If decay reaches the nerve of a tooth, the tooth needs to be treated with a nerve treatment.
WHAT IS A NERVE TREATMENT? This is a method of saving a tooth, by removing a part of the nerve of the tooth. In dental terminology this is called a PULPOTOMY. 
If the tooth is infected or abscessed a complete nerve treatment or PULPECTOMY is required.
WHY SAVE A BAD TOOTH LIKE THIS? If teeth are lost too soon, the “space” that they maintain in the jaw for the permanent teeth will close. This will lock the unerupted permanent tooth in the jaw. It may also cause the bite to collapse, and the teeth to shift. This will eventually lead to crooked teeth and a poor bite and may require orthodontia at a later time.
ADVANTAGES? In spite of the fact that the primary teeth are badly broken down after being repaired, they still act as the best space-maintainers for the permanent teeth.
DISADVANTAGES? About one in ten of these teeth, even after this treatment, causes further trouble and has to be extracted. There is no assurance that teeth with nerve treatments may not cause future difficulty.
After a nerve treatment the tooth will most likely need a STAINLESS STEEL CROWN (CAP)
WHAT ARE THEY? A crown that covers the entire tooth as it appears in the mouth. The crown is fitted under the gum all the way around the tooth so further decay is greatly inhibited.
WHERE ARE THEY USED? They are used on badly decayed primary teeth and permanent six year molars.
ADVANTAGES? We can save teeth that are so badly decayed they will no longer hold a filling.
DISADVANTAGES? Occasionally a crown may come off due to eating certain foods like caramels, popcorn, or through excessive wear (grinding teeth.) It can usually be recemented.
Pediatric Dental Center Warren, MI Dr. Shah, Dr. O’Riordan