Glossary

Question 1

Define a ledge in endodontics

Answer 1

An artificial irregularity created on surface of root canal wall, that impedes the placement of instruments to the apex of an otherwise patent canal

Question 2

What is zipping in endodontics

Answer 2

Tear drop shape formed about the apical foramen due to prep of a curved canal when a file extends through apical foramen and subsequently transports outer wall.

Question 3

What is transportation

Answer 3

Removal of canal wall structure on outside curve in apical half of the canal due to tendency of files’ shape memory.

May lead to ledge formation and perforation

Question 4

What is perforation?

Answer 4

Mechanical or pathological communication between RC system and the external tooth surface

Apical perforation

Furcation perforation

Strip perforation

Question 5

What is cyclic fatigue?

Answer 5

Instrument failure due to repetitive stress of work hardening and metal fatigue on files. Microcracks form eventually leading to fracture.

Stress caused by rotation in curvature where file exposed to periods