A small or a moderate size cavity can be restored with a filling but a deep cavity where the decay is already touching the nerve will need a root canal treatment.
There are three layers of your tooth – Enamel, Dentin and Pulp.
Enamel is the outer layer and Dentin is the middle layer. If the cavity is only in the enamel or dentin, a filling would be good enough to restore it. If the decay or bacteria went into the pulp (commonly known as the nerve tissue), then you would need root canal therapy. While a tooth’s pulp tissue does contain nerve fibers, it is also composed of arteries, veins, lymph vessels, and connective tissue. Each tooth’s nerve enters the tooth at the tip of its roots. From there, the nerve runs through the center of the root in small “root canals,” which join up with the tooth’s pulp chamber.
When the nerve becomes infected or inflamed due to a deep cavity or fracture, the blood supply to the tooth may be lost and the tooth pulp may die. This can cause pain and pressure while biting down, chewing, eating or drinking hot or cold foods and drinks. This pain is usually not relieved by over the counter pain medications alone.
Without treatment, the infection will spread to the bone around the tooth and an abscess will form. That’s when a swelling appears on the face and the pain gets worse. At this point, the treatment will include antibiotics and drainage of the abscess and then root canal therapy if the tooth can still be salvaged.
AVOID THESE PROBLEMS WITH PREVENTIVE CARE. If you go for a check-up regularly even if you have a cavity we can catch it early and treat it before it involves many appointments, high costs and pain.
At the first visit, Decay is removed from the tooth and the infected tissue is removed. Medication may be inserted into the area to fight bacteria. A temporary filling will be placed to prevent re-contamination. Medication may be given to control the inflammation. At the second appointment the medication is removed, the tooth is checked and the canals in the root are filled in.
Once the root canal treatment is finished, temporary fillings are usually removed and if the tooth was weakened substantially with the original decay, a post may be inserted above the canal filling to help rebuild the tooth.
Then, a crown is normally placed over the tooth to strengthen its structure and improve its appearance. The crown also prevents the fracture of the treated tooth. Once the root canal is done, the external tooth is intact but it is not alive anymore so there is no blood or water supply to the tooth and it becomes brittle over a period of time. Most times full coverage of the treated tooth with a crown is necessary. Sometimes if the access space is small, a filling or an inlay or an onlay may be sufficient.
The only alternative to root canal therapy is to extract the tooth; however, this alone can cause the surrounding teeth to move, resulting in a bad bite. Though a simple extraction may be perceived as less expensive, the empty space left behind will require an implant or a bridge, which ultimately can be more expensive than the root canal therapy.
Post and Cores
A post and core is the connection between the tooth and the crown. Once the root canal therapy is completed, the tooth hallowed out where there originally was decay; and the remaining tooth structure may be thin and susceptible to fracture. Also because the tooth is dry and there is no blood or water supply because of the root canal, the tooth becomes brittle over a period of time.
The original decayed part and the space made to get the root canal done has to be replaced by a post and core. If there is not too much tooth structure missing, a pre-fabricated post is used and the best size is picked out for your tooth. If there is barely any tooth left, a custom made post and core is created by making a pattern of the inside of your tooth and canal and sent to the lab to be fabricated. It is then cemented on to your tooth.
Once the post is done, your tooth needs to be restored by a crown which covers the remaining tooth and the post.