Root Canal Preparation 1 and 2 Flashcards
What are the aims of root canal preparation
- A continuously tapered preparation is produced
- The original anatomy is maintained
- The foramen position is maintained
- The apical foramen is kept as small as possible
What motions are used for hand files
- Rotational (best)
- Push and Pull Filing
When do we use push pull filing
- Not for the preparation and only for the final refining
Describe Rotational motion hand filing in detail
- Clockwise until dentin is lightly engaged
- Then anticlockwise rotational motion back and forth with light apical pressure
- Be gentle and regularly clean the flutes of the instruments
- Make sure you precurve the files
What types of file primarily uses push-pull filing
Hedstrom files
What issues can arise from using push and pull filing with K files
Zips and elbows can form
NOTE - need to do circumferential filing to no cause grooves
What do we use in the labs for irrigation
Sodium hypochlorite
How should we irrigate when doing an RCT
- Use a shit load of irrigation
- use in between each instrument
- Deposit in canal until is runs clear
- Ensure to do patency after irrigation
How can we ensure safe irrigation
- never bind the irrigation needle?
- Use a side venting needle
- Always inject solution using index finger v slowly
What size needle is used for irrigation
27 gauge - 0.4mm diameter
Why do we use sodium hypochlorite for irrigation
- Antimicrobial
- Dissolves organic tissue remnants
What should you do if you have an accident with the sodium hypochlorite and patient becomes fooked
- irrigate with sterile water
- reassure patient
- immediate referral to max fax on call
What solution other than sodium hypochlorite can we use for irrigation
- EDTA (17%)
- Chlorhexidine
- Aqueuous Iodine based compounds
When do we use EDTA for irrigation
- EDTA is helpful in sclerosed canals and can be alternated with NaOCl to allow deeper penetration of NaOCl into infected tubules
AY BAWS CAN I HABE DE NOTE PLZ
EDTA removes the smear layer and inorganic tissue remnants
What are the issues with using chlorhexidine as an irrigant
- Doesn’t dissolve organic tissue
- Cannot be used with NaOCl
How would you use Aqueuous iodine based compounds as an irrigant
- Used in therapy resistant cases
- After use you’d flush through with NaOCl to remove brown colouration
What is a potential issue with using Aqueuos iodine base compounds as irrigants
Has allergic potential
Describe the all the steps of a Canal Preparation
- Explore coronal 1/3-2/3s with size 10 file and DG16
- Prepare coronal 1/3-2/3s with SX protaper or GGs
- Establish patency
- Find the definitive working length radiograph
- Prepare apical 1/3 and apical gauge
- Step back filing
- Smooth the canal circumferentially
ENSURE COPIOUS IRRIGATION AND PATENCY
Why do we prepare the coronal portion of a canal first
- removes bacteria from being introduced apically
- Helps reduce curvature and achieve straight line access
- Improves tactile sense
- Greater volume of irrigant can be used
Which direction should we use the SX protaper in
In the safe zone which is the outer curvature of the canal
Where do you finish the apical preparation
at the apical constriction before the apical foramen
How do we determine the working length
We use apex locators that tell us how long the canal is and then we go back about 1mm, which is considered the working length
What patients can you not use an apex locator on
Patients with cardiac pacemakers
When do we start patency filing
Only after the coronal 1/3-2/3s shaping has been done
What are the advantages of patency filing
- Prevents blockage
- Checks whether there is exudate present
- Helps maintain and follow anatomy
- Helps to deliver irrigant apically
What is the aim of the apical preparation and why
To get a file to the WL slightly larger than the natural size of the canal
This ensures that we have optimal cleaning and allows for resistance form with which to obturate against
THERES A BIT ABOUT INTRACANAL MEDICAMENT BUT I DONT REALLY GET THAT YET
THERES A BIT ABOUT INTRACANAL MEDICAMENT BUT I DONT REALLY GET THAT YET
What problems can occur from incorrect instrumentation
- Ledges
- Zips
- Perforations
How can we avoid ledges from incorrect instrumentation
- Precurve a size 10 handfile at the tip that may help it to negotiate a ledge
- Create a good coronal flare
