FAQs about the Mtwo system

1. How often can Mtwo instruments be used?

It is safest to use Mtwo® instruments only once. Should you use an Mtwo instrument more than once, it is very important to document the frequency of use by means of control stickers. The number of times an instrument can be used depends on the strain put on it during root canal preparation.
Examine the Mtwo instrument visually for signs of material fatigue after use. Optical means of magnification are very helpful: e.g. magnifiers, dental loupes and microscopes. Discard the instrument immediately if it shows
the following defects:

  • Instrument bent (plastic deformation)
  • Spirals deformed
  • Cutting edges damaged
  • Cutting edges blunt
  • ISO colour coding missing
  • Corrosion
2. Is it necessary to clean the instruments during canal preparation?

We recommend removing accumulated debris from the instrument during preparation by using an interim stand. The instrument is cleaned by simply inserting the instrument into the foam disk. This procedure prevents debris from accumulating in the instrument’s flutes which would increase the friction within the canal.

3. When should the working length be determined with an apex locator?

When starting root canal treatment with rotary nickel-titanium instruments, the canal patency should be determined with a hand instrument, and a glide path should be created. The working length should be determined with an electronic apex locator and the hand instrument before using an Mtwo® instrument. In order to verify the working length, e.g. in curved canals, the measuring result can be rechecked after each Mtwo instrument.

4. Is it necessary to enlarge the canal access before preparation with Mtwo?

The brushing file movement and the excellent lateral cutting efficiency of Mtwo® ensure removal of obstructions within the coronal third. Thus, with every instrument used, the canal access is gradually enlarged. A separate root canal enlargement is, therefore, not mandatory. However, the canal access can be enlarged with an Mtwo 25/.06, for example.

5. How to determine that the apical preparation size has been reached?

After carrying out apical gauging and subsequent preparation, a visual inspection can be carried out. Humid or red debris located on the lower instrument third is a signal that further apical preparation is necessary. Dry and white dentine chips however mean that the apical target size is reached.

6. When do I irrigate the root canal most efficiently during preparation with Mtwo?

The root canal can be irrigated at any time during preparation. Thanks to the instruments‘ conicity in combination with Simultaneous Shaping to full working length, irrigation of the root canal can already be carried out after use of the second Mtwo® instrument size 15/.05 to 3 mm short of full working length. We recommend using an ISO size 30 irrigation cannula.