Dental endo motor Root canal instruments are widely used in oral clinics. So the question is, what are the common questions when using the Dental endo motor?
A. Can Dental endo motor be used for any root canal treatment?
R. The curved and calcified root canal hand、machine combination is safer
A. The surgeon feels that the preparation speed is too slow?
R. 250-400rpm is the safest and most efficient speed for Nitinol
A. Is the torque smaller the better?
R. It is very important to limit the torque, a reasonable torque is the guarantee of cutting force
A. Is it possible to expand while measuring?
R. The main purpose of expanding while measuring is to prevent the expansion of the apical foramen. For conditions that cannot be accurately adapted to root measuring, the expanding while measuring cannot be used.
A. Can measuring and expanding at the same time replace the root canal measurement alone?
R. Root canal measurement is affected by a variety of environments, and root canal treatment should strictly follow the sequence of "establishing a straight path - root canal measurement - preparation" to prevent accidental risks
A. What kind of machine do users use to expand needles?
R. Generally speaking, any brand of nickel-titanium expansion system can be used, each with its own characteristics, which mainly depends on the cost-effectiveness and the familiarity of the doctor.
How to prevent broken endomotor root canal file
① To prevent endomotor root canal files breakage, the operator's experience is the key
1. Learning about the machine and endomotor root canal files allows you to reduce the risk of use;
a. Control the torque and speed It is best to set the torque control motor and the matching speed. Following the torque recommended by the endomotor root canal files manufacturer, speed is especially important for treatment safety.
b. Measure the length of the instrument each time it enters the root canal. Instruments that are too long increase the risk of torsional fracture. Equipped with root canal length measuring instrument, calipers, etc. for working length measurement.
2. The correct operation method is very important: do not pressurize and force the tip. The instruments cannot stay in the root canal for too long;
3. Instruments should be checked before surgery,
a. The fracture of instruments mostly occurs in molars, especially in small and narrow root canals such as the mesial root canals of upper and lower molars, and special care should be taken before treatment;
b. Curved root canals, re-treatment and calcified root canals require special requirements for instruments and manipulations, and it is best to use a new root canal files;
4. Establish a straight path to maintain an unobstructed root canal, pay attention to gestures during operation, and try to ensure that the enlargement root canal files and the root canal path are in a straight line to reduce the bending resistance of the enlargement root canal files at the crown and the stress on the instrument;
5. The root canal should be kept fully lubricated and should be flushed every time it is prepared;
6. Because the inside of the root canal is narrow, do not put pressure on the enlargement root canal files during operation, and the cutting should be done completely by the power of the machine itself and the sharp edge of the enlargement root canal files;
7. In the case of inexperience, it is safest to use the recommended minimum torque. In general, lower rotational speeds will extend the clinical life of the device and reduce the chance of breakage.
② Efficient and safe, excellent equipment is the guarantee
1. Nickel-titanium expansion requires both rotational speed and torque. Inappropriate rotational speed and overloaded torque are important factors for root canal files breakage.
2. Control the torque and speed Follow the torque recommended by the expanding root canal files manufacturer.
3. Measure the length of the instrument each time it enters the root canal. Equipped with root canal length measuring instrument, calipers and other tools for working length measurement.
③ Select and use the expanding root canal files
1. In addition to the difference in material and design, different endomotor
root canal files are very knowledgeable, including the bonding of the blade spiral.
Familiar with the performance of nickel-titanium instruments, use methods and root canal preparation techniques. Such as: the endomotor root canal files of mature big brands, such as Protaper, profile, K3, etc., all advocate the use of root-oriented technology;
2. With the continuous update of nickel-titanium root canal instrument technology, the domestic enlarged needles have made great progress. The design and manufacture of nickel-titanium root canal enlargement root canal files with higher cutting efficiency, better forming ability, less stress and stronger fracture resistance have been improved in new materials and manufacturing processes. For example, the sc enlarged file has special channel file and open file. The system is 0.02 and 0.08 respectively, and its tip diameter is 15mm and 30mm, respectively. The special heat treatment process makes the nickel-titanium resistant to torsion and bending fatigue, and can rebound. Performance and life be greatly improved.
3. Choose and use the endomotor root canal files well, and control the number of times of use when using it: when using it, you should observe more whether there is wire drawing or deformation, and if you find it, you must discard it in time, otherwise you will regret it;
4. Taking SC-Pro as an example, it is recommended to have 25-30 root canals for anterior teeth and 1 or so root canals (or 5 posterior teeth) for posterior teeth. The preparation of sharply curved root canals will cause great damage to the instruments and is recommended for one-time use. After each use, it is best to record the number of uses to prevent the equipment from fatigue; the debris of the enlarged root canal files blade should be cleaned repeatedly and in time, and a cleaning table should be equipped.
Clinical treatment steps and precautions
① Requirements for opening the pulp hole (medullary cavity preparation):
removal of the entire medullary roof;
The wall of the pulp opening should be in line with the apex 1/3 of the root canal, and there is no resistance between the instrument and the wall of the coronal root canal;
Make the temporary sealing drug retain well;
Provide a space for the irrigation fluid to flow, and minimize the damage to the tooth tissue.
Steps: local anesthesia---adding the rubber dam---removing all the humus---removing the pulp top---forming a straight line with 1/3 of the root tip.
② Determination of root canal length
Be sure to have the exact working length before doing the apical 1/3 preparation.
(1) Subtract 2mm from the preoperative film as the estimated root canal length (IL)
(2) 06 or 08# file and pre-bend the tip to estimate the length of the root canal, prepare the root canal to the 10 or 15# file and enter the root canal, and feel stuck, if the root canal diameter is larger than 10 or 15 #File, you can directly select a file that can be held for diagnostic root length measurement.
(3) Parallel projection X-rays.
(4) WL=IL±d-1, + if the instrument is shorter than the root hole, - if the instrument exceeds the root hole.
(5) If the instrument is more than 4mm away from the root hole, the diagnostic wire photography should be readjusted.
(6) If the length of the diagnostic wire is adjusted with a root length measuring instrument before the diagnostic wire is used, the distance between the diagnostic wire and the apical foramen can be avoided.
③ Principles of root canal irrigation
Flushing should include the number of flushes, the amount of fluid to be flushed and the depth of flushing. Before root canal preparation, every file change, before trying the main gutta-percha and before sealing the medicine, it should be rinsed, and the amount of each rinse should be more than 1-2mm. The role of the rinse solution: rinse, disinfect, lubricate, dissolve organic matter, bleach. The most commonly used rinsing fluid is NaOCl. Root canal preparation must be done in moist conditions. The irrigator should be open on the side of the tip, and the irrigator should be loosely placed in the root canal. The mechanical flushing effect only occurs at the part where the flusher reaches, therefore, the flusher should be placed at a sufficient depth, and the flushing speed should not be too fast and the force should not be too large.
④Principles of root canal preparation
Before the root tip 1/3 is prepared, the working length must be accurate; the root canal must be kept moist during root canal preparation to ensure adequate irrigation; the root canal file should not be skipped; the root canal file should be pre-bent; the minimum expansion of the root apex is 25 #, easy to fill; according to the difference of the initial filing, the MAF of each tooth is different, generally 2-3 sizes larger than the initial filing. If the MAF is less than 60#, a 4mm retreat preparation should be done, 1mm each time. If the MAF is greater than 60, it should go back and expand by 2. Preparation of the coronal 2/3: The purpose is to provide sufficient access for the lateral compression device to reach the apical region. The lateral pressure device should be able to reach the apex of 2 mm, otherwise it will not be able to form a good apical sealing effect. GG BUR 2# should reach no less than 6mm apex, or 2/3 of the working length, GG BUR 3# is 2-3mm shorter than GG BUR 2#. Reconditioning of the root canal wall: The MAF file is pre-bent to the working degree to make the root canal wall smooth. Check the taper of the root canal preparation with a lateral pressure. The lateral pressure device corresponding to the MAF should be able to freely reach 1-2 mm from the apex; the apical stenosis is obvious and there is a clear stop (STOP); no debris is deposited within a few mm of the apical area; the root canal wall is smooth without Step; 2/3 taper of root canal crown is sufficient, greater than the taper of gutta percha and the corresponding taper of lateral pressure
⑤ Notes on root canal filling
Choice of main gutta-percha tip: freely enter 1-2mm from the apex and feel tight (TUGBACK); consistent with or slightly larger than the prepared MAF; within 0.5mm of the working length; in the apical stenosis blocked.
Notes for root filling: The root filling paste should be applied only to the root canal wall; the paste should be applied using a paper twist or a file equivalent to MAF; the tip of the main gutta-percha dipped in paste is inserted to the working length; the lateral pressure device should be able to reach The distance from the working length is 1-2mm; generally, only 2-3 auxiliary tips with the same taper as the lateral pressure device are recommended; if the main apex is found to be short or over 2mm on the postoperative apical radiograph, it should be refilled.
Problems in root canal preparation
(1) Loss of working length
Causes: root canal blockage, shoulder formation, instrument breakage, accumulation of dentin debris in the apical area, etc.
The precautionary principle: reference point fixation
Fixed stopper position
Pre-bent all root canal files
Note that the curve of the root canal file should be consistent with the curve of the root canal
The X-ray projection angle should be consistent
Preservation of root canal preparation
Repeated use of small files to open the root canal (recapitulation)
Prepare root canals one by one.
(2) Root canal blockage:
Causes: dentin debris, filling material blocking the apical area, etc.
Preventive principle: remove carious tissue and unbase glaze before pulp opening
The root canal orifice should be adequately prepared;
Rinse extensively to remove debris;
The root canal file should be cleaned when it enters the root canal again;
The root canal file cannot be skipped;
Repeated use of small files to open the root canal (recapitulation);
Do not over-rotate or force the file;
Do not prepare root canals in dry conditions;
Temporary seal perfect;
Treatment method: try 15#K file or expander to pass the blockage
The tip of the 10#K file is bent 3-4mm into a 45-degree angle, and it is rotated along the circumference of the blockage to find the feeling of being stuck (catch). blockage. And according to X-ray to determine. EDTA helps.
If the blocked part cannot pass, it should be prepared to the blocked part, and root filling should be done, and regular observation; the root tip can also be plasticized, and the root filling can also be plasticized. Root surgery if necessary.
(3) Ledging and shoulder passing:
Reason: root canal file has no pre-bending, shoulder formation, etc.
Change the file too fast, skip the number.
Prevention of Shoulder Formation: Preparatory Steps for Small, Curved, Calcified Root Canals
exact working length
The medullary cavity is filled with NaOCl
Pre-bend 06#, 08# and 10# root canal files, and gradually reach the working length. Use the step-by-step root canal file preparation method and 1-3mm short strokes (in-and-out strokes).
The shoulder can be removed if detected early, but it is more difficult to remove the shoulder produced by the 25# or 30# file. The method is the same as through the root canal blockage.
(4) The method of breaking and taking out the instrument:
prevention:
① Replace the new file in time:
② After the root canal file reaches the working length, you can only do the file action, 1-3mm pulling; do not rotate
Use of H file: H file can only be used for lifting in loose root canals.
Treatment: The instrument is broken at the root canal orifice, and the instrument can be exposed for 2mm along the periphery of the instrument with a small bur, and taken out with a small blood vessel forceps.
The instrument is broken deep in the root canal, and the ultrasonic method is used.
If the broken instrument is firmly stuck in the root canal, apical surgery should be performed. The broken instrument is closely combined with the dentin of the root canal wall, and the prognosis is good. If the broken instrument is loose in the root canal or out of the apical foramen, surgery should be performed.
(5) Changes in the position of the apical foramen (zipping, transposition, transportation)
Reason: The root canal file was not pre-bent, and the preparation device for the root canal curve was too large and too hard.
Appearance: teardrop
Prevention: pre-curve root canal file; prepare in the opposite direction of curvature (anticurvature filing).
Treatment: teardrop-shaped formation, which can be filled by various methods; if the apical foramen is displaced and perforated, a paste containing Ca(OH)2 should be used; elbow-shaped structure formation (elbow) is best to use vertical compression method root Charge. Radical surgery should be performed if treatment fails.
(6) Insufficient or excessive root canal preparation
Problems and countermeasures in root canal filling
(1) The main gutta percha tip cannot reach the working length
Cause: dentin debris clogging the apical area;
shoulder formation;
Insufficient taper or poor continuity of the root canal;
Artificial root canal formation or straightening of curved root canals, loss of working length;
The gutta-percha tip is too large or the taper is not standard.
Treatment method: The main file is used to prepare the root canal again to reach the apical area, and each file should be properly pre-bent; diagnostic wire photography is used to determine the problem; a lot of rinsing to remove the blockage; after the root canal is re-prepared and dried, the main file should be used again to determine The apical area is well prepared.
(2) The main gutta-percha tip has no tightness
Reason: The apical area is prepared at 25-40#, sometimes it is difficult to feel tightness, and it is easy to feel tightness above 40#;
The taper of the main gutta-percha tip is poor, and the main gutta-percha tip is too small;
Discontinuous taper of root canal preparation, displacement and deformation of the apical foramen;
dentin debris remains in the root canal;
Treatment method: Change the taper of the tip of the main gutta-percha tip
The use of gutta percha (GP gauge): the too-fine gutta percha tip must have a diameter hole one size larger than the gutta percha gauge, and cut off 0.5-1mm.
(3) The root filling in the apical area is not dense
Reasons: The apical area is not patency or the taper is insufficient, and the lateral pressure device cannot reach the apex;
The auxiliary gutta-percha tip is not dipped in root filling paste, the auxiliary gutta-percha tip is not long enough to reach the depth reached by the lateral pressure device, or the tip is curved;
Side pressure is too large;
Too much root filling paste;
Excessive accumulation of dentin debris in the apical area (1-3mm)
