When Is a Dental Crown Needed?
A dental crown is needed in this situations:
- For the protection of a tooth are damaged by caries, when the polymer restoration can no longer restore it qualitatively.
- For the restoration of a broken or a badly worn tooth.
- For fixing a dental bridge.
- To hide large aesthetic imperfections (discolored teeth).
- As a prosthesis installed in dental implantation.
Children also get crowns to save baby teeth that are damaged by caries.
Types of dental crowns
According to the material, dental crowns are made of stainless steel, alloys of precious metals (high content of gold or platinum), cermets and metal-free ceramics (press ceramics, zirconium and lithium dioxide).
Crowns from medical steel are used as a temporary measure. They are quite cheap and fully functional. They are often placed on children as they do not require multiple visits to the dentist.
Crowns from Gold or Platinum well withstand chewing loads. Since gold is a rather soft metal, gradually, in the process of chewing, their shape almost completely adapts to the opposite tooth. Plus, the natural abrasion of tooth enamel and gold occurs very evenly. Therefore, such crowns do not require correction and are the most durable. Their unnatural color and high price are the main drawbacks. But for molars in the chewing area, they are the best option. Precious metals prevent the development of pathogenic microflora and passively protect teeth from caries.
Porcelain-fused-to-metal dental crowns are made in accordance with the color of near teeth, so they look more like normal teeth. However, they cause more wear on the opposite teeth. The ceramic part of the crown can crack or break from strong pressure. Also, the metal underlying the crown, in individual cases, can show through with a dark line on the gum line. These crowns are a good and inexpensive choice for anterior or posterior teeth and for long bridges where metal is essential for strength.
All-Ceramic dental crowns have the highest aesthetics than other types of crowns. However, over time, they wear out and are more susceptible to fractures than sintered metal. Yet hypoallergenic and superior optical properties make them the best choice for anterior teeth restoration. The two most common crown types are zirconium and lithium dioxide (IPS E-Max).
Temporary crowns are made from acrylic or stainless steel right in the dentist’s office and are used as a temporary restoration until a permanent crown is made in the laboratory.
Functions of temporary crowns:
- Restore short-term functions of the tooth;
- In cases where the nerve has not been removed, such a crown will dull the sensitivity of dental tissues to temperature extremes and other irritants;
- Ensure preservation of diction;
- Prevents infection from getting into the area of prepared dental tissues;
- Prevents the growth of gum tissue on the tooth.
- They fix the tooth, prevent it from loosening and shifting to the sides.
- Accelerate addiction to the artificial product.
Partial dental crowns
If a full crown is not feasible, two more types of partial crowns are often encountered:
Onlay сovers most of the damaged tooth.
Inlay it’s are microprostheses that restore individual parts of the teeth. To do this, a stump tab is installed in a specially prepared “socket” in the tooth, which is then covered with a partial crown. They are installed only on the chewing teeth.
Crowns for Chewing Teeth
When choosing a crown for posterior teeth, it is worth distributing the importance of its characteristics as follows:
- Reliability
- Price
- Aesthetics
The most logical choice as a cheaper option (from 110 USD) would be Porcelain-fused-to-metal crown’s or Lithium dioxide (IPS E-Max – from 245 USD) – if money isn’t problem for you.
Anterior Crowns.
For restoration of anterior teeth, crowns should be selected differently. Unlike chewing teeth, the choice here will be based on a this principle:
- Aesthetics
- Price
- Reliability
And the best choice would be zirconium crowns. Teeth made from this material are almost indistinguishable from the original. E-Max crowns will be more reliable, but with slightly less identical natural optical properties.
Stages of installing a crown on a tooth.
For installation a crown on a tooth usually needs two visits: the first stage includes examination and preparation of the tooth, the second visit – the installation of crown.
First visit: examination and preparation of the tooth
On your first visit, you will be given an X-ray to check the roots of the tooth on which the crown is being placed. If there is extensive caries or there is a risk of infection, root canal treatment is performed first.
Your dentist will anesthetize the tooth and gum tissue around the tooth. The tooth is then ground to make room for the crown. The amount of turning depends on the type of crown to be installed. Conversely, if most of the tooth is missing, your dentist uses a filling material to “strengthen” the tooth to support the crown.
After turning, the orthopedist uses a special paste to take an impression for making a crown. Less commonly, this procedure is performed using a digital scanner. The impressions take into account the position and shape of the adjacent teeth so that the crown does not change your bite.
Then the dentist will select the shade that best matches the color of the near teeth.
At the same time, at the time of making a permanent crown, the orthopedist will make and fix a temporary crown to protect the prepared tooth.
The impressions or scanned images are sent to the dental laboratory, where your crown will be made. The crown is returned to the orthopedist after one to two weeks.
Second visit: installation of a permanent dental crown
During the second visit, the dentist will remove the temporary crown. He will check how the constant matches in color and shape. And, if all is acceptable, will fix it in its place, using local anesthesia if necessary.
What problems with dental crowns can be?
- Discomfort or sensitivity . The most common problem faced by patients after the installation of crowns. Hypersensitivity, especially if the nerve has not been removed, may bother you for the first two to three weeks. Unpleasant sensations can occur in the form of a high sensitivity to cold or hot and usually begins after the anesthesia begins to weaken. This is completely normal. We recommend that you brush your teeth for a while with a toothpaste for sensitive teeth. If the discomfort manifests itself in the form of pain arising from the bite, then most likely the crown is fixed too high on the tooth and you should contact your dentist. The solution to this problem is quite simple.
- Chipped crown . Ceramic crowns, like metal-ceramic, can sometimes crack. If the chip is small, then the dentist using composite material will restore it right in the mouth. If the crown is extensively damaged, it will need to be replaced.
- Loose crown. If the cement for some reason begins to wash out from under the crown and it begins to loosen, this will allow bacteria to freely penetrate under it and cause caries of the remaining tooth, which will further weaken its fixation and eventually lead to the crown falling out.
- Crown falls off. If your crown falls off, before visiting the dentist, try to clean the part of the tooth adjacent to the gum so as not to injure it and contact the dentist immediately. You will receive instructions on how to care for your tooth and crown prior to your visit. If possible, the podiatrist will re-cement the crown. In extreme cases, you will need to make a new one.
- Allergic reaction. May occur when using porcelain-fused-to-metal. It is extremely rare, but still there is an individual intolerance to one of its components. In this case, a replacement will be prescribed.
- Dark line near to the gum line. A dark line on the crown next to the gum line is a fairly common problem with Porcelain-fused-to-metal crowns. This line represents the metal part of the crown that shines through a thin layer of ceramic. From a cosmetic point of view, this is indeed a problem and you may have to replace such a crown with a ceramic one.
How long do dental crowns last?
Dental crowns last from five to 15 years. This period depends on the degree of “wear” of the crown, compliance with the rules of oral hygiene and personal habits associated with the oral cavity.