HYBRID TECHNIQUE

[Drsumitra]

 A µCT image demonstrates the importance of treating root canal systems. (Courtesy of Dr. Frank Paque of Zurich, Switzerland.

        

[Drsumitra]

 

anthogyr® Endo-Handpieces

Contra-angles with continuous rotation for NITI FILES : Recent endodontic research recommends the use of Nickel and Titanium files due to their high flexibility.  This allows them to follow the natural curvature of the tooth perfectly allowing a simple and fast technique. The files, whatever the brand, are used in continuous rotation at low speed (from 150 rpm to 2000 rpm depending on the type). Our range of Niti handpieces can be used with your usual motor which avoids to buy a new one. Today, all experts agree that the main drawback of all Niti instruments, whatever their brand is, is breakage.                  NITI-Control contra-angle : EXCLUSIVELY MAILLEFER Automatic declutching  The NiTi Control contra-angle presents a ring located in its head, allowing torque adjustment.  Each position corresponds to a different torque value. According to the file diameter and length, we will use the best adjustment, that is to say the torque corresponding to the maximum value which can be applied and endured by the file. When this brink-value is reached, the driving device is automatically stopped. Micro head The NiTi Control contra-angle presents a thin push-button head, particularly well -adapted to endodontic treatment as it procures easy access and maximum visibility. New micro push button head available on all endo Niti handpieces   FASTER > Insertion of the file without    pushing the button. > Possibility to change file    before complete stop of the    motor.    ONE HAND USE > The handpiece can be used    with one sole hand, even for    torque adjustments.    The treatment time is    reduced to the minimum.   EASIER > Smoother mecanism.     • without spray (irrigation with a syringe). • standard attachment (ISO) "E" type, compatible to any kind of pneumatic and electrical motors • sterilisation into autoclave at 134° C. • exclusively for MAILLEFER NiTi files.   Ref. 4290MBP- DM : 64:1 reducing NiTi Control handpiece for motor with maximum speed of 20000 rpm. Ref. 4297MBP- DM : 128:1 reducing NiTi Control handpiece for motor with maximum speed of 40000 rpm.                   ENDO-NITI and MICRO-NITI contra-angles : Technical features   Ref. 4280MBP • E type standard attachment (ISO). • Can be autoclaved at 134°C.   To obtain a micro push button head, add MBP or BPI after the mentioned references in the table below.  (except for the reference 4282 – 4296) Your motor’s  highest speed Required speed for the files 300 to 350 rpm 600 to 650 rpm 5 000 Ref. 4280 Réduction 16:1 Ref. 2100 Réduction 8:1 10 000 Ref. 4282 Réduction 32:1 Ref. 4280 Réduction 16:1 20 000 Ref. 4290 Réduction 64:1 Ref. 4282 Réduction 32:1 30 000 Ref. 4296 Réduction 100:1   40 000 Ref. 4297 Réduction 128:1 Ref. 4290 Réduction 64:1   Ref. 4297

 

        

[Drsumitra]

The objective of working length determination is to establish the length (distance from the apex)
at which canal preparation and subsequent obturation are to be terminated.
Importance of accurate working length determination:
· Confine the instrumentation to the canal system (within dentin).
· Create and maintain an apical stop or seat at the minor constriction.
· Prevent under-instrumentation that could leave tissue and debris in the apical segment.
· Prevent over-instrumentation which could cause patient discomfort, damage periapical
tissue, or potentially cause an infection or cyst development from the placement of
irritating materials beyond the apex.
Methods for determining working length:
· Radiographs
· Electronic apex locators
· Tactile sense
Additional adjunctive methods:
· Paper points
· Microscopic magnification
· Average tooth length

 

        

[drmithila]

The Obtura Maxpack delivers heat consistently at the desired temperature, resulting in the predictable clinical performance required for warm vertical compaction. An extremely lightweight, cordless unit, it offers 4 different temperature settings, 6 angles for pluggers to be inserted, a long-lasting lithium-ion battery, and a 12-month warranty.

 

        

[drmithila]

Written by Barry L. Musikant, DMD, and Young Bui, DDS

Using instruments limited to a short arc of motion provides the dentist with several advantages,4 the most obvious ones being the virtual elimination of torsional stress and cyclic fatigue,3 the 2 factors that lead to rotary Ni-Ti separation.5 This has been such a consistent problem for rotary Ni-Ti that the industry continues to introduce newer systems, each supposedly having an incrementally increased resistance to fracture. The problem cannot be switched off like a lightbulb, because fatigue and torsional stress6 are indigenous to the weakness of all metals including Ni-Ti when used in rotation. In that regard, some rotary systems are now incorporating what is best described as hybrid rotation or hybrid reciprocation, depending upon your point of view. By that, we mean that for each motion of 150° there is a compensating motion of 30° in the opposite direction. Reciprocation is occurring, but there is still a net increase of 120° per 2 oscillations. With a frequency of 600 cycles/minute, that still amounts to 200 full rotations per minute, producing a similar degree of rotations that have been in existence since their introduction. As we know, rotations around a curve lead to cyclic fatigue7 and an increasing instance of separation as the tip size and taper of the instruments increase and the curvature of the canal becomes more acute.

Up to this point, we are emphasizing the safest method of instrument utilization: short arcs of motion either manually or in a 30° reciprocating handpiece. Of at least equal importance is the design of the instruments. Used predominantly with a horizontal watch winding motion, the blades remove dentin most effectively when the cutting edges of the flutes are more or less at right angles to the plane of motion. To understand this concept, think of shaving one’s face with a razor blade. It works quite well because the cutting edge is at a right angle to the plane of motion.8 That is why the blade is on a T; if the blade were in the same plane as the plane of motion, we would be slicing into our face, removing nothing but blood, which we all agree is not our goal. Yet, when we use K-file,9 we are using instruments whose flutes are more or less in the same plane as the plane of motion only to pull up after engagement to shave away the dentin. While this second application of motion removes dentin, it does so at the expense of straightening the outer wall of curved canals on the upstroke while the horizontal flutes along length tend to impact dentin upon the downstroke.

Please note the difference in the angles of flutes along the shank of a K-file file compared to the angle of the flutes along the length of the relieved reamer. It is the vertical orientation of the flutes along the length of the relieved reamer that account for their great efficiency when used in shaping canals (Figure 5).

When we use relieved reamers,10 instruments with a flat along their entire working length and vertically oriented flutes with the customary watch-winding stroke, we are immediately shaving dentin away, freeing up the instrument for further apical negotiation while reducing the engagement along length, the exact opposite that occurs when using an instrument designed as a file. In other words, the relieved reamer is the proper design to maximize the penetration of the instrument to length with the least resistance encountered during the process.

To sum up where we are at the moment, we are establishing the fact that K-files represent an incorrect instrument design that nullifies the benefit of being used with the correct motion. Rotary Ni-Ti, an instrument correctly designed as a reamer, is unfortunately utilized incorrectly. Relieved reamers, on the other hand, represent both the correct design and correct utilization of instruments to accomplish the task of cleansing and shaping canals.

 

        

[Drsumitra]

Forendo Paste is a non-setting, premixed calcium hydroxide paste with iodoform for root canal therapy. Forendo Paste is a temporary or permanent endodontic filling material that promotes healing and inhibits bacterial growth in the root canal.
Forendo Paste contains calcium hydroxide and iodoform in a silicone oil base. It has a pH greater than 12 and is radiopaque. The paste is bactericidal and bacteriostatic. It is recommended for routine use as a disinfecting root canal dressing between office visits to prevent flare-ups and for treatment of infected root canals, abscesses, periapical lesions, perforations, exudation, root resorption, traumatic injuries, and for apexification and apexogenesis. Forendo Paste can be used alone as a temporary canal disinfectant, in conjunction with gutta percha for permanent filling, and for vital pulpectomies in deciduous teeth

 

        

[Drsumitra]

 Are you a quack doing RCT

Vast majority of dentists in India (may be elsewhere) do not use apex locator for working length determination while doing RCT. Based on science it can be concluded that such practice is highly unethical and incorrect exposes the practitioners to litigation.

Recent study in Ind J of Dent Res and again confirmed and highlighted the same fact. 

READ ALL THAT YOU Need TO KNOW FOR SUCCESSFUL rct ON http://www.healthmantra.com/rotary/WL-study.pdf

        

[Drsumitra]

Single file technique with reciprocating motion

Simplicity is the real innovation reciprocating motion

Using a large rotating angle in the cutting direction and a smaller angle in the opposite direction allows the WaveOne Reciprocating File to successfully progress along the canal path, while respecting the root canal anatomy.

The advantages of the reciprocating technique are numerous:

Makes it possible to shape most root canals using only one single file.
Decreases total shaping time up to 40% versus a traditional rotary technique in continuous motion.
Optimized reciprocating angles reduce the risk of a screwing effect and file breakage.
Has a geometry conceived specifically to provide maximum user benefits from the reciprocating movement of the e3® torque control motor.

 

        

[Drsumitra]

 Research papers and studies conducted to discuss the efficiency of rotary files in endodontics

Root canals from single-rooted teeth were instrumented using either hand NiTi instruments in the alternated rotation motion technique or rotary BioRaCe instruments. The irrigant used in both groups was 2.5% NaOCl. DNA extracts from samples taken before and after instrumentation were subjected to quantitative analysis by real-time polymerase chain reaction (qPCR). Qualitative analysis was also performed using presence/absence data from culture and qPCR assays.

Results
Bacteria were detected in all S1 samples by both methods. In culture analysis, 45% and 35% of the canals were still positive for bacterial presence after hand and rotary NiTi instrumentation, respectively (p>0.05). Rotary NiTi instrumentation resulted in significantly fewer qPCR positive cases (60%) than hand NiTi instrumentation (95%) (p=0.01). Intergroup comparison of quantitative data showed no significant difference between the two techniques.

Conclusion
There was no significant difference in bacterial reduction in infected canals after instrumentation using hand or rotary NiTi instruments. In terms of incidence of positive results for bacteria, culture also showed no significant differences between the groups, but the rotary NiTi instrumentation resulted in more negative results in the more sensitive qPCR analysis.

© 2012 International Endodontic Journal. Published by Blackwell Publishing Ltd

        

[drmithila]

A nice summary of importance of controlled irrigation Dr. Philippe Sleiman
Irrigation is a major step in endodontic treatment. A variety of chemicals are used to achieve what I like to consider the chemical preparation of the root-canal system.
Sodium hypochlorite (NaOCl) is a major component of the chemical preparation, mainly owing to its ability to attack the collagen component of the pulp tissue, and it is very cost-effective. However, one of the problems of using NaOCl is its safety, especially during its delivery inside the root-canal system and the ability to limit its delivery strictly to root-canal space and nothing but the root-canal space.
Going beyond the limit of the root-canal space causes serious problems, the gravity of which depends on the amount of NaOCl passing to the margins of the periodontal ligament or even attacking the periodontal ligament. A small amount can result in pain or discomfort after treatment, whereas a larger amount, especially in cases of large andor open apices, can accidentally be delivered inside the maxillary bone, travel via veins and arteries to primary anatomical organs and cause extensive, serious and very dangerous reactions. It is possible that the majority of such incidents are treatable with steroids and antibiotics, as they are limited to muscle and bone inflammation and slight reversible necrosis.

Sometimes we are not that lucky. Irrigating the last few millimetres in the root-canal space is an important key to treatment success, and a certain amount of NaOCl may be delivered into the maxillary sinus especially in the area of the maxillary second premolar and first molar. The case discussed below was the result of accidental NaOCl delivery into the maxillary sinus.
Case report
The patient was referred to my office for a complaint regarding the maxillary molar. After examining the patient and looking at her preoperative X-ray, I saw nothing wrong with the existing root-canal treatment, at least concerning the roots, but found a vague image in the sinus that I thought could be related to the maxillary molar and could be the cause of the problem. I asked my assistant to take a panoramic X-ray, which demonstrated a much larger problem inside the sinus but at that point I did not realise the scale of the issue.
Turning back to the patient, I went into some questions related to the issue, such as “Do you have problems breathing through your nose on this side?”, “Can you describe to me the pain or discomfort you are having?”, “Can you tell me if anything unusual happened during your previous root-canal treatment?” and “What were the indications for this treatment several months before?”. The patient, quite unexpectedly, told me that during the procedure she had had a chlorine taste in her throat arising from her nose as if a liquid was dripping internally. Also, after the treatment was over and she was on her way home, a strange liquid with the same chlorine smell began dripping from her nose.
Upon hearing that, I asked the patient to have a CBCT scan of the maxilla because it was necessary to establish the situation in the sinus. The patient was nervous and anxious, so I asked the radiology centre if they could capture the CBCT scan for her on the same day as a favour.
A couple of hours later, the patient returned to my office and I took the time to examine the images. In the panoramic view, it was clear that half of the sinus was filled with inflammatory tissue in the sectional views, I noticed that the posterior wall of the sinus was non-existent in some places . Potentially, it could be the position of the patient during the root-canal procedure that made NaOCl stagnate on the posterior wall and aggravate the damage.
The patient was informed of my opinion and recommended to see her otorhinolaryngologist, who took over the case, since it was already beyond the specialty of the dental profession and so she did.
Conclusion
As we have seen, what seems to be a normal root-canal treatment can hold serious implications for human health. Although it is very true that we need irrigation to clean the root-canal system, those chemicals need to be limited to the root-canal system only, as even a few drops of NaOCl approaching the periodontal ligament may create an inflammatory region and area of tissue damage as a result of an aggressive chemical reaction.
Sometimes this process is limited and may only cause minor discomfort for a couple of days, but when the amount of chemical is larger more severe problems may occur, for which the use of steroids and antibiotics is recommended. A major accident can still happen at any time when an amount of chemical travels outside the oral cavity and causes a more serious complication.
One of the safest options that we currently have at our disposal is the EndoVac system (SybronEndo), which is designed specifically to deliver fresh irrigant all along the root-canal system and, most importantly, to clean the last 3 mm of the root-canal system using the MicroCannula. It allows us to be certain that no chemicals can go beyond the limits of the root-canal space, nor cause any serious or even minor damage.

        

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