Endo - techniques

Question 1

In what patient groups do you have to exercise caution with in regards to endodontic treatment? (4)

Answer 1

1st trimester
Diabetics - poor healing/outcomes
Use of bisphosphonates
Cancer - chemo/radiotherapy compromises healing

Question 2

In what patients is endodontic treatment contraindicated? (1)

Answer 2

myocardial infarction within last 6 months

Question 3

what are the complications of endodontic treatment? (4)

Answer 3

perforation
broken instruments/separation
extrusion of the irritant NaOCl
Pain

Question 4

what chemicals are used for irrigation? (2)

Answer 4

sodium hypochlorite 3%

EDTA 17%

Question 5

what are the advantages of irrigation? (5)

Answer 5

cools the file and the tooth 
prevents packing 
disinfectant as it is antimicrobial 
reduces friction
dissolves tissue

Question 6

why do we irrigate the canal with saline in-between the use of sodium hypochlorite and EDTA?

Answer 6

EDTA reduces the effectiveness of the sodium hypochlorite

Question 7

when can Endo treatment not be carried out in one visit? (1)

Answer 7

If the patient has an acute infection and has symptoms

- need to use intra-canal medicaments

Question 8

what inter canal medicaments can be used between visits? (2)

Answer 8

GOLD STANDARD = NS calcium hydroxide

odontopaste - contains steroids

Question 9

When would we opt to use odontopaste over NSCaOH (medicament)?

Answer 9

if the patient has a hot pulp which doesn’t respond to LA

Question 10

what are the advantages of using NSCaOH as medicament? (3)

Answer 10

Easy to remove since doesn’t set
Antimicrobial since very alkaline
removes tissues debris

Question 11

what are the DISADVANTAGES of using sodium hypochlorite as irrigation? (6)

Answer 11

allergy 
apical extrusion 
modifies the organic content of dentine 
doesn't remove the smear layer
ophthalmic injury 
discolouration of clothes

Question 12

what irritant removes the smear layer?

Answer 12

EDTA

Question 13

list the constituents of GP. (4)

Answer 13

gutta percha 20%
zinc oxide 65%
plasticisers 5%
radio pacifiers 10%

Question 14

Describe the Herb Schilder principle for Endodontics treatment (2)

Answer 14

smooth continuously tapering funnel shaped canal

With an apical restriction that remains at the same point and the same size

Question 15

list the ideal properties of sealers (7)

Answer 15

tacky
radiopacity 
bacteriostatic 
insoluble in tissue fluids 
slow set
easily mixed 
no shrink when set

Question 16

list the uses of sealers (3)

Answer 16

lubricates
seals the spaces between the dentine wall and the core
seals voids and irregularities

Question 17

define estimated working length

Answer 17

the estimated length from the reference point that instrumentation is limited to

Question 18

define corrected working length

Answer 18

The length in which the instrumentation and obturation should be limited to.

Question 19

What is the function of a NaOCl irrigant? (3)

Answer 19

• Dissolves: organic matter, necrotic tissue and vital tissue i.e. pulp remnants and collagen.
• Helps disrupt the smear layer (but doesn’t entirely remove)
• Hypochlorite = antibacterial action.

Question 20

What are important factors to consider in NaOCl use? (5)

Answer 20

Concentration - 3%
Volume - 30ml
Contact - for 10 mins

Mechanical agitation - manual dynamic irrigation using gutta percha points and pumping motion.

Exchange - improved by mechanical agitation

Question 21

How would we manage NaOCl/irrigant extrusion? (7)

Answer 21

• Stop all treatment
• Inform patient
• If patient in pain - use block local anaesthetic at the site
• If there is bleeding - allow it to continue until haemostats occurs
• Place a steroid-containing intracanal medicament (Odontopaste) in the root canal - do not use pressure to apply.
• Do not obturate but seal the coronal access cavity
• Review after 24 hours

Question 22

What is the aim of obturating? (2)

Answer 22

To fill the whole canal to prevent the passage of microorganisms and fluid.

To block the apical foramen, accessory canals and dentinal tubules

Question 23

when is it ok to obturate?

Answer 23

No symptoms or signs of active disease
- If the patient has acute infection with symptoms present the chemomechanical disinfection and obturation will have to be done in separate visits.

Question 24

What are the ideal properties of an obturation material? (8)

Answer 24

• Biocompatible
• Dimensionally stable
• Able to seal
• Unaffected by tissue fluids
• Insoluble
• Non-supportive of bacterial growth
• radiopaque
• Removable from the canal in the need for pretreatment

Question 25

what material do we use to obturate? what is it?

Answer 25

Gutta Percha- Polymer of isoprene

Question 26

what obturation technique do we use with GP cones?

Answer 26

cold lateral compaction

Question 27

what sealer do we typically use?

Answer 27

GI sealer - bonds to dentine