Endodontics

Question 1

Ideal properties of an endodontic sealer?

Answer 1

no shrinkage with setting
bacteriorstatic
radiopacity
insoluble to oral fluids/tissues
adhesiveness
slow setting time

Question 2

Ideal properties of an endodontic obturation material?

Answer 2

bacteriostatic
non-irritant to periapical/peri-radicular tissues
easy to handle
can be removed if RCT fails
sterile
provide a good seal, not shrink, be impervious to water/liquids

Question 3

What length should the Gates-Glidden be set too?

Answer 3

height of the clinical crown

Question 4

What materials can be used for a core?

Answer 4

Amalgam
Composite
GIC
RMGIC
Metal - cast post cand core

Question 5

Advantages of composite as core material

Answer 5

Strong
immediate set
tooth coloured
bonds to tooth

Question 6

Disadvantages of composite as core material

Answer 6

technique sensitive
moisture control
polymerisation shrinkage
may be difficult to distinguish between tooth and composite when preparing crown margins

Question 7

What can an increased probing depth and BoP be indicative of?

Answer 7

Resorptive lesion
External - in late stages can also result in abscess
Internal - only has increased probing depth and BoP when resorption has perforated entirely through the root

Question 8

What factors contribute to success of endo treatment?

Answer 8

Reaching WL
Adequately disinfecting the canal
Keeping all RCT procedures/materials within the canal itself
Dense obturation with no voids, 2mm from radiographic apex
Having enough dentine for ferrule effect
Achieving adequate coronal seal
Cuspal coverage

Question 9

Advantages of retaining existing crown for retreatment

Answer 9

Cost for patient
Occlusion preserved
Rubber dam placement easier
No change in aesthetics

Question 10

Disadvantages of retaining existing crown for retreatment

Answer 10

Removes dentinal core and hence reduces strength and retention
Increases chance of iatrogenic mishap as restricted visibility (crown may have rotated)
May miss something such as caries or extra canal

Question 11

Complications of removing a post?

Answer 11

inability to remove
heat transfer to PDL from ultrasonics
tooth or root fracture
perforation
tooth is unrestorable (recurrent caries)
fracture of post

Question 12

Methods of GP removal

Answer 12

solvents
mechanical
thermal

Question 13

Example of solvents to remove GP

Answer 13

oil of turpentine
chloroform
eucalyptus oil
MESSY and should only be used if experienced

Question 14

Examples of mechanical methods to remove GP

Answer 14

ProTaper D series (D1-D3)
MtwoR

Question 15

Irrigant protocol for retreatment

Answer 15

NaOCl – EDTA or citric acid – Povidone iodine soak – NaOCl again

Question 16

Range of success of retreatment if tooth has no periradicular pathology?

Answer 16

92-98% for 10 years

Question 17

Range of success of retreatment if tooth has periradicular pathology?

Answer 17

74-86% for 10 years

Question 18

Intervisit medicament materials?

Answer 18

non-setting calcium hydroxide (does not remove e.facaelis)
iodine potassium iodine
chlorhexadine and calcium hydroxide

Question 19

What changes may occur to the tooth structure after endodontic treatment?

Answer 19

Access cavity leads to change in tooth architecture (marginal ridge, occlusal isthmus)
collagen depletion with a predisposition to fracture
changes to proprioception
caries, cracks, trauma

Question 20

What is the aim of re-endodontic treatment?

Answer 20

• regain access to the periapical area of the tooth previously treated, in order to adequately disinfect the whole root canal system again

Question 21

Size of patency file?

Answer 21

ISO 10

Question 22

Where must your irrigant reach?

Answer 22

Within 1mm of the apex

Question 23

What size ISO file should the canal be prepared too and why?

Answer 23

Size 25 or 30
Irrigant needle corresponds with size 30 file