Preparation for Endodontic Treatment and Temporisation during Treatment Flashcards
What considerations should be made to assess the prognosis of a tooth?
Is there sufficient tooth structure remaining for further restoration?
What type of restorations will be required?
Post-retained core required?
Any other alternative restorations?
Periodontal (crown lengthening) surgery required?
Why is assessing prognosis difficult when restored?
Cracks and/or fractures
Marginal breakdown
Caries - coronal, and root
What are the general principles for treating all diseases?
Identify the disease and its cause
Remove the cause of the disease
Treat the effect of the disease
Prevent further disease and complications
Restore to normal function
Monitor healing and stability over time
How is the disease and its cause identified?
History
Examination
Diagnosis
Cause
What should be used during investigation of all teeth?
Rubber dam isolation (cuff technique)
How do radiographs compare to actual findings of caries under restorations?
Periapical radiographs are poor indicators of caries under existing restorations
Can restorations be examined effectively clinically for caries under restorations without removing the restorations?
No, clinical AND radiographic examinations do not provide sufficient information to enable clinicians to accurately assess teeth that have been restored and have pulp and/or periapical pathosis
Why must existing restorations be removed when investigating teeth with restorations and periapical pathosis?
The presence of most causative factors of pulp and periapicla diseases can not be fully assessed without removing the existing restorations
What must be done during investigation of a tooth?
Remove causative factors for the disease
Prevent bacterial penetration during treatment
Assess suitability for further restoration of tooth
Help assess if endodontic treatment is required
Assess long term prognosis
Where does bacteria that affects restored teeth come from?
The pathway of entry for the bacteria to infect the root canal systems must have been between the tooth and the restoration. (No other pathways were present and all restorations examined had bacteria under them)
What must be done to restorations of a tooth prior to endodontic treatment?
All the restorations on that tooth must be removed.
Why must caries and restorations be removed from the tooth completely?
Caries and restorations … must be removed to:
1. Eliminate as many bacteria as possible
2. Eliminate the possibility of saliva getting into
the prepared cavity.”
“The last point is especially true of proximal caries.”
“It is much easier to complete the radicular preparation
through an open cavity than through the restored crown.
As a matter of fact, the more of the crown that is
missing, the easier the canal preparation becomes”
What are the clinical recommendations based on the study showing the need to remove restorations and caries completely from the tooth?
Endodontic access cavities should not be made through existing restorations
When is it ok to make an access cavity through an existing restoration?
Where a recent restoration has been placed and pulpitis has developed as a result of operative procedure
Where the history established that the canal was infected prior to the current restoration being placed
What is the purpose of temporization during endodontics?
Prevent bacterial ingress during and after treatment
Provide a sound base for rubber dam placement
Protect against tooth fracture during treatment
Provide a stable reference point
Provide aesthetics where required
What are the considerations that need to be made during endodontics?
Restoration of the:
Tooth (after previous restorations have been removed)
Access cavity
What is used for restoration of the tooth?
Glass ionomer (eg Ketac fil and ketac silver)
What is the main function of SS ortho bands?
To retain the interim restoration
Other functions include:
To prevent tooth fracture
To act as a base for rubber dam placement
Stable reference point for WL measurement
To assist with aesthetics
What are the features of GIC ideally be used for temporisation?
Ideally using traditional chemical set GICs. (recommended materials include ketac silver and ketac fil)
No light curing can be done through stainless steel band.
Minimal shrinkage is important
Colour contrast helps removal and helps conserve tooth structure
Stronger material - less brittle
Less sensitive to moisture loss during setting. (will be isolated with a rubber dam)
When should ketac fil be used instead of ketac silver?
When aesthetic restoration is required.
Upper 1st premolars
Some lower premolars and upper second premolars.
What must be done before and after placing temporary restoration?
Must follow manufacturer’s instructions.
Before: Use dentin conditioner (improves sealing but not much the retention)
After: Use resin cover while setting (for moisture control)
What options are there following post/crown removal?
CW/cavit deep in the post hole followed by temporary restoration (Temporary post/crown)
CW/cavit in pulp chamber (GIC over exposed dentin and temporary overlay denture)
CW/cavit in pulp chamber (temporary composite bridge bonded to root and to adjacent teeth)
How is the access cavity temporization done?
Cavit in the first appointment and then IRM in the next appointment
What are the properties of cavit?
Prevents moisture penetration (No research reported about bacterial penetration effects)
Poor strength
Poor wear resistance
High solubility
What is the composition of cavit?
Calcium sulphate primarily;
Zinc oxide
Glycol acetate
Polyvinyl acetate
Polyvinyl chloride acetate
Triethanolamine
Red pigment
How do repeated vertical loads affect microleakage of IRM and calcium sulphate-based temporary fillings?
IRM - no change
Calcium sulphate materials deteriorated rapidly and totally. Equivalent to an open access cavity.
What is the composition of IRM?
ZnO reinforced
What are the properties of IRM?
Prevents bacterial penetration
Releases eugenol which is anti-bacterial and anti-inflammatory
High wear resistance
Low solubility
However:
Does not prevent moisture penetration
What is the solution to the lack of moisture penetration resistance of IRM and the lack of bacterial penetration resistance of cavit?
The use of both in a double seal.
Why is cotton wool placed into the teeth during endodontic fillings?
Prevents filling from going into the canal during placement of temporary and during removal.
Provides a stop against which cavit can be placed.
Can cotton wool cause bacterial penetration?
No evidence that sterile CW allows bacterial penetration if adequate temporary filling is placed.
