Endodontics
Dynamic Access Cavity Preparation

Designing the access cavity to allow straight line access (SLA) is a dynamic process. The shape of the access cavity is changed during flaring of the canal, to allow the flare to penetrate deeper.
The dynamic process involves
Create initial access cavity
Penetrate canal
Flare canal
Adjust access cavity
Penetrate deeper
Flare canal
Adjust access cavity
... and so on
This animation shows 3 ways of deeply penetrating a canal, then combines the techniques to achieve deep penetration with maximum conservation of tooth tissues. An upper incisor is used in this example, but the principles apply to all canals.