Elution of Monomers from Commercial and Newly Synthesized Dental Composite. Hina Khalid¹, Natasha Hussain¹, Abdul Samad Khan¹ ,Haffsah iqbal ², Zenab Sarfraz¹. Interdisciplinary Research Centre in Biomedical Materials, COMSATS Institute of Information Technology, Lahore, Pakistan Government college university, Lahore².

Objectives: The resin-based composites have been used to restore the carious tooth structure. However, the un-reactant monomers can cause local, systemic, cytotoxic, genotoxic and mutagenic effects and these residual substances may inflame oral mucosa and irritate pulp by diffusion through dentinal tubules. Therefore, the objective of this study was to evaluate and compare the release of monomer from commercially available Nano-hybrid bulk-fill and micro-hybrid composite with newly developed experimental composites
Methods: Two commercially available nano-hybrid bulkfill and micro-hybrid composite resin-based composites i.e. SDR^TM (DENTSPLY, Germany) and Filtek P60^TM (3M ESPE, Germany) respectively, were used. The experimental composite based on dimethacrylates monomers were prepared. In order to evaluate the degree of conversion and elution of monomer after polymerization both Fourier Transform Infrared Spectroscopy (FTIR) and High Performance Liquid Chromatography (HPLC) were performed. The control and experimental composites were immersed in deionized water at 37°C. FTIR (Photoacoustic cell, Thermo Nicolet 6700, USA) of composites before and after polymerization was evaluated. HPLC (Schmadzu, Japan; with C-18 column) of the specimen at different time interval was analyzed
Results: The control and experimental composites showed degree of conversion and new peaks corresponded to cross-linking of polymer composites. HPLC results showed that both commercial composites released high amount of monomers (BisGMA, UDMA, and TEGDMA) compared to experimental composites, whereas, SDR (bulkfill composites) showed significantly high elution of monomers compared to other composites. Experimental composites showed minimal elution of monomers.
Conclusions: Degree of conversion after polymerization showed cross-linking behavior. Leaching of unbound dental monomer from bulkfill and micro-hybrid composites have a potential to cause adverse effect, whereas, newly developed experimental composite has potential to act as an alternative restorative material.