Access cavity preparation is a step of Root Canal Treatment which marks the start of RCT and is one of the most important step as it requires knowledge of location and number of Root Canals present in every tooth, to understand the proper technique and location of starting and preparing the Access Cavity. Maxillary first molars are known to have an additional MB2 canal more often than not and that should always be in the back of your mind to search for the MB2 canal during access cavity preparation. Maxillary Second Molars are also known to have an additional MB2 canal but not as often as the First molar.
An IOPA, RVG or CBCT is the best visual aid to determine the shape of the Roots which are mostly curved, this helps you is determining the BMP procedure, the instruments to be used and the number of appointments.
Here is the image and the details of the Shapes of Access Cavities of Maxillary Teeth:
- Maxillary Central Incisor: Access cavity is Rounded Triangular shape access cavity with base towards the Incisal edge
- Maxillary Lateral incisor: Access cavity is Rounded Triangular shape access cavity with base towards the Incisal edge
- Maxillary Canine: Access cavity is Oval in shape with greatest diameter Labiopalatally
- Maxillary 1st Premolar: Access cavity is Oval in shape
- Maxillary 2nd Premolar: Access cavity is Oval in shape
- Maxillary 1st Molar: Access cavity is Rhomboid with acute Mesio-buccal angle, obtuse distobuccal angle and palatal right angles
- Maxillary 2nd Molar: Access cavity is Rhomboid with acute Mesio-buccal angle, obtuse distobuccal angle and palatal right angles
During Access cavity preparations care must be taken not to perforate and make sure that there are no canals missed. This can be done by properly reading the X-ray to make sure that there are no additional root canals or Roots and the locations of which should be kept in mind to expose them during access cavity preparation. There will be many changes in the location of the access openings and this image shows us the relative position of the access openings taken by studying hundreds of canal positions. So it might be different in every tooth and you have to be ready to make the necessary changes according to your case. As we say every tooth is not the same it holds same for the access cavity preparations as well.