The effects of cyclic loading on the mechanical properties of the fiber reinforced provisional restorative materials :
Date
2015
DOI
Authors
Cokovska, Elizabeta
Version
OA Version
Citation
Abstract
Intro: The resin-impregnated glass-fibers have significant impact on flexural strength and flexural modulus of provisional restorative materials used in fixed prothodontics, according to many studies previously done. The current study examines the effect of cycling loading on mechanical properties of reinforced provisional restorative materials.
Objective: To evaluate the effect of resin-impregnated glass-fibers on flexural strength and flexural modulus of provisional restorative materials used in fixed prosthodontics.
Materials: Two self-curing provisional materials: PMMA (Coldpac, Yates Motloid) and Bis-acrylic (Protemp Plus, 3M) reinforced with light-curing unidirectional glass-fibers (Dentapreg) were tested.The custom metal molds were used to prepare specimens (3mmx3mmx24mm ) (n=5-10 /group): Coldpac (A); B. Coldpac with Dentapreg (A1) ; Protemp (B); Protemp with Dentapreg (B1). For the control group the provisional materials were applied into the mold, removed after the complete setting was done and polished. For the reinforced specimens the provisional material was applied into the lower l/3 of mold. A coating of bonding agent and 24mm fiber were placed and cured for 5 seconds by Bluphase16 i (Ivoclar). Another coating of adhesive was applied on the top of the fiber and the remaining 2/3 of the mold were filled with the provisional material and then cured for 40 seconds. All specimens were kept in water in incubator at 37 degree C for 48 hours prior to testing. Each group was futher divided in two subgroups (n=10/group) for three point bending test (Instron 5566A) and cyclic loading testing (cycles 20 K, 30 K, 40 K, and 50 K). Flexural strength and flexural modulus data were analyzed using SAS JMP11 software.
Results: The analysis of variance shows a statistically significant difference (P[less than]0.001) between the unreinforced and reinforced provisional materials. The flexural strength and flexural modulus were significantly increased in aIl fiber-reinforced groups. The cyclic loading have shown no significant difference in flexure strength and flexure modulus of Protemp Plus material, however the cyclic loading has significant impact on flexural strength of unreinforced Coldpac and flexural modulus of reinforced Coldpac.
Conclusion: within the limitations of this in vitro study, we can conclude that the resin preimpregnated unidirectional glass fiber Dentapreg have a significant effect in reinforcement of PMMA and Bis-acryl provisional restorative materials. This study is clinically relevant showing that fiber reinforcement may increase the strength and longevity of temporary fixed partial dentures.
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Thesis (MSD) --Boston University, Goldman School of Dental Medicine, 2015 (Department of Restorative Sciences and Biomaterials).
Includes bibliographic references: leaves 65-68.
Thesis (MSD) --Boston University, Goldman School of Dental Medicine, 2015 (Department of Restorative Sciences and Biomaterials).
Includes bibliographic references: leaves 65-68.
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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.