Endo Flashcards
When would you root canal teeth with healthy pulps?
- If tooth can’t be restored without seriously endangering pulp
- Tooth cannot be restored without using pulp chamber and canal system to retain restoration (post)
- There is intractable dentine hypersensitivity
On what teeth are RCTs not possible?
- Gross caries
- Vertical fracture
- Advanced perio disease
How can you help teeth to not fracture during treatment?
Flatten cusps or matrix band around tooth
Why is shaping done?
To enlarge the original canals for:
- Mechanical cleaning
- Irrigant exchange
- Ease and control of filling
After access what are the stages of canal preparation and filling the canal?
- Find electronic working length
- Establish glide path
- Coronal flare
- Confirm WL
- Deep flare
- Apical stop preparation
- Irrigation
- Master GP point
- Cold lateral condensation - spreader and accessary points
- Cut off and warm compaction with plugger
What burs are used in access cavity preparation?
- Medium tapered diamond
- Endo Z and Batt bur (safe ended for unroofing pulp chamber)
- Gooseneck and LN pin burs (for locating pulp spaces and canal entrances)
What is a Gates Glidden bur used for and how do you know its size?
Slow speed for canal preparation
Bands on shank
Flame shaped bur
What are barbed broaches made of and what way to twist?
Stainless steel
Clockwise engages and removes pulp
For the ISO hand files, what is the length, taper and diameter of the active part of the file?
16mm
0.02mm/mm taper - 2% taper
Depends on ISO size e.g. ISO 35 = 0.35mm
When were the ISO regulations?
1961
What is the cutting motion for
a) ISO K hand files
b) ISO Hedstroem files?
a) Rotation - watchwind or balanced force motion. Rasping - filing on outward stroke
b) Rasping not rotation. Milled to have a sharp angle so aggressive but fragile
For the non ISO Protaper hand files/ engine driven rotary files, what is the tip size and taper of Shaper 1 (Purple)?
0.17mm
2-11% taper
For the non ISO Protaper hand files/ engine driven rotary files, what is the tip size and taper of Shaper 2 (White)?
0.2mm
4-11.5% taper
For the non ISO Protaper hand files/ engine driven rotary files, what is the tip size and taper of Finisher 1 (Yellow)?
0.2mm
7% taper
For the reciprocating files (Reciproc, WaveOne) what is the tip size, taper and max diameter?
25
8% taper in apical 3mm, 4% taper in remainder
1.05mm
What materials can be used as lubricants and chelating agents?
a) EDTA/ peroxide paste (glyde)
b) Medicated soap (hibiscrub)
What materials can be used as irrigants?
a) Sodium hypochlorite (NaOCl) 0.5-5% - kills microorganisms and dissolves organic matter but must have seal on rubber dam
b) Chlorhexidine gluconate 0.2-2% - antimicrobial but no solvent action
c) Sterile saline or local anaesthetic - flushes debris and lubricates but no other action
What is the reason for antimicrobial dressings?
- Clean and disinfect canals between appointments
- Kill microorganisms that leak around temporary dressings
- Prevent pain after canal prep
What is it called when there is disruption of perfusion that causes pulp death?
Ischaemic pulp necrosis
In reversible pulpitis, what fibres cause pain? and in irreversible pulpitis?
A delta
C fibres
What is the success rate of RCT in necrotic pulps for healing AP?
70-90%
How does AP occur?
Necrotic pulp - toxins leak into PA tissues, host inflammatory and immune defenses cannot enter tooth but attempt to contain infection - bone loss consequence
Why do we use a rubber dam?
- Prevents saliva entry to tooth
- Protects airway
- Allows use of strong disinfectants
- Retracts cheeks and tongue
- Stops pt talking/rinsing
- Improved pt comfort?
What pH is non-setting calcium hydroxide paste? How long does it last? What else can be used? How are they placed?
pH11/12. 3 months
Odontopaste (steroid/antibiotic paste)
File rotated anticlockwise