Influence of dietary solvents on strength of nanofill and ormocer composites.

: The objective of this study was to determine the influence of dietary solvents on the shear punch strength of nanofill (Filtek Supreme [FS], 3M-ESPE) and ormocer (Admira [AM], Voco) composites. The strength of these materials was also compared to a minifill composite (Z250 [ZT], 3M-ESPE), a compomer (F2000 [FT], 3M-ESPE) and a highly viscous glass ionomer cement (Ketac Molar Quick [KM], 3M-ESPE). Thirty-two specimens (8.7 mm diameter and 1-mm thick) of each material were made, randomly divided into four groups of eight and conditioned for one week as follows-Group 1 (control): distilled water at 37 degrees C; Group 2: 0.02M citric acid at 37 degrees C; Group 3: 50% ethanol-water solution at 37 degrees C and Group 4: heptane at 37 degrees C. After conditioning, the specimens were restrained with a torque of 2.5 Nm and subjected to shear punch strength testing using a 2-mm diameter punch at a crosshead speed of 0.5 mm/minute. The shear punch strength of the specimens was computed and data subjected to ANOVA/Scheffe's tests at significance level 0.05. With the exception of AM, the strength of all materials was not significantly influenced by dietary solvents. For AM, conditioning in heptane resulted in significantly higher shear strength values. The strength of the nanofill and ormocer composites was lower than the minifill composite but higher than the compomer and highly viscous glass ionomer cement investigated.