Investigating the limits of resin-based luting composite photopolymerization through various thicknesses of indirect restorative materials |
| |
Authors: | CMF Hardy S Bebelman G Leloup MA Hadis WM Palin JG Leprince |
| |
Institution: | 1. School of Dental Medicine and Stomatology, at Cliniques Universitaires Saint-Luc, Universite catholique de Louvain, Belgium;2. Advanced Drug Delivery and Biomaterials (ADDB), Louvain Drug Research Institute (LDRI), Université catholique de Louvain, Brussels, Belgium;3. Bio- and Soft- Matter (BSMA), Institute of Condensed Matter and Nanoscience (IMCN), Université catholique de Louvain, Louvain-la-Neuve, Belgium;4. CRIBIO (Center for Research and Engineering on Biomaterials), Brussels, Belgium;5. Biomaterials Unit, University of Birmingham, College of Medical and Dental Sciences, Institute of Clinical Sciences, School of Dentistry, 5 Mill Pool Way, Birmingham B5 7EG, UK |
| |
Abstract: | ObjectiveTo determine the limitations of using light-curable resin-based luting composites (RBLCs) to bond indirect ceramic/resin-composite restorations by measuring light transmittance through indirect restorative materials and the resulting degree of conversion (DC) of the luting-composites placed underneath.MethodsVarious thicknesses (0–4 mm) and shades of LAVA Zirconia and LAVA Ultimate were prepared and used as light curing filters. A commercial, light curable RBLC, RelyX Veneer (control) was compared with four experimental RBLCs of the following composition: TEGDMA/BisGMA (50/50 or 30/70 wt%, respectively); camphorquinone/amine (0.2/0.8 wt%) or Lucirin-TPO (0.42 wt%); microfillers (55 wt%) and nanofillers (10 wt%). RBLCs covered with the LAVA filter were light-cured for 40 s, either with the dual-peak BluephaseG2 or an experimental device emitting either in the blue or violet visible band. The samples were analyzed by Raman spectroscopy to determine DC. Light transmittance through the filters was measured using a common spectroscopy technique.ResultsAll the factors studied significantly influenced DC (p < 0.05). RBLCs with increased TEGDMA content exhibited higher DC. Only small differences were observed comparing DC without filters and filters ≤1 mm (p > 0.05). For thicknesses ≥2 mm, significant reductions in DC were observed (p < 0.05). Transmittance values revealed higher filter absorption at 400 nm than 470 nm. A minimal threshold of irradiance measured through the filters that maintained optimal DC following 40 s irradiation was identified for each RBLC formulation, and ranged between 250–500 mW/cm2.SignificanceThis work confirmed that optimal photopolymerization of RBLCs through indirect restorative materials (≤4 mm) and irradiation time of 40 s is possible, but only in some specific conditions. The determination of such conditions is likely to be key to clinical success, and all the factors need to be optimized accordingly. |
| |
Keywords: | Degree of cure Degree of conversion Light transmittance Light transmission Polymerisation kinetics Resin based luting composite Indirect restorative materials Lucirin-TPO Irradiation time Camphorquinone |
本文献已被 ScienceDirect 等数据库收录! |
|