Abstract: 2,3,5-triiodobenzyl methacryloyloxyethylcarbamate (TIMEC),an iodine-containing methacrylate mono- mer,was synthesized,and the consistency of its structure with the designed one was confirmed by means of 1 H- NMR and FT-IR. Then,the monomer was incorporated into the Bis-GMA/TEGDMA light-curable dental resin sys- tem to prepare a X-ray radio-opaque dental resin,and the effects of the monomer mass concentration on the relative radiopacity (RXO),double bond conversion (DC),volumetric shrinkage (VS),water sorption (WS),solubili- ty (SL) and mechanical properties of the TIMEC-containing resin formulations were investigated.It is found that,as compared with the control resin，namely the Bis-GMA/TEGDMA without TIMEC,the TIMEC-containing resins are of higher RXO and lower WS,SL and VS.Moreover,although the DC and mechanical properties of part resins are moderately reduced,the resin containing 20% TIMEC is excellent in each index,specifically,its RXO,DC,VS,WS,SL,flexural modulus and flexural strength are 113%,57. 5%,6. 41%,2. 65%,0. 49%,3038MPa and 123. 1MPa respectively,all of which are superior to those of the control resin except the DC.The results show that TIMEC is of potential application prospects.

Key words: dental resin, methacrylate monomer, physicochemical properties, contrasting agents, X-ray radiopacity