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Replacing and Repairing Teeth.
Crowns.
Veneers.
Inlays and onlays.
Etch-retained restorations.
Fixed bridge.
Crowns (jacket and post).
What are they?
A crown completely covers a weakened tooth above the gum line an protects it.
Crowns are made of metal, or porcelain, or porcelain with metal inside for strength.
What does the dentist do?
- A local anaesthetic to numb the area may be given;
- The tooth is shaped so that, with the crown, it will be the same size as a normal tooth;
- Preparation time will depend on how damaged the tooth is and whether it needs to be built up with a filling first;
- The tooth might have to be root-filled first - this is sometimes called 'removing the nerve'. The crown is sometimes held in place by a peg in the root canal if a lot of tooth is missing;
- Soft, mouldable material is used to make a precise 'impression' of the tooth to be crowned and the nearby teeth. A dental technician uses the impression to make the crown the exact height and size needed;
- A thin cord may be used to hold the gum away from the neck of the tooth so that the impression is accurate around the edges;
- A temporary crown made of plastic or metal is put over the tooth until the crown is made. You can chew on a temporary crown but it won't be as strong as the finished one;
- When the crown is fitted, small adjustments are made to ensure you can bite comfortably. The crown is tried on first, and then 'glued' into place.
What are the benefits?
- A crown is strong and can look and feel almost exactly like a natural tooth. The colour and shape can be matched to your own teeth.
- Depending on the strength of the tooth underneath a crown can last for many years if your oral hygiene is good and the crown is not accidentally damaged;
- Crowns can also improve the appearance of misshapen or discoloured teeth.
Veneers.
What are they?
A veneer is a thin layer of tooth-coloured material put onto the front of a tooth to make it look better. The tooth might have been damaged by decay or accident, or be discoloured.
What does the dentist do?
Sopme veneers are built up on the tooth directly using white filling material, while you are with the dentist. Others are made out of porcelain by a dental technician, from an impression of the tooth taken by the dentist. This type of veneer needs more than one visit.
- Any fillings in the teeth will be checked first;
- Very little tooth preparation is needed - just enough to prevent the veneer making the tooth feel bulky, so it may not be necessary to numb the tooth;
- For veneers made in the surgery, the surface of the tooth is roughened with a mild acid. Then 'composite' (white filling) is applied in layers until the look and shape of the teeth is right;
- For a veneer made by a dental technician, an impression is taken by the dentist first. This shows how the teeth bite together as well as telling the technician the shape and size of the veneer needed;
- A veneer made by a technician is glued to the tooth by the dentist at your next visit.
Veneers sometimes come away from the tooth or break if the tooth is knocked. They can sometimes be glued back on but will have to be replaced if they are damaged.
What are the benefits?
- Veneers can greatly improve appearance. They hide imperfections and you lose very little natural tooth;
- Veneers also protect teeth from further damage. For example, acid in foods and drinks or from the stomach can cause erosion. The teeth become thin and weak, but veneers can protect them;
- If the tooth is sound and strong, a veneer is often a better option than a crown for improving a tooth's appearance.
Inlays and Onlays.
What are they?
Inlays an onlays are alternatives to fillings. Fillings start soft, and are carved to shape in the mouth. Inlays and onlays are made outside the mouth, usually in a dental laboratory, and then glued to the tooth in the surgery.
An 'inlay' sits in a hole in the tooth. An 'onlay' sits on the tooth and builds up its shape. Inlays and onlays can be made in tooth-coloured porcelain, gold, or a material called composite. Different materials are suitable for different parts of the mouth and different parts of the teeth.
What does the dentist do?
- A local anaesthetic to numb the area may be given;
- Old filling material and any decayed or damaged tooth is removed first;
- A soft, mouldable material which sets in the mouth is used to record the shape of the tooth being repaired and of the surrounding teeth;
- A dental technician uses the impression to make the inlay or onlay;
- A temporary filling may be used to protect the tooth being repaired while you wait for the inlay or onlay to be made;
- At your next visit the inlay or onlay is glued into place. Small adjustments can be made so that the tooth is comfortable to bite on.
What are the benefits?
- Inlays and onlays are strong and can last longer than fillings;
- They are especially suitable for the chewing surfaces of back teeth and for large repairs to front teeth where it can be difficult to make a white filling look natural; They can be colour-matched to your other teeth.
Etch-Retained Restorations.
What are they?
Many of the newer dental materials are 'adhesive', which means that they stick or 'bond' to the teeth.
The surface of the tooth needs to be made slightly rough so that the repair - the 'restoration' - can grip properly. This is called 'etching' - a harmless mild acid is used.
'Etch-retained resotorations' are any repairs attached to the tooth in this way - either fillings, crowns, veneers, inlays or onlays.
What does the dentist do?
- Sometimes the tooth will be numbed, but this is not always needed;
- After shaping the tooth, the etching acid is dabbed onto the tooth surface that needs to be roughenend;
- The acid is left on the tooth for a short time while you keep your mouth open;
- The tooth is then washed very thoroughly with a jet of water, which is sucked out of your mouth through a tube held by the dental nurse;
- The tooth is then dried and the surface checked. It might need to be etched again, in the same way;
- The 'bonding agent' - a sort of glue - is then painted oto the roughenend area, before filling the tooth or applying some other sort of restoration.
What are the benefits?
- The bond between the tooth and the restoration can be very strong so that the restoration stays in place for a long time;
- Even if the bond breaks, it may be possible to re-glue the restoration in place;
- Because restorations are held in place by the bonding agent and not just by the shape of the tooth, less of the natural tooth is lost.
Fixed Bridge.
What are they?
A bridge replaces a missing tooth (or teeth) by fixing the replacement to the natural teeth at each side of the gap. Some bridges have crowns at each end. Others are fixed to the surface of the teeth beside the gap. Sometimes a bridge is only fixed to the tooth on one side of the gap.
Bridges are made of metal and porcelain, or occasionally of porcelain alone.
What does the dentist do?
There are several stages in making a bridge:
- The dentist uses soft, mouldable material to take impressions of your mouth. A dental technician makes exact plaster models of your upper and lower teeth and gums, which show how your teeth bite together.
- The teeth which will support the bridge are prepared so that the bridge is not too bulky;
- Another impression is taken of the teeth and any gaps, and the dental technician uses this to make the bridge. A plastic temporary bridge or temporary crown may be fitted in the meantime;
- At your final visit, the dentist will check that the bridge fits, make minor adjustments, and then fix it permanently in place.
Your dentist or hygienist will show you the best way of keeping your new bridge clean.
What are the benefits?
A bridge almost lets you forget that you have missing teeth;
- It can improve the way you look, bite, chew and speak;
- The teeth can be matched to the colour of your own teeth;
- A bridge can last many years if kept clean, and if there is no accidental damage;
- Natural teeth are protected from wear and tear, and from moving or tilting out of line which could cause your teeth to bite together incorrectly.
The alternatives to a bridge would be a removable partial denture, or a dental implant. The dentist will explain the chances of success with a bridge. If the supporting teeth are not strong enough a denture or dental implant might be a better treatment choice. If teeth have just been extracted, a denture might be made first, with a bridge fitted later when the gum has healed.
