Review of endodontic principles and dealing with curved canals Flashcards
What causes endodontic disease
Bacteria AND host AND time
Describe the difference in ecological conditions from the coronal to apical region of a tooth
- 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
What are the 2 types of microflora in root canals
Planktonic (free floating)
Biofilm
What’s the difference between planktonic microflora and biofilm in terms of removal of the bacteria
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
Describe biofilm (3)
Aggregation of microorganism growing on a solid substrate
Complex community interactions
Extracellular matrix of polymeric substances
Why are biofilms resistant to eradication
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
What can you see
Host inflammatory response
What is endodontology
Diagnosis and management of pulpal disease and periapical disease
Whats the first step of endodontology
Need to decide if the patients needs pulp therapy or RCT
Whats the biggest problem when trying to diagnose endodontic disease
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
What does SOCRATES, the acronym used to diagnose endodontic disease, stand for
Site
Onset
Character
Radiation
Alleviation
Time
Exacerbation
Severity
Other than SOCRATES, what other aids can be used to diagnose endodontic disease
Special tests and radiographs
What is a problem with using radiographs for diagnosing endodontic diseases
Until cortical plate lost, lesion may not be visible with conventional radiography
How can you alleviate the issue with using radiography for diagnosing endodontic disease
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
Issue with cont CBCT imaging technology
Higher dose
In a clinical exam, what would you examine in the soft tissues
Palpation, swelling, sinus
In a clinical exam, what would you examine with the hard tissues
Palpation, percussion, mobility
Name 3 special tests for endodontic diagnosis
Endo ice
Heat
Electric pulp test
Which of the 3 test have food speciality and sensitivity
What is an issue with testing a multi-rooted tooth
Can give false negatives
How can you minimise the chances of false-negative results
Always use a control tooth (e.g. contralateral tooth)
What is imperative after anaesthetic when completing a RCT
Isolation using a rubber dam and oraseal
What is used to shape the canal
What is used to clean the canal
Instruments for shaping
Irrigants for cleaning
What is the aim for the mechanical
Produce a shape that optimises irrigation and simplifies obturation
What are the two types of comtemporary instrumentation techniques
Hand or automated
What do you do first
Coronal flare
Files
GG burs
Orifice shapers
Name 2 types of hand instrumentation preparation techniques
Step back
Modified double flare
What are hand instruments used for
Scouting
Glide path
Potency filing
Recapitulation
What is patency filing
Passing a small file (size 10) 1mm through the apex to help remove debris and aid irrigant flow
What is recapitulation
Checking that the master apical file still passes to working length
What are the two types of file manipulation
Balanced force
Step winding
4 common errors
Dentine debris
Ledge
Perforation
Transportation
Name 2 automated instrumentation
Rotary-rotation in one direction
Reciprocation- rotation in both
What are some instrumentation problems
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
What are the 2 types of file fractures
Torsional failure
Cyclic fatigue
How to avoid file fractures
Don’t use too much pressure
Keep instrumentation moving, distributes stress
How to avoid uses with automated instrumentation
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
