Our natural tooth can be divide in three visible parts:
Root of the tooth is embedded inside the jaw bone and provides the support for the tooth
Crown of the tooth is the visible part of the tooth, it is covered by the enamel which protects
inner surface of the tooth – dentin and the nerve with vessels-pulp, from outside bacteria
Neck or dentino-enamel junction is the area where crown part
of the tooth connects to the root
Restoration, which substitutes the natural crown of the
tooth to its anatomical and functional state is also called crown. Many people outside dentistry call it
There are many situations, why crowns can be the only right solution
for the patient. Here are some examples:
- Any endodontically
treated tooth ( tooth that had Root Canal Treatment ) recommended to have a crown. When
the root canal treatment is done on the tooth, along with the nerve, all blood vessels are removed from the tooth. The
removal of blood vessels stops nutrition process to the tooth, with out it
the tooth becomes brittle and eventually will break if not restored properly.
- If a lot of tooth structure has been lost
due to decay. (Sometimes the onlay or partial crown can be done instead of the crown.)
- Repeateadly failing more conservative restorations, such as fillings or onlyas may
be the indication for a cap.
teeth were worn down due to Bruxism, crowns could be the only option.
- Crown may be needed to give necessary support to the
removable partial denture.
comprehensive full mouth, rehabilitations when we have to increase vertical dimension (open bite).
- Cosmetic considerations are one of the reasons to put
may be a part of fixed bridge, which is used to restore missing teeth.
- Implant supported
crowns. Dental implant is a substitution for the root of the tooth. This implant needs to be restored. One of the most frequently
used restorations for the dental implants are crowns, either single or a part of the bridge.
dental crown (cap ) is done?
Crowns can be made from different materials,
utilizing different technique and methods. However, the main principals remain the same.
Before the crown is done all
nesseccary treatment has to be performed. All decay has to be removed. Leaving caries in the tooth under
the crown will lead to demolishing of the tooth under the cap, due to continious decay process. If indicated,
gum treatment has to be completed prior to the cap placement. First, the tooth has to be prepared to accept the new
crown. The doctor using special diamond burs does the preparation. About 1 to 2 mm (depending of the type of the crown) of
tooth structure is removed all around. The tooth is cone shaped. The doctor places the finishing line on the prepared tooth,
depending on type of restorations and given conditions. Many patients mistakenly think that the crown has to end under the
gum line. It is true that in most cases the margins of the crown are placed under the gum for the cosmetic reasons. Another
reason for placing the crowm slightly under the gum is the the decay which was extended to or below gum line. However,
the rule is, that the margin of the crown has to end at the finishing line placed by the doctor, and if the cosmetic is not
major consideration, supragingival (above the gum line) placement of crowns is more desirable. Another, rule that the
finishing line of the crown has to end at the sound tooth structue and not on the filling underneath or the post. After the preparation is
completed, doctor will place the retraction cord or special retraction paste between the gum and the tooth for a few minutes.
Cord will push the gum away from the tooth to allow impression material to flow in for perfect impression. Impression of opposing
teeth and bite registration (if needed) are done, and case is ready to go to the dental lab. Before you leave, the doctor
will make the temporary crown and fix it with temporary cement. Besides, the cosmetic reasons the temporary crown
prevents the tooth from shifting, and protects it from decay, as the natural protective layer of tooth enamel was
removed during the preporation process.
Depending on doctors
preferences and difficulty of the case, additional appointments for try in may be needed.
When your custom made crown returned
from the lab you are ready for your cementation appointment. When you come for your visit, doctor will remove your temporary
crown and will check the fit of you new restoration:
After all necessary adjustments
are done the crown is ready to be cemented in.
- Margins of the crown should cover all prepared surfaces
of the tooth and sit tightly on the tooth structure
- The new crown should have a tight contact with adjacent teeth. The floss
should be able to pass through with a slight pop sound. This will prevent you from
the food stocking in between the teeth.
- The height of the crown should be corresponded to other teeth and should not interfere with
- The crown should
be within your dental arch, and should not be much a bother. Slight new sensations to the tongue or cheeck are normal.
- Cosmetic appearance will also be checked, including shape, shade and position.