Review of endodontic principles and dealing with curved canals

Question 1

What causes endodontic disease

Answer 1

Bacteria AND host AND time

Question 2

Describe the difference in ecological conditions from the coronal to apical region of a tooth

Answer 2

• Coronal has higher oxygen tension, apical lower
• Coronal gets its nutrients from carbohydrates in the oral cavity, apical from proteins and glycoproteins from the periradicular tissues
• Coronal has higher bacterial counts, apical lower
• Coronal microorganisms more accessible to treatment, apical microorganisms less

Question 3

What are the 2 types of microflora in root canals

Answer 3

Planktonic (free floating)
Biofilm

Question 4

What’s the difference between planktonic microflora and biofilm in terms of removal of the bacteria

Answer 4

Planktonic bacteria is easy to remove with sodium hypochlorite
Biofilm is how plaque presents itself, more organised, more difficult to remove, physically adheres got the walls

Question 5

Describe biofilm (3)

Answer 5

Aggregation of microorganism growing on a solid substrate
Complex community interactions
Extracellular matrix of polymeric substances

Question 6

Why are biofilms resistant to eradication

Answer 6

They have a physical barrier- poor antimicrobial penetration and sequesters cells from host immune cells
Difficult to remove mechanically
Varying metabolism of cells: slow growth, starvation survival, and formation of persisted cells
Transfer of genes: virulence factors, resistance

Question 7

What can you see

Answer 7

Host inflammatory response

Question 8

What is endodontology

Answer 8

Diagnosis and management of pulpal disease and periapical disease

Question 9

Whats the first step of endodontology

Answer 9

Need to decide if the patients needs pulp therapy or RCT

Question 10

Whats the biggest problem when trying to diagnose endodontic disease

Answer 10

Reliant of patients description of symptoms which can be confusing
Can’t see the tissues
Poor correlation between symptoms and histological status of the pulp

Question 11

What does SOCRATES, the acronym used to diagnose endodontic disease, stand for

Answer 11

Site
Onset
Character
Radiation
Alleviation
Time
Exacerbation
Severity

Question 12

Other than SOCRATES, what other aids can be used to diagnose endodontic disease

Answer 12

Special tests and radiographs

Question 13

What is a problem with using radiographs for diagnosing endodontic diseases

Answer 13

Until cortical plate lost, lesion may not be visible with conventional radiography

Question 14

How can you alleviate the issue with using radiography for diagnosing endodontic disease

Answer 14

Contemporary CBCT imaging technology
Takes a series of different thickness slices
75 micron slices
Can see slice
Gets round issue of having thick cortical plate which may mask the lesion

Question 15

Issue with cont CBCT imaging technology

Answer 15

Higher dose

Question 16

In a clinical exam, what would you examine in the soft tissues

Answer 16

Palpation, swelling, sinus

Question 17

In a clinical exam, what would you examine with the hard tissues

Answer 17

Palpation, percussion, mobility

Question 18

Name 3 special tests for endodontic diagnosis

Answer 18

Endo ice
Heat
Electric pulp test

Question 19

Which of the 3 test have food speciality and sensitivity

Question 20

What is an issue with testing a multi-rooted tooth

Answer 20

Can give false negatives

Question 21

How can you minimise the chances of false-negative results

Answer 21

Always use a control tooth (e.g. contralateral tooth)

Question 22

What is imperative after anaesthetic when completing a RCT

Answer 22

Isolation using a rubber dam and oraseal

Question 23

What is used to shape the canal
What is used to clean the canal

Answer 23

Instruments for shaping
Irrigants for cleaning

Question 24

What is the aim for the mechanical

Answer 24

Produce a shape that optimises irrigation and simplifies obturation

Question 25

What are the two types of comtemporary instrumentation techniques

Answer 25

Hand or automated

Question 26

What do you do first

Answer 26

Coronal flare
Files
GG burs
Orifice shapers

Question 27

Name 2 types of hand instrumentation preparation techniques

Answer 27

Step back
Modified double flare

Question 28

What are hand instruments used for

Answer 28

Scouting
Glide path
Potency filing
Recapitulation

Question 29

What is patency filing

Answer 29

Passing a small file (size 10) 1mm through the apex to help remove debris and aid irrigant flow

Question 30

What is recapitulation

Answer 30

Checking that the master apical file still passes to working length

Question 31

What are the two types of file manipulation

Answer 31

Balanced force
Step winding

Question 32

4 common errors

Answer 32

Dentine debris
Ledge
Perforation
Transportation

Question 33

Name 2 automated instrumentation

Answer 33

Rotary-rotation in one direction
Reciprocation- rotation in both

Question 34

What are some instrumentation problems

Answer 34

Ni-ti vs stainless steel
V diff characteristics
Ni-ti more flexible than stainless steel
Stainless steel can’t be used for automated instrumentation
Rotary Ni-ti less likely to cause procedural errors but still possible

Question 35

What are the 2 types of file fractures

Answer 35

Torsional failure
Cyclic fatigue

Question 36

How to avoid file fractures

Answer 36

Don’t use too much pressure
Keep instrumentation moving, distributes stress

Question 37

How to avoid uses with automated instrumentation

Answer 37

Consider both angle and radius of curvature
Thicker files more likely to fracture due to cyclic fatigue in curved canals-tighter radius more problematic
Always keep the file moving in the canal
Don’t force engagement of files can lead to torsional failure