Effect Of Poorly Maintained Crown Or Bridge

What is a Crown or Bridge Restoration?

A crown is extra-coronal restoration, also known as a cap. Crowns are indicated when the entire remaining tooth structure needs protection or vulnerable to fracture. The tooth that needs to be crown will be reduced in size, to create space for the crown restoration which will be cemented after it is made in dental lab. (Figure 1)

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Figure 1: Crown restoration

A bridge is a costum-made device anchored to neighbouring natural teeth, which replaces one or more missing teeth. When a lost tooth needs to be replaced with bridgework, the teeth on either side of the missing one are prepared as a crown to hold the bridge in place. It’s also known as a fixed-partial denture.

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Figure 2: Bridge restoration

How Long a Crown or Bridge Can Last?

Literatures have shown that crowns and bridges can last at least ten years (Smith 1990) or lifetime; but it usually do not last forever. The main factors affecting lifespan of a bridge or crown is the level of oral hygiene. Therefore, it is very important to get proper guidance on proper oral hygiene instruction when you have a crown or bridge cemented so you can practice good oral hygiene or self care at home.

What is Self-care?

Here are some ways how to take care your crowns and bridges restoration that need to be done by yourself at home or self-care;

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Figure 3: Proper tooth brushing		Figure 4: Flossing interdental crowns
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Figure 5: flossing underneath the pontic of a bridge using superfloss.		Figure 6: brushing interspaces crown using interdental brush

What are The Effect of Poorly Maintained Crown and Bridge?

Here are some of the effects that can occur if the crowns and bridges are not maintained properly;

1. Tooth decay
   1. Caries

      Dental caries is a disease caused by bacteria found in dental plaque. It can cause an infected tooth decay and broken. If the condition is happen on the abutment tooth crown or bridge, it will cause a failure of the crowns or bridges restoration.

      Caries usually occurs at the crown margin (Figure 7 & 8), which can lead to failure of adhesion between the crowns to tooth surface. Crowns and bridges restoration are still susceptible to tooth decay usually on the surface of the gums if you are not practising good oral hygiene at home. Caries can affect the lifespan of the crowns or bridges restoration by starting somewhere else in the mouth and spread.

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      Figure 7: caries at crown margin		Figure 8: Caries at crown margin detected using dental instrument

      What are the treatments for caries related to crown or bridge?

      1. Make direct restoration with conventional filling material

         If the caries not interfere with the adhesion of crown or bridge, it can be restored using the direct restoration whether using composite or glass ionomer.

      2. Repair the crown or bridge if possible

         In circumstances involving small crowns or bridges damaged such small cracks in the lining of porcelain or slightly rough surface; it can cause the accumulation of plaque on the surface of the restoration that resulted in damage to teeth. Broken porcelain can be repaired using special dental material, depending on the surface of the teeth involved. While the rough surface, can be smoothen using a polishing bur.

      3. Make a new crown or bridge

         In the situation of severe teeth damage, where complex dental treatment such as root canal treatment of tooth due to bad caries has spread and caused damage to the nerve of the tooth . In this situation, there is failure on adhesion of the crown to the tooth surface. These crowns or bridges should be replaced.

         If the whole tooth structure of abutment tooth totally damaged due to caries, the tooth has to remove. Crowns or bridges needs to be replaced with new restoration bridge, implant or removable partial denture.

2. Gum disease / inflammation of the gums
   1. Gingivitis (Figure 9)

      Gingivitis is a gum disease condition can usually be reversed with brushing and flossing every day and also periodontal treatment by the dentist and gum specialist or Periodontist. Form of gum disease does not involve any loss of bone and tissue that hold teeth in place. Gingivitis is usually presented with bleeding and swelling gum.

   2. Periodontal Disease/ Periodontitis (Figure 10)

      When gingivitis is not treated, it can be changed to periodontitis (which means inflammation around the tooth). In periodontitis, gums adhesion between the teeth will be lost and the situation will cause the resulting space (called pocket) that are infected. The body’s immune system against bacteria as the plaque spreads and grows below the gum line. Bacterial toxins and natural reaction resulting from the infection began to break down bone and connective tissue that hold teeth in place. If not treated, the bones, gums and tissues that support the teeth are destroyed. Teeth become loose and may eventually need to be removed. If gum disease infected the crowns or bridges abutment tooth, it must be extracted together with crowns and bridges restoration.

      Image courtesy of bucodental. Comule.com		Image courtesy of bucodental. Comule.com
      Figure 9: Gingivitis		Figure 10: Periodontal Disease

What are the treatments for gum disease related to crowns or bridges?

The main goal of treatment is to control the infection. Number and type of treatment will vary, depending on the stage of gum disease. Any type of treatment requires patient care practice good oral hygiene daily on a continuous basis at home.

Dentist, periodontist or dental hygienist removes the plaque through scaling and root planning teeth involved. Full mouth scaling is scraping out the calculus plaque from the surface of the tooth at above and below the gum line using the machine.

In severe gum disease, the infected tooth needs to be removed due to severe mobility. Crowns or bridges restoration may need to be replaced with a new restoration either new bridgework, implant supported tooth or removable partial denture.

In conclusion, the crown strengthens the tooth above the gum but the adhesion of the crown to tooth surface need special care. Brushing and flossing every day at home is a must to prolong the life span of the crowns and bridges restorations. Get guidance from your dentist about how to keep the crowns and bridge restorations is very important to maintain the cleanliness of the crowns or bridges restorations and the mouth as a whole is very important. This is because, however perfect, polished and contoured crowns or bridges are; dental caries and periodontal disease can occur if oral hygiene is not well managed.

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