Step 3.Creating the access cavity 

For a better idea about the access cavity preparation and root canal procedure in general you need to know the basic structure of tooth. The tooth has an outer layer called Enamel covering the inner portion dentin. At the center of the tooth there is the pulp that the dentist wants to remove. So the idea is to make a hole in enamel and dentin till the pulp chamber, so that dentist can remove the infected pulp by instrumentation and remove it.

As a first step, your dentist needs to gain access to the infected pulp. For this they will :

Drill the surface of the tooth to make a wide hole that can extend a passage from the surface till the pulp chamber of the tooth. This access cavity exposes the roof of the pulp chamber.

Then the dentist perforates the roof of the pulp chamber to make a direct passage to the pulp of the tooth .

Measuring The Tooth :

After access cavity is prepared the next work is to measure the exact length of the root canal. After determining the exact length of the canal, instruments of the exact size is used to remove the infected pulp tissue.

As a consumer/patient you must know that

Your dentist’s goal will be to treat the entire length of your tooth’s nerve space but not beyond.

The technical terms might be little confusing for you. So we will try to explain you the measuring steps in the most simple manner. The calculation of the root length is carried out using x-ray and electric pulp canal length instruments. For your simple understanding :

Suppose the length of your tooth from the tip to the end of the canal is X then the extent till which the dentist should insert the root canal instruments and file is ( X – 1 )

X = Actual Length of the Tooth till Root Canal End

X – 1 = Length till which the the dentist is allowed to do the canal treatment = Working Length

In case of multi-rooted tooth measurement is done for each of the root separately.

See Next Slide : Step No.4 – Cleaning & Shaping The Tooth