Access and instruments for endodotics in posterior teeth Flashcards
Pre-treatment assessment includes
Clinical assessment
Radiographic assessment
Two questions to ask during pre-treatment assessment
Can we isolate tooth with rubber dam?
Is tooth restorable following the endodontic treatment?
Clinical assessment - endodontic diagnosis
Caries Restorations Status of remaining tooth structure -amounts -cracks -structural durability Rotation or tilting of tooth Mobility Periodontal pocketing Status of mucosa -swollen -red/ inflamed -sinus tract TTP? Colour change?
Parallax
Can be used to determine difference between canals which overly each other on radiograph e.g. premolars, mesial canals in lower molars
Can be used prior to or during treatment
MBD rule
When xray tube moves to Mesial, the Buccal canal moves to the Distal in the image
SLOB rule
Same = lingual
Opposite = buccal
The xray tube moves mesially so the lingual (palatal) canal moves in same direction (mesially) and buccal canal moves in opposite (distal) direction
Preliminary treatment
Ensure tooth is adequately restored
-restore any caries
-replace any defective restorations
Dismantle coronal restorations (if appropriate)
-any suspect indirect restorations should be removed and replaced with either new core build-up or a provisional indirect restoration
Access cavity preparation criteria
No undercuts
Smooth axial walls
All canal orifices visible
Objectives of an access prep
Ideal access forms funnel to allow instruments straight entry into canal orifices and into apical third
Allows safe irrigation
Allows ease of shaping
To straighten out curves to allow more accurate working length determination
Lower premolars
30% of lower premolars have 2 root canals
It is the lingual canal which is often missed due to access
Ensure access is adequate to identify a lingual canal if present
Where are upper premolar canals located
One buccal, one palatal
Where are lower premolar canals located
One canal buccolingual
Where are upper first molar canals located
4:
- one lingual
- one buccal
- 2 mesio-buccal (main and secondary)
Where are upper second molar canals located
3:
- one palatal
- one occlusobuccal
- one mesiobuccal
Where are lower first molar canals located
3:
- one mesiobuccal
- one mesiolingual
- one occlusodistal (central)
