instrumentation

Question 1

demonstrated that mechanical instrumentation reduced bacterial numbers in human root canals from an initial count of 〖10〗^4-〖10〗^6 cells to a count of 1000-10000 cells

Answer 1

Bystrom and Sundqvist

Question 2

All instrumentation techniques are reported to cause apical extrusion of debris, even when preparation is maintained short of the apical terminus

Answer 2

Al-Omari; Dummer 1995

Question 3

Copious and frequent irrigation during chemo-mechanical procedures significantly enhances the removal of excised dentine, microbial cells and pulpal debris from the root canal reducing the risks of procedural accidents, such as blockages and apical extrusion of debris

Answer 3

Siqueira et al. 2000

Question 4

crown-down techniques using instruments with some sort of rotary action combined with abundant irrigation have at least theoretically the potential to reduce the risks of flare-up

Answer 4

Siqueira et al. 2003

Question 5

Chemomechanical preparation partially removed necrotic tissue from the entrance of lateral canal/apical ramifications, whereas the adjacent tissue remained inflamed, some- times infected, and associated with periradicular disease

Answer 5

Ricucci ; Siqueira 2010

Question 6

Tissue within ramifications remain relatively unaffected by instruments and irrigants after chemomechanical preparation, regardless of the preoperative pulp conditions

Answer 6

Ricucci ; Siqueira 2010

Question 7

With MicroCT, it has been shown that the amount of mechanically prepared canal surface and perhaps equally disturbed biofilm in main root canal, depending on canal type, is frequently below 60% of the canal surface

Answer 7

Peters 2010

Question 8

bacteria cannot be removed completely from the canal system using current techniques in both primary root canal treatment and retreatments

Answer 8

Nair et al. 2005, Haapasalo et al. 2011

Question 9

either method, 40-60% of the dentin is untouched using balanced force and circumferential filing

Answer 9

Wesselink; Wu 2003

Question 10

There was no significant difference in intracanal bacterial reduction when Ni–Ti GT rotary preparation with NaOCl and EDTA irrigation was used with or without apical enlargement preparation technique.
It may therefore not be necessary to remove dentine in the apical part of the root canal when a suitable coronal taper is achieved to allow satisfactory irrigation of the root canal system with antimicrobial agents.

Answer 10

Coldero 2001