step back

Root canal preparation should end apically at

• radiological opening

• anatomical opening

• physiological opening

• none of the above is true

Working length is

• the length of the root canal from the entrance to the clinical foramen

• the distance from the reference point to the anatomical foramen

• distance from the bottom of the pulp chamber to the anatomical foramen

• the distance from the reference point to the inner opening

The following statement about the endometers (apex locators) is correct

• the principle of operation is based on the difference in the electrical conductivity of the tissue around the root of the tooth and within the canal itself

• it consists of four electrodes that close the circuit

• they serve to examine the patency of root canals

• they are unreliable and complex to use

Sodium hypochlorite is used

• as an oxidizing agent for dissolving the organic content of root canals

• as a chelator for negotiation of calcified canals

• only at the beginning of the instrumentation

• in a concentration of 15%

H-files (Hedström instruments) are employed using

• filing movements

• reaming movements

• watch-winding movements

• everything stated is correct

The master apical file in the step-back instrumentation technique is

• the first instrument that binds in the area of ​​the internal opening and cannot be pushed over the apex without pressure

• the largest instrument to reach working length

• the last instrument by which we instrument the coronal part of the root canal

• none of the above is true

The recapitulation in the step-back instrumentation technique is

• irrigation procedure after each instrument

• the procedure of inserting the initial apical file, which we introduce to full working length, after each larger instrument

• the procedure of inserting the master apical file to full working length, after each larger instrument

• the procedure of inserting 3 - 5 consecutively larger endodontic instruments than the master apical file, which is introduced every 0.5 - 1 mm shorter than the previous one

In the step-back instrumentation technique, the coronary part of the root canal is shaped by

• K-reamers

• K-files

• H-files

• Gates-Glidden drills

The formation of so-called ledges in the root canal is diagnosed by the appearance of

• sudden pain in the patient

• sudden appearance of blood in the canal

• loss of working length and feeling as if the instrument is hitting a wall

• shortening the length of the instrument