Background: Effective cleaning and shaping are essential for successful endodontic treatment. Nickel–titanium instruments have improved root canal preparation by making it faster and more efficient while maintaining the natural shape of the canal. However, these instruments can still break during use, so evaluating surface changes is important because they often indicate a risk of failure. Aims: To assess types of surface defects on Kedo S Plus rotary files and WaveOne Gold reciprocating files after root canal preparation of molar teeth using SEM. Design: A total of 20 files were used: Group I (10 Kedo S Plus files) and Group II (10 WaveOne Gold files). Method: After pre-operative records, access cavities are prepared, and the working length (WL) will be determined. In group I, biomechanical preparation will be done by Kedo S Plus files and in group II by WaveOne Gold files according to the manufacturer’s instructions. The samples will be sent for evaluating surface defects after preparing the root canals of the molar teeth. Results: Kedo S Plus appears more resistant to microstructural damage. In contrast, WaveOne Gold demonstrates superior cutting efficiency but a higher tendency for fatigue-related surface defects. Conclusions: Neither file system can be considered unequivocally superior, as each exhibits a distinct wear profile. Kedo S Plus tends to lose cutting ability earlier; still, it appears structurally safer. In contrast, WaveOne Gold maintains cutting ability for longer but exhibits more fatigue-related defects.
1*Dr. Preksha Khare, 2Dr. Satish Maran, 3Dr. Anaya Kulkarni Kale, 4Dr. Saarika Suresh, 5Dr. Madiha Khan, 6Dr. Sahiba Khan (Sun,) studied this question.