Crowns are generally placed on teeth that are very heavily filled and the filling has failed or is failing, if some of the tooth has come away leaving very little tooth remaining, or there is extensive decay and very little healthy tooth remaining. Your dentist can usually anticipate when a crown is likely to be needed in most situations, as the tooth will have been carefully assessed clinically and on an xray before any treatment starts. In many cases your dentist will tell you your tooth needs a crown immediately or soon after you have had a root canal treatment on that tooth. Crowns are also sometimes carried out for cosmetic reasons, or to replace an old damaged or unsightly crown, with a newer, more natural looking one.
The dentist will normally take an impression of the tooth needing a crown before the tooth is prepared, and an impression of the opposing teeth. The tooth is then prepared for a crown. If a crown is being replaced, the old one is removed with a special device, or it is cut off. The aim of the tooth preparation is to remove a small amount of tooth to make space for the crown to fit over the top of the tooth. The amount of tooth removed will depend on the shape of the tooth as well as the type of crown being provided. Generally, the tooth circumference is reduced by around 1-1.5mm, leaving the sides of the tooth with slight taper, and with a finishing line near or just under the gum line. A special cord is then sometimes put around the gum to temporarily retract the gum back and allow an accurate record of the crown margin to be taken. An impression is then taken for the crown and a temporary crown is made chair side.
In some cases, where a tooth has had a root filling and there is hardly any tooth left, it may be necessary to make a post crown (crown on a peg). The dentist will need to remove part of the root filling to make a customized hole for the post. A temporary crown can usually be made with a temporary post.
If you have a tooth or even several teeth missing, then your dentist may offer you a bridge as an option to replace the missing tooth or teeth. The bridge may either be an adhesive bridge, where one or both of the adjacent teeth are used to attach the missing tooth to. This type of bridge is called a Maryland bridge and is made of a metal alloy, with porcelain fused to it. The bridge is attached to the adjacent tooth or teeth with metal wings that extend over the back of the support tooth/teeth and is fixed on with a special cement.
A fixed bridge normally utilizes the teeth on either side of the gap(s) for support. These teeth have to be prepared the same as crowns, but may sometimes need even more preparation to get them parallel.
This gentleman was treated with two 3 unit bridges to replace the upper lateral incisor teeth on both sides. The patient opted for bridges rather than implants.
This gentleman had worn his upper teeth down so that the bite was over closed and he was not happy with the appearance. A full examination revealed the nerves were almost exposed on the teeth due to the extent of the wear. Tooth wear like this is often seen in elderly patients due to years of normal tooth wear and erosion. I treated him with 10 porcelain fused to metal crowns, restoring the bite to where it should be.
This lady was treated with a single all ceramic crown. There crowns do not have a metal core and therefore they look very natural, especially when you look at the fit where they meet the gum. If the tooth is not so badly decayed then it will usually be possible to achieve an excellent result with a more conservative approach using bonded tooth coloured filling.
"I have been a patient at Optima Dental Care at High Wycombe for several years. I had extensive treatment in 2009, involving 5 crowns and a 3 teeth bridge to replace a missing tooth. I am more than pleased with the result.
Although I was apprehensive at the start of treatment, I was immediately put at ease by Dr Chawla and his excellent team. Dr Chawla worked quickly, while explaining everything he was doing. The whole treatment was carried out professionally and with the minimum of discomfort.
I would certainly have no hesitation in recommending Dr Chawla to anyone requiring dental treatment. In my case it has made such a difference as I can now smile without feeling self conscious about my teeth."
Rosina Putnam, Flackwell Heath