Light transmittance and micro-mechanical properties of bulk fill vs. conventional resin based composites
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The aim of this study was to quantify the blue light that passes through different incremental thicknesses of bulk fill in comparison to conventional resin-based composites (RBCs) and to relate it to the induced mechanical properties.
Materials and methods
Seven bulk fill, five nanohybrid and two flowable RBCs were analysed. Specimens (n = 5) of three incremental thicknesses (2, 4 and 6 mm) were cured from the top for 20 s, while at the bottom, a spectrometer monitored in real time the transmitted irradiance. Micro-mechanical properties (Vickers hardness, HV, and indentation modulus, E) were measured at the top and bottom after 24 h of storage in distilled water at 37 °C. Electron microscope images were taken for assessing the filler distribution and size.
Bulk fill RBCs (except SonicFill) were more translucent than conventional RBCs. Low-viscosity bulk fill materials showed the lowest mechanical properties. HV depends highly on the following parameters: material (ηp2 = 0.952), incremental thickness (0.826), filler volume (0.747), filler weight (0.746) and transmitted irradiance (0.491). The bottom-to-top HV ratio (HVbt) was higher than 80 % in all materials in 2- and 4-mm increments (except for Premise), whereas in 6-mm increments, this is valid only in four bulk fill materials (Venus Bulk Fill, SDR, x-tra fil, Tetric EvoCeram Bulk Fill).
The depth of cure is dependent on the RBC’s translucency. Low-viscosity bulk fill RBCs have lower mechanical properties than all other types of analysed materials. All bulk fill RBCs (except SonicFill) are more translucent for blue light than conventional RBCs.
Although bulk fill RBCs are generally more translucent, the practitioner has to follow the manufacturer’s recommendations on curing technique and maximum incremental thickness.
KeywordsBulk fill resin-based composites Micro-hardness Translucency Micro-mechanical properties Irradiance
- 3.Rueggeberg F (1999) Contemporary issues in photocuring. Compend Contin Educ Dent Suppl (Jamesburg, NJ: 1995) (25):S4–15; quiz S73.Google Scholar
- 7.Heraeus Kulzer (2013) Venus Bulk Fill DFU.http://venusbulkfill.com/media/webmedia_local/media/pdfs/VenusBulkFillDFU_English.pdf. Accessed 1 Oct 2012
- 8.Ivoclar Vivadent Pty. Ltd. (2013) Tetric EvoCeram Bulk Fill DFU. http://www.ivoclarvivadent.com/zoolu-website/media/document/11227/Tetric + EvoCeram + Bulk + Fill. Accessed 1 Oct 2012
- 9.VOVO GmbH (2013) x-tra fil DFU. http://www.voco.com/en/products/_products/x_tra_fil/x-tra_fil_22spr_049.pdf. Accessed 1 Oct 2012
- 10.VOVO GmbH (2013) x-tra base DFU. http://www.voco.com/en/products/_products/x-tra_base/GI_x-tra_base_22spr_0811.pdf. Accessed 1 Oct 2012
- 11.DENTSPLY Caulk (2013) SureFil SDR DFU. http://www.caulk.com/assets/pdfs/products/51C006_SureFilSDR_(1–24–12).pdf. Accessed 1 Oct 2012
- 12.3M ESPE Dental Products (2013) Filtek Bulk Fill DFU. http://multimedia.3m.com/mws/mediawebserver?mwsId = SSSSSufSevTsZxtUoYtUn8_GevUqevTSevTSevTSeSSSSSS–&fn = filtek_bf_ifu_na_en.pdf. Accessed 1 Oct 2012
- 13.Kerr Corporation (2011) SonicFill DFU. http://www.kerrdental.com/index/cms-filesystem-action?file=/kerrdental-products-dfu/2011_SonicFill_[NA].pdf. Accessed 1 Oct 2012
- 29.ISO (2013) Dentistry—polymer-based restorative materials. ISO 4049:2009Google Scholar
- 31.ISO (2013) Metallic materials—instrumented indentation test for hardness and materials parameters—part 1: test method. ISO 14577–1:2002Google Scholar