Degree of conversion of dual-cure luting resins light-polymerized through various materials.
OBJECTIVE
The aim of this study was to investigate the degree of monomer conversion of four dual-cure luting resins irradiated through various restorative materials or dentin.


METHODS
RelyX ARC (3M-ESPE), RelyX Unicem (3M-ESPE), Variolink 2 (Ivoclar,Vivadent), and Panavia F 2.0 (Kuraray) were mixed in accordance with the manufacturer's instructions. They were placed under the disks (thickness 1.5 mm) representing a metal restoration, a composite restoration (Sinfony D A3), a fiber-reinforced composite (EverStick 0.5 mm + 1.0 mm Sinfony D A3) restoration, and dentin. Five specimens (thickness 0.6 mm) in each group were irradiated through the disks for 40 s (Optilux-501, 800 mW/cm(2)). Light polymerization of the dual-cure luting resin without the covering disk was used as control. The degree of monomer conversion (DC%) was determined by Fourier transform infrared spectroscopy (FT-IR)/ATR spectrometry from the bottom of the resin. The infrared spectra were recorded at every 5.2 s for 15 min beginning from the mixing of the resin.


RESULTS
ANOVA revealed significant differences in DC% between the luting resins tested (p<0.001) and the different restorations (p<0.001). RelyX ARC showed the highest degree of conversion 15 min after the start of polymerization, whereas Panavia F 2.0 and RelyX Unicem showed the lowest.


CONCLUSIONS
The degree of conversion of dual-cured luting resins differed significantly. Furthermore, the restorative material significantly influenced the DC% of the dual-cure luting resin underneath.
Tezvergil-Mutluay
Arzu
A
Department of Prosthetic Dentistry and Biomaterials Science, Institute of Dentistry, University of Turku, Finland. arzu.tezvergil@utu.fi
Lassila
Lippo V J
LV
Vallittu
Pekka K
PK
D000180:Acrylic Resins / Q000737:chemistry* / Q000528:radiation effects; D000465:Algorithms; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D003738:Dental Cements / Q000737:chemistry* / Q000528:radiation effects; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects; D003793:Dental Restoration, Permanent / Q000379:methods; D003804:Dentin / Q000737:chemistry; D007700:Kinetics; D008422:Materials Testing / Q000379:methods; D011140:Polyurethanes / Q000737:chemistry* / Q000528:radiation effects
D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; D011140:Polyurethanes