Smear Layer Removal/intracanal Medicaments/temporary Restorations Flashcards
What creates the smear layer? How thick is it?
Cleaning and shaping. 1-5 micrometers
Organic components of smear layer?
Pupal remnants, odontoblasts, microorganisms
Inorganic components of smear layer?
Dentin, irrigant remnants, hydroxyapatite
3 reasons why a smear layer may affect the prognosis of RCT?
- Sealed dentin tubules prevents adequate penetration of the irrigant into the tubules
- Results in poor adaptation of the sealer and obturation material to the canal walls
- May allow bacterial growth within
What type of solution do we use to remove the inorganic components of the smear layer?
Chelator solutions
What do we use to remove the organic component of smear layer?
Sodium hypochlorite for no more than 1 minute
How does the use of chelator solutions improve the use of sodium hypochlorite use?
Allows deeper penetration of sodium hypochlorite into dentin tubules
What is the problem with excessive sodium hypochlorite rinsing after use of a chelator solution?
Could result in corrosion of the dentin
What chelator solution do we use in clinic? How long do we rinse canals with this?
17% EDTA - ethyldiaminetetracetic acid
1 minute
3 properties of EDTA (chelating solution)?
- Minimal-no antimicrobial activity
- Non-lubricating
- Allows deeper penetration of irrigant and sealer
3 other smear layer removal products other than EDTA?
- MTAD
- Citric acid
- Smear clear
After we used chelator (17% EDTA) for 1 min and then sodium hypochlorite for minute. How do we dry the canals for placement of sealer and obturation material?
Dry canals with paper points
What is the purpose of using intracanal medicaments? (3 points)
- Persistent anti-microbial effect
- Improves prognosis of long term microbial colonized canals that have resistant microbiota
- Acts as a physical-chemical barrier to reinfection between final obturation and restoration
What is the most common intracanal medicament?
CaOH
Why is CaOH an effective intracanal medicament? How long does it take to have an effect?
Because it has a high pH of 12.5.
Takes 1-2 weeks to take effect (sufficiently change the pH of the canals.