When a tooth needs a restoration more extensive than a filling or an onlay, a crown (also known as a “cap”) is frequently recommended. Usually a tooth in need of a crown would have extensive decay, a missing cusp as a result of a fracture, a large defective previous restoration, or a recent root canal. Sometimes, crowns are recommended to prevent the propagation of a crack further into the tooth, or down the root. Alternatively, crowns are done as a means of restoring proper occlusion to worn teeth, or in the process of cosmetically enhancing the front teeth.
Crowns have undergone some major changes over the years. In the late 1900s, and very early 2000s we had essentially two options for crown construction. Gold crowns were a tried and true procedure then, and remains so today, but there are obvious cosmetic limitations associated with them. PFM (porcelain fused to metal) crowns were the best option we had in a crown that looked somewhat like a tooth. Although we could do pretty well in matching the color of the crown to the adjacent natural teeth, matching the natural translucency of a tooth was always a problem because of the need to prevent the metal under the porcelain from showing. In addition, PFM crowns are frequently characterized by a visible line at the margin (the edge adjacent to the gumline), especially in situations where the patient has had some slight recession of the gums.
Even as early as the 1950s, there has been a third option for a crown, namely a “metal-free” porcelain crown. The problem has been that, until recently, these all ceramic crowns were either very weak and exhibited frequent breakage, or were very limited as to color options.
Dental materials scientists bring us an almost constant stream of new products, many of which are designed to be “easier” though not necessarily “better”. We have to be very careful in selecting materials that are well tested and founded in solid science. In the past ten years, we have seen the introduction of “high strength dental ceramics” that have truly revolutionized the practice of restorative and cosmetic dentistry. With these modern ceramics, our technicians can create beautiful and truly lifelike crowns which are many times stronger than a similar PFM. These materials also allow us to use ceramic tooth colored crowns in areas where previously we had no choice but to use gold.
Although there are still occasional situations calling for the use of the PFM technique, Dr. Hunting will almost always suggest the use of a “metal-free” crown. In the past, most dentistry looked like dentistry. Our goal is to provide dentistry that is undetectable. We replace existing crowns and fillings with restorations that look and feel like your natural teeth.
The process for making a crown generally consists of two appointments. At the first visit, the tooth is prepared for the crown. This may consist of removal of an old restoration, cleaning out decay, placement of a “buildup” filling to restore the ideal shape of the preparation, and ultimately, shaping the tooth by shaving down the sides and the biting surface to create a smooth peg over which the crown will be cemented. A mold of the completed preparation will be made and a temporary crown will be placed. The mold will be sent to the dental laboratory along with detailed instructions from Dr. Hunting for the fabrication of your crown. After about a week, your crown will be ready. Your second appointment will be very short. All we need to do is to remove the temporary crown and cement the permanent crown. Generally, local anesthesia is not required at cementation. The cement sets in just a few minutes, and your new crown will be “ready to chew”.
A well made crown can be one of the most beautiful and durable dental restorations. Though longevity is to a great extent determined by the effectiveness of the home care of the patient, it is not at all uncommon for crowns to last in excess of 15 years. Dr. Hunting has several patients whom he has treated for nearly 30 years, and many of his original crowns are still providing good service today.