Access in posterior RCTs Flashcards
Pre-treatment assessment
Stages
Clinical assessment
Radiographic assessment
Pre-treatment assessment - two things to ask
Can we isolate the tooth with rubber dam
Is the tooth restorable following endodontic treatment - PROGNOSIS
Endodontic diagnosis - clinical assessment criteria
Caries Restorations Status of remaining structure and durability Mobility Rotation/Tilting of tooth Perio pocketing Status of mucosa TTP Colour change
Parallax is used to
When can it be used?
Can be used to determine difference between canals which overly each other e.g premolars and mesial canals in lowers
Prior or during treatment
MDB RULE
x ray moves to mesial
buccal canal moves to distal in image
SLOB rule
Same lingual
Opposite buccal
Preliminary treatment
Ensure tooth is adequately restored by
Restore caries, replace any defective restorations
Dismantle coronal restorations - any suspicious indirect restorations should be removed and replaced with either a new core build up or a provisional indirect
Objectives of access
Access requirements
Forms a funnel to allow instruments straight entry into canal orifices and into apical 1/3
Allows safe irrigation
Allows ease of shaping
To straighten out curves to allow more accurate working length determination
What dictates access cavity shape?
Examples
Pulp chamber anatomy
Incisors are rounded arcs
Premolars are ovals
Molars are rounded
Root canal outline - ideally
Consistent circular cross section
Pulp chamber nature
very jagged outline
often deeper in upper premolars
Lower premolar advice
which canal is usually missed
30% have 2 root canals
Lingual canal often missinf
Upper molar
Roots?
MB P B Identify one root and orient yourself like that Palatal is widest
Lower first molar
Roots canals?
Access cavity is best as C shape
MB
M
D
Multi rooted teeth - important that
Each tooth should have its own reference point on occlusal and own WL
Risk of strip perforation is
increased by use of
managed with
Gates Glidden
Anti-CURVATURE filling
Curve file to same shape
Filing away from high risk area
As curved canal straightens
Working length becomes shortened
Different file sizes =
Different
Ideal access cavity prep
No undercuts
Smooth axial walls
All orifices visible
Stages of access
Access through porcelain with diamond bur and metal with jet bur
Long neck bur
Access through dentine with Long shank
Access into pulp chamber followed by de roofing
Smooth sides of access cavity with endo z
Strip perforation definition
Strip of canal is perforated vertically
