Purpose: The purpose of the present study was to compare the Vickers hardness numbers (VHNs), roughness numbers (RNs) and biological compatibility of glass carbomer (Glass Fill), resin-modified glass ionomer (Fuji II LC) and self-adhering flowable composite (Vertise Flow) materials. Materials and methods: Disc-shaped specimens of test materials (n=15/group) were prepared, and VHNs and RNs were determined after 24h. A direct contact test was used for cytotoxicity evaluation. Cell viability was measured for 24h post-exposition with a photometric test (MTT assay; n=16). Data were analysed using one-way analysis of variance with a post hoc Tukey's test, the Kruskal-Wallis test and the Mann-Whitney U-test (p<0.05). Results: Fuji II LC had the highest VHN. The VHN of Fuji II LC differed significantly from those of the other materials (p<0.05). The RNs of Fuji II and Glass Fill were higher than that of Vertise Flow (p<0.05). The self-adhering materials were not significantly cytotoxic compared with the control group (p>0.05). Conclusions: The materials tested in this study showed a similar lack of cytotoxicity. The VHN of Fuji II LC was the highest, and the RN of Vertise Flow was the lowest.