Which action is typically the first major component of nonsurgical retreatment?

• A. Irrigation and disinfection
• B. Canal negotiation and cleaning
• C. Remove obturation material
• D. Final restoration

Answer: (C)

Removing the existing filling is the first major step because you must gain access to the root canal system before any cleaning or disinfection can be effective. The obturation material (gutta-percha and sealer) blocks the canals, hides anatomy, and can prevent irrigation from reaching all surfaces. By removing it, you can directly inspect for missed canals, posts, cracks, or other problems and determine the true shape and contents of the canal space. Once access is regained, you can negotiate the canals, clean and shape them thoroughly, and then irrigate to disinfect the system. Only after this cleaning and disinfection is the tooth ready for retreatment obturation and final restoration. The other steps—irrigation, canal negotiation, and cleaning—depend on having removed the obturation material first, and final restoration comes after the retreatment process is complete.