TREATMENT : 4 steps
Step 1 
Exploring the coronal 2/3 of the canal and making it permeable:
Instruments used:
K-files No. 10 and 15 and/or Presequence used until
they move freely in the canal.
Objective:
Securing and preparing the access for CMA instruments into the coronal 2/3 of the canal.
Step 2
Flaring the coronal and middle part of the canal:
Instruments used:
CORONAL
Flares out the coronal part of the canal.
MEDIAN
Enlarges the middle part of the canal.
Objectives:
• Straightening the root canal entry.
• Enlarging the root canal entry and coronal 2/3 of the canal to provide continuity between the pulp chamber and the canals, so as to allow the tools a free access to the apical one-third.
Step 3
Determining the working length:
Instruments used:
K-files No. 10 and 15 and/or Presequence used until they move freely in the canal.
Objectives:
• Determining the working length.
• Preparing for the NiTi rotary instruments to pass safely all the way to the apical one-third.
Step 4
Preparing the apical portion of the canal:
Instruments used:
APICAL 1 is used on the whole length of the root canal, to be followed by APICAL 2 to increase the taper of the apical one-third by 6%.
Objectives:
• Preparing the apical portion.
• Making a space where the irrigation solutions can collect.
• Providing the apical taper which will give the best obturation.
• Keeping apical diameter small.