Endodontic access is frequently overlooked as an essential step in creating excellent clinical results. Interestingly, our mental conceptions of a root canal are generally images of instrumentation and seldom opening the tooth.
Achieving proper access is a vital precursor and predictor of ideal results. If access is less than ideal, it is very difficult – if not impossible – to achieve adequate cleansing and shaping.
The surgical operating microscope (SOM) makes visualisation during access more predictable and is highly recommended. The author uses the LA Axxess kit (SybronEndo, Orange, CA, USA) for access procedures due to the wide range of burs contained within – burs that make virtually any access preparation possible.
Having given a large number of hands-on courses globally, it is my opinion that the vast majority of endodontic access is too small in the mistaken belief that tooth structure must be conserved. While it is possible that access can be excessively wide, this is very uncommon.
Access has often been made far too small, resulting in poor visualisation, inadequate irrigation, missed canals, lack of tactile control and a lack of ability to manipulate instruments of all types into the canal.
Access that’s too small stops the clinician from achieving excellent results by preventing intimate control over intra-canal cleansing and shaping. For example, if a distal root of a lower molar should have a second canal which branches off the first but does so just below the orifice floor, it can be easily missed if it is not anticipated or no effort is made to find it.
Having an access that is wide enough from the start gives the clinician the best chance to locate it, especially in combination with adequate visualisation.
The route to success
The steps that clinicians must take to achieve access are:
1. Make access as small as possible but large as necessary. Within reason, access openings can’t really be too big but can certainly be too small
2. Remove all caries and overhanging (unsupported) tooth structure
3. All canals should be visualised in one mirror view
4. Files should lie in canals passively and without deflection upon entry
5. In crowns and while removing fillings, occlusal access outline should be made before entering canals to prevent metal chips and debris from becoming compacted apically
6. Clearly locate all canals before entering any individual canal
7. Be certain that the floor of the chamber is clearly exposed before entering canals, i.e. don’t leave the chamber floor unroofed.
Following these seven simple steps will go a long way to creating an adequate access upon which ideal treatment results can be based. I welcome your questions and feedback.