Introduction to Rotational Instrumentation
In view of the difficulties encountered in the longest step of endodontic treatment, such as constricted or calcified conduits, complex anatomies, curvatures, difficult access, etc., the time invested in the enlargement and disinfection of the root canal system ends up extending too much, in some cases more extreme, be responsible for the need for a second consultation to conclude the case. This, added to the fact that the routine of consecutive endodontic treatments can cause intense physical and mental tiredness, as well as the appearance of repetitive strain injuries (RSI / WRMSD), in the region of the fingers, hands, and also in the shoulders and region of the feet. the back, the endodontist needs other options to accelerate this step, in addition to reducing stress and tiredness caused by the use of hand instruments.
Thus, mechanized instrumentation arises, which, driven by an engine, electric or powered by compressed air, reduces the use of manual instruments, reducing instrumentation time, formatting the conduits with greater quality, producing less wear on the dental structure and also facilitating the filling, by standardizing the final taper. In order to make it possible to rotate or reciprocate the instruments by 360 degrees, it was necessary to produce more flexible files, equipped with a large elastic memory, so that they could move through the anatomy of the conduits without deviating from the original paths or submitting themselves. to fractures. Then came nickel-titanium instruments, with 5 times more flexibility than conventional flexible files. In order to optimize the operation of such instruments driven by the engines in question, they were machined in different shapes for the number of turns, number and type of cutting blades, length of the active part and cross section. Such characteristics mainly influence the cutting power, the flexibility, the resistance and the capture of debris, among others.
The driving motors of these instruments were initially designed to be used connected to the low speed micromotor of the conventional equipment. These contra-angles, despite being low cost, do not allow any speed or torque control, both of which are subject to the compressed air pressure of the compressor that will drive them. This lack of control impairs the operation of rotating instruments, reducing their useful life.
In the case of reciprocating movement, this control is not so important, since the speed is fixed or varies little, and the torque is always high. For this reason of lack of control, the engines evolved, moving to the phase of electric motors with only speed control, but still without torque control, and later, to electric motors with both controls available to the operator. Nowadays, electric motors for Endodontics have reached an incredible level of technology, offering in addition to speed and torque control, micro-heads with push-button, which facilitate access to posterior teeth and the fitting and removal of files in the contra-angle . Other benefits such as extremely light pens and internal batteries for use away from plugs are also present in some models.
As of 2011, Endodontics was delighted with the reciprocating engines, which brought us more possibilities with the speed of preparation and the use of a smaller number of instruments.
The choice of these state-of-the-art engines gives, in addition to greater safety in the use of the instruments, comfort to the operator and the patient, who can enjoy quiet, smooth and very light operation.
But what would be the disadvantages?
Despite the innumerable advantages inherent to mechanized instrumentation, some points can be considered disadvantages. Among them, the costs of the drive equipment, as well as the instruments used in these engines, which are quite high, when compared to those instruments used conventionally.
Given the reduced number of reuses of each file, the option for mechanized instrumentation can greatly increase the cost of treatment. As the various electric motors available have high prices, where the cheapest, both electric and powered by compressed air, lack important characteristics for the proper use of the instruments, it is important to choose a good equipment, since the cost of the same only is spent only once. As these characteristics can also prolong the life of the instruments, the costs of replacing them can be reduced indefinitely. Therefore, we only have two more ways to reduce this cost, in addition to having a good electric motor, which are:
1-) Use cheaper instruments. However, in general, such instruments are of inferior quality, which reduces their useful life, making their use more expensive.
2-) Use quality instruments, in a way that allows a better distribution of stress across the files in the sequence. Raising safety and the number of reuses, which are already promising, starting from a good instrument.
There are instrument kits on the market (3 to 6 files) costing between USD 30,00 and USD 65,00; which, being reused for 10 to 20 times, generate an approximate cost of USD 2,00 to USD 4,00 per pipe, or USD 7,00 to USD 15,00 per molar of 4 conduits, which can vary for much more. These values are a little high in a reality where molar treatments are charged from USD 45,00 to USD 90,00, depending on the location, greatly impacting the cost of treatment for the professional. Other cheaper systems, around USD 21,00; would still cost a mole USD 4,50 if used in 20 conduits. Considering that in a 2-hour session of endodontic molar treatment, around USD 13,00 to USD 18,00 of general costs of structure and materials are spent, an increase of USD 4,50 is equivalent to a 25 to 35% increase in expenses, a value quite high. It is worth remembering that these systems do not offer many guarantees of instrument integrity until the aforementioned 20 instrumented’ conduits. In summary, in addition to a high cost, we would still have risk of fracture. Having seen the expenses mentioned; is it feasible for those professionals who cannot charge more, the use of such systems?
And if it was possible to reduce the values per molar to around USD 2,00 to USD 3,00, using an average of up to 60 conduits? Moreover, if we still maintained great security when using them? Probably any professional would be able to incorporate them into their reality. In this way, we could popularize rotary instruments and more professionals would benefit from the speed, comfort and increased quality of the treatments provided by such systems.
Source: Endodontia Avançada Vivacqua. Available at: https://www.endodontiaavancada.com/introducao-a-instrumentacao-rotatoria/. Access on: 02/11/2021.