All teeth have different tooth anatomy.  Baby teeth, or primary teeth have different tooth anatomy from adult teeth, or secondary teeth as well.


The outer layer on all teeth is called the enamel.  This layer is the hardest, and does not have any nerve sensation.  This is the layer that covers your teeth to prevent you from feeling pain every time you breathe or eat.  Also, if a cavity is confined to the enamel, you likely will not feel it, and if your dentist is doing work only in enamel, you should not feel it as well.  Veneers are often done with minimal preparation, and left in the enamel, in which case local anesthetic would not need to be used.

There are genetic disorders such as amelogenesis imperfecta, which is basically the lack of proper enamel formation on teeth.  This obviously can cause serious dental problems and may require all teeth to be crowned.


Underneath the enamel is the dentin.  This layer is softer than the enamel, and does have nerve endings.  When a cavity extends into the dentin, you may start to get symptoms.  Cavities also progress much quicker once it invades the dentin.  Dentin can be exposed without being an active cavity, in which case often times sensitive toothpastes can be used to try to desensitize the area(s).  This can happen when the gum has receded or when a tooth has significant wear due to grinding or even toothbrush abrasion.


This is the layer of tooth that covers the root surfaces of teeth.  This layer also has nerve endings but usually does not come into play since it is normally under the gums.


This is the chamber in the center of the tooth, which houses the nerve and blood supply to the tooth.  When a cavity progresses to the pulp, or nerve of the tooth, this will usually cause a significant amount of pain.

When that happens, either a root canal or extraction will need to be done in order to alleviate the pain.

As you age, the pulp chamber gets smaller, so teenagers have very large pulp chambers while the elderly generally have much smaller pulps.

This means that deep cavities in teenagers may end up needing root canals faster than in an elderly adult; and root canals are generally easier in younger people than in older people (the larger the pulps, the easier to find and clean out).


The main differences are,

  • larger pulps in primary teeth
  • thinner layer of enamel
  • cavities progress faster due to thin enamel


These are the 2 front teeth on top and bottom.  They generally only have 1 pulp/nerve canal.


These are the 2 similar looking teeth on either side of the centrals, and also generally have 1 pulp/nerve canal.


These are the pointy, teeth next to the laterals, and generally have 1 pulp/nerve canal.


There are 2 premolars, so 4 pairs in the 4 different quadrants (upper right, upper left, lower right, lower left), and are the 2 teeth next to the canines.  These usually either have 1 or 2 pulp/nerve canals.


There are 3 molars in each quadrant, the last being the wisdom teeth, which often are not visible in the mouth or have been removed.  These usually have 3-4 pulp/nerve canals, but sometimes have 2 or even 5 nerve canals.


These are the furthest teeth back, also known as the third molars, and are often removed.

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