endodontics Flashcards
what are the treatment objectives of endodontics?
- remove the cause of disease
- treat the effect of the disease and prevent further disease and complications
- restore to normal function and monitor health and stability over time
when is direct pulp capping used?
how is direct pulp capping carried out?
exposure of the pulp has occured but patient management is a concern
- apply rubber dam
- remove all caries
- clean with sterile saline
- wash site with sodium hypochlorite
- place CaOH or MTA on pulp followed by GIC or bio-dentine
- restore tooth with restoration
what are the properties of calcium hydroxide?
- alkaline pH & antimicrobial
- intiaites dentine bridge formation
- soluble
- does not seal well nor prevent microleakage
what are the properties of Mineral Trioxide Aggregate (MTA)
- prevents micro-leakage - sealability
- biocompatible
- promotes regeneration of tissues
- high alkaline pH
- less probability of failure in comparison to calcium hydroxide
what are the advantages of NiTi rotary instruments?
- safe, flexible with shape memory
- predictable
- uncomplicated - simple sequence
- efficient - rapid dentine removal
- easy to learn, simple technique
what are the disadvantage of NiTi rotary instruments?
- high cost
- adaptability
- deformation/fracture
- requires a ‘guide path’
- unable to pre-bend
how should NiTi rotary instruments be used?
- use in slow speed (200-300rpm)
- light even pressure
- continuous movement
- brushing movement on withdrawal
what are the properties of sodium hypochlorite?
we use NaOCL 1% (gold standard)
dissolves:
* endodontic micro-organisms
* necrotic tissue
* organic components of smear layer
inactivates endotocins
acts as a disinfectant
minimal irritation at low concentrations
reduces the elastic modulus and flexural strength of dentine
how can hypochlorite accidents be avoided?
- avoided by premeasuring irrigant needle
- gentle pressure and continuous movement of syringe
- use a maximum of 1% NaOCl
what is the protocol for a hypochlorite accident?
- tell supervisor & stop treatment
- remove NaOCl with paper points
- dress canal with non-setting CaOH
- give appropriate analgesics and chlorhexidine mouth wash
- consider oral antibiotics for 3 days
- OS may suggest steroids IM
- observe patient for 3-4 hours to observe any swelling
- cold compression initially, followed by warm compress after 24 hours to manage swelling
- review patient in 12 days time
what is the smear layer?
1-2 μm thick layer on the surface of the canal walls.
it has the potential to:
* harbour micro organisms
* create an avenue for leakage
* act as a substrate for microbial proliferation
* interfere with physical properties and addaptation of root canal sealer materials
what is used to remove the smear layer?
EDTA
* ethylenediamine tetracetic acid
* 17% after NaOCL use
citric acid
* 10-55% solution after NaOCl use, following canal preparation
NaOCl combined with 15% EDTA is most effective in antibacterial activity
when should EDTA be used?
during the final debridement of the canals
this is followed by saline to remove the chemicals
how can NiTi instrument fracture be prevented?
- don’t use instruments with signs of plastic deformation & clean regularly
- use a low speed & light pressure
- use a smaller angle of curvature
- create a glide path with hand instruments
- use controlled torque motors
- use instruments for short time within canal & keep it moving
- pre-flare canals by using a ‘crown-down’ technique
what is the goal when assessing a root filling?
- homogenous
- appropriate length
- no voids
