This study investigated the effect of bulk-fill composites on proximal contact tightness (PCT) of composite restorations using different matrix systems. 150/standardized-MO-ivorine cavity preparations were divided into 5 groups; Smart Dentin Replacement (SDR), SonicFill (SF), Tetric EvoCeram Bulk-Fill (TEB), G-aenial Universal Flo (GF) and Tetric EvoCeram (TE). Each group was subdivided into 3 subgroups (n=10); Dixieland band in Tofflemire retainer, FenderMate and Palodent plus matrix systems. PCT was measured 24 h post-curing using Tooth Pressure Meter. PCT means were calculated and statistically-analyzed using ANOVA and Tukey's post-hoc test (p<0.05). Means and SD of PCT for Tofflemire subgroup were: 1.75(0.13), 3.21(0.1), 3.06(0.19), 2.49(0.21) and 3.18(0.1) for (SDR), (SF), (TEB), (GF) and (TE), respectively. Using FenderMate, values were: 1.87(0.08), 3.35(0.12), 3.17(0.16), 2.64(0.1) and 3.26(0.11) for (SDR), (SF), (TEB), (GF) and (TE), respectively, while with Palodentplus; 3.16(0.17), 4.23(0.11), 4.1(0.1), 3.46(0.17) and 3.98(0.1) for (SDR), (SF), (TEB), (GF) and (TE), respectively. ANOVA revealed significant differences (p<0.05) between all samples except between (SF), (TEB) and (TE) and also significant difference between Palodentplus and two subgroups. Effect of bulk-fill composites on PCT is material dependent. Separation ring is recommended for proper PCT.
