INTERIM RESTORATION AND PROTECTION OF POSTERIOR TEETH UNDERGOING ENDODONTIC THERAPY Flashcards
endo tx aims
to eliminate bacteria from the tooth
interum restoration
- restoration that has been placed in a tooth after the previous restoration, caries cracks tc have been removed before the commencement of endodontic treatment
- this restoration will remain in place whilst the endo is being performed and after the RCT has been completed until the definite coronal restoration is placed
- interim restoration could end ip being a core if an indirect resto is being placed
temp resotration
- placed in the endodontic access cavity
- likely to have been cut through an interim restoration in most cases
pathways of entry
- caries
- cracks
- exposed dentine
- broken down restoration margins
advantages of placing an interim restoration
structural integrity
support for weakened cusps
Coronal seal
Rubber dam will be easy to apply, with appropriate tooth/restoration structure for the clamp to grip to
An ‘ideal’ access cavity can be cut
No risk of leakage though the coronal restoration when using
irrigants
A temporary restoration will be retained better
A well restored tooth will be more comfortable and functional to the patient
The restoration can be used as a core restoration if an indirect restoration is required later
materials for interim restorations
- composite
- RM GIC
- amalgam
Not - IRM (ZnO eug)
- GIC
what can be used for teeth with cracks
a metal band to prevent fracture
Options for the band include
- an ortho band
- copper rings
advanayges of metal bands
1) support of weakened tooth structure esp cusp
2) prevention of progression of cracks
alternatives to metal band
- can reduce the occlusal surface and rebuild the tooth using a strong restorative material
- directs occlusal forces appropriately
- eg amalgam or composite
- RMGIC not suitable material
advanages of removal of crown before endo
- through assessment of underlying tooth structure
- identification of hidden pathology
- better orientation when undertaken endo treatment
- better coronal seal
requriement of temp restorations and desrirable properties
Occupy the access cavity between appointments
Main requirement
- to provide effective and durable coronal seal
Other desirable properties include:
- ease of removal at the next appointment
- obvious difference between tooth tissue or interim restoration to allow removal without risk of removing more tooth tissue
- inexpensive
mateirals for temporary restorations (ie on top of the CaOH and sponge)
- zinc oxide based reinforced intermediate restorative materials eg IRM (but IRM does not bond to tooth structure|)
- GIC
- RM GIC
- reinforced GIC eg ketac fil, ketac silver
- composite
requirments of temporary restorations
- temp material must be min 3mm in depth to provide adequate seal
- cotton wool should not be used underneath the temp material as it wicks saliva and bacteria through restoration
- sponge pellets don’t do this and are compressed under temp restoration – easier removal
- Cavit/coltisol provides good double seal but more difficult to remove
Pt should be told to return if temp resto is lost to minimise the bacterial contamination
why should yoi protect posterior teeth undergoing endo therapy
- reduced tooth structure
- access cavity
- loss of marginal ridges
- axial forces can flex cusps
- non axial forces are even more damaging (excursive forces)
why is canine guidance ideal
- protects posterior teeth
- group function is damaging to posterior teeth esp if they have been root treated
- pre molars are at most risk as more commonly involed in group function compared to molars
- often weakened due to comparatively more tooth tissue loss
- Other forces such as non working side interferences are also extremely damaging for toot treated teeth
