🔍Step 1: Preliminary exploration
Use a hand chain (such as C-type pioneer file, K chain, H chain) to preliminarily explore the root canal orifice and determine the root canal length, curvature and calcification. Gradually use hand chains No. 8, No. 10, and No. 15 for preliminary root expansion to reduce the resistance of subsequent chains entering the root canal and improve clinical safety.
🛠️Step 2: Establish a straight channel
When the root canal is confirmed to be unobstructed, use an open lithium (speed 400, torque 3.5) to establish a straight channel and open the upper third of the root canal, not more than two-thirds at most.
📏Step 3: Accurate working length
Use a dredging file (speed 300, torque 1.5) and use the lifting technique with the motor to clean to the working length. Then use a root canal measuring instrument with a dredging file to measure the precise length.
🛠️Step 4: Root canal shaping
Use shaping chains (such as 04/20, 06/25, speed 400, torque 3.5) to gradually expand the root canal. When working, still use the lifting technique, lifting every 1 to 2mm forward, and each shaping chain can be completed after 3 to 5 times of lifting on average. When filling, use a gutta-percha that matches the taper model of the shaping chain used last.
🚫Precautions:
All root canal treatments must be accompanied by preliminary exploration with hand files (such as C-type pioneer files, K files, and H files). If the root canal is found to be blocked, machine files must not be used. Hand files should be used with ultrasound to gradually open up the calcified root canal. Machine files can only be used after the root canal is unobstructed, and each replacement of the root canal file in subsequent treatment should be accompanied by a large amount of root canal flushing to reduce debris accumulation.