Implants, Crowns, and Bridges vs. Natural Teeth

Nothing can replace the natural teeth you were born with for chewing and function. However, very few people go through life without having teeth filled, crowns (caps) placed, or bridges and implants used to replace missing teeth. Crowns, bridges, and implants are the best answer and closest to your natural teeth, but they are not the same as healthy, natural teeth.

Crowns

Crowns are used to reconstruct a single tooth broken down by dental decay. Crowns are made of ceramic, resin, porcelain, porcelain plus metal, or resin plus metal materials. They are bonded or cemented onto the prepared tooth and cannot easily be removed from the tooth once placed. If the tooth was in good alignment before the crown was prepared, the crown will be in good alignment. If the tooth was misaligned before the crown, sometimes the crown may be made to obtain a more ideal shape and position. It is cleaned and flossed just like a natural tooth and is most like real teeth.

Bridges

Bridges are crowns that are attached together, suspending the crown portion of a false tooth in or over the space left by the missing tooth. A bridge can be used to replace one or several teeth. Sometimes a bridge is used to splint loose teeth together in order to make the teeth more stable. Bridges are usually made of metal covered with either porcelain or resin. Some of the newer bridges are made of all resin or all ceramic materials. They are cemented or bonded onto the existing prepared teeth and are not easily removed once placed. The bridge teeth can be brushed the same as natural teeth, but since they are attached together, must be flossed differently by using a floss threader or other device.

The teeth are generally the same shape as natural teeth. However, if the existing teeth (abutments) that are used to anchor the bridge have moved from their original position because a tooth or teeth have been missing for years, the added tooth (pontic) may be longer or shorter than the tooth that it is replacing. With a bridge, the false tooth will most often butt up against the soft tissue ridge where the removed tooth was.

The shape of the tongue side of the false tooth varies. It is usually smaller on the tongue side and completely fills the space. Food will have more of a tendency to collect in this area, so you must be prepared to clean it. If the missing tooth has been gone a long time, the ridge may have shrunk considerably, and the pontic tooth will be longer that the teeth on either side. If this is the case, there are several periodontal procedures that can be done prior to the construction of the bridge. These procedures will build up the tissue to its former height. The more your mouth has changed from its normal state, the harder it is to make new teeth look and feel natural.

Implant Crowns

Implant crowns are used to replace single or multiple missing teeth. They are either cemented or screwed-retained onto an implant fixture. The crowns are made of porcelain or resin and metal. But they have some significant differences from the natural teeth they replace. Teeth are supported by a root or roots that are irregular in shape. Implants are round. The cross-sectional of the implant will never match that of the tooth it is replacing. A multirooted tooth may be replaced by a single implant, so the manner in which an implant crown comes out of the soft tissue ridge will appear different from a natural tooth. There will be more space between the implant root and the adjacent teeth. Implant crowns are often cemented with temporary cement. This allows the dentist to easily take off the crown and evaluate how the implant is doing. Crowns on teeth are usually cemented with a final cement. Implant-supported crowns are wonderful, but not the same as natural teeth with crowns. Be prepared for some differences. Expect more maintenance on your part and in the dental office with crowns, bridges, and implants.

Smokers take note: There is a heightened risk of dental implant failures among smokers—as much as 20% greater failure rate!

Implants: Procedural Overview

Compared to a routine dental filling or crown (cap), replacement of a missing tooth or teeth with implants is a more complicated and lengthy process. It will take several phases. A periodontist or an oral surgeon will place the implant surgically. Then we will place the tooth or visible portion.

Phase One
The specialist evaluates the position, suitability, and strength of the bone that will surround the implant. This information determines the length and width of the implants and how many implants will be necessary to replace the missing teeth. Impressions of all your teeth will be taken for study models in order to design the shape of the tooth or teeth to be implanted. A surgical guide will be made to indicate to the surgeon where the implants should be placed.  

Phase Two
Surgical procedure is done to place the implant in the bone. A local anesthetic is given, and the gum tissue is lifted to expose the implant site. The implant is placed into the bone and the gum is closed over it. You will not see the implant while integration with the bone takes place. The integration takes 4 to 6 months. After this time, the site is opened again and a healing collar will be threaded into the implant. This will guide the tissue into a shape that is needed for the future crown(s). The time that the healing collar needs to be in place will vary from person to person, but will be at least several weeks.

Phase Three
Once the tissue shape is sufficient, specific attachments and components will be fitted to the implant. The implant components are similar in function to the wall or plaster anchors used to hang pictures on drywall. The healing collar is removed. Implants transfer copings, analogs, and other items are used to take an impression of the site. The healing collar is then put back on. The impressions and implant components are sent to the laboratory for fabrication of implant posts and temporary acrylic crowns.

When the temporary crown or bridge is returned from the laboratory, the healing collar is removed and the implant attachments are fasted to the implant. The temporary crowns are then seated and adjusted. They will be held in place by temporary cement or with screws, depending on your certain situation. We will explain the advantages and disadvantages of each in your particular case at the time you decide to have the implant

Temporary crowns are placed because the bone that supports and surrounds the implant must be given the opportunity to be put into function gradually. Implant techniques dictate that the implants be slowly brought into biting function. This means you will be returning several times to have more acrylic added to the temporary crown. After the implant and temporary crown have been in biting function for a few months, the final crown(s) will be fabricated and cemented or screwed into place.

Maintaining All Your Teeth
To keep your implants and your natural teeth healthy and functional for the longest time possible, clean the implant and your other teeth daily, as instructed. You will also need to come in for dental hygiene recare appointments at a 3- to 4-month interval. You have invested time and money in these state-of-the-art tooth replacements. Maintaining them as instructed will give you the best chance of success.

We feel that the benefits of replacing teeth with implant-supported crowns and bridges far outweigh the inconvenience of the long start to finish time. This is especially true when the teeth on either side of the implant are sound, unfilled teeth that would not otherwise require dental treatment. Implants help you preserve your nature tooth structure.

If you have any questions about dental implants, please feel free to ask us.

Cracked Tooth Syndrome (CTS)

What is CTS?
Minuscule cracks can form on your teeth, threatening your dental health. Why? 

• Age plays a factor - as we get older, our teeth tend to weaken, making them susceptible to tiny hairline fractures that are not visible to the naked eye. 
• We increase our chances of developing cracked teeth by exposing them to trauma, such as bruxism and chewing on hard objects.
• When teeth have been heavily filled, it is not unusual that they develop cracked (or split) tooth syndrome (CTS). 

Symptoms include a sharp pain when you bite down into something hard. When you open your mouth and the teeth are no longer touching, the pain goes away. The pain does not usually linger after the biting action is finished. The fact that you feel pain when pressure is applied to the tooth means that the nerve is being affected. If the problem is not solved quickly, the nerve may die and the tooth will then require endodontic treatment (root canal).

Why does it hurt when I eat?
Pressing an object against the tooth opens the crack, causing the underlying dentin to move and irritating the pulp chamber (which contains the tooth's nerves). When the pressure is released, the crack immediately closes, causing a sharp pain. If left untreated, the pulp will eventually become damaged, and you will start to feel sensitivity to hot and cold or prolonged pain.

Common sites of cracked teeth

• Premolars and molars, the back teeth that grind and crush food 
• A tooth that has recently been drilled and a great amount of tooth structure has been lost
• A tooth that has an extensive filling (usually silver amalgam) that has been in place for a long time 
• Or a tooth that only has a small silver filling  
• The filling has weakened the tooth just enough so that when you chew or bite, the tooth and filling separate slightly (flex), causing immediate and sometimes severe pain.

Types of cracked teeth:

• Fractured Cusp: When the cusp (the raised section of the biting surface of your tooth) becomes fractured. If a fractured cusp does not break off on its own, it will need to be removed by a dentist and replaced by a dental crown.
• Cracked Tooth: Run vertically, originating from the top part of the crown and working their way down. Treatment typically entails a root canal followed by a dental crown. If the crack has extended below the gum line, the tooth may require a tooth extraction. 
• Split Tooth: When a cracked tooth is not treated, the crack can extend beyond the root, causing the tooth to split. Although these teeth are difficult to save, they can sometimes be treated with a root canal. 
• Vertical Root Fracture: Sometimes the crack starts at the bottom of the root and works its way up. If caught early, endodontic dental surgery may correct the situation. 

Treatment

Vertical Fracture

• Treatment will involve at least one x-ray to assist in the diagnosis and to rule out other causes. We will try to find the section of the tooth that is causing the problem by pushing on the various sections of the tooth or having you bite on a hard object.  
• When the section of the tooth that is cracked is found, it makes treatment easier. First, the tooth is anesthetized and the old filling is removed. 
• Then we carefully inspect the area to determine whether the cracked section can be seen. Very often it is visible at this point. 
• The next step is to see whether the split area can be fixed with a direct filling (bonded). This is the ideal situation if the crack is small.  If the crack is small enough, it may be removed by replacing the filling. Bonded white fillings and bonded amalgam filling will hold the tooth together making it less likely to crack



Crown

• Your dentist may first place an orthodontic band around the tooth to keep it together. If the pain settles, the band is replaced with a filling that covers the fractured portion of tooth (or the whole biting surface).
• Unfortunately, this rarely occurs. If the crack goes too far vertically, there is a possibility the tooth may need to be removed and replaced with an artificial one (bridge, denture, or implant). More often (over 95% of the time), the biting surfaces of the tooth must be entirely covered and protected first with a provisional (temporary) onlay or crown. 
• If this is successful in eliminating the pain (we usually wait for a few weeks to be sure the problem is resolved), an impression for a laboratory-fabricated casting - either a porcelain or resin onlay or a crown - is made. If adequate tooth structure remains, a partial coverage restoration - an onlay - is preferred. If the tooth has been badly cracked or if not much tooth remains, then a crown will be necessary. The purpose of either type of cast restoration is to unite all sections of the tooth so it cannot move or separate under normal biting forces. If the provisional restoration is successful in eliminating the pain, we expect that the final cast crown or onlay will correct the problem. 
• The nerve may sometimes be affected so badly that it dies. Root canal treatment will be required if the tooth is to be saved.

The earlier a split tooth is diagnosed and treated, the better success there is in treating it. If the split is severe, a root canal may be necessary to save the tooth. Depending on the symptoms you describe, we may choose to treat it as a bite adjustment, small filling, or larger preparation for an onlay or  crown. If these do not work, the treatment plan will be modified. If left untreated, the tooth may eventually be lost. It is also possible that the initial split of the tooth may be such that it cannot be saved, despite our best efforts.

Delaying Treatment
What happens if CTS is not treated quickly? The best you can hope for is that the tooth continues to hurt only when you chew or bite. This does not often happen. Usually, the broken section of tooth gets weaker and weaker until it fractures off. Additionally, if the crack gets deeper into the tooth, the nerve will die and the tooth will need endodontic treatment before the crown or onlay is placed. Sometimes the nerve is immediately affected by the initial split and dies. This may occur quickly or may take years before it is evident. Every case of CTS is unique. If it is any consolation, the cracked tooth is not your fault. It is a result of your teeth being drilled and filled with big silver fillings when you were younger. We see this particular dental problem mostly in patients who are between 25 and 45 years old.

Unfortunately, cracked teeth do not go away. Many times, they only hurt when you bite on them from one particular angle. If the fractured segment is not stressed, the tooth feels normal. You might also be able to "train" yourself to chew on different teeth and avoid the cracked tooth. At best, you only postpone necessary treatment while the nerve may be slowly dying.

After Treatment
If treated by adjusting your occlusion (bite) on the tooth
This will lessen the symptoms. If the discomfort you feel when you bite is not eliminated within one week of treatment, please call our office and let us know. If the split is still present, a different approach will have to be tried. Give the tooth a few days to "calm down" before you try to bite down on hard foods.

If treated by removing the old restoration and placing a bonded filling in its place 
If the split is small, this may eliminate the problem. Do not bite down hard on the tooth for a few days, then gradually place more pressure on the tooth. Call our office in one week and let us know how it feels. If the split is still causing a problem, a different approach must be tried. If left untreated, the tooth may split further and you may need endodontic treatment and a crown. If the tooth splits severely, it may have to be extracted.

If treated by cementing a temporary crown onto the cracked tooth with temporary cement 
Because the crack was so severe, this procedure was used to determine whether or not the tooth can be treated without performing a root canal. Please give the tooth several days of rest before you try biting down on hard foods. Expect the tooth to be sensitive for a few days after the temporary is placed. This is normal. Gradually apply more force when you bite into foods, and gradually try to eat harder foods. Expect the temporary crown to remain in place for several weeks, until it can be determined whether or not the problem is solved.

If you have any questions about cracked tooth syndrome, please feel free to ask us.