The crown is the visible cover that is affixed to the dental implant after it has fused to the bone. Crowns come in various shapes and sizes. Given below in the following paragraphs are details of the various types of dental crown used by dentists.
There are two basic types of dental crowns – Temporary Crowns and Permanent Crowns.
Temporary Crowns are those that are prepared by the dentists themselves at their clinics. They are rough structures meant to last out till permanent crowns can be readied. These crowns are either stainless steel crowns or acrylic crowns. They are not reliable for the long term and their continuous usage will result in their fracture and breakage. They may even splinter when used to chew hard substances.
Permanent crowns can be made either of metal, porcelain (Porcelain Veneers are often used as crowns), ceramic, or resin. They are longer lasting and are made to resemble the surrounding teeth, except for the metal crowns which look shabby compared to the others. Given below are details of the different types of dental crowns.
1. Metallic Crowns – They are the strongest of all the crowns used with dental implants. They can withstand a lot of pressure generated during bite and can bear the pressure generated by repeated mastication. They cause minimal amount of wear and tear of the opposite teeth. They are made using alloys of metals like palladium, gold, nickel and chromium. An advantage of using metal crowns is that lesser quantity of gum tissue and surrounding teeth need to be removed for fixing them. They last the longest of all the crowns used. It is rare to find a metal alloy crown that fractures or gets chipped. The only disadvantage is that they look dark and unsightly. That is why metallic crowns are used as replacements for molar teeth, which lie at the rear end inside the mouth and where most of the food is chewed.
2. Ceramic Crowns – They resemble the natural teeth and hence are mostly used as replacements for missing front teeth. They are manufactured in a dental laboratory to match the color of the surrounding teeth. A disadvantage with ceramic crowns is that they induce a lot of wear and tear in the opposite teeth. This is another reason why they are used in the front row teeth which are thin and have little contact with the opposite teeth. People who may develop allergies to metal crowns are recommended ceramic crowns. They are not as strong as metal teeth and hence are not used in the molar region.
3. Porcelain Crowns – These crowns have similar characteristics as ceramic crowns. They are used for the front row of teeth and are similar in appearance to the natural teeth.
4. Resin Crowns –They are used as cheaper alternatives to metal crowns or porcelain and ceramic crowns. They are also weaker than these crowns. Though they are used as permanent teeth they can fracture or break apart after some time.
5. Porcelain-Fused-To-Metal Crowns – Off all the different types of dental crowns available in the market, these are the most preferred by dentists. They are not so strong as metal crowns but they are considerably stronger than resin crowns. They can be used to replace any teeth. They look somewhat similar to natural teeth but they can’t be compared in looks to ceramic crowns which look as real as natural teeth. Over a long period of time they can develop fractures or may get chipped in places or break completely. They tend to cause a greater degree of damage to the opposing teeth compared to metal teeth. Another disadvantage with this type of dental crown is that the metal base can sometimes appear as a dark patch near the base of the crown which can make them unsightly.
The various types of dental crown used in dentistry today are much advanced due to the developments in the field of ceramics and metallurgy. However each of these crowns has its own positives and drawbacks.