Endodontics

Question 1

Pulp chamber definition

Answer 1

Portion of pulp space within the anatomic crown of the tooth.

Question 2

Pulp chamber is bordered by:

Answer 2

• pulp chamber roof = most coronal extent of the pulp chamber
• pulp chamber floor = most apical extent of the pulp chamber

Question 3

Pulp horn definition

Answer 3

Extension of pulp tissue into occlusal/incisal projections that follow the cusp tips

Question 4

Canal orifice definition

Answer 4

Opening leading from pulp chamber into root canal

Question 5

Root canal definition

Answer 5

Chammel in the root of tooth extending from the pulp chamber to apical foramen

Question 6

Accessory canal definition

Answer 6

Any branch of the main pulp canal that connects with external surface of root

Question 7

Furcation canal definition

Answer 7

Accessory canal at furcation

Question 8

Lateral canal definition

Answer 8

Horizontal accessory canal that branch from coronal or middle zone

Question 9

Apical foramen definition

Answer 9

Opening at root apex

Question 10

Apical constriction definition

Answer 10

Narrowest portion of root canal. Usually 0.5-1.0 mm from foramen

Question 11

Apex definition

Answer 11

End of tooth root. Not necessarily the end of the canal

Question 12

Pulp chamber location

Answer 12

• Centred in crown of tooth

- Reflects outline of tooth at CEJ

Question 13

Root canal location

Answer 13

• Centred or symmetrically disturbed in roots

- Reflects the shape of the root

Question 14

Define ‘Law of centrality’

Answer 14

Outline of the pulp chamber mirrors the outer border of the tooth at the CEJ level. Pulp chamber is always centred in tooth at level of CEJ.

Question 15

Define ‘Law of symmetry 1’

Answer 15

Except for maxillary molars, paired orifices are equidistant from a line drawn in a mesiodistal direction through the pulp chamber floor AND unpaired orifices lie on the line.

Question 16

Define ‘Law of symmetry 2’

Answer 16

Except for maxillary molars, paired orifices lie on a line perpendicular to a line drawn in a mesiodistal direction through the pulp chamber floor

Question 17

Define ‘Law of colour change’

Answer 17

The colour of the pulp chamber is always darker than the walls

Question 18

Define ‘Law of orifice location 1’

Answer 18

Orifices are located at the junction of walls and floors

Question 19

Define ‘Law of orifice location 2’

Answer 19

Orifices are located at the angles in the floor-wall junction

Question 20

Define ‘Law of orifice location 3’

Answer 20

Orifices are located at the terminus of the root developmental fusion lines

Question 21

Purpose of rubber dam in endodontics

Answer 21

• Infection control of root canal
• Protection of patient - prevent aspirating files
• Efficiency - Keeps area clear, patient relaxed, tissue retracted
• Improves visibility
• Reduce risk of litigation
• decrease aerosols

Question 22

Rubber dam technique:

Answer 22

• Punch single hole in rubber dam - only for tooth you’re operating on
• Use floss to secure rubber dam clamp
• ensure clamp has 4 points of contact
• rubber dam frame - used to ensure tension in dam so that tissue is retracted
• Management of difficult to isolate teeth:
  1) composite buttons- add composite to buccal and palatal surface to allow clamp to grip
  2) Use wedjets or piece of rubber to secure rubber dam to tooth
  3) Oraseal- putty-like substance to fill gaps around teeth (especially teeth with orthodontics)

Question 23

Access cavity define

Answer 23

Opening prepared in a tooth to gain entrance to the root canal system

Question 24

Working length

Answer 24

Distance from a coronal reference point to the point where instrumentation/obturation terminates in root canal

Question 25

Pre-access analysis step for endo

Answer 25

1) know root anatomy and match access cavity 2) radiographic exmination 3) Periodontal probing to locate CEJ

Question 26

Second step to access cavity

Answer 26

Removal of pulp chamber roof completely 1) Start in largest pulp horn 2) Make access wide enough for straight-line access to all roots 3) Access of maxillary incisors

Question 27

Describe steps of access of maxillary incisors

Answer 27

1) Use of ENDO ACCESS BUR to enter pulp chamber 2) Use ENDO Z BUR to refine access cavity once pulp chamber is reached 3) Use No. 17 Explorer to find pulp horns 4) Use Gates-Gliddens burs or Slow-speed Long Shank Burs to remove palatal hump 5) Use DG No. 16 Explorer to check for straight-line access to orifices

Question 28

Identification of pulp chamber, pulp floor and root canal orifices

Answer 28

Use Krasner and Rankow Laws

Question 29

Endo Access Bur is used for?

Answer 29

Used for initially entering pulp chamber

Question 30

Endo Z burr is used to?

Answer 30

Used to widen access cavity once pulp chamber has been reached. Non-cutting end

Question 31

No. 17 explorer

Answer 31

Use to find pulp horns

Question 32

DG No. 16 explorer

Answer 32

Use to check for straight-line access to orifices

Question 33

Gates-Gliddens burs

Answer 33

Use to clear pulp horns and achieve straight-line access to canal. Also used in coronal zone of canal only

Question 34

Slow-speed long shank burs

Answer 34

Use to clear pulp horns and achieve straight-line access to canal. Used to smooth and finalize margin of access cavity