Background To evaluate root surface roughness after instrumentation with Gracey curettes Ultrasonic scaler and diamond coated piezo-surgery tips using scanning electron microscope SEM.Methods Sixty-six mandibular premolar teeth indicated for extraction were collected stored mounted and analysed. These were divided randomly into three groups with 22 samples in each group. In Group A instrumentation was done with Gracey curettes Group B with ultrasonic scaler and Group C with piezosurgery driven diamond coated tips. The samples were then subjected to SEM analysis at a magnification of 1500x. The collected data was analysed using both descriptive and inferential statistics. Chi-square test t test ANOVA and other necessary statistical tests were used. P lt0.05 was considered to be significant. The analysis of the data was carried out using SPSS version 20 software.Results Multiple comparisons of mean surface roughness scores showed no significant difference between Gracey curette and Ultrasonic scaler tip P0.063. No statistical significant difference was found between Gracey curette and Piezo surgical unit P0.984. However there was a statistically significant difference between Ultrasonic scaler tip and Piezo surgical unit P lt0.004. It can be inferred from the results that the surface roughness is different in both Ultrasonic scaler tip and Piezo surgical unit groups.Conclusion The use of diamond-coated tips tends to produce more surface roughness than routinely used ultrasonic scaler tips and manual instrumentation.