From Dentinal Tubules – Bhavin Bhuva – http://www.dentinaltubules.com/articles/expert_columns
The platform for the blog will change for the forthcoming eChronicle, but the content will look much like below. This posting from Dentinal Tubules is a bit more than will be offered, but it’s a beginning. The intention is to include graphics and animations to develop the truest format of blended learning possible. Your contributions at this seminal phase are encouraged and welcome.
Of interest, once again, the most vital piece of equipment for endodontic access is missing……a Danville micro-etcher. Nothing is more important or purposeful in detecting orifices, fissure and fusion lines and delineating the topography of the pulpal floor and yet, it is almost NEVER mentioned in access articles.
Access cavities
The objectives of access cavity preparation are to:
1. Do no harm
2. Remove the entire roof of the pulp chamber
3. Remove all of the coronal pulp and necrotic tissue
4. Identify all canals
5. Achieve straight line access to all canals
Straight-line access
This is not just to get into the canals but to allow passive instrumentation of the entire length of each root canal.
It is very important to modify the access cavity throughout the procedure, to ensure that the access is correct. Once the canals are located, the use of small files will tell you where the files ‘want to go’ and if further modification is necessary. The process of access cavity preparation can be thought of in three stages:
1. Access cavity outline
2. Pulp chamber modification – to include removal of dentinal interferences
3. Initial coronal flaring
These stages should all be intertwined so that straight-line access flows from the occlusal access, through the entire length of the pulp chamber and into the root canals.
See this example of an upper molar retreatment…. Although the occlusal access (i.e. the amalgam restoration) in the pretreatment radiograph appears sufficient, there does not appear to have been any modification of the pulp chamber, and so straight-line access into the mesiobuccal root has not been obtained. As a result of this, the root canal obturation only reaches the level of the curvature. The post-treatment radiograph shows how by modifying the pulp chamber to allow straight-line access, the mesiobuccal canals are easily negotiated to full length.
