Background: The purpose of root-end cavity preparation is to remove irritants from the root canal system inaccessible to the operator via a coronal entry. However, this predisposes the tooth to microcrack formation which further increases the possibility of bacterial contamination and susceptibility to root fracture. Aim: To evaluate and compare the dentinal microcrack formation after root-end cavity preparation with bur and ultrasonic tips using different imaging techniques. Methodology: Forty atraumaticaly freshly extracted, single-root premolars were collected for the study. All the samples were decoronated and working length was established. Biomchanical preparation was done till F4 protaper and obturated using single cone obturation technique. Root resection was carried out and number of cracks was evaluated using Stereomicroscope, Dental Operating Microscope and CBCT. Samples were then divided into four groups of 10 teeth each depending on the instrument used for retrocavity preparation: Group 1 (control): no preparation was done, Group 2: retrocavity prepared with stainless steel ultrasonic tip, Group 3: retrocavity prepared with diamond coated ultrasonic tip, Group 4: retrocavity prepared with stainless steel round bur. Samples were immersed in methylene blue dye and number of cracks were again evaluated using the three imaging techniques. Percentage increase in the number of cracks was calculated and data was subjected to statistical analysis using Wilcoxon and Kruskan Wallis Test. The level of statistical significance was set at 5% . Results: With stereomicroscope and Operating Microscope, maximum increase in the percentage of microcracks was observed in Group 2 (Stainless steel retrotip) followed by Group 3 (Diamond coated retrotip) and Group 4 (Stainless steel bur). Conclusion: Within the limitation of the study, it was concluded that there was increase in the percentage of microcracks after root end resection and root end cavity preparation. Stainless steel ultrasonic tips produced more dentinal cracks as compared to diamond-coated ultrasonic tips followed by stainless steel bur. Also, more number of microcracks was observed in stereomicroscope as compared to Dental Operating Microscope