Biomechanical Preparation - Instrumentation Flashcards
Name 3 aims of endodontic treatment
- Clean
- Shape
- Fill
Name 2 types of cleaning during endodontic treatment
- Remove microbes
2. Remove pulpal remnants and organic debris
Between what 2 stages does biomechanical preparation occur during RCT?
Between accessing tooth and isolation with rubber dam, and obturation
Describe how mechanical preparation is achieved
Through using variety of instruments to clean and shape root, with a crown down approach
Name 4 aims of mechanical preparation
- Remove pulpal debris and microbes
- Allow effective irrigation of the root canal system
- Allow placement of medicaments
- Provide optimal shape and resistance for the root canal filling
Describe the equipment used in mechanical preparation
- Rubber dam
- SS hand files to create preflare and glide path
- Rotary files
Describe how to use SS hand files
Enlarge canals with reciprocal insertion and withdrawal motions known as circumferential filing
Describe the process of hand filing if a canal is curved
SS handfile should be precurved to match the root before filing to help avoid ledge formation
What is the machine used for rotary filing?
X-Smart machine
What is torque?
Force of rotation
What are the files which are attached into the X-Smart machines called?
ProTaper GOLD Nickel Titanium System
Describe the ProTaper GOLD files in order
- SX, S1, S2, F1, F2, F3
- SX is shorter as works in top 1/3 of canal
- S1 and S2 work in middle 1/3 and F1-F3 in apical 1/3
Why do ProTaper files have multiple taper design?
- Not the same taper the whole way down the file
- Better debris removal
Name an advantage of ProTaper files being made from NiTi
Very flexible material so follow curve of the canal and remove the risk of ledges forming
Describe 3 key points of mechanical rotary instrumentation
- Always enter and leave the canal with file rotating
- Do not force files - Brushing for shaping and pecking for finishing
- Reduce stresses on files by moving them up and down continuously
What is used to irrigate canal?
NaoCl 2.0%
Why are ProTaper files colour coded?
Enables the clinician to have a simple order to follow sequentially
Describe the rules for ProTaper rotary files
- Used constant and stable speed of 250rpm
- Withdraw file once working length reached
What is recapitulation?
Go back into canal and file with SS hand files and copious irrigation to remove any debris formed by the rotary instruments which may have fallen to the bottom of the canal
When should you recapitulate?
Following use of shaping files - Recapitulate with size 10 and 15 following SX and only size 10 following S1 and S2
How can you determine whether the F1 file is the correct size for the foramen of the tooth?
Gauging
Describe how to gauge
- Insert the SS hand file which corresponds to the finishing file used
- Rotate it once to see whether it engaged the tooth
- If it does then the finishing file was correct and if not, rotary file using the size up
What is a checking method which can show rotary filing is finished alongside gauging?
Correct finishing file will have debris filling the flutes right down to the apex
Describe 5 common problems caused by incorrect hand filing techniques
- Dentine and pulp debris packed into apical part of canal
- Ledging due to not precurving file or forcing it into canal
- Apical zip caused by rotating file not using circumferential filing
- Perforation due to consistant filing with too large an instrument
- Strip perforation caused by straightening a curved canal
