Please cite this article in press as: Munhoz T, et al. Effect of nanoclay addition on physical, chemical, optical and biological properties of experimental dental resin composites. Dent Mater (2016), http://dx.doi.org/10.1016/j.dental.2016.11.016 ARTICLE IN PRESS DENTAL-2882; No. of Pages 9 d e n t a l m a t e r i a l s x x x ( 2 0 1 6 ) xxx–xxx Available online at www.sciencedirect.com ScienceDirect jo ur nal home p ag e: www.intl.elsevierhealth.com/journals/dema Effect of nanoclay addition on physical, chemical, optical and biological properties of experimental dental resin composites Tais Munhoz a,∗ , Yann Fredholm b , Pascaline Rivory c , Sandra Balvay c , Daniel Hartmann c , Pedro da Silva d , Jean-Marc Chenal a a INSA de Lyon, Laboratory MATEIS, UMR CNRS 5510, Bâtiment Blaise Pascal, 7 Avenue Jean Capelle, 69621 Villeurbanne, France b Noraker, 13 Avenue Albert Einstein, 69100 Villeurbanne, France c Université de Lyon, Laboratory MATEIS, UMR CNRS 5510, ISPB Faculté de Pharmacie, 7 rue Guillaume Paradin, 69372 Lyon, France d INSA de Lyon/INRA, Laboratory BF2I, UMR203, Bâtiment Louis Pasteur, 20 Avenue Albert Einstein, 69621 Villeurbanne, France a r t i c l e i n f o Article history: Received 22 May 2016 Received in revised form 23 November 2016 Accepted 30 November 2016 Available online xxx Keywords: Dental material Resin composite Montmorillonite clay Nanoclay Nano composite Dynamic mechanical analysis Vickers hardness Water sorption HPLC Biocompatibility a b s t r a c t Objective. To prepare organically modified montmorillonite (OM MMT) and assess mechani- cal, physical, chemical and biological effects of its introduction into resin-composites. Methods. Natural MMT clay was modified by a methacrylate functionalized quaternary ammonium intercalating agent. Interlayer distance was measured by X-ray diffraction. Den- tal composites were then prepared with x = 0, 1, 2.5, 5 or 7.5 wt.% of OM MMT, (75 − x) wt.% of silanated barium glass and 25 wt.% of methacrylate based matrix). Relative weight loss was measured and the effect of the substitution on mechanical properties was studied by dynamic mechanical analysis and hardness tests. Properties of resin composites were evaluated in terms of water sorption, light transmittance, biological tests and by high- performance liquid chromatography (HPLC). Results. Resin based composites with well-dispersed organically modified MMT were suc- cessfully prepared. There were no significant weight loss differences shown by TGA within all samples. The DMA analysis showed that the introduction of clays have a beneficial effect in increasing the storage and elastic modulus of composites. Clay presence was shown to interfere with the blue light transmittance, affecting Vickers hardness and water sorption levels. The amount of released monomers measured from extracts was below expected levels for this type of materials and biological tests show satisfactory cell compatibility. Significance. This paper reports the successful functionalization of MMT by a methacrylate group and further incorporation in experimental dental composites. Physical and biological results show a potential interest to the application of nanoclays into dental resin composites. © 2016 Published by Elsevier Ltd on behalf of The Academy of Dental Materials. ∗ Corresponding author. E-mail addresses: tais.munhoz@insa-lyon.fr, tais.munhoz@gmail.com (T. Munhoz), y.fredholm@noraker.com (Y. Fredholm), pascaline.rivory@univ-lyon1.fr (P. Rivory), sandra.balvay@univ-lyon1.fr (S. Balvay), daniel.hartmann@univ-lyon1.fr (D. Hartmann), pedro.da-silva@insa-lyon.fr (P. da Silva), jean-marc.chenal@insa-lyon.fr (J.-M. Chenal). http://dx.doi.org/10.1016/j.dental.2016.11.016 0109-5641/© 2016 Published by Elsevier Ltd on behalf of The Academy of Dental Materials.