Though you won’t become a member of some centuries-old monarchy, this coronation will help protect some of your most faithful servants…that is your teeth! A dental crown is most often recommended to restore the shape, health, and strength of a tooth. And in many cases, a crown may be the only option available to reestablish function. So before proceeding with this adornment, let’s explore what is behind your “crowning achievement”. A dental crown or “cap” is placed over the part of the tooth that is visible above the gum line. Most crowns today are made of porcelain and designed to match the shape and color of the existing permanent teeth.
There are several reasons why your dentist may diagnose the need for a crown. They are recommended to protect a weak tooth from further damage and cracking. Visible fracture lines in the enamel are an indication of a tooth that is at a greater risk of breaking, and a crown will help hold these pieces together. Teeth with large fillings and thin enamel walls are also at risk of breakage with regular use due to the delicate condition of the enamel, which is sometimes just a shell of its original thickness. A tooth with an existing large filling that develops additional decay may be required to have a crown instead of a replacement filling due to the undermining nature of decay and the further loss of tooth structure. Also, because of the expansion and retraction properties of old amalgam alloys, or silver fillings, they can begin to act more like a wedge in the tooth and if not covered can put subsequent internal pressure on a thinner tooth wall.
Crowns are required as part of a permanent dental bridge, which is used to replace missing teeth. When there is a missing tooth, crowns are fabricated to cover the teeth on either side of the space, with a “fake” tooth, or PONTIC suspended in between, which fills in the edentulous area. This treatment restores chewing function in that area, maintains proper positioning and spacing of the existing teeth and alleviates the cosmetic concerns of having a missing tooth.
Another option in the replacement of missing teeth is a dental implant, which also requires a crown that covers a titanium post that has been placed directly into the jaw below the gum tissue. The implant crown is permanently delivered onto an abutment or extension of the post and functions as well as the original tooth as if it was never missing. Dental implants eliminate the need for crowns surrounding the edentulous area, thereby minimizing treatment to potentially healthy teeth. Implants are becoming the preferred treatment option in most cases of missing teeth, as long as certain biological criteria are met. Discuss this option with your dentist to see if you are a candidate.
Following endodontic treatment, or root canal therapy, a crown is placed to protect a tooth from breaking. A tooth that has been treated with a root canal has had the nerve and blood supply removed from the center, rendering the tooth more brittle and at a greater risk of fracture. There is also a good chance that the tooth is already in a compromised state due to deep decay, the development of an abscess or a large break, all which may have led to the need for a root canal. Broken teeth from trauma may be required to have a crown placed if the break is too large to repair with a filling and genetically misshapen or discolored teeth can also have crowns placed to restore a cosmetically pleasing smile and help a patient feel better about their appearance.
Though there is no pageantry in the placement of a dental crown, allowing us to care for your dental needs is an honor we bow to! As is the case with any dental appointment at Seidner Dentistry, headphones with music, television, laughing gas and blankets are always available to help make our patients feel as regal as possible. Once anesthesia is given, and the patient is comfortable, the doctor will prepare the tooth by removing any concerning decay and reducing the size so the new crown can be placed over the tooth while maintaining its original shape. In some cases, an impression is taken to send to a lab for fabrication of the new crown. Other circumstances allow for a digital camera to be used to take pictures and measurements of the tooth, which is then sent to a technician that makes the crown and may potentially be delivered the same day. If the new permanent crown cannot be available the same day, the patient will have a temporary acrylic or resin crown made specifically for the tooth that is being treated; however it is not designed for long-term use and should be replaced as soon as the newly made tooth is available. The temporary “cap” is just that and will need to be treated with more care than the final new “cap” that is soon to be placed. The temporary cap will be cemented with temporary cement and will not withstand some occlusal forces that may be normal to the rest of the mouth. It is recommended that care is taken with chewing and that sticky and hard foods be avoided in the area until the permanent covering is placed.
Once the permanent crown is available, the patient returns for the final cementation appointment. The occlusion is evaluated and adjusted if necessary, and the enthronement is complete! It is important to remember that the crown only covers the part of the tooth that is above the gum line and may extend slightly below the surface. Any areas below the gum tissue are original uncovered tooth structure and are susceptible to decay. In some instances and if possible, the margin of the crown may be positioned above the gum, like in the areas between the teeth or on back teeth if not visible. This allows for more thorough brushing and flossing success and helps to minimize plaque accumulation. In many cases, however, a crown margin is placed below the gum line due to the location of damaged tooth structure or to hide the edge or margin for a more natural appearance. It is important then to make sure one’s flossing technique is spot on and concentrated below the gum tissue as well as above. Fluoride rinses also help to maintain good health on the part of the tooth that is not covered by the porcelain cap.
Though crowns are considered permanent restorations, as mentioned above, they can develop a decay around the edge that extends underneath the crown, requiring full replacement. Also, excessive occlusal forces such as those seen in patients that clench or grind their teeth may cause a breakdown in the root structure at the edge of the crown. The “notch “that can develop from the extreme forces would also need to be repaired and filled in with bonding material, as long as the damage does not affect the integrity of the seal between the tooth and the crown. Despite these possible breakdowns, crowns deliver a long-term solution to an otherwise lost cause in tooth function. Crowns are most often bestowed upon teeth that have lived a grandiose existence of extensive use and service. Because of their noble favor, it is only proper to honor them with well-earned life-long protection. And though you may feel like we have just thrown you into the dungeons with the diagnosis of a crown, we want to assure you our hope is to restore your smile and make you feel like a Queen or King throughout the process!
-By Julia Guerra, RDH, BA