Dental crowns are tooth-shaped caps that are placed over or around the teeth to cover them and restore their shape, strength and size, and to enhance their appearance.
Typically, crowns are necessary when huge cavities threaten the health of the teeth. Crowns are cemented (bonded) to the teeth using dental cement and fully encase the whole visible portions of the teeth, which lie at and above the gum lines.
The most common technique of dental crowning is the indirect method that uses dental impressions of prepared teeth to fabricate crowns from outside the mouth. The crowns are then inserted during a subsequent dental appointment.
The indirect crowning method allows for the use of strong restorative materials such as casting metal and firing porcelain that require time-consuming fabrication which cannot be done from inside the mouth.
Types of Dental Crowns
Available dental crown options include:
Metallic crowns are durable and can withstand chewing and biting forces. Rarely breaking or chipping and using less tooth structure, metallic crowns provide minimal tooth wear to opposing teeth and are a good option for out-of-sight molars.
The most common materials used to create metallic crowns are gold alloys, base-metal alloys (such as chromium or nickel) and other alloys (like palladium). However, metallic crowns are cosmetically imperfect because of their color.
Stainless Steel Crowns
These prefabricated crowns are typically used as temporary protection or filling while permanent crowns are still being fabricated from appropriate materials. Children also benefit from stainless steel crowns that are often used to fit primary teeth until they are replaced by permanent teeth.
Porcelain-Fused-to-Metal Dental Crowns
These crowns offer a blend of metallic durability and porcelain’s cosmetic appeal. They can also be fabricated to match the color of adjacent teeth. As good choices for both the front and back teeth, porcelain-fused-to-metal crowns look like normal teeth and give their users the confidence they would have with their normal teeth. Nonetheless, they cause greater wearing to opposing teeth than resin or metallic crowns, and their porcelain parts can easily break or chip.
These crowns are amazingly affordable and offer a desirable natural appearance. Nonetheless, they are very prone to fractures and wear down quickly.
All-Porcelain or All-Ceramic Crowns
The crowns can be fabricated to offer perfect natural color, which is perfect for the front teeth. They are also appropriate crowns for individuals with allergy to metals. However, they wear down opposing teeth quicker than metallic and resin crowns, and are less durable than porcelain-fused-to-metal crowns.
Benefits of Dental Crowns
Customized to suit the look, shape, color and size of natural teeth, the crowns offer immense cosmetic value. For instance, individuals with cracked, misshapen, broken or awfully discolored teeth can use porcelain-fused-to-metal or composite resin crowns to replace their terrible teeth and restore their smiles.
Secondly, the crowns mimic the translucency and luster of natural teeth hence providing the feeling and confidence similar to that given by natural teeth. Made from stain resistant materials such as porcelain and metals, dental crowns are stain resistant and durable, and are a better choice than dental prosthetics. In fact with better care, the crowns can last up to 15 years.
As opposed to dentures that can slide and shift, dental crowns are cemented over implants and damaged teeth or anchored firmly in place by dental bridges. Hence, the crowns save their users the embarrassment of shifting teeth.
Besides, crowns are strong and come with natural tooth-like features, which restore the full function of damaged or missing teeth and allow their users to chew and smile with freedom.
Similarly, the crowns offer protection to decayed, cracked or damaged teeth by encasing the teeth and acting as shields against plaque build-up and further decay. Crowns are stable and do not irritate the gums, eliminating the pain and discomfort that is experienced by users of dentures.
For children, crowns can be used over primary (baby) teeth to prevent tooth decay among children having problems with dental hygiene and to minimize the frequency of general anesthesia and sedation for children who cannot fully cooperate during dental care.
The Dental Crown Procedure
The procedure for fitting a dental crown usually occurs in two stages that require two visits to the dentist. The first stage involves the examination and preparation of the teeth while the second stage involves the placement of permanent crowns.
Examination and Preparation of the Tooth
In preparation for the dental crown, the dentist will take a few X-rays to assess the roots and the surrounding bones to the tooth that is to receive the crown. When the tooth has high risks of injury to its pulp, infection or extensive decay, the dentist will first perform a root canal treatment.
After the examinations, the dentist will anesthetize (numb) the area around the tooth, especially the gum tissue, to reduce the pain during the procedure. After that, the dentist will reshape the crown-receiving tooth along the sides and the chewing surface to create room for the crown.
The amount of material removed usually depends on the type of crown to be applied. On the contrary, if the tooth is already too damaged or decayed, the dentist will use a filling material to cover up space and allow the crown to fit.
After reshaping the tooth, the dentist will use dental wax (putty/paste) to take an impression of the tooth. The dentist will request the patient to bite into the wax so that tooth imprint is left, which is sent to the dental laboratory for use as the blueprint for fabricating the crown.
To ensure that the completed crown fits well and does not affect your bite, the dentist will also take the impression of the tooth above and the tooth bellow the crown-receiving tooth. Manufacturing dental crowns usually takes 2-3 weeks and the dentist will give a temporary crown made of acrylic or stainless steel to cover and shield the tooth while the permanent crown is still being fabricated.
The material chosen by the dentist will depend on the location, type and condition of the receiving tooth. Commonly, all-porcelain crowns are placed on front teeth, metal crowns on out-of-sight back molars, and porcelain-fused-to-metal crowns on either back or front teeth.
Placement of the Permanent Crown
During the second visit, the dentist will take out the temporary crown and etch the surface of the receiving tooth with an acid in order to make the surface rough. The rough texture will help to improve the ability of the dental cement to create a stronger bond between the dental crown and the tooth.
The procedure requires localized anesthesia to numb the tooth and gum tissue. The dentist will then fit the crown and check its alignment with the other teeth before using dental cement to fix it into position.
How Much Do Dental Crowns Cost?
The cost of dental crowns depend on the materials used, location where they are to be placed, size, immediate condition of the tooth, and the experience and training of the dentist. Often, dental insurance will cover up to 50-percent of the costs of having dental crowns, but such coverage is not offered for cosmetic treatments.
Typically, porcelain-fused-to-metal crowns cost £250-£900 per tooth, gold-alloy metal crowns cost £300-£1,800 per tooth, base-metal alloy crowns cost £500-£1,200 per tooth, and all-porcelain crowns cost £400-£1,500 per tooth.
Initial examination is usually free (depending on the dentist) while dental X-rays will cost up to £150. Any additional preparatory work will vary in price depending on how much is needed and what specific treatments are required.