Pre-clinical skills

Question 1

What are teh clinical objectives of RCT?

Answer 1

removal of canal contents

Eliminating infection

Question 2

What are the design objectives of root canal treatment?

Answer 2

Create a continuouslt tapering funnel shape

Maintian the apical foramen in original position

Keep apical opening as small as possible

Question 3

What type of radiogrpah needs to be taken before endodontic treatment? What must you be able to see?

Answer 3

• periapical radiograph
• must show all the root and 2-3mm of surrounding peri-radicular tissue

Question 4

What are we looking for in the pre-treatment radiograph?

Answer 4

• is there any peri-radicular pathology and how far does it extend?
• The anatomy of the root canal system
• canal calcifications
• check angularion of the root in relation to adjacent teeth
• number length and morphology of root
• proximitel of vital structures

Question 5

If you have an existing restoration/caries on the tooth, what needs to be done before you root treat? Why?

Answer 5

Remove all previous restorations and caries

It allows you to assess the restorability and created and environment suitable for obtaining adequate isolation

Question 6

Why is dental dam mandatory for all procedures involving the pulp?

Answer 6

• to eliminate bacterial contamination
• to prevent inhalation of instruments etc
• retracts and protects soft tissues and tongue
• prevents patients from rinsing and chatting
• reduces chairside time and operator stress

Question 7

What can you do without the dental dam in place and why might you want to do this?

Answer 7

Can cut most of access without dental dam so you dont lose your orientation

Question 8

What is the access shape for a 11 and 21?

Answer 8

Triangular

Question 9

What is the shape of access for an upper canine?

Answer 9

Oval

(only has one pulp horn so can be done this way)

Question 10

What is the access shape for lower incisors? What might differ about where you start your access?

Answer 10

Ovals

Might want to start more incisally (especially for laterals in order to get both canals)

Question 11

What are the objectives of access cavity preparation?

Answer 11

• Remove entire roof allowing complete removal of pulpal tissue
• allow visualisation of root canal entrance
• produce smooth walled preparation with no overhangs
• allow unimpeded straight line access of instruments

Question 12

What kind of files are most commonly used in endo?

Answer 12

K-files (ISO instruments)

Question 13

What are the ISO instruments made from and what is their taper?

Answer 13

• stainless steel
• 2% taper (or 0.2 taper)

Question 14

What are the standardised lengths of the K-files/ISO instruments?

Answer 14

21, 25 and 31mm

Question 15

What are the different file motions that can be used?

Answer 15

• filing
• reaming
• watch winding
• balanced forced motion

Question 16

What is the purpose/objectives of using root canal irrigants?

Answer 16

• to disinfect root canal
• dissolve organic debris
• flush out debries
• lubricate root canal instruments
• remove endodontic smear layer

Question 17

What is used to irrigate the root canal?

Answer 17

sodium hypochlorite

Question 18

Where do you want your preparation to end?

Answer 18

• at the junction of the pulpal and periapical tissues
• the WL should be as close as possible to the cemento-dentinal junction
• this is usually the narrowest part of the canal called the apical constriction

Question 19

Why might your working length change?

Answer 19

curvatures in the root canal that does not show up on the radiograph

Question 20

Where should the corrected working length be to?

Answer 20

1mm from the radiographic apex

Note: make sure you use a sound and reproducible reference point (cusp tip etc)

Question 21

What roughly should the apical preparation size be?

Answer 21

ISO 25 (at the least) or 30

Question 22

Why do we want early flaring of the apical protion?

Answer 22

• avoid hydrostatic pressure in the canal (space for the irrigant to move and not cause this)
• Allows early removal of heavily contaminated contents from this area (and not push them down the canal)
• Improves straight line access to apical 1/3rd of the root

Question 23

What methods can be used for flaring of the coronal portion of the canal?

Answer 23

• step-down technique
• double-flare technique
• crown down pressureless technique

Question 24

What is the estimated working length?

Answer 24

Its the estimated length at which the instrumentation should be limited to initially

Is obtained by measuring the pre-operative radiograph to determine the distance between the coronal reference point and the radiographic apex then subtracting 1