Endodontic instruments and materials Flashcards
In order to carry out effective endodontic treatment what is vital?
Adequate anaesthesia should be achieved
How would you anaesthetise an upper lateral incisor?
Buccal infiltration and in some cases a palatal infiltration
How would you anaesthetise an upper first molar?
Buccal infiltration and a palatal infiltration
How would you anaesthetise a lower canine
Would do a mental infiltration
How would you anaesthetise a lower second molar
An inferior dental block plus lingual block and a long buccal infiltration will be needed
Why in some cases is the level of anaesthesia achieved not be sufficient for pulp extirpation?
- Acute pulpal inflammation
- Hyper excitability of the nerve fibres
- Patient factors
Hyperaemic pulp
Give examples of some patient factors that might affect oral aesthetic effectiveness
- variation in individual response to local anaesthesia
- pain threshold
- anxiety level
Which fibres, if hyperactive, could lead to local aesthetic failure ?
Hyperactive C fibres may mean the local anaesthetic solution is unable block conduction of these impulses
Why can inflammation lead to failure of LA
Increased vascularity of the tissues may remove LA solution more rapidly
And the pH of the inflammatory products in the region of the tooth may be more acidic potentially making the local anaesthetic solution less effective.
How can the problem of inadequate LA be solved?
Alternative methods of delivery can be used such as:
- intraligamentary
- intra pulpal
- intraosseous
- Sedative dressing could be used
Name the steps involved in endodontic treatment
- Anaesthesia
- Isolation of the tooth
- Accessing the pulp canal
- Preparation
- Intra canala medicaments
- Temporisation
- Obturation
Name the best way to isolate teeth during endodontic treatment
Rubber dam
What are the main functions of rubber dam in endodontic treatment
- Protection of the airway
- Protection from irrigants
- Prevention of contamination
- Improved access and visualisation
- Patient comfort
Where is gauze placed during endodontic treatment
Gauze is placed at the bottom of the rubber fam between the rubber and the patients face
Why is gauze and aspiration used during endodontic treatment?
For patient comfort
What response do patients have to rubber dam?
Can have increased salary flow which tends to poo at the back of the patients mouth
What can be used to tackle the problem of increased salivary Flow during endodontic treatment?
A small flexible saliva ejector can be placed down the side of the rubber dam and the saliva removed very easily
What is floss used for during endodontic treatment?
Floss is used to secure clamps and prevent swallowing/ inhalation and help the dam through the contact points
What is a wedgit used for during endodontic treatment?
Used to secure the rubber dam between the teeth
What is oraseal used for during endodontic treatment?
Oraseal putty is syringed around the tooth once he rubber dam is placed to seal any small gasps
What does a basic endodontic instrument tray contain?
- Mirror
- Standard tweezers
- End locking tweezers
- A long shank excavator
- A flat plastic
- An endodontic explorer probe
- A pugger
- Measuring devie
- File stand
- Containing files
- Finger spreaders
- Safe ended burs
What do you do once you’ve isolated your tooth?
Once you’ve placed rubber dam you need to access the pulp chamber
Where is access gained from during endodontic treatment?
Must be gained through the coronal aspect of the tooth
What should be ensured regarding the condition of the tooth before endodontic treatment is commenced
It is extremely important that all the caries and defective restoration are removed and sound coronal restoration is placed
Before commencing endodontic treatment treatment what should you take?
It is important to obtain a pre operative radiograph
What does a pre operative radiograph show?
It should:
- project the tooth as near to its natural size as possible
- Show the full roots
- Show approx 2-3mm of the periodical tissues
What should you look for when reading a radiograph?
- Number of roots
- Number of canals
- Morphology of roots/canals
- Extent of current restoration
- Presence of caries
- Presence of canal sclerosis/ pulp stones/ previous RCT/ fractured instruments
What is the aim when gaining coronal access
To remove the roof of the pulp chamber allowing the removal of eh coronal pulp
What is important to make sure when you’re gaining coronal access
It is important that the pulpal floor reins undamaged
Make sure the access is a straight line and is conservative giving good
What does the shape of the pulp chamber often mean?
That the cavity is naturally retentive
What can you do to help locate the pulp chambers and canals?
- Good lighting
- Magnification
- Using an endodontic explorer
What are high speed burrs used for?
High speed burs are used to remove tooth tissue
What are slow speed burrs used for?
Used to remove the roof of the pulp chamber and to carefully remove dentine around the canal orifices
What quality do slow speed burs have that make them safe to remove the pulp chamber?
These burs dont have cutting flutes or diamonds at the tip and hence they can be used quite safely around the floor of the pulp chamber to remove dentine laterally
What can ultrasonic instruments be used to do?
Can be used to carefully remove dentine around canal orifices as well as preparation of the canals themselves
What do you need to do once you have located the pulp chamber
You need to prepare the the canals
What is a successful root canal treatment dependent on?
Depends upon thorough cleaning and shaping of the root canal system and the placement of a 3D root canal filling
What is the aim of cleaning and shaping he canals?
Aims to remove as many bacteria as possible whilst not compromising the strength of the tooth and allowing for adequate filling or obturation
What does preparation of root canals involve?
Involves mechanical cleaning and shaping with files and chemical disinfection of the canal system
What is the preparation of the root canals called?
It is known as chemomechanical preparation
What is preparation split into?
- Mechanical stage
2. Chemical stage
What does mechanical preparation involve?
Involves the use of hand and/or rotary files
What is used to carry out mechanical preparation
- Files
- Gates Glidden burr
- Hand files
- Rotary files
- K-files
What are Gates Glidden burs used to do/
Can be used in the straight coronal portion of the canal to produce a smooth and gentle taper
Talk through the steps of coronal preparation
- Create a funnel shape
- Removes bacteria and necrotic tissue and prevents this being carried apically
- Keep the canal in the centre of preparation
- Use files and then gates - gladden burs in the straight part of the canal
- Files are then used to prepare the remainder of the coronal 2/3rds of the canal
What is the aim of coronal preparation?
It aims to remove the most heavily infected tissue and prevents bacteria being carried apically
Also gives improved access to the apical part of the canal
When carrying out coronal preparation what would you constantly be doing/
Copiuos irrigation should be used throughout preparation.
How many sized do the gates Glidden burs come in?
6 sizes (size being indicated by the number of grooves on the shank)
What do gates Glidden burrs not do?
They do not cut outside the canal as the burs do not cut at the tip
How should the gates Glidden burrs be used?
Should be used slowly in a handpick and only whee there is a pathway fro the tip to follow
What are the gates Glidden burs designed to do?
They are designed to break where the shank meets the neck if too much stress is placed on the bur (this makes it easier to retrieve)
What do you need to do once you’ve prepared the coronal 2/3RDS
Need to prepare the apical 1/3
How is the apical 1/3 Prepared?
Prepared using K files
What are K files?
They are stainless steel files with a standard taper
What are K files sized according to?
They are sized according to their diameter at the tip in 1/100ths of a mm (this means a 10 file has a diameter of 0.01mm at the tip)
What is the hall rubbers ti used for on a K file?
Used to indicate the length of the canal as it is moved to touch a reproducible landmark eg cusp tip.
After mechanically Prepare the canal what do you need to do?
Chemically prepare it
How do we chemically prepare the canal?
Chelating agents such as EDTA are used with files to lubricate the canal and remove smear layer.
What is essential when carrying out chemical preparation?
Copious irrigation throughout treatment is essential.
Give some ideal qualities a goodendodontic irrigant
- Needs to destroy micro organisms
- Dissolves organic matter
- Wets the canals (lubrication)
- Removes debris by flushing
- Biocompatible
Name the most commonly used dental irrigant?
Sodium hypochlorite
After preparing the canal what do you need to do?
Carry out intra canal medicaments
What are intra canal medicaments?
They are therapeutic materials which may be placed into the root canals between visits
What are the requirements for an intra canal medicaments
- antibacterial
- Aids periapical healing
- Therapeutic
- Anti inflammatory
- Long lasting
- Non irritant
- Easy to use and remove
- Cheap**
When might you need to use an intra canal medicament?
- If theres persistent infection
- If you’re unable to dry prepared canal
- Incomplete apex
- Incomplete preparation
- Insufficient time fro obturation
Why do we use calcium hydroxide paste?
- Long lasting bactericidal action
- Aids repair
- Apexification
- Dissolves organic debris
- Easy to sue
- Relatively easy to remove
What is the next step After applying an intra canal medicament
If the treatment is incomplete in a single visit then some form of temporary restoration needs to be placed
What is the aim of temporisation
- Seal the tooth
- Restores function
3, Prevents over eruption/ drifting - Restores aesthetics
Name soem materials that can used during temporisation
- Kalzinol (zincoxide eugenol),
- glass ionomer,
- polycarboxylate cement,
- intermediate restorative material
- composite
What do you need to do to the temporary restoration to ensure re access is easier?
A pleglet of cotton wool is placed into the pulp chamber before the temporary restoration is placed into the access cavity
After the canals have been cleaned and shaped and infection has been removed what do you do?
They are filled or obturated
What is the aim of obturation?
To prove a 3D hermetic seal of the canal system
This prevents microorganism from entering and re infecting the Canal system
What do we use to obturate the canals?
Cones of gutta percha
What are cones of gutta percha?
They are natural rubber materials combined with zinc oxide and radioopaquers
What is gutta percha often referred to as?
GP
Describe the properties of GP
It has has visco-elastic properties and can be softened by heat or solvents
What are sometimes used alongside GPs
Matched ‘finger spreaders’ are also available which are used to condense the GP into the root canal.
What is used in conduction with GPs?
Endodontic sealers
What are some ideal qualities of endodontic sealers?
- Cementation of root filling material to canal
- Fill in voids
- Antibacterial
- Radio-opaque
