Yazar "Burrow, Michael F." seçeneğine göre listele

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    Comparison of the effect of storage media on shear punch strength of resin luting cements
    (Elsevier Sci Ltd, 2010) Bagheri, Rafat; Mese, Ayse; Burrow, Michael F.; Tyas, Martin J.
    Objectives: To measure the shear punch strength of eight resin-containing luting cements before and after immersion in acidic solution and ethanol at different temperatures (37 degrees C and 60 degrees C). Method: Specimens were prepared from six resin luting cements; Set (SDI), Panavia F (Kuraray), RelyX Veneer (3M/ESPE), Varioloinkll (Ivoclar), Maxcem (Kerr), Nexus2 (Kerr) and two Resin-modified glass-ionomer luting cements (RM-GICs); GC Fuji Plus (GC Corporation), RelyX Luting 2 (3 M/ESPE). For each material a total of 114 disc-shaped specimens were prepared. Six specimens were immersed in distilled water for 24h at 37 degrees C, polished and subjected to baseline measurement for shear punch strength. The remaining 108 specimens were randomly divided into 18 groups of six, and immersed in three solutions; distilled water, 0.01 mol/L lactic acid, and 50% ethanol at 37 degrees C or 60 degrees C, for 1 week, 1 month or 3 months. Specimens were washed, dried and tested for final shear punch strength. Results: Values were material and solution dependent. Values of Nexus 2 and Rely X Veneer are the highest, and Rely X Luting 2 the lowest. Ethanol and lactic acid specimens showed significantly lower values compared with the distilled water specimens. Conclusion: The shear punch strengths of the resin-containing luting cements were affected by time and storage solution. While some of the resin luting cements had significantly higher values compared to that of the RM-GICs, there were no significant differences between the RM-GICs and resin cements such as Panavia F and Set. (C) 2010 Elsevier Ltd. All rights reserved.
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    Fracture toughness of seven resin composites evaluated by three methods of mode I fracture toughness (KIc)
    (Japanese Soc Dental Materials Devices, 2016) Mese, Ayse; Palamara, Joseph E. A.; Bagheri, Rafat; Fani, Mehdi; Burrow, Michael F.
    This study compared the fracture toughness values of seven resin composites and analyzed the consistency of data values using three methods: compact tension, three point and four point bending for Mode I failure. Seven resin composites were selected: Estellite Sigma Quick, Esthet X HD, Filtek Supreme XTE, Heliomolar, Ice, Rok, and Vit-l-escence. For each material, 18 specimens (n=6 for each test) were prepared. Maximum load to failure was recorded using a universal testing machine and fracture toughness was calculated. There was a direct significant correlation among all tested methods. Rok showed the highest and Estelite the lowest K-Ic values. SEM of the fractured surface of compact tension method showed propagation of the cracks from stresses concentrating at the corner of the notch and the surface of the sample. Four-point test gave the largest range in K-Ic, and was a simple method to discriminate between the resin composite values of K-Ic.
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    Sorption and solubility of luting cements in different solutions
    (Japanese Soc Dental Materials Devices, 2008) Mese, Ayse; Burrow, Michael F.; Tyas, Martin J.
    This study examined the solubility, sorption, and dimensional change of eight luting cements in two different solutions: 50% ethanol:water and distilled water. Ten disk specimens were prepared of each material following the manufacturers' instructions, and then ground with silicone carbide paper. Sorption and solubility were calculated by weighing the specimens before and after immersion and desiccation. Data were analyzed by two-way ANOVA, Tukey's HSD and Fisher's PLSD tests. GC Fuji Plus and RelyX Luting2 showed the highest values of sorption and solubility both in water and ethanol:water. The percentage changes in volume for Maxcem, Nexus 2, Panavia F, RelyX Veneer, and VariolinkII were considerably smaller than for GC Fuji Plus, RelyX Luting2, and seT in both water and ethanol:water and after desiccation. Stability occurred within 2 weeks for all the eight materials when in water, while GC Fuji Plus, Maxcem, Panavia F and seT took 3 to 4 weeks to stabilize in ethanol:water.