This study was done to determine the number of voids present in repaired resin composite restoration using different types of composite. M & M: 60 premolars were selected, Class I cavity preparation was done having two standardized mesial and distal defect to be further repaired. Teeth were aged for 1 month then followed by the repair procedure. Teeth were divided into four group according to surface treatment (S0) no surface treatment, (S1) Etching only, (S2) was etch-and-rinse while (S3) self-etch group. Then repair was done using conventional composite (M1), flowable composite (M2), and sonicfill composite (M3). Teeth were cut into two halves using Isomet saw to be further examined under Digital Handheld Light Microscope. Conclusion: A statistical significant difference was found between different materials with no surface treatment with p value < 0.005, while no statistical significant difference with other surface treatments with different material