek (Original) framewoks after cyclic fatigue.
- The overall effect of cyclic fatigue for both Zirconia groups is significant (P = 0.025). There was no difference (P = 0.906) in the effect of cyclic fatigue between the two zirconia groups.
- Although similar under static testing, after cyclic fatigue Cercon frameworks were significantly stronger than Lava frameworks (P=0.032).Lava frameworks after cycling were stiffer (P = 0.014) than Cercon frameworks after cyclic fatigue.
- By comparison, the effect of cyclic fatigue on sintered alloy frameworks was not significant (P = 0.37) while the zirconia frameworks were significantly affected (P=0.025).
Description
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Dissertation (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2010 (Department of Restorative Sciences and Biomaterials).
Includes bibliographic references: leaves 100-112.
Dissertation (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2010 (Department of Restorative Sciences and Biomaterials).
Includes bibliographic references: leaves 100-112.
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This work is protected by copyright. Downloading is restricted to the BU community. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.