comparison of flexural strength of several composite resins available in iran

objective: despite great advances made in dental composite resins, their use is associated with some concerns regarding their mechanical properties such as their flexural strength. considering the introduction of different composite resins into the market, there is a need to compare their mechanical properties and particularly flexural strength. this study aimed to compare the flexural strength of 12 types of composite resins.   methods: in this in-vitro experimental study, 120 specimens were fabricated of 12 different composite resins using a mold according to iso 4049 standard. samples were then subjected to 3-point flexural test in surface mount techniligy (smt) device with a crosshead speed of 0.75±0.25 mm/min. obtained data were analyzed using one-way anova and scheffe’s test. p<0.05 was considered statistically significant.   results: flexural strength of understudy composite specimens was significantly different (p<0.0001). pair-wise comparison of groups revealed significant differences between the following composite resins: artemis and swiss tec (p<0.004), venus and swiss tec (p<0.02), charisma and swiss tec (p<0.0001), charisma and spectrum (p<0.03), artemis and z250 (p<0.0001), synergy and z250 (p<0.007), point 4 and z250 (p<0.02), cermax and z250 (p<0.02), venus and z250 (p<0.001), charisma and z250 (p<0.0001) and charisma and tetric ceram (p<0.03).   conclusion: all under study composite resins had the minimum required flexural strength according to iso 4049 standard. their flexural strength ranged from 134.0 mpa for charisma to 263.0 mpa for z250. use of tetric ceram, spectrum, swiss tec and z250 is recommended for restorations in high stress-bearing areas due to their high flexural strength.