FAQ

Frequently asked questions about the SAF System:

 

Q
How does the Self-Adjusting File (SAF) System work?
A

SAF mode of operationThe SAF System is based on a hollow file that adapts itself to the irregular shape of the root canal, and overcomes many of the drawbacks of conventional instrumentation systems (hand files, rotary). It is composed of nickel-titanium (NiTi) and designed as an elastically-compressible, thin-walled pointed cylinder. The SAF is operated with gentle vertical vibration, at the rate of 5,000 rpm, and its abrasive surface scrubs the walls of the canal to achieve a gradual circumferential enlargement. Its hollow lumen allows the continuous flow of an effective irrigant (sodium hypochlorite, EDTA, etc.) through the SAF simultaneously during shaping, turning its operation into a true chemo-mechanical instrumentation, to achieve superior cleaning and disinfection within 4 minutes of operation.  

The SAF is not a rotary instrument, as it does not rotate inside the root canal like other motorized instruments. Instead, vertical vibration is operated by a special handpiece head, to grind against the canal walls, remove very fine dentin (or as we like to call it "dentin dust"), and immediately wash it away. The handpiece is operated by short pecking motions, which allow the SAF's slow, low-torque rotation to shift its position whenever it unbinds from the canal walls.
For more details, read more about the SAF System or watch our instructional video.

 

Q
How does the SAF adapt to the shape of the canal?
A

The SAF is available in two diameters - 1.5 mm and 2.0 mm.

The 1.5 mm SAF compresses down to 0.2 mm, which is equal to the size of a #20 K-file. This compression allows the lattice-like structure of the SAF to adapt to the irregular shape of the canal.

While the SAF is compressed to 0.2 mm in one aspect, in another aspect it can adapt in a range from 0.2 mm to 2.4 mm, allowing it to shape the canal according to its original shape. This way the SAF passively takes the form of the root canal – oval, tear-shaped, C-shaped, round, etc., to enable a minimally-invasive preparation.

At the end of the preparation, the canal will be expanded by 2-3 ISO sizes larger than its initial size, an expansion that occurs in all aspects, and not just in the narrow diameter of the canal, as happens with hand files or rotary instruments.

 SAF tooth - picture by Dr. Roheet Khatavkar  SAF 1.5 round to long oval s 

 

Q
Canals are usually round, why is adaptation even needed?
A

The common misconception that root canals are usually round is based on lack of knowledge in the past and disinformation in the present. Wu & Wesselink (OOOOE, 2000) defined that long-oval root canals in the apical third consist of more than 25% of the cases, and that in some teeth the prevalence is higher than 50%, and sometimes reaches more than 90%.

Countless micro-CT endodontic researches have presented the high prevalence of the irregular root canal anatomy, and anyone working with cone-beam computer tomography (CBCT), as well as a clinical microscope, should be well-aware of that. And still, many dentists consider root canals to have a round cross-section, simply because the instruments that we use to clean them have a round cross section. Those of us who are aware of the irregular shape of the root canals, but still work with instruments with a round cross-section, may attempt to work circumferentially or with brushing motions, in an attempt to compensate for the irregular shape of the canal. This is done despite researches such as the one of Elayouti (Int Endod J, 2008), that showed that such instruments cannot accommodate to the oval outline of the canals, and that operation of the instruments in brushing motions only causes excessive removal of sound dentin, while still unable to contact most of the canal walls. Paqué (J Endod, 2009) also showed that rotary instruments and hand files cannot touch most of the canal walls, and still – the round-cross-section instruments are commonly used.

The SAF, on the other hand, is able to adapt to the irregular shape of the root canal, can shape, clean and irrigate the canal simultaneously, and allows avoiding most of the damages created by rotary endodontic instruments and hand files.

 

Q
Does the SAF shape the canal, or is it just an irrigation device (a "finisher")?
A

Part of the paradigm-shift in the SAF's mode of operation is the fact that it irrigates and agitates the irrigant simultaneously during the shaping of the canal. This revolutionary new concept makes it a little difficult to conceptually differentiate the SAF from irrigation systems, which causes some dentists to label it as an irrigation device, simply because it irrigates.

Much as other instrumentation systems, the SAF requires an initial glidepath preparation, to ISO size #20. It is operated at working length for four minutes, during which it shapes the canal and expands it, both longitudinally and circumferentially, by 2-3 ISO sizes. Since the SAF can compress and adapt itself to the irregular shape of the canal (oval, tear-shaped, etc.), this expansion will be most conservative and will retain the original morphology of the canal, while expanding it in a minimally-invasive way.

The SAF is an all-in-one shaping-irrigation-agitation system, and provides supreme results in compare with any other instrumentation or irrigation system, so it certainly cannot be defined as "just a finisher".

 

Q
What is the required initial preparation before the SAF can be operated inside the root canal?
A

The 1.5mm SAF can be compressed down to 0.2mm, which is equal to an ISO #20 file with a 2% taper. In most cases this glide path is sufficient, but in narrow and curved canals a slightly wider initial taper (4%) is required.
 

Q
Wouldn't it be better to prepare a larger glidepath before using the SAF?
A

Some people suggest that preparing a larger initial preparation might help relieve some stress from the SAF and will allow to use it mainly as an irrigation tool. This is a misconception, since the SAF is not solely an irrigation tool, and using it only as such would take away many of the benefits it provides.

It is important to keep a minimally-invasive glidepath preparation before the SAF:

  1. To assure the penetration of the SAF into canal recesses. If those recesses are already filled by debris created by an excessive glidepath preparation, the SAF might not be able to sufficiently penetrate those areas.
  2. To avoid drawbacks related to excessive initial preparation, by rotary instruments of hand files, that include packing of debris, apical extrusion of debris, canal transportation, excessive removal of sound dentin and creation of dentinal micro-cracks.

 You can read more about the glidepath preparation in the Clinical Guidelines.

 

Q
For how long do I need to operate the SAF in each root canal?
A

The advised time of operation of the Self-Adjusting File in each root canal is 4 minutes. In those four minutes, the SAF achieves shaping of the canals, cleaning and disinfection, as well as agitation of sodium hypochlorite by its sonic vibration. This means that many of the goals of the endodontic treatment are achieved by the same instrument, during this short period of operation.

 

Q
What are the dimensions of the final preparation (apical size and taper)?
A

The SAF has no blades and no rigid predetermined form; therefore, it does not impose its shape on the canal but rather complies with the canal’s original shape. This is true both circumferentially and longitudinally.
Hence, the final dimensions of each canal greatly depend on its original morphology.

As a rule-of-thumb, final canal dimensions will be apically 2-3 ISO sizes larger than the initial apical size, with a taper of 4%. For example, if the initial apical size was ISO #20, the final apical size is expected to be ISO #30-#35.
To determine accurate final dimensions it is recommended to gauge the prepared canal using a gutta-percha master cone or a NiTi hand file.

 

Q
How should I obturate the canal after SAF instrumentation?
A

Most root canals are irregular in shape and not completely straight and round in cross-section. This means that in most cases standardization is not an advantage - Long-oval root canals, for example, cannot be turned into round ones even at the expense of significant loss of sound dentin. Such canals will remain oval regardless of the instrumentation mechanism (SAF or otherwise), and need to be obturated according to their natural irregular morphology.

The SAF provides a higher level of cleanliness before obturation (De Deus, J Endod; 2013), leading to higher bond strength of obturation materials (Pawar, Int Endod J; 2015). Almost every obturation technique is suitable for the obturation of irregularly-shaped canals, as detailed in the Clinical Guidelines for the SAF system.  Most obturation techniques can be used, with slight modifications, including lateral compaction, heat-softened gutta-percha, flowable gutta-percha, obturators, various sealers (BioCeramic sealer and others) or customized gutta-percha.

obturation

 

Q
Can the SAF be used in re-treatment ("re-endo")?
A

The SAF cannot act as a single instrument in case of a retreatment, and requires prior removal of the previous obturation material by other means. Then, the SAF System can provide a very high level of cleanliness, as shown in various researches, either with the use of gutta percha softeners such as Chloroform (Abramowitz, Int Endod J; 2012 , Solomonov, J Endod; 2012) or without the use of gutta percha softeners (Voet, J Endod; 2012).

You are invited to read the retreatment chapter on the Clinical Guidelines for the SAF System to learn more about this issue.

 

Q
How do I control the amount of dentin removed?
A

In order to remove dentin, the SAF needs to be sufficiently compressed inside the root canal. As can be seen in the chart below, the amount of dentin removed during operation time significantly decreases when the SAF becomes less compressed inside the canal, once a certain amount of dentin was already removed circumferentially.

 Enlargement by ISO#

 

Q
Can I over-instrument the canal?
A

The canal cannot be over-instrumented, as the force applied by the SAF diminishes with the enlargement of the canal to the extent of not removing any more dentin (see chart below). This means that even when the SAF is operated for longer than the advised operation time, it will not over-instrument the canal, and will not create a risk of perforation.

 Canal diameter - SAF Force

Q
Can the SAF activate (agitate) sodium hypochlorite inside the canal?
A

The SAF carries the sodium hypochlorite into the canal mechanically, without pressure. The SAF's operation at 5,000 gentle vertical vibrations a minute induces sonic agitation of NaOCl inside the canal, and pushes the irrigant into very narrow areas which the SAF cannot reach mechanically. Since the SAF washes away the debris immediately upon its creation, the activation of the irrigant allows the sodium hypochlorite to reach into very narrow areas and to thoroughly clean and disinfect the labyrinthine root canal structure.

The SAF was shown (Lin, Shen, Haapasalo, J Endod 2013) to be significantly more efficient in disinfecting very narrow areas which were incubated by bacteria, when compared to hand files and rotary instruments, and was shown to be most efficient in removing debris from the apical area of the root canal (Çapar, Sca; 2014).

 

Q
Can drip-irrigation by the SAF be more effective than syringe-and-needle irrigation?
A

When it comes to narrow areas, pressure cannot help the irrigant reach in, and poses a safety risk. Irrigation by syringe and needle requires significant initial expansion, and is very confined, as only a small amount of the Dakin's solution can reach the apical area, where the use of hand files or rotary instruments has already blocked the narrow areas by debris that is very difficult to remove.

The SAF achieves efficient irrigation even when the canal is still sized #20, which helps to preserve sound dentin. Sodium hypochlorite has a high surface tension, which allows the SAF to carry it mechanically into the canal, without pressure. NaOCl flows into the SAF by a peristaltic irrigation pump, at a rate of 4mL/min, and is continuously refreshed in the apical region every 20-30 seconds, as can be seen in the video below. Irrigation is enhanced by the sonic agitation of the sodium hypochlorite solution by the vibration of the SAF, to achieve results which are much better than syringe-and-needle irrigation.

 

Q
Does the SAF provide better irrigation than negative-pressure irrigation (EndoVAC, for example)?
A

Negative pressure irrigation systems, such as EndoVAC, were invented to allow better irrigation while overcoming the risk of creating a sodium-hypochlorite accident.

Such complementary devices indeed provide irrigation that is more efficient than syringe and needle, but still suffer from several shortcomings, including the need for a significant initial apical size (#40 or more), inability to be operated in curved canals, and disregard of the basic problem – irrigation alone cannot remove the debris that is packed by conventional rotary or hand instrumentation.

In oppose to negative-pressure irrigation, the SAF System is not an irrigation device, but a shaping-cleaning-irrigation system. The SAF does not pack infected debris into narrow areas in the canal, allows simultaneous irrigation without excessive removal of sound dentin even when the canal is only size #20, can operate in curved canals, and sonically activates the irrigant during its operation. This way, the SAF provides a safe irrigation solution, while shaping the canal at the same time.

 

Q
Does the SAF provide better irrigation than the combination of passive-ultrasonic irrigation (PUI) and EDTA?
A

Passive Ultrasonic Irrigation (PUI) and Ethylenediaminetetraacetic Acid (EDTA) are perhaps the strongest tools in the hands of dentists and endodontists to clean the root canals from both organic remains and inorganic debris. The ability of PUI to activate sodium hypochlorite and facilitate its penetration into narrow areas, as well as the ability of EDTA to remove inorganic debris and smear layer, are nothing to be taken lightly. However, when these techniques are being used after conventional instrumentation techniques (hand files, rotary or reciprocating instruments), the damages that were already caused are far too much for these techniques to handle. Paqué, Boessler and Zehnder (Int Endod J, 2011) showed that 50% of the packed debris cannot be removed even with the combination of EDTA irrigation and PUI – simply because the instrumentation techniques pack debris into the narrow areas so forcefully that it cannot be removed.

On the other hand, the Self-Adjusting File enables a chemo-mechanical instrumentation, of creating very fine debris, immediately washing it away by the simultaneous NaOCl irrigation, continuously refreshing the irrigant and sonically agitating it by the vibration of the SAF. This is why Metzger (J Endod, 2010) showed that after SAF instrumentation the canal is 100% free of debris and 65%-100% free of smear layer. On Another research, Paqué (Int Endod J, 2012) showed that instrumentation by ProTaper and irrigation with NaOCl and EDTA leaves 7.9% of the volume of the canal still filled with debris, while SAF instrumentation that combines NaOCl and EDTA irrigation leaves only 1.3% of the volume of the canal with debris. Not perfect – but much better.

 

Q
Does the SAF provide better results than non-centralized rotary instruments?
A

Non-centralized rotary instruments (TRUshape, etc.) were recently introduced in an attempt of rotary instruments manufacturers to overcome the severe drawbacks of the conventional techniques, including the inability to adapt to the irregular shape of the root canals and packing of debris into narrow areas. The non-centralized instruments are used as finishers, after the canal was already machined by rotary instruments (causing excessive removal of sound dentin, dentinal micro-cracks, debris extrusion, etc.), to stir the irrigant inside the canal and to try to contact more of the canal walls in order to remove some of the packed debris.

The admission of the inability of rotary instrumentation to adapt to the canals and to provide proper cleaning is indeed noble, especially since these issues have been disregarded by these manufacturers for many years. However, this attempt to repair the errors created by rotary instruments is only partial, as only a minority of the errors is being dealt with.  These finishers have been hastily launched, without any prior scientific research (such research is yet to be published), while ignoring the basic fact - it is better to avoid the errors (as the SAF System successfully does) than to try to eventually repair a few of them.

 

Q
Continuous irrigation with sodium hypochlorite sounds dangerous… is that a risk?
A

Indeed, large quantities of sodium hypochlorite are used during the SAF's operation (4 mL/min for 4 minutes in each canal – you can do the math).

When used in other techniques (such as with a syringe and needle) the use of NaOCl might create a risk, such as of extrusion of the irrigant or excessive exposure to either the irrigant itself or to byproducts such as trihalomethanes (THMs), which are suspected as carcinogenic. However, the use of the SAF is very safe, as it generates a NO-PRESSURE irrigation. NaOCl has a high surface tension, and is carried mechanically into the canal by the SAF, to reach working length even when the canal is only size #20. The irrigant at the apical area is constantly refreshed by the SAF, and then flows back coronally, to the access cavity. The use of a properly adapted rubber dam and suction will help ensure the safe use of the irrigant.

The irrigant does not extrude periapically, since the Self-Adjusting File only takes up to 62% of the volume of the canal (Hof, J Endod; 2010), which allows the backflow of irrigant. The lattice-like structure of the SAF does not allow it to act as a piston, so it can only create a pressure of 396 Pa, which is significantly lower than the eruption pressure required to go beyond the apex, which is 832 Pa. This video, of a sized #20 root canal with an open apex, illustrates the level of safety of using the SAF. This is why the use of sodium hypochlorite with the SAF is safer than with other methods, at various commonly-used concentrations (see Alves, J Endod; 2011).

 

Q
Can minimally-invasive shaping and no-pressure irrigation really clean the root canal?
A

The Self-Adjusting File may seem passive and delicate, but its ability to adapt to the natural shape of the canal and remove the infected dentin in a very conservative manner, while simultaneously delivering continuous irrigation – allow it to achieve an extremely high level of cleanliness, as shown in dozens of scientific researches. Just to quote a few:

 

Q
Is the SAF safe to use?
A

The SAF provides a very high level of safety in treatment. This is reflected in the following aspects (see other questions on this FAQ section to read about the various aspects):

      1. There is no risk of creation of dentinal micro-cracks, since the SAF is hollow and cannot inflict much force in its operation.
      2. The use of no-pressure irrigation allows using copious amounts of sodium hypochlorite without the danger of sodium hypochlorite accidents.
      3. The risk for file separation is extremely low, and is as low as 0.1%.
      4. The risk of apical extrusion of debris is very low, due to the continuous no-pressure irrigation.
      5. The risk of canal transportation or perforation virtually doesn't exist, and was shown in various researches to be significantly lower than other instruments.
      6. The SAF shapes the canal in a minimally-invasive way, leaving as much sound dentin as possible.

This way, the SAF provides a very high level of cleanliness in the endodontic treatment, without the need to compromise on the various risks and damages created by other instruments.

 

Q
The structure of the SAF seems delicate. Does it break easily?
A

The SAF is actually very safe to use, and has an extremely low chance for separation. Despite its fragile appearance, the lattice-like structure provides the SAF more strength than instruments with a solid central core. The SAF works in vertical vibration and does not rotate inside the root canal, in contrary to rotaries, that bind with the canal walls, rotate and tend to break when they encounter increased strain.  

As other instruments made of Nickel-Titanium, the SAF is very flexible, but is bound to break eventually. However, its operation in vertical vibration and not rotation, as well as its lattice-like structure, prevent it from screwing into the walls of the canal as rotary instruments do when they break. This means that a broken SAF fragment can easily be removed or bypassed, without unnecessarily sacrificing sound dentin.

Farmakis (Int Endod J, 2013) showed that deformation of the SAF occurs mainly as detachment of one of the arches or struts at the connection point on one of the longitudinal beams of the file, and that in no case did the metal fragment block the canal. When such a strut starts to separate, the initiation of separation can be seen before it separated, and the dentist can stop using the file.

Solomonov (J Conserv Dent, 2015) showed that the chance for file separation of the SAF inside the canal during clinical use is 0.6%, and that the separated part can almost always be easily retrieved, to a level that non-retrievable separation only occurred in 0.1% of the cases. Even when the separated fragment remains inside the canal and cannot be retrieved, the separation always occurs in an environment with copious amounts of sodium hypochlorite, the fragment is very thin, and no excessive removal of sound dentin is required to bypass it.

Scanning Electron Microscopy    SAF breakage s

 

Q
How can I reduce the chance of breakage of the Self-Adjusting File?
A

As previously noted in the FAQs about the low chance of breakage of the SAF, the chance of breaking the SAF inside the canal is extremely low, and when that happens it is usually very easy to remove.

However, there are several clinical tips that can help reduce the chance of breakage and extend the useable life of the SAF:

  1. Create a proper glidepath – both coronally (coronal funneling by an orifice shaper) and to working length (by Pre-SAF 2 or another #20/.04 glidepath instrument). Make sure that the preparation of the glidepath eliminates gross pulp tissue remnants, which may make it difficult for the SAF to reach working length. More information is available on the Clinical Guidelines.
  2. Following the glidepath preparation, manually verify that the SAF is able to reach working length. Do so according to the instructions in the Clinical Guidelines about the manual verification, to check both the working length compatibility, as well as the vertical axis of the root canal. Insert the SAF manually in a vertical motion, without using clock-winding motions, and if necessary, check several different angles after disengaging the SAF from the canal.
  3. When connecting the SAF to the irrigation tube, adjust the rotation speed by pulling the tube, to a level that assures slow rotation of the SAF.
  4. During the motorized operation, make sure to work only according to the vertical axis and avoid brushing motions. Make sure that your outbound motions are just sufficient to disengage the SAF from the canal walls sufficiently for it to shift position. Any lateral motions of brushing motions will apply unnecessary lateral pressure onto the file.
  5. Choose the right size of SAF. If you choose a 1.5mm file for a canal which is size #35 or larger, the file might not be compressed enough in the canal, might rotate, and subsequently might tear quicker.
  6. Due to its asymmetrical shape of the SAF, in curved canals it may not reach working length in every in-bound stroke of the pecking motions. When you encounter resistance – do not push, as the SAF is not a penetrating tool - but withdraw, let the SAF shift its position, and in other positions the file will be able to reach working length. After a minute or two the narrow curvature will be expended to a level that allows the SAF to reach working length in every position. In case that the SAF shows resistance to pulling, due to an isthmus or a curvature, release it gently and don't pull forcefully.
Q
Does the SAF create dentinal micro-cracks?
A

The philosophy of the Self-Adjusting file is to adapt the instrument to the canal, rather than force the shape of the instrument onto the canal (as occurs with conventional instruments). Since it is hollow and compressible, the pressure inflicted by the SAF is minimal, and cannot create dentinal micro-fractures, in contrary to rotary instruments.

The following chart (adapted from Kim, J Endod 2010; Kim J Endod 2013) shows how the reaction force generated by the SAF is only 10% of the tensile strength of the dentin, while rotary instruments create forces that are 3-4 times higher than the tensile strength of the dentin, which is the reason for the micro-cracks formation.

Kim stress graph

 

Q
Can the SAF cause canal transportation?
A

The SAF provides a minimally-invasive instrumentation and does not impose its shape onto the canal. Since it has a hollow lumen, the Self-Adjusting File does not apply much pressure onto the canal walls, and its ability to remove dentin and expand the canal depend mostly on its ability to compress its NiTi mesh inside the root canal and apply repetitive light pressure to scrub the canal walls.

This is opposed to the machining pressure that rotary instruments inflict onto the canal walls, which in combination with their attempt to straighten back to their original form – is likely to cause canal transportation, especially in curved canals, as shown in various researches (Peters, Int Endod J 2003).

This is why the SAF was found by Burroughs (J Endod 2012) to cause significantly less canal transportation when compared to some of the most flexible rotary instruments.

 

Q
Does the SAF cause extrusion of debris?
A

The SAF uses continuous irrigation during the instrumentation process, which turn its operation into a chemo-mechanical preparation of the canal. This means that the very fine debris that is created by the scrubbing motion of the SAF is washed away immediately, and is not extruded beyond the apex.

The continuous refreshment of NaOCl has an important part in avoiding the extrusion of debris. De-Deus (J Endod, 2014) showed that the SAF is associated with significantly less debris extrusion compared with the use of hand files and rotary instruments. The importance of the copious continuous irrigation can only be emphasized when viewing the results of another research (Kirchhoff, J Endod, 2015), in which the SAF was used with a very low irrigation rate (1 mL/min), leading to more debris extrusion than shown in De-Deus's research, which used the recommended irrigation rate of 4mL/min.

 

Q
What equipment do I need to operate the SAF?
A

The SAF System is motor-driven, and requires the designated RDT3 handpiece head, a suitable endodontic motor and a peristaltic irrigation pump.

The SAF can be operated by either:

      1. The SAFedge System, including the EndoStation-mini, a lightweight rechargeable multifunctional endodontic instrumentation system that includes an integral irrigation pump and two interchangeable micromotors (SAF and Rotary).
      2. The SAFpro System, including the EndoStation, an advanced ergonomic all-in-one system that includes a motor and an irrigation pump in the same device, enabling to operate the SAF, as well as rotary and reciprocating instruments.
      3. The SAFbasic System, including the VATEA irrigation pump that acts as a supplement to various endodontic motors or electronically-controlled dental units, and provides the ability to use the SAF System with continuous and simultaneous irrigation.
      4. Compatible endodontic motors with SAF mode (including an integral peristaltic pump): EndoPilot by Schlumbohm, EndoCenter by Acteon, EndoSurgix by Oviron, and EndoEST by GeoSoft.
      5. Various physiodispensers that allow torque control and provide sufficient speed and continuous irrigation.

Please note that regardless of the type of unit, the purchase of the SAF Systems includes a hands-on instruction, which is necessary due to its' unique mode of operation.

 

Q
Which SAF sizes are available?
A

Two SAF diameters are currently available: 1.5 mm and 2.0 mm.

The SAF 1.5 mm is designed to shape and clean root canals with initial apical size of ISO #20-40, and the SAF 2.0 mm is designed for canals with initial apical size of ISO #35-60. The SAF 2.0 mm may also be used in wider canals (≥#70), but would then require the dentist to pay attention to the possible rotation of the file inside the canal.

The SAF 1.5 mm is available in three lengths (21, 25, 31 mm) and the SAF 2.0 mm is available in two lengths (21, 25 mm).

SAF length and active part s

Q
How do I choose which size of SAF to use?
A

The choice of the length of the file should take into consideration the length of the entire preparation, from the access cavity to working length, but also the length of the canal itself, from the orifice to working length.

If the canal is short, you would not want to choose a long SAF, since this may not allow the SAF to carry the irrigant into the canal as it should.

On the other hand, you would also not want to choose an SAF too short for a long canal, as it might not reach working length due to the non-compressible shaft of the SAF. The key is to make sure that the active part of the SAF can compress inside the canal.

More information is available on the Clinical Guidelines.

 

Q
Is the SAF a single-use instrument? Is it re-usable?
A

As other NiTi instrumentation systems, the Self-Adjusting File is CE and FDA approved for a single-use. It is autoclavable and can be used in more than one case in the same patient.

 

Q
Can the SAF be sterilized?
A

The Self-Adjusting File is provided non-sterile, and should be sterilized prior to use.

The sterilization temperature is 121°c, and from the second half of 2015 the new version of the file, "SAF-neo", will be introduced, to allow sterilization at 134°c.

 

Q
Is it possible to operate the SAF with any endodontic motor? How about manually?
A

The Self-adjusting File is motorized, so manual operation of the SAF would not be possible.

The SAF has two requirements for operation:

  1. The motorized use of the designated RDT3 handpiece head, which is the only handpiece head designed to accommodate the SAF friction grip attachment, and provide it with the movements necessary for its proper action (vertical vibration combined with a low-torque rotation).
  2. Simultaneous no-pressure irrigation at a rate of 4-5 mL/min, by an integral peristaltic pump.

The two most convenient and comprehensive solutions for the operation of the SAF are the SAFedge System, that includes the rechargeable EndoStation-mini, and the SAFpro System, that includes the EndoStation by Acteon (Satelec). Both systems enable to ergonomically use an advanced endodontic motor and a built-in irrigation pump in the same device.

There are several endodontic motors on the market that include a peristaltic pump, and enable using the SAF System with the RDT3 head. Such motors are the EndoPilot (Schlumbohm) and EndoCenter (Acteon / Satelec). Another option would be some types of physiodispensers, subject to their support of 5,000rpm rotation with a 1:1 handpiece and flow rate of 4-5 mL/min. 

Q
Can I use the SAF without continuous irrigation?
A

In order to achieve the expected results one should always use continuous irrigation with the SAF. Without continuous irrigation, or with insufficient level of irrigation, the dentin that was removed by the SAF will not be washed away, and will remain in the canal in the form of a thick "muddy" residue.

 

Q
What is the recommended irrigation protocol for working with the SAF System?
A

The best documented results were achieved when the SAF was used in a sequence of continuous irrigation of NaOCl and EDTA. The recommended operation and irrigation protocol for the SAF System can be found in the Clinical Guidelines.

  

Q
Is the SAF more time-consuming than rotary instruments?
A

The Self-Adjusting File (SAF) performs several procedures at the same time, and replaces a sequence of operations conventionally carried by the dentist. It shapes the canal, cleans and effectively irrigates the canal with copious amounts of sodium hypochlorite, and sonically agitates the irrigant to make it more active. This way, a single instrument replaces a number of procedures – sequential instrument replacement, irrigation protocols, irrigant agitation, etc. This allows saving time and performing the procedure more efficiently.

Siqueira (J Endod, 2010) compared the level of disinfection with SAF instrumentation to rotary instrumentation with syringe-and-needle irrigation (percentage of infected canals - 20% and 80%, respectively), and showed that the SAF achieved significantly higher disinfection although the treatment took half the time.

Solomonov (J Endod, 2012) compared retreatment with the SAF to retreatment with rotary instruments, showing that the SAF was able to remove more gutta percha than rotary instruments (percentage of remaining GP – 0.4% and 5.4%, respectively), despite the fact it took only half the treatment time.

 

Q
Can I use the SAF without a rubber dam?
A

rubberdamA rubber dam is a strict requirement in any root canal treatment, and can help the dentist keep an isolated working area while avoiding various dangers and mistakes. Since the SAF is operated with continuous NaOCl irrigation, it is strongly advised to use a rubber dam as part of every clinical procedure.

 

Q
Some peer-reviewed articles did not find the SAF to be favorable. Is that true?
A

In the few years that the SAF is in the market, it has been the subject of dozens of scientific researches, by renowned researchers from around the world which were intrigued by its revolutionary mode of operation.

The vast majority of articles have shown the supremacy of the Self-adjusting File over the traditional rotary instruments and hand files. Some researches, however, were not done according to the Clinical Guidelines for the SAF System – by not choosing the right size of SAF (by length or by diameter), by not using the irrigation correctly (type of solution or flow rate), etc.

The abstracts of all the major research articles about the SAF System are available on this website, and the ones that were not conducted according to the clinical guidelines are accompanied by a remark. You are invited to read more and find for yourself.

 

Q
Where is the SAF System sold? Can I purchase it online?
A

The SAF System is available in various countries around the world – to check the availability of the SAF in your country, please check our Distributors page.

The SAF System is not sold online, as the purchase does not only include the required equipment, but also a hands-on course, which is necessary since the work with the SAF System is different from any other motorized endodontic instrument.

 

Q
What is the price of the SAF System?
A

The Self-Adjusting File is sold with small price differences in different countries. Please contact your local distributor for the specific price on your market.

 

Q
Is the SAF more expensive than rotary instruments?
A

saf profileThe short answer is NO.

The long answer is that the Self-adjusting File is price-competitive to common rotary instrumentation systems, such as ProTaper, Twisted File (TF), MTwo and others.

Indeed, a single SAF costs more than a single rotary instrument. However, what the patient pays for is the treatment as a whole, not the instrument alone. When comparing the sequence of operation and the fact that the SAF enables simultaneous cleaning, shaping, irrigation and agitation, it is clear that the SAF replaces more than a single instrument. Considering those factors brings the cost per root canal when using the SAF System to be parallel or better than the cost of treatment with other motorized instrumentation systems.

Other than the parallel price and the savings on additional irrigation equipment, the cost of the treatment cannot be addressed only from the narrow aspect of the price of the file. There is significant economic value thanks to the SAF's additional clinical benefits, including the avoidance of post-operative pain, the highly efficient endodontic treatment, the ability of the dentist achieve significantly improved cleaning and disinfection in a short time, with less risks and less complications – benefits that have a clear economic value by themselves, for the dentist as well as or the patient.