Endodontics
Endodontics is a specialized branch of dentistry that deals  with the complex structures found inside the teeth. The Greek word  “Endodontics” literally means “inside the tooth,” and relates to the tooth  pulp, tissues, nerves and arterioles. Endodontists receive additional dental  training after completing dental school to enable them to perform both complex  and simple procedures, including root canal therapy.
Historically, a tooth with a diseased nerve would be  removed immediately, but endodontists are now able to save the natural tooth in  most cases. Generally, extracting the inner tooth structures, then sealing the  resulting gap with a crown restores health and functionality to damaged teeth.
Signs and symptoms of endodontic problems:
- Inflammation and tenderness in the gums.
 - Teeth that are sensitive to hot and cold foods.
 - Tenderness when chewing and biting.
 - Tooth discoloration.
 - Unexplained pain in the nearby lymph nodes.
 
Reasons for endodontic treatment
  Endodontic treatment (or root canal therapy) is performed  to save the natural tooth. In spite of the many advanced restorations  available, most dentists agree that there is no substitute for healthy, natural  teeth.
  Here are some of the main causes of inner tooth damage:
  Bacterial infections - Oral bacteria is the most common cause of endodontic problems.  Bacteria invade the tooth pulp through tiny fissures in the teeth caused by  tooth decay or injury. The resulting inflammation and bacterial infection  jeopardize the affected tooth and may cause an abscess to form.
  
Fractures and chips - When a large part of the surface or crown of the tooth has become  completely detached, root canal therapy may be required. The removal of the  crown portion leaves the pulp exposed, which can be debilitating painful and  problematic.
  
Injuries -  Injuries to the teeth can be caused by a direct or indirect blow to the mouth  area. Some injuries cause a tooth to become luxated, or dislodged from its  socket. Root canal therapy is often needed after the endodontist has successfully  stabilized the injured tooth.
  
Removals - If a  tooth has been knocked clean out of the socket, it is important to rinse it and  place it back into the socket as quickly as possible. If this is impossible,  place the tooth in special dental solution (available at pharmacies) or in  milk. These steps will keep the inner mechanisms of the tooth moist and alive  while emergency dental treatment is sought. The tooth will be affixed in its  socket using a special splint, and the endodontist will then perform root canal  therapy to save the tooth.
  
What does an endodontic procedure invlove?
  Root canal therapy usually takes between one and three  visits to complete. Complete X-rays of the teeth will be taken and examined  before the treatment begins.
  
Initially, a local anesthetic will be administered, and a  dental dam (protective sheet) will be placed to ensure that the surgical area  remains free of saliva during the treatment. An opening will be created in the  surface of the tooth, and the pulp will be completely removed using small  handheld instruments.
  
The space will now be shaped, cleaned and filled with gutta-percha. Gutta-percha is a biocompatible material that is somewhat similar to rubber. Cement will be applied on top to ensure that the root canals are completely sealed off. Usually, a temporary filling will be placed to restore functionality to the tooth prior to the permanent restoration procedure. During the final visit, a permanent restoration or crown will be placed.
If you have questions or concerns about endodontic procedures, please ask your dentist.
Cracked Tooth
Cracked and fractured  teeth are common dental problems. As people retain their natural teeth longer  (due to advances in dental technology), the likelihood of cracked teeth  increases. There are many reasons why teeth may crack, for example, biting on  hard objects, trauma, grinding and clenching of teeth. All of these behaviors  place the teeth under extra strain and render them more susceptible to  cracking. 
  
When tooth enamel is  cracked, pain can become momentarily debilitating. When no pressure is exerted  on the crack there may be no discomfort. However, as the cracked tooth performs  a biting action, the crack widens. The pulp and inner workings of the tooth  then become exposed, and painful irritation occurs. As pressure is released  again, the two parts of the crack fuse back together, and pain subsides. If  left untreated, the pulp becomes irreversibly damaged and constantly painful.  The resulting pulp infection can affect the bone and soft tissue surrounding  the tooth. 
  
Symptoms of a cracked tooth may include:
- Unexplained pain when eating.
 - Sensitivity to warm and cold foods.
 - Pain with no obvious cause.
 - Difficulty pinpointing the location of the pain.
 
A composite (tooth colored) filling is used to repair a tooth that is affected by decay, cracks, fractures, etc. The decayed or affected portion of the tooth will be removed and then filled with a composite filling.
There are many types of filling materials available, each with their own advantages and disadvantages. You and your dentist can discuss the best options for restoring your teeth. Composite fillings, along with silver amalgam fillings, are the most widely used today. Because composite fillings are tooth colored, they can be closely matched to the color of existing teeth, and are more aesthetically suited for use in front teeth or the more visible areas of the teeth.
As with most dental restorations, composite fillings are not permanent and may someday have to be replaced. They are very durable, and will last many years, giving you a long lasting, beautiful smile.
Reasons for composite fillings
- Chipped teeth.
 - Closing space between two teeth.
 - Cracked or broken teeth.
 - Decayed teeth.
 - Worn teeth.
 - How are composite fillings placed?
 
Composite fillings are usually placed in one appointment. While the tooth is numb, your dentist will remove decay as necessary. The space will then be thoroughly cleaned and carefully prepared before the new filling is placed. If the decay was near the nerve of the tooth, a special medication will be applied for added protection. The composite filling will then be precisely placed, shaped, and polished, restoring your tooth to its original shape and function.
It is normal to experience sensitivity to hot and cold when composite fillings are first placed, however this will subside shortly after your tooth acclimates to the new filling.
You will be given care instructions at the conclusion of your treatment. Good oral hygiene practices, eating habits, and regular dental visits will aid in the life of your new fillings.
What kind of cracks can affect the teeth?
  There are many ways in  which a tooth can be cracked. The specific type of crack will determine what  type of treatment is viable. In many cases, if the crack is not too deep, root  canal therapy can be performed and the natural tooth can remain in the mouth.  In other situations, the tooth is too badly damaged and requires extraction. 
  Here is a brief overview  of some of the most common types of cracks: 
Crazes – These are generally tiny  vertical cracks that do not place the teeth in danger. These scratches on the  surface of the teeth are considered by most dentists to be a normal part of the  tooth anatomy. A craze rarely requires treatment for health reasons, but a wide  variety of cosmetic treatments can be performed to reduce the negative  aesthetic impact. 
  
Oblique supragingival  cracks -  These cracks only affect the crown of the tooth and do not extend below the gum  line. Usually, the affected part of the tooth will eventually break off. Little  pain will result, because the tooth pulp (that contains the nerves and vessels)  will remain unaffected. 
  
Oblique  subgingival cracks - These cracks extend beyond the gum line, and often beyond where the  jawbone begins. When a piece breaks off, it will usually remain attached until  the dentist removes it. Oblique subgingival cracks are painful and may require  a combination of periodontal surgery (to expose the crown), and endodontic  treatment to place a crown or other restorative device. 
  
Vertical furcation  cracks -  These cracks occur when the roots of the tooth separate. This type of crack  almost always affects the nerve of the tooth. Because the tooth will not  generally separate completely, root canal therapy and a crown can usually save  the tooth. 
  
Oblique root  cracks -  These cracks tend not to affect the surface of the tooth at all. In fact, the  damage is only apparent below the gum line and usually below the jawbone. Root  canal therapy may be possible; depending on how close the fracture is to the  tooth surface. However, extraction is almost always the only option after  sustaining this classification of fracture. 
  
Vertical apical  root cracks -  These cracks occur at the apex (tip of the root). Though the tooth does not  require extraction from a dental perspective, many patients request an  extraction because of the high degree of pain. Root canal therapy alleviates  the discomfort for a while, but most often, teeth affected by such cracks are  eventually extracted. 
  
How are cracks in  the teeth treated? 
  
There are many different  types of cracked teeth. Some can only be exposed using X-ray machines, while  others are clearly visible to the naked eye. In cases where the tooth root is  affected, root canal therapy is the most viable treatment option. The pulp,  nerves and vessels of the tooth will be removed, and the resulting space will  be filled with gutta-percha. A crown or filling will be added to stabilize the  tooth and it will continue to function as normal. 
 
When the crack is too severe for the tooth to be saved, the dentist will perform an extraction. There are a number of restorative options in this case, such as bridges, dental implants and partial dentures. All of these structures can restore biting, chewing and speaking functions.
If you have any questions or concerns about cracked teeth, please ask your dentist.
Root Canal Retreatment
  In rare cases, root canal therapy fails to work as  expected. The treated tooth might not heal properly or a patient might  experience post-surgical complications that jeopardize the tooth. Root canal  retreatment involves the removal of the previous crown and packing material,  the cleansing of the root canals, and the re-packing and re-crowning of the  tooth. In short, root canal retreatment is almost identical to the original  procedure, aside from the structural removal. The success rate for a root canal  retreatment runs at around 75%.
  
Root canal treatments and retreatments are a better  alternative than extraction for most individuals. If a tooth has good bone  support, a solid surface and healthy gums beneath it, it stands a good chance  of being saved. Opting for root canal retreatment can be far less expensive  than the alternatives. Dental implants, extensive bridgework and the creation  of aesthetically pleasing prosthetic teeth cost far more than working with the  natural tooth. They also require maintenance and feel less natural than a  “real” tooth.
  
Why is root canal  retreatment required? 
  
Though the prospect of more endodontic surgery might not be  pleasant, root canal retreatment is fairly simple. In general, the whole  treatment can be completed in 1-3 visits.
  
There are a number of reasons why root canal therapy unexpectedly fails, including:
- Cracked crown leaking filling material.
 - Curved or narrow canals not treated during the original procedure.
 - Delay in the placement of restorative devices following the procedure.
 - New decay to the tooth.
 - New fracture in the treated tooth.
 - Saliva entering the restorative structure.
 - Undetected complex canal structures.
 
What does root canal  retreatment involve? 
  
On the day of the retreatment procedure a local anesthetic  will be administered, unless another type of anesthetic has been selected. The  affected tooth is isolated with a rubber dam. The dam protects the tooth during  treatment from bacteria and saliva. The amount the dentist can do within a  single appointment will much depend on the amount of inflammation present, and  the complexity of the treatment.
  
The first step in a root canal retreatment is to gain  access to the inner tooth. If a crown and post have been placed, these will be  removed.
  
Next, filling material and obstructions that block the root  canals will be removed. This removal is conducted using an ultrasonic  handpiece. The advantage of using this tool is that any unwanted material is  vibrated loose. Tiny instruments will then be used to clean and reshape the  root canals. X-rays may be taken to ensure that the roots are thoroughly clean.  If this part of the treatment proves to be complex, medicated packing material  will be applied, and the rest of the cleansing procedure will be done at the  next visit.
  
When the dentist is confident that the root canals are  completely clean, gutta-percha is used to pack the space. This rubbery material  seals the canals to prevent bacterial invasion. Finally, a temporary crown or  filling is applied to tooth. At a later date, the color-matched permanent crown  will be placed.
  
If you have any questions or concerns about root canal retreatment, please ask your dentist.
