Recently, a patient arrived with a toothache. Unfortunately, the pain was due to a fractured tooth. It was not possible to fix this tooth. The dentist removed the tooth right away.
It is important to replace most missing teeth. Today, there are more options than before. Two of the most common techniques to replace a single tooth are the three unit fixed bridge and the implant retained crown. The dentist examines their patient and understands their oral and medical health before recommending the best way to replace a missing tooth. Ultimately, it is the patient’s prerogative to choose the best replacement technique for them.
Dentists do not replace teeth until the patient’s gums are healthy and all teeth are free of decay. To replace a tooth with a three unit bridge, the dentist reshapes the two teeth (abutment teeth) on either side of the missing tooth to allow for a thickness of gold and/or porcelain in order to fully or partially cover the tooth. In other words, the dentist will shave down two teeth up to 2 millimeters to be able to place a bridge to replace one missing tooth. Those teeth could become sensitive and may need root canal treatment before or after the bridge is in place. The dentist sends a mold of the teeth with instructions to a dental lab. Normally, the patient leaves with a temporary bridge after the first appointment, and the porcelain/metal bridge is in place within a few weeks, by the end of the second or third visit.
The three unit bridge is a natural choice for a patient who will benefit from crowns on the abutment teeth. Dentists recommend crowns (also known as caps) for teeth with large restorations (fillings), or teeth that would benefit from a cosmetic change of shape or color. Crowns and bridges can be instrumental in correcting a malocclusion or bad bite.
Three unit bridges feel pretty natural. The three teeth are a single unit. That means that it is important to clean around and under the replacement tooth — the pontic. Some people find feeding floss under the pontic to be tedious. Depending on the construction of the bridge, there might be a space between the pontic and the gum, or a space may develop over time. Dentists charge about the same price for a three unit bridge that they charge for three crowns.
Many patients who replace missing teeth with implant retained crowns report that the new teeth feel identical to the originals. An implant retained crown is a crown anchored in place to a titanium cylinder or screw that is set into the same bone that previously supported the natural tooth.
Replacing a tooth with an implant supported crown is very technique sensitive. First, placing the implant is a surgical procedure and success depends on thorough healing. The patient must be in good health. The dentist must account for any medications the patient takes, or medical conditions that affect the patient. For example, diabetes is a disease that delays or interferes with healing. The dentist will need to know that the patient’s diabetes is under control before the surgery. Bisphosphonates are medications people take to treat osteoporosis and Paget’s disease of bone. Bisphosphonates will delay healing of bone. That delay in healing can cause dental implants to fail. Sometimes, the dentist will confer with the patient’s physician to be sure that their patient has a clean bill of health.
Next, the dentist determines the position of the crown on a model of the patient’s teeth while consulting radiographs (X-ray images) or a CAT scan as a reference. A surgical stent made on the model guides the placement of the implant. The surgical dentist will line up the stent with the natural teeth, then line up the drill with the stent. That is how the surgeon places the implant where the restorative dentist needs it.
Some dentists prefer for the patient to be asleep during the implant surgery. Most dentists prefer to use a local anesthetic (something like Novocaine); the patient is awake during the procedure. The dentist creates a hole in the bone using a very slow auger drill to carefully cut the bone. Then, the dentist taps or twists the implant firmly into the bone, and sutures the gum over the implant.
Six months later, the dentist who placed the implant, or the dentist who will place the crown will uncover the implant and attach a healing screw. The gum will heal in a couple of weeks, leaving the healing screw exposed. During the next appointment, the restoring dentist removes the healing screw and firmly attaches a small device to the implant, a transfer coping. After making a mold of the teeth and gums with the transfer coping in place, the dentist sends the mold, transfer coping and instructions, including a color match, to make the crown. The dentist will be ready to install the implant retained crown in two or three weeks.
Some dentists are using new procedures to place the implant and a temporary crown on the same day. This is an experimental technique. Ask the dentist what their success rate is for this procedure. Ask them what their definition for success is, and how long they follow their cases.
Deciding how best to replace a tooth is more than simple preference. Some patients may not be able to tolerate the surgical phase of implant treatment. It may be that teeth on either side of the space will benefit from the crowns that support a three unit bridge. Patients with a high rate of tooth decay will appreciate that implant retained crowns are impervious to tooth decay. Tooth decay can ruin a three unit bridge; expensive crowns and bridges are not appropriate for patients with active tooth decay. Active gum disease, gingivitis or periodontitis, must completed prior to surgical placement of implants or making the mold for a three unit bridge. Implant treatment usually takes from several months to a year to complete. A temporary three unit bridge can be ready in less than a week and the long term restoration in two weeks.
Which is better for you, bridge or implant retained crown? Speak with your dentist. Bring insurance information. The dental office staff will be able to determine coverage for these procedures. Expect the dentist to explain your options. Ask the dentist to explain answer your questions and explain whatever you do not understand. Expect the dentist or office staff to give you a written estimate and explain your insurance coverage.
By Dr. David Leader / Al Dente
GateHouse News Service
Posted Dec 03, 2009
Dr. David Leader has practiced in Malden since 1989. He is a member of the Health Advisory Committee of the Lynnfield Schools, the medical advisory board of the New England Chapter of the Scleroderma Foundation, and the Massachusetts Dental Society Council on Dental Care and Benefits Programs. Dr. Leader is an Assistant Clinical Professor of General Dentistry of Tufts University School of Dental Medicine.
from wickedlocal.com 4-17-2010