Anterior Reconstruction

In the past when patients had missing, broken, or unsightly front teeth, options were limited to porcelain fused to metal restorations. While it did serve to replace missing teeth and tooth structure, treatment suffered from a variety of problems.

First, there are safety concerns. The metal in porcelain fused to metal crowns often contains nickel and bretilium. These non-precious metals have been diagnosed as allergens. Perhaps you or someone you know can't wear inexpensive jewelry because it causes a rash. It is usually because of the presence of these metals. They can cause sore and bleeding gum or gum recession, as well as more serious health problems.

There are also esthetic problems. The metal in porcelain fused to metal crowns prevents the normal transmission of light through the tooth. This makes the crown of the tooth look bulky, opaque and unnaturally bright. It also makes the gum tissue look dark and stained.

The older style porcelain is also very hard and people complain about the hard "clunky" feeling of the porcelain. It was also much harder than natural tooth structure, wearing the opposing teeth dramatically. It was not uncommon to place a porcelain fused to metal crown on a tooth one year then need to place a crown on the opposing tooth soon afterward due to breakage caused by the new crown!

The big breakthrough in dentistry came when we discovered how to "bond" teeth. Technology developed from the space shuttle program taught dentists how to get strong, long-lasting chemical reactions between tooth and porcelain.

Today we have the ability to eliminate the metal in porcelain restorations. This gives the restorations a translucence similar to natural tooth. No longer do we have to tolerate teeth that look and feel fake. Also, the new generations of porcelains are kinder to teeth, allowing for a more natural feel and they also eliminate the wear on opposing teeth.

Posterior Reconstruction

For many years, when we had cavities in our back teeth, our restorative options were very limited. We could place amalgam (commonly known as silver or mercury fillings). Later, dentists tried to use composite. Both of these options were very limited. Amalgam fillings are easily placed and, for the short-term, inexpensive. However, they are certainly unaesthetic, being black in color and the black color can leach and stain the surrounding teeth and gums. Long-term, the amalgam oxidizes or rusts. When amalgam rusts, it expands. This expansion is so great that it will fracture teeth. Patients often come into my office wondering how they broke a tooth eating a soft food such as pancakes. Unless they ate at my mother's house (mom makes a dangerous pancake), the reason most teeth break is related to the expansion of the amalgam filling. A lot has been said and written in the press about the health effects of mercury in dental amalgam. Mercury is in fact the largest component of amalgam. To my knowledge no one has ever done a study that shows the amalgam fillings in someone's mouth has had a negative effect on that person's health. Many people have had their fears manipulated by a dentist to have their amalgams removed. Amalgams do wear out and need to be replaced, but I don't think it is ethical to remove on fears of mercury alone. That doesn't mean I think mercury is a safe restorative material. My concern is what happens when amalgam is removed. My dental unit does a good job of removing the large pieces but the small pieces and dust are discharged into the sewage system and can show up in the environment. Concern for the environment, and not some unproven health concern, is the reason amalgam has been banned in several countries and I believe will be banned in America too.

Composite or teeth colored fillings have been used to fill front teeth for thirty years. They have good strength for the biting activities for the front teeth. But the mastication or chewing that occurs in the posterior teeth are only adequate for a small filling. When they have to replace large surface areas, they wear more rapidly than tooth structure or amalgam. There are other problems with composites. They are very moisture sensitive, so a rubber dam or dental dam should be used. They also shrink upon placement. If the dentist doesn't try to compensate for the shrinkage (and sometimes, even if he does) the patients can have wicked thermal and biting sensitivity. Until recently the best option was to place crowns. Personally, I dislike crowns on posterior teeth. A crown requires circumferential removal of 1.5 to 2.0 mm. The tooth ends up looking like a teepee. You end up traumatizing the nerve (10% of teeth with crowns end up needing a root canal) and you destroy a lot of tooth structure. I have worked with many restorative materials and nothing is as good as the bodies enamel. We needed a way to replace the infected tooth structure with something similar to the natural tooth and can reinforce the remaining tooth structure. And it would be great if the material looked good too, and cost less than a crown. The tooth-colored inlay or onlay meets the above requirements. Inlays are laboratory-fabricated inserts that have identical wear characteristics as tooth structure and are dimensionally stable. Through the use of bonding technology, we can reinforce the remaining tooth structure, restoring the tooth to its original strength. It is necessary to schedule two appointments. At the first appointment we remove the existing restoration and prepare the tooth walls so they are slightly divergent to allow for the path of draw. We take an impression of the prepared teeth and place temporary restorations. I usually take several 35mm slide photographs to communicate with the laboratory the color and contour I want. The laboratory custom makes each inlay to fit precisely. The fit of each inlay is crucial. If the gap between the tooth and the inlay is greater than 25 microns, the restoration will fail. Luckily, I have been blessed to find two dental laboratories who have the artistic ability as well as the commitment to excellence needed to make a successful restoration.

The second appointment is scheduled one month after the first. The temporaries are removed and the teeth are cleaned. The same bonding system is used, as with all-ceramic crowns and only a minuscule amount of resin cement is needed to bond the inlay into place. A successful inlay should disappear into the tooth. An onlay is the same as an inlay except that it replaces a cusp of a tooth as well as defective tooth structure. They are larger and usually cost more. The indications for an inlay are pretty straightforward. The patient must have the ability to adequately clean their teeth. Inlays are long-term restorations that should last at the minimum ten years. If I feel the patient will be prone to a lot of decay due to hygiene or other problems, such as medications, I feel better placing an amalgam or composite restoration. The defect in the tooth should cover at least one-half of the chewing surface of the tooth. The inlay needs to have adequate bulk, and to be honest, a restoration smaller than this could be effectively treated as a filling. Finally, some teeth require a crown. Teeth that have had root canal therapy tend to be prone to cataclysmic fractures. They are best served by crowns. The ferule effect of a crown helps to hold the tooth together. For most cases, an inlay can restore a tooth to its original strength, in a conservative manner, with unsurpassed beauty, and is less expensive than a crown.

Bleaching

Tooth bleaching or whitening is very popular today and for good reason. It is the most conservative and economical method for getting a whiter, brighter smile. The products available over-the-counter work by either including a mild abrasive or a dilute bleach solution. The abrasive agent will remove extrinsic or surface stains but it can't remove intrinsic stains which are deep inside the teeth. There is also evidence the abrasives could damage the teeth. The over-the-counter bleaching solution is safe but usually too dilutive to be very effective. Also, the trays that contain the whitening material usually don't fit well enough to hold the whitening solution in the tray. The bleaching material used by the dentist work the best for three reasons: the material doesn't damage the teeth, it provides the best results and the dentist can work with the patient to customize the program for the patients individual needs and comfort. The process requires two fifteen minute appointments. At the first appointment, the dentist makes impressions of the patient's teeth. He uses these impressions to make a tray similar to the mouthguard pro athletes wear. This mouthguard is customized to fit your mouth exactly and deliver the correct amount of whitening gel to each tooth. At the second appointment, the patient tries in the trays for size and comfort and reviews the instructions. The amount of time required to whiten your teeth depends on the darkness of your teeth, the degree of whiteness desired, and the type of bleaching material used. It can range from two weeks up to several months. The only common side effect is slight sensitivity which can be effectively treated with the use of a fluoride-containing gel delivered by the bleaching trays. In certain cases, some relapse occurs. These cases are usually people who have highly pigmented diets, containing high amounts of nicotine, caffeine, or tannins from red wines. These patients can simply "freshen-up" by using the trays every few months for one to two days and keep their teeth looking white and bright.

Implants

I don't know of a dental condition that is more discouraging than the patient who cannot wear a denture or partial. It doesn't just affect their appearance or their ability to eat a normal diet. It seems to affect their perceptions about themselves. People tend to picture themselves as old or worn out. Often these are healthy people who have had poor dental health or have not had exposure to proper dental treatment. I see these patients suffering from depression as much as insufficient bone to support a Prosthesis. Implants allow us to restore retention and thus confidence to patients. Implants are a titanium screw that is placed into the bone. The body doesn't recognize implants as foreign and the bone attaches directly to the implant. The implant is solid and can be used as retention for a denture. The denture will now be as solid as normal teeth. The patient can enjoy a normal variety of foods and can speak with clarity and confidence. I particularly like this type of appliance because the patient can easily remove the denture for easy cleaning. Implants can also be used to replace a single missing tooth. Rather than construct a fixed partial denture or bridge that requires the destruction of the teeth adjacent to the missing tooth, an implant can be placed where the tooth was. The crown will be cemented onto the implant. The big advantage here is that if something breaks, or the patient isn't comfortable with the appearance of the crown in the future, the crown can be easily removed off the implant. Removing a bridge is one of the hardest things for a dentist. Worse, often when a bridge fails, it requires a bigger bridge to replace it. This means cutting down another healthy tooth. And, of course, a bigger bridge is more expensive. There are limitations to implants. Due to poor blood oxygenation, smokers are not good candidates for implants. People with autoimmune conditions such as lupus or organ transplants are not good candidates. Almost no dental insurance programs will pay for dental implants, though some will pay for the crown or denture. In the past, implants were very expensive, however the cost of implants has come down. They still require a significant financial investment. But, that's exactly what they are- an investment in overall health.

Other Advances

Composites (often called bonding or tooth colored fillings) fill a special niche in dentistry. While it cannot be used for larger fillings, it works well for smaller fillings when all of the walls of the tooth are intact.

For front teeth, it can also work well when patients decline preparation of teeth or when more complex restorations may not be indicated (children or teeth with questionable prognosis). It can produce a dramatic result in cases where finances are limited. I like to use it for children who are self-conscious about their appearance or who have had a traumatic incidence such as a fall or hit in the face with a ball.

I think in our excitement with new materials, sometimes we overlook our oldest restorative material, gold. Gold has been used to restore teeth for thousands of years and in my experience, it certainly has done well over time. I often see gold crowns and inlays that are nearly fifty years old. Whereas, our composite restorations seem to hold up well over time, we have not had the history yet to compare them with gold. Gold does have its limitations however. It obviously is not as esthetic as our tooth colored restorations. It is also very difficult to bond gold to tooth, so the restoration must be either conservative or extra reduction must be done for retention. Sometimes I find I must place a gold crown to get the same tooth strengthening as I can achieve with a tooth colored inlay. A crown requires more removal of tooth and costs more money. My feelings about gold could be surmised by one of my mentors, a leading cosmetic dentist in New York City: "I place a lot of esthetic dentistry and it looks great and works well. But in my mouth, I have a couple of gold crowns on my second molars. They are more than twenty years old. One has a hole in it from a root canal and they just keep going. They aren't beautiful but no one can see them but my hygienist."