Cleaning & Shaping with the SAF

1. Adjust the rubber stopper on the SAF to indicate the desired working length.
2. Please note: To verify the adequacy of the glidepath, it is recommended to manually insert the SAF to working length before proceeding (see the "Manual Verification" chapter above).
3. Continuous irrigation should be applied throughout the procedure. The choice of irrigant is at the discretion of the dental professional operator. The recommended irrigant flow rate is 4 mL/min (new users may initially use a lower flow rate). The use of NaOCl irrigant with the SAF system is recommended, as the SAF also inflicts sonic activation of this irrigant.
4. A power suction tip, preferably a surgical one, should be placed near the tooth, to collect the expected continuous overflow of the irrigant. Irrigation can be applied by the peristaltic irrigation pump of the given device.
5. Attach the irrigation tube to the SAF's irrigation barb, and then pull the tube slightly back. Stretching the irrigation tube that is connected to the file helps to control the speed of the file's rotation. Some rotation is required, to repeatedly shift the circular position of the file when entering the canal, but excessive rotation will inflict unnecessary mechanical stress on the file. The colored stripe on the SAF's rubber stopper allows to visualize the rotation and estimate its speed.
6. Insert the SAF gently into the canal while operating the motor, and continue with light pecking motions. Do not force the SAF apically. This file is not a penetrating tool, as opposed to common rotary/reciprocating instruments, and attempting to force the file to working length when difficulty is encountered may result in buckling and damage to the file . Working length will be reached during the SAF operation, usually within 30 seconds of operation. Move your hand in continuous short in-and-out pecking motions to prevent binding of the file in the canal and to allow the file to shift its circular position when entering the canal during every outbound stroke of the pecking motion. View the colored stripe on the rubber stopper to verify that the file indeed rotates when disengaged from the canal and shifts to a different position when it re-enters the canal. If it does not rotate, check (a) if your outbound strokes reach far enough coronally to allow the file to unbind and rotate; (b) if the tube tension is not too tight; or (c) if there is some malfunction of the clutch mechanism in the handpiece head that prevents it from rotating the SAF.
7. If resistance to insertion or inability to reach working length within the initial 60 seconds are encountered - stop, remove the file and try the following steps:
   1. Make sure that the shaft (tubular part) of the SAF does not engage the access cavity walls; this may happen in incisors or premolars that present exceptionally small pulp chambers / access cavities. If so, use a longer SAF, but make sure it does not buckle (fold upon itself) during operation. Further enlargement of the access cavity is usually not required.
   2. Make sure your coronal canal preparation has been adequately flared by the Pre-SAF OS rotary instrument.
   3. Re-establish the glidepath by using the Pre-SAF 2 rotary instrument, which at this point may be able to remove gross pulp tissue remnants from the canal, if present. Such remnants may prevent the advancement of the non-penetrating mesh-like SAF.
   4. Make sure that the length of the active part of the SAF is at least equivalent to the length of the canal from its coronal orifice to working length.
   5. Optionally, use EDTA lubricant (i.e. Glyde, RC Prep, etc.) when introducing the file into the canal.

    

   Most of the dentin removal by the SAF is accomplished during the first 2 minutes of operation. The remaining 2 minutes of operation allow the agitated irrigant to thoroughly clean the canal.

   In extremely contaminated canals, extremely convoluted canals or canals with persistent bleeding, 1-2 additional minutes of operation may be required.

    

8.  The advised irrigation protocol for the SAF instrumentation is a sequence of sodium hypochlorite and EDTA. Such combination allows to dissolve organic materials inside the canal (pulp tissue, bacteria, etc.), and to remove inorganic debris and smear layer. Research has shown that this technique of altering between sodium hypochlorite and EDTA may achieve a high level of cleanliness and disinfection.
   The following irrigation protocol is advised, although modifications are possible, at your professional discretion:

1. 1. 1. Use NaOCl (sodium hypochlorite, Dakin's solution, etc.) for the first 3 minutes of the SAF operation. The sodium hypochlorite, which has otherwise a high surface tension, will be carried mechanically by the SAF to working length, without pressure, to be continuously refreshed in the apical area every 20-30 seconds. The SAF will not only irrigate the canal with fresh, fully active sodium hypochlorite, but will also sonically agitate it, due to its continuous 5,000 vibrations-per-minute. Any clinically-acceptable efficient concentration of sodium hypochlorite may be used (2.5%, 5.75%, etc.). It is advised not to use certain commercial products that contain surfactants, that reduce the surface tension of the irrigant and might not enable sufficient refreshment by the SAF.
      2. Flush the canal with EDTA solution (17%): Disengage the SAF from the canal. Flush the canal with EDTA solution to remove the remaining NaOCl. Leave the remaining EDTA inside the canal, and turn off the irrigation pump. Operate the SAF for 30 seconds with vibration and pecking motions, without the continuous flow of the NaOCl irrigant, with only the EDTA in the canal. The SAF will push the EDTA into narrow areas and enable the removal of debris and smear layer.
      3. Use NaOCl again for 30 seconds: turn on the continuous flow from the irrigation pump and operate the SAF inside the canal for additional 30 seconds. This will flush out the remaining EDTA and provide final irrigation of the canal, to affect any organic materials and bacteria under and/or within the smear layer that were exposed by the EDTA action. 
      4. Dry the canal using sterile paper points, according to standard clinical procedure.

9. Gauge the apical region of the canal using a .02 taper gutta-percha cone or with NiTi hand-files to confirm root canal enlargement. Final apical canal dimensions will typically be 2-3 ISO sizes larger than the initial apical size. If apical enlargement is less than desired, another 1 minute of work with the SAF may be applied, including the simultaneous irrigation.

10. Canal shaping is now complete, and your preferred obturation method may be used.