To assess the effect of filler on the presence of voids within resin-composite. Eight Light cure resin-composites were used in this study, seven models and one commercial composite. A disc (6mm in diameter and 2mm thickness) was used to prepare samples (n=8). Each sample was then scanned, reconstructed and analysed using Micro-CT. The percentages of voids obtained were then imported into SPSS and analysed using ANOVA and post hoc methods to check any significant differences between materials tested (p < 0.05). The Mean (SD) of % of voids for each group were obtained which ranged from 0.28% within Tetric Ceram to 3.48% within I4 model composite (1500nm). The different between means was statistically significant at p < 0.05. The filler size and distribution has an effect on the percentage of voids in resin composite which was greater with larger filler content. © Haitham Elbishari, and et al.