Permanent crowns can be either all metal, porcelain-fused-to-metal, all resin, metal free zirconium or full ceramic.
Metals used in crowns include gold alloy, other alloys (for example, palladium) or a base-metal alloy (for example, nickel or chromium). Compared with other crown types, less tooth structure needs to be removed with metal crowns, and tooth wear to opposing teeth is kept to a minimum.
Porcelain-fused-to-metal dental crowns can be colour matched to your adjacent teeth (unlike the metallic crowns). However, more wearing to the opposing teeth occurs with this crown type compared with metal or resin crowns. The crown’s porcelain portion can also chip or break off. Next to all-ceramic crowns, porcelain-fused-to-metal crowns look most like normal teeth. These crowns can be a good choice for front or back teeth.
All-resin dental crowns are less expensive than other crown types. However, they wear down much quicker over time and are more prone to fractures than porcelain-fused-to-metal crowns.
Zirconium metal free crowns provide the best natural colour match than any other crown types above and may be more suitable for people with metal allergies. They have the same strength as porcelain fused to metal, but provide a much better aesthetic result. They are recommended in the front region and for Hollywood Smile makeovers.
Temporary versus permanent: Temporary crowns can be made in your dentist’s office whereas permanent crowns are made in a dental laboratory. Temporary crowns are made of acrylic or stainless steel and can be used as a temporary restoration until a permanent crown is constructed by the dental laboratory or for implants as a temporary bridge.
A dental crown may be needed when at least one of the following occurs:
Preparing a tooth for a dental crown usually requires two – three appointments – the first step involves examining and preparing the tooth, the second visit involves placement of the permanent crown.
Examining and preparing the tooth. At the first visit, your dentist may take a few x-rays to check the roots of the tooth receiving the dental crown and surrounding bone. If the tooth has extensive decay or if there is a risk of infection or injury to the tooth’s pulp, a root canal treatment may first be performed.
Before the process of making your dental crown is begun, your dentist will anaesthetize your tooth and the gum tissue around the tooth. Next, the tooth receiving the crown is filed down along the chewing surface and sides to make room for the crown. The amount removed depends on the type of dental crown used (for instance, all-metal crowns are thinner, requiring less tooth structure removal than all-porcelain or porcelain-fused-to-metal ones). If on the other hand, a large area of the tooth is missing (due to decay or damage); your dentist will use filling material to “build up” the tooth enough to support the crown.
After reshaping the tooth, your dentist will use impression paste or putty to make an impression of the tooth to receive the crown. Impressions of the teeth above and below the tooth to receive the dental crown will also be made to make sure that the crown will not affect your bite.
The impressions are sent to a dental laboratory where the dental crown will be manufactured. The crown is usually returned to your dentist’s office in 5 -14 days (in Budapest 5 and in London 14). Your dentist will also select the shade that most closely matches the colour of the neighbouring teeth. During this first office visit your dentist will make a temporary crown to cover and protect the prepared tooth while the crown is being made. Temporary crowns usually are made of acrylic and are held in place using a temporary cement.
Receiving the permanent dental crown. At your second visit, your dentist will remove your temporary crown and check the fit and colour of the permanent crown. If everything is acceptable, a local anaesthetic will be used to numb the tooth and the new crown is permanently cemented in place. Some degree of pain and sensitivity is normal for a weeks or so and the tooth should settle down naturally. Your new crown may require a small bite adjustment to achieve a comfortable fit.
On average, dental crowns last between 10 and 15 years. The life span of a crown depends on the amount of “wear and tear” the crown is exposed to, how well you follow good oral hygiene practices, and your personal mouth-related habits (you should avoid such habits as grinding or clenching your teeth, chewing ice, biting your fingernails and using your teeth to open packaging) and if you wear your night-guard during sleep.
Emma Powerell’s problems started as a child when many of her adult teeth failed to grow. She was left with baby teeth that were out of proportion with her adult face and were also crooked. As she grew up, Emma perfected her closed mouth, ‘Victoria Beckham’ style smile. Whilst she knew it made her look tense and unhappy, at least she wasn’t showing her crooked, baby teeth.