Publications (2)2.48 Total impact
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Article: Bulk-fill Resin-based Composites: An In Vitro Assessment of Their Mechanical Performance.
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ABSTRACT: SUMMARY The study aimed to assess the mechanical performance of seven bulk-fill RBCs (Venus Bulk Fill, Heraeus Kulzer; SureFil SDR flow, Dentsply Caulk; x-tra base and x-tra fil, VOCO; Filtek Bulk Fill, 3M ESPE; SonicFill, Kerr; Tetric EvoCeram Bulk Fill, Ivoclar Vivadent) by determining their flexural strength (σ), reliability (Weibull parameter, m), flexural modulus (Eflexural), indentation modulus (YHU), Vickers hardness (HV), and creep (Cr). The significant highest flexural strengths were measured for SonicFill, x-tra base, and x-tra fil, while x-tra base, SureFil SDR flow, and Venus Bulk Fill showed the best reliability. The differences among the materials became more evident in terms of Eflexural and YHU, with x-tra fil achieving the highest values, while Filtek Bulk Fill and Venus Bulk Fill achieved the lowest. The enlarged depth of cure in bulk-fill RBCs seems to have been realized by enhancing the materials' translucency through decreasing the filler amount and increasing the filler size. The manufacturer's recommendation to finish a bulk-fill RBC restoration by adding a capping layer made of regular RBCs is an imperative necessity, since the modulus of elasticity and hardness of certain materials (SureFil SDR flow, Venus Bulk Fill, and Filtek Bulk Fill) were considerably below the mean values measured in regular nanohybrid and microhybrid RBCs. The class of bulk-fill RBCs revealed similar flexural strength values as the class of nanohybrid and microhybrid RBCs, and significantly higher values when compared to flowable RBCs. The modulus of elasticity (Eflexural), the indentation modulus (YHU), and the Vickers hardness (HV) classify the bulk-fill RBCs as between the hybrid RBCs and the flowable RBCs; in terms of creep, bulk-fill and the flowable RBCs perform similarly, both showing a significantly lower creep resistance when compared to the nanohybrid and microhybrid RBCs.Operative Dentistry 04/2013; · 1.24 Impact Factor -
Article: Resin-based Composite Light-cured Properties Assessed by Laboratory Standards and Simulated Clinical Conditions.
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ABSTRACT: SUMMARY The following parameters were varied: 1) irradiation technique: top and bottom polymerization according to the ISO standard, and polymerization from only the top, simulating clinical situations; 2) polymerization time: 5, 10, 20, and 40 seconds; 3) storage conditions: 24 hours in distilled water, thermocycling followed by storage for four weeks in artificial saliva or alcohol. Flexural strength (FS), flexural modulus (E(flexural)), indentation modulus (E), Vickers hardness (HV), and degree of conversion (DC) were measured. The laboratory results were similar to those measured by mimicking clinical conditions only at high polymerization times and mild storage conditions (20 seconds and 40 seconds and storage for 24 hours in water, and 40 seconds with aging and storing in saliva). Significantly higher DC values were measured on the top than on the bottom of a 2-mm layer for all polymerization times. Overall, 5-second and 10-second irradiation times induced significantly lower DC values compared to the currently recommended polymerization times of 20 and 40 seconds at both the top and bottom of the samples. The initial DC differences as a function of irradiation time are leveled at 24 hours of storage but seem to do well in predicting long-term material behavior. A minimum irradiation time of 20 seconds is necessary clinically to achieve the best mechanical properties with modern high-intensity light emitting diode (LED) units.Operative Dentistry 07/2012; · 1.24 Impact Factor
