Crowns are made out of a variety of materials. The most common materials that are used include zirconia, porcelain, metal or ceramic. Some of these materials, such as porcelain, create crowns that have the same color as teeth, thus are highly favored for teeth that are in the front section.
Oftentimes, the prevention component is comprised of dental x-rays, cleanings, regular dental exams, etc. Fluoride and sealants are also stellar preventive treatments that are designed to protect the patient's teeth.
If you have a tooth that is badly damaged by tooth decay, then it might be necessary to place crowns on the tooth. This might also be the case if the doctor has placed a bridge to cover gaps left by one or several teeth. In most of these cases, your dentist will advise you on whether you need a crown, based on his or her assessment of the damage on your tooth.