Root Canals: What they are and why do I need one??
A root canal is a procedure during which your dentist or an endodontist (a dentist who specializes in root canals) cleans out all of the decay in a tooth including the roots of the tooth which have been infected by bacteria that are not supposed to be inside of your tooth.
Most of the time a root canal is needed when a large cavity grows to the point where it penetrates the pulp chamber of the tooth. Teeth are basically made of four parts: The enamel is the outermost layer and gives teeth their whitish color. It is the hardest material in the human body, but it can be broken down by a cavity or fracture. (see cavity and fracture links.) Underneath the enamel is a yellowish layer called the dentin. This layer has millions of tiny holes and is much softer than the enamel. Once a cavity spreads into the dentin, it moves much faster towards the pulp. The pulp or pulpal chamber is the "heart" of the tooth. It is a collection of nerves and tiny blood vessels that supply the tooth with nutrients and sensation. The normal "flora" or group of bacteria that are normally present in your mouth and not normally present in the pulp and will quickly irritate or destroy the pulp if the cavity is allowed to progress deeply enough into the tooth. Once the bacteria in a cavity spread into the pulp, a root canal is necessary. Without the root canal, the bacterial will infect the pulp chamber and then spread down into the root or roots of the tooth.
Each tooth has its own shape of pulp chamber and the different teeth in your mouth have a varying number of roots and therefore canals that run down those roots. For example, your front teeth most often have only one canal, but your molars (the ones in the far back) have 3 or 4 active canals. Once the pulp chamber is infected, each of the canals must be "instrumented" or cleaned out and sealed so that the infection cannot return. Otherwise the infection will start to destroy the bone and tissue around the end of the root. This build up of dead tissue and bone is referred to as an periodontal abscess. This abscess puts a lot of pressure on the surrounding area and this is often times what causes the pain that you may be feeling.
There are a few other times when a tooth may require a root canal. One of which is if the tooth has a trauma that disrupts the blood supply long enough for the tooth to die without having a cavity. Falling down, being hit by a baseball or any other object make up the majority of these accidents. Alternately, high fever can cause a tooth to overheat- killing the pulp in the process. When the pulp dies we refer to it as necrotic. Another rare yet possible event is during orthodontic treatment, commonly referred to as braces, when the tooth moves too quickly and loses its blood supply. Then we have fractures-- often times as we age, our teeth become more brittle. This could be amplified by large fillings in the teeth which heat up and cool down at different rates then out natural tooth structure. Most of the time these previous factors are present when we bite down on something hard such as a pop-corn kernel and fracture off a large part of our tooth. If the fracture exposed the pulpal chamber, a root canal is necessary. We may not know for sure if the fracture exposed the nerve until we remove the fractured portion and see what we have left. Some times the fracture may be too deep to restore the tooth leading to an extraction. Lasty, there are times when a cavity spreads very close to the pulp chamber without actually penetrating it. Often times, your denist will place some medicine into the tooth after removing the decay and then repair the tooth with a filling. Sometimes this is sufficient and the pulp is able to recover from the irritation and no further treatment is necessary. Sometimes the pulp is irritated to the point where it becomes very sensitive to biting, and or hot or cold. We refer to this as irreversible pulpitis or inflammation that cannot be fixed without a root canal.
Pain-- the interesting thing about teeth is that they are individual, each able to tolerate varying degrees of irritation. As a cavity spreads into the pulp chamber, you may have pain for a day or two as the pulp chamber is destroyed. Then, as is often the case, the pain will go away and you may forget about the tooth pain altogether. Eventually, and this could take days or years depending upon what type of bacteria are involved as well as how strong your immune system is, the bacteria will travel out the ends of the roots and begin to break down the bone and tissue around the root. This is normally the second time the tooth will hurt and it is normally much more severe. Often this abscess can be seen on an x-ray. Once a tooth gets to this point, it can keep you awake for days in incredible pain. Our goal as dentists is to examine our patients often enough to stop this process before things get out of hand. This is why, even without pain, regular visits to the dentist are vital.
Q and A
So I have a bad tooth, how do you actually fix it??
In essence, the root canal procedure is very simple. We anesthetize the tooth with local anesthetic (injections); then we clean out all of the decay and/or old filling material until we reach the pulpal chamber. We then give more anesthetic into the tooth itself which normally eliminates all remaining sensation in the tooth. We then use a series of small files to clean out the roots of the tooth, removing debris, dead tissue and most importantly, bacteria. At Sandalwood we use rotary files that fit into our handpiece to speed up the cleaning and shaping process. We then fill the canals and pulpal chamber with a rubber-like material to seal the tooth and prevent the re-infection of bacteria.
I have heard horror stories about root canals. Are they true??
The vast majority of the time, patients leave the office after a root canal thinking, "That was it?? I don't see what the big deal is." This is the reaction that we look for with every root canal. Dentistry as a science has evolved in the last twenty years and there have been advancements made in anesthetic and our knowledge of root canal therapy which have allowed us to better manage each case. If your tooth has already abscessed, your dentist may ask that you take antibiotics for the week or two prior to the root canal to decrease the amount of infection and inflammation present in the tooth. When a tooth is actively infected, the chemical PH of the tissue drops which inactivates our anesthetic. This is commonly referred to as a "hot tooth." The horror stories all seem to stem incidents where the patient was unable to get fully numb during the procedure. This happens very infrequently and normally we will start the process and complete it on a second visit once the inflammation subsides rather than put our patients through any unnecessary discomfort.
Why do I need a crown after I have had my root canal??
The majority of the time, if a tooth needs a root canal, it means that a significant portion of the tooth is compromised by the cavity. After the root canal treatment, teeth become brittle and prone to fracture as they are no longer receiving any blood supply from the pulp chamber. These factors lead to near certainty of fracture without a crown which holds the tooth together. Dentists hate to see patients who spent their time and money on a great root canal only to lose the tooth due to fracture. There are times however where a crown is not necessary and a filling will be sufficient based upon how much good tooth is left after the decay has been removed.
What is a buildup?? Why do I need it??
After all of the decay is removed and the root canal is completed, the tooth generally has a large hole or is missing one or more of the walls of the tooth altogether. The buildup replaces the missing tooth structure and supports the crown.
What is a post and why do I need one?
Occasionally, there are multiple walls of the tooth missing and there is not enough tooth left even to hold the buildup in place. If this is the case, your dentist will perform the root canal, then place a titanium or composite post into one of the canals. Then the buildup will be completed around the post. The post supports the buildup. The buildup supports the crown.
What does it mean if my root canal has failed??
Root canals are generally effective around 92% of the time, but occasionally, the bone and tissue around the tooth does not heal or gets re-infected by bacteria. Though we strive to never have this happen, every tooth is unique and some have tiny accessory canals that may harbor bacteria or fractures that cannot be seen all of the time. If this is the case, you may be referred to an endodontist who specializes in root canals. They have operatory microscopes that help them diagnose the problem and assess if anything can be done to fix the tooth. They often retreat the root canal by removing the rubber-like material and re-cleaning checking for any hidden or accessory canals. They also have specialized training in
Why don't I just go straight to an endodontist the first time??
Sometimes this is the best option based upon the patient's exaggerated fear of the procedure or if the tooth has abnormal roots that are very curved or highly calcified. Your dentist will let you know if this is the best decision based upon your individual tooth and situation.
What are the potential complications involved??
There are several complications that can occur during root canal treatment, all of which are rare, but happen nevertheless. One such complication is perforation of the root or crown. This is where a small hole is made in the crown or root where it is not supposed to be. This can occur due to extensive decay or during the cleaning process. If this happens, we will either complete the procedure as planned and observe the tooth at regular intervals or refer you to an endodontist to complete the treatment. Another complication is the breakage of an instrument or file inside of the tooth during treatment. If this occurs, depending on the amount of file broken and where in the tooth it is located, your dentist will decide to attempt to retrieve the broken piece or seal the tooth around the piece. We may also refer you to an endodontist for further treatment. In some cases, the tooth may need to be extracted if the piece cannot be removed and the tooth continues to be symptomatic. There are also times when after we remove all of the decay it becomes apparent that the tooth is non-restorable. This is often due to the decay spreading below the level of the bone, making it impossible to repair.
Okay, I've just had a root canal completed, what should I expect??
Depending upon how inflamed the tooth was at the time of treatment and how challenging the procedure itself was, you should expect to have some soreness for the next few days. Your dentist has probably adjusted the tooth so that you cannot put pressure on it when you bite. You will also want to avoid eating on the tooth for several days, and even after that, you will want to chew cautiously until your crown can be made so that you do not fracture the tooth. Your dentist may have prescribed you narcotic pain reliever and may also ask you to take anti-inflammatory medication such as ibuprofen.
What are my alternatives to root canal therapy??
You may choose to extract your tooth in lieu of having a root canal treatment, but it is important to remember that after the tooth is gone your neighboring teeth will drift into the new space. This drifting can cause several future problems which can be discussed with your dentist. Also, you will need to replace the missing tooth with either a partial denture, a bridge or an implant, all of which tend to be more costly and time consuming than having the root canal performed.