IADR Abstract Archives

Effect of LEDs on the micromechanical properties of a nanohybrid-composite

Objectives: To investigate the effects of different curing modes of two LEDs from two exposure distances on the micromechanical properties of a nanohybrid-composite.
Methods: Seventy-two composite (Kalore/GC) specimens with 2mm thickness (n=6) were cured with two high irradiance LEDs (Bluephase 20i/Ivoclar, FlashMax P3/CMS Dental) at 0 and 7 mm exposure distances. The curing conditions were; Grup a: Bluephase20i–10s–High power, Grup b: Bluephase20i–15s–High power, Grup c: Bluephase20i–5s–Turbo, Grup d: Bluephase20i–15s–Soft start, Grup e: FlashMaxP3–4mm tip–3s, Grup f: FlashMaxP3–without tip–3s. The transmitted light power and energy density were evaluated at specimens’ bottom in real time during curing with a radiometer (MARC Resin Calibrator). Vickers hardness(HV) and modulus of elasticity(E) were measured with an automatic universal hardness indenter(Fisherscope H100C) at specimens’ top and bottom surfaces after storing 24 hours in distilled water at 37°C. Effects of energy densities, exposure distances and surface conditions were analyzed using One-way ANOVA, Tukey and t tests(p=0.05).
Results: Different energy densities were observed for all groups in terms of distance and surface conditions. A decrease in intensity and energy density was formed when the exposure distance was removed from 0 to 7 mm in all groups. The highest HV(76.61±5.85N/mm2) and E(10.42±5.85GPa) values were observed in the Group b at 0 mm, whereas the lowest HV(49.41±13.11N/mm2) and E(6.63±1.87GPa) values were observed in the Group e at 7 mm at the top surfaces (p<0.05). Increasing the exposure distance significantly impaired the micromechanical properties of the top and bottom surfaces in the Group e(p<0.05).
Conclusions: The light intensities of LEDs were higher than the manufacturers’ report. Different light energy densities(0.01J/cm2-23.13J/cm2) and exposure distances(0-7mm) influenced the micromechanical properties of top and bottom surfaces of a nanohybrid-composite. The micromechanical properties of a nanohybrid-composite were more affected by the energy density than the light intensity.
Continental European and Scandinavian Divisions Meeting
2015 Continental European and Scandinavian Divisions Meeting (Antalya, Turkey)
Antalya, Turkey
2015
0381
Dental Materials 7: Polymer-based Materials-Physical Properties and Performance
  • Kutuk, Zeynep  ( University of Munich , Munich , Germany )
  • Gurgan, Sevil  ( University of Munich , Munich , Germany )
  • Hickel, Reinhard  ( University of Munich , Munich , Germany )
  • Ilie, Nicoleta  ( University of Munich , Munich , Germany )
  • none
    Oral Session
    Dental Materials: Composite, Properties - Repair
    Friday, 10/16/2015 , 01:30PM - 03:30PM