Precautions for using endodontic file?

There are many types of endodontic files, and the scope of application and method of use are also different. Therefore, we need to pay special attention to the characteristics, performance, usage and other precautions of each machine when using endodontic files. This article will give you a detailed introduction to some information that needs to be paid attention to.

Key points of preparation technique of rotating nickel-titanium crown

Root canal file separation type

1.Key points of preparation technique of rotating nickel-titanium crown

The core of the under-crown method is to use large instruments to provide space for small instruments to penetrate into the apical region. According to the principle of surgical debridement, the root canal crown is prepared with an endodontic file with a larger diameter, and then gradually deeper into the apical area with instruments with smaller diameters. Clinically, non-ISO standard mobile nickel-titanium instruments are used to complete the preparation. The advantages of the under-crown method are: first remove the root canal crown resistance, obtain a good access to the root canal of the apex, measure the working length of the root canal more accurately; the preparation feel is better, which helps the instrument control and enter the apical area; Most of the infectious materials have been removed in the upper part of the root canal. The rotary motion avoids the piston effect, the apical debris is reduced, and the postoperative complications are reduced. The open upper part of the root canal is conducive to the irrigation fluid into the deep root canal. The root canal prepared by the mobile nickel-titanium file system can keep the original root canal running to the greatest extent, greatly reducing the labor intensity of the surgeon and improving the clinical work efficiency.

Nickel-titanium alloy was introduced into the dentistry in the 1990s due to its super elasticity, good memory and biocompatibility. It was quickly designed as a file system, including Niti taper file, Niti Protaper Gold heat-activated, Niti Protaper Blue heat-activated. After nearly 10 years of clinical trial application, it was rapidly popularized in the early 21st century. The motorized nickel-titanium instrument operating system is the best embodiment of the principle of crown-down preparation. It requires the operator to have good judgment and feel feedback, otherwise it is easy to form complications such as steps, side penetration and instrument breakage. No matter what kind of nickel-titanium system is used, the first step is to use small ISO standard stainless steel hand instruments to probe the root canal, establish a smooth access, determine the working length, and then use the mobile nickel-titanium instruments.

2. Root canal file separation type

The main movement mode of motorized nickel-titanium instruments is the drilling type, that is, rotating the root canal wall, just like the drilling mode. In clinical operation, the surgeon is most concerned about the sudden breakage of the device without any signs. The free broken end is stuck in the root canal, also known as device separation. During the rotation of the motorized nickel-titanium file in the root canal, the file blade is constantly subjected to resistance, and the power of the rotation is continuously driven. The two resist each other. When the torque is greater than the resistance, the instrument blade can "bite" the dentin; but if the resistance If the torque is greater than the torque, the needle of the endodontic files is stuck in the root canal. The handle end of the instrument is still driven to continue to rotate. The high torque load exceeds the elastic limit of the instrument. The needle can be suddenly broken. This phenomenon is torsional fracture.

Another situation is that the instrument is in a curved root canal, and there is no compression in the root canal. During the continuous rotation, the metal in the bending section is repeatedly subjected to alternating tensile and compressive stress cycles. Cracks, which eventually break as the cracks extend, are fatigue fractures.

For the use of endodontic files, especially nickel-titanium alloy materials, the above points must be paid attention to during use. Of course, if you have other suggestions and opinions, you can also visit our website to discuss with us.