endo procedures stuff

Question 1

what is the aim of RCT

Answer 1

split into both BIOLOGICAL and MECHANICAL

BIOlogical:
- remove bacteria
- entomb bacteria so they cant colonise
- prevent reinfection of canal
- promote healing and control pain

Mechanical:
- maximise area of instrumentation in canal space
- achieve retention and resistance form
- create hermetic seal of canal

Question 2

what is your understanding of root canal WL in endo tx?

Answer 2

is the length from a coronal reference point to the apical limit of the preparation/ instrumentation

should be reproducible

optimal end of root canal instrumentation and obturation is around 0.5 to 1mm from apex of the tooth

Question 3

what are the recommended contemporary techniques used in the determination of working length?

Answer 3

• using of PA film to get estimated WL of root canal
• apx locator. must dry canal with paper point to get accurate reading
• take IAF xray with a file of at least size 15 that fits snugly into the root canal

Question 4

importance of achieveing accurate WL?

Answer 4

TO AVOID over or under instrumentation

overinstrumentation cause
- apical extension of infected debri which may lead to acute peri radicular inflammation

• also can cause loss of apical constriction which leads to difficulty in achieving a good apical fill

underinstrumentation causes
- inadequate debridement which can lead to changes in root canal microbiota
- for root fills ending more than 3mm from radiographic apex, only 68% of teeth with apical periodontitis healed

Question 5

physical properties AND DESIGN of Niti that make them useful in root canal instrumentation

Answer 5

1) super elasticity and shape memory
- reduces the chance of ledge formation

2) increased resistance to cyclic and torisonal fatigue
- helps to decrease risk of instrument breakage

3) shaping files have active tip, finishing files are safe ended which will PREVENT OVERinstrumentation

Question 6

describe how and why a niti could separate

Answer 6

in a curved canal
- there is greater cyclic fatigue which may lead to Niti file separation

in a narrow canal
- torsional or shear stress can induce file separation

Question 7

discuss how you would prvent separation of ni ti files

Answer 7

• note down in logbook how often niti files is used
• always observe cutting edge first before using it
• motion should be in and out pecking motion without heavy apical pressure
• use instrument in fixed sequence and do not skip files
• copious irrigation of canal is indicated. dry canal leads to blockage
• dont stop rotary instrument healfway in canal, need constant movement to distribute force and prevent breakage