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dc.contributor.authorNafash, Fredericken_US
dc.date.accessioned2020-03-04T16:43:25Z
dc.date.available2020-03-04T16:43:25Z
dc.date.issued2010
dc.date.submitted2010
dc.identifier.other(OCoLC)752597014
dc.identifier.other(OCoLC)752597014
dc.identifier.otherb36998916
dc.identifier.urihttps://hdl.handle.net/2144/39688
dc.descriptionPLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.en_US
dc.descriptionDissertation (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2010 (Department of Restorative Sciences and Biomaterials).en_US
dc.descriptionIncludes bibliographic references: leaves 100-112.en_US
dc.description.abstractPurpose: 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).en_US
dc.language.isoen_US
dc.publisherBoston Universityen_US
dc.rightsThis 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.en_US
dc.subjectDental implantsen_US
dc.subjectDental materialsen_US
dc.titleCyclic fatigue of sintered alloy and zirconia three units FPD frameworks supported by two dental implantsen_US
dc.typeThesis/Dissertationen_US
etd.degree.nameMaster of Science in Dentistryen_US
etd.degree.levelmastersen_US
etd.degree.disciplineRestorative Sciences and Biomaterialsen_US
etd.degree.grantorBoston Universityen_US


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