Endodontic Access Flashcards
(70 cards)
What should be part of the pre-op assessment?
Diagnosis, assess restorability and radiographs, plan access, dental dam, magnification, recorded and informed consent.
Why should we not treat through carious access?
File may bend or break; decreased chance of debris removal.
When can you access directly through an existing restoration?
If the restoration is new and the tooth has subsequently developed irreversible pulpitis.
What are the characteristics and purpose of an access cavity?
Through sound tooth tissue/restoration if recent placement; uncover and locate all canal entrances; ideally all canals from 1 view.
What can leaving the pulp horns cause?
Discolouration from blood products.
What dictates the shape and position of the access cavity?
Tooth anatomy - where canals are and pulp anatomy.
Which teeth can have 3 or 4 distal canals?
Mandibular molars.
Which aspect do you access for anterior teeth?
Palatal/lingual.
What proportion of canals can be identified with the naked eye?
Up to 51%.
What proportion of canals can be identified with a microscope?
Up to 82%.
Which bur to use for the initial outline form?
Long fissure bur.
Which bur to use once into the pulp chamber, and why?
Non end cutting bur to avoid damaging the floor.
Which bur for refining the access cavity?
Safe/ended/non cutting bur e.g. endo Z.
Why might you not feel the drop into the pulp chamber in an older patient?
Due to secondary and tertiary dentine.
What can affect the size of the pulp chamber?
Age of tooth, history of trauma.
What to do when you have located the pulp chamber?
Place rubber dam and seal with caulk, refine cavity, irrigate with NaOCl.
What to do if pulp is bleeding a lot?
Gain control of haemorrhage before refining access cavity because otherwise can’t see.
What to do in emergency appointments if pulp is bleeding a lot?
Relieve pressure i.e. make hole in chamber, let it bleed, dress, bring patient back to refine access cavity.
What probe can be used to help identify the canals?
DG16 explorer.
What can go wrong?
Wrong tooth - mark tooth with articulating paper before dam placement; not in long access of tooth - can perforate the pericervical dentine; can’t locate canal; false canal creation; perforation.
Consequences of an access cavity that is too small?
Pulp debris not removed, increased pressure on files, unable to locate canals, poor vision.
Consequences of an access cavity that is too big?
Weakened tooth, susceptible to fracture, files may catch on a step or ledge.
What are Krasner and Rankow’s laws about the pulp chamber?
Law of centrality - pulp chamber is always in the centre of the tooth at the level of the CEJ; law of concentricity - walls are concentric to the external surface of the crown at the level of the CEJ; distance from external surface of crown to wall of pulp is the same throughout tooth circumference at the CEJ; law of CEJ - CEJ is the most consistent, repeatable landmark for locating the position of the pulp chamber.
What are Krasner and Rankow’s laws about the pulp chamber floor?
Floor is always darker than the walls, creating a distinct junction where walls and floor meet; orifices of root canals are always located at the junction of the walls and floor; orifices of canals are located at the angles in the floor wall junction; orifices lay at the terminus of developmental root fusion lines, if present; developmental root fusion lines are darker than the floor; reparative dentine or calcifications are lighter than floor and often obscure the orifices.
