EFFICIENCY OF DENTAL OPERATING MICROSCOPE OVER STEREOMICROSCOPE IN EARLY DETECTION OF SURFACE DEFECTS OF Ni-Ti ROTARY INSTRUMENTS

Authors: Elsy P Simon, Rishana P, Kavya Belaram

DOI: 10.18231/j.ijce.11518.1758363327

Keywords: Dental Operating Microscope, Stereomicroscope, Surface defects, Ni-Ti Rotary Instruments

Abstract: Aim and objective: Aim: To evaluate the efficiency of a dental operating microscope and stereomicroscope in detecting early surface defects of Nickel titanium (Niti) rotary instruments after multiple use. Objective: To compare the efficiency of a dental operating microscope over a stereomicroscope in detecting early surface defects of Nickel titanium (Niti) rotary instruments after multiple use. Introduction: Endodontics often involves operating without direct visual access, making instrument integrity crucial. Advances in biomaterials and nickel-titanium (Ni-Ti) rotary systems have improved treatment, but these instruments are prone to fatigue and fracture, especially in curved root canals where stress is concentrated. Instrument separation is a common and challenging complication that can compromise treatment outcomes. Since fatigue-related microcracks in Ni-Ti files are difficult to detect visually, especially without magnification, careful inspection is essential. While stereomicroscopy (STM) is the gold standard for identifying such defects, the dental operating microscope (DOM) is more widely available in clinical settings. This study compares the effectiveness of the naked eye, DOM, and STM in detecting early signs of instrument fatigue, with the null hypothesis stating no difference among these methods Material and Methods: 30 unused heat-treated Niti Rotary 6% files of size 20 were selected. Prior to use each file were view under a stereomicroscope (STM) of 40X magnification and dental operating microscope (DOM) of 14 X magnification to ensure the absence of manufacturing defects. They were then used to shape mesial roots of molars. After a cycle of usage and sterilization at the first, third and sixth use the files were viewed with the naked eye, DOM and STM. The defects observed were recorded and classified. Result: The results show that magnification significantly enhances defect detection in endodontic files. No manufacturing defects were found initially. After one use, both the dental operating microscope (DOM) and stereomicroscopy (STM) detected defects in 10% of the files, while the naked eye detected none. After three uses, defect detection rose to 46.6% with DOM and STM, compared to 10% with the naked eye. By the sixth use, DOM and STM identified defects in 66% of files, while the naked eye detected only 16%. DOM proved as effective as STM in identifying instrument fatigue. Conclusion: The number of defects of Ni-Ti rotary instruments increases with increase in clinical usage. DOM was as effective as STM in detecting defects on the rotary files. Both magnification tools proved to be significantly more reliable than the naked eye for detecting defects after use.