Both crowns and bridges are fixed prosthetic devices. Unlike removable devices such as dentures, which you can take out and clean daily, crowns and bridges are cemented onto existing teeth or implants, and can only be removed by a dentist. The basic difference between crowns and bridges are that crowns are placed over the tooth structure which is present and bridges are placed where the tooth structure is missing so in this case, support is taken from adjacent teeth on each side and the bridge is fixed by means of cement.
How do Crowns Work?
A crown is used to entirely cover or "cap" a damaged tooth. Besides strengthening a damaged tooth, a crown can be used to improve its appearance, shape or alignment. A crown can also be placed on top of an implant to provide a tooth-like shape and structure for function. Porcelain or ceramic crowns can be matched to the color of your natural teeth. Other materials include metal alloys, acrylic. Porcelain bonded to a metal shell is often used because it is both strong and attractive. The other option available is metal free porcelain and Zirconia crowns. These are newer available materials for crowns and bridges and provide more aesthetic value as well as strength.
Accurate Zirconia copings
Crowns are the good option to :
Replace a large filling when there isn't enough tooth remaining
Protect a weak tooth from fracturing
Restore a fractured tooth|
Attach a bridge
Cover a dental implant
Cover a discolored or poorly shaped tooth
Cover a tooth that has had root canal treatment
How do Bridges Work?
A bridge may be recommended if you're missing one or more teeth. Gaps left by missing teeth eventually cause the remaining teeth to rotate or shift into the empty spaces, resulting in a bad bite. The imbalance caused by missing teeth can also lead to gum disease and temporomandibular joint (TMJ) disorders.
Bridges are commonly used to replace one or more missing teeth. They span the space where the teeth are missing. Bridges are cemented to the natural teeth or implants surrounding the empty space. These teeth, called abutments, serve as anchors for the bridge. A replacement tooth, called as pontic, is attached to the crowns that cover the abutments. As with crowns, you have a choice of materials for bridges. Your dentist can help you decide which to use, based on the location of the missing tooth (or teeth), its function, aesthetic considerations and cost. Porcelain or ceramic bridges can be matched to the color of your natural teeth.
POST AND CORE RESTORATIONS
There are times when the tooth that needs to be restored is fractured upto the level of gums or the substructure of the tooth is weak to restore the tooth. In those cases, post n core restoration can prove to be a good option.
In post and core restorations the tooth is first treated by means of root canal treatment. After the gutta percha is filled in the canals, space is created by means of special drills for the post in the filled canals. When the post has been stabilized in the tooth, core build up is done by means of core-build up cement to support for the future restoration by means of crown.
The advantage with post and core treatment can be very well appreciated in cases of older patients where lot amount of wearing of tooth structure has occurred and the teeth has become smaller in size. In those patients, where there is generalized wearing of tooth structure and all the teeth has become smaller in size, then in those cases the facial height decreases giving senile look to the patients. In these cases, endodontic treatment can be done of all the teeth followed by post n core build up rehabilitated later on by means of crowns and bridges.
Other cases where it is strongly recommended are:
Tooth with most of its structure missing
Fractured tooth at gum level or with one or more walls missing
Badly carious tooth where after RCT and excavation of caries thin shell of tooth structure remains.