Pain and Dentistry Part Ways: Laser Light Shows the way
It is a rare person who can listen to the distinctive whine of a dentist's drill without shuddering. The sound and feel of the drill, the pinch of the anesthesia needle, and waiting for it to take effect, and the inconvenient and awkward numbness are all part of unpleasant memories of trips to the dentist. Effective preventive care has made cavities less and less common, but they still happen. Luckily, the unpleasant aspects of cavity treatment will soon exist as only memories. With the advent of laser treatment for many fillings, the dreaded drill and the need for injected anesthesia are quickly becoming things of the past.
Lasers are used to prepare cavities in this way: the light produced by the laser most commonly used for cavity preparation, an erbium:yttrium aluminum garnet (Er:YAG) laser, is highly absorbed by water. Because decayed tooth material has a greater water content than healthy tooth material, the laser light breaks down the decayed material preferentially and quickly, leaving the healthy tooth behind. This difference in water content also allows the dentist to control the amount of tooth removed very precisely.
As tooth material absorbs the laser energy very effectively, the need for anesthesia is eliminated. Without the transfer of energy to the tooth nerve, no pain, or really any sensation, is felt. In fact, only a small percentage of persons can even feel the procedure as it occurs and the feeling is described as mere awareness rather than pain. As an added benefit, the laser light decontaminates the tooth, greatly reducing the possibility of a secondary infection.
Er:YAG laser preparations leave the tooth surface in an ideal state for the popular tooth-colored bonded fillings. And the final advantage of laser treatment cannot be overlooked -- there is no anxiety-producing drilling noise.
Laser use in dentistry is not limited to cavity preparations, however. Lasers have also been approved for use in cosmetic dentistry, specifically curing restorative materials and accelerating tooth-bleaching procedures. Argon lasers are often used to cure the tooth-colored bonded fillings discussed above. Argon lasers are also used during the teeth bleaching to speed the bleaching process. Using the laser, the procedure is very fast and doesn't require the use of dental trays or overnight application of the bleaching material, such as those used with at-home dentist-supervised bleaching. Pro-laser dentists emphasize that severely stained teeth, like those caused by exposure to the antibiotic tetracycline, particularly benefit from the use of the laser. If a patient is dealing with that type of staining, that might be a consideration when deciding what type of bleaching procedure to undergo.
Lasers are also adding to the dentist's arsenal of preventive techniques. In addition to fluoride and sealants, dentists can now use carbon dioxide (CO2) lasers to make teeth more resistant to the acids produced by bacteria in the mouth that cause decay. The heat from the lasers reduces the amount of demineralization, or loss of minerals, from the enamel, and the specific absorption of the light by the tooth surface avoids damage to the central tooth pulp. Reducing demineralization makes the tooth more decay resistant without any visible change to the tooth surface. This newly developed laser treatment could help reduce further the already falling rate of cavity development. Another laser, the Diagnodent from Kavo, detects cavities early so that the bacteria aren't able to get into the nerve or cause more unhealthy damage. It does this by detecting decay, which is undetected by x-rays and a dentist's explorer.
Lasers have also been approved for dental soft-tissue surgery. In fact, that was the first dental procedure that the Food and Drug Administration (FDA) approved for lasers. Like hard tissue surgeries, such as cavity preparation, soft tissue or gum surgeries using a laser avoid the need for anesthetic. There are generally no scalpel incisions. Persons suffering from periodontal disease, caused by bacterial infections that often necessitates the gum surgery, benefit from the reduction of microorganisms from the surgical site. Lasers can also be used to do deep cleaning under gum tissue. The neodymium: yttrium aluminum garnet (Nd:YAG) laser or diode lasers are two types of commonly used to do soft tissue surgery. The wavelengths of the light produced by both of these lasers are strongly absorbed into pigmented tissue, such as the gums, thus they are used to perform such procedures. Lasers have proven to have many benefits in cavity preparation, cosmetic procedures, enamel strengthening, and soft tissue surgery, but there are disadvantages to using this tool in dentistry. For cavities and other hard tissue surgeries, the laser cannot be used to remove large amounts of the tooth, so it is appropriate for treatment of only small-sized cavities. This drawback means that the laser cannot be used to prepare a tooth for a crown. Because of the angle and bulk of the laser wand and the need to actually contact the tooth with the tip of the wand, it is difficult to use the laser on far back teeth. However, as the laser technology develops the wands are becoming smaller and more maneuverable, so this problem will likely be solved in the future.
The greatest disadvantage to the use of lasers can be stated in one word: cost. The equipment is extremely expensive, especially when compared to traditional drill set-ups. The dentist passes the high cost of the equipment onto the patient, making the laser procedures several times more costly than the traditional procedures. For example, an in-office non-laser bleaching session costs from about $600 - $1,200, depending on the area of the country and the number of visits necessary to achieve the desired results. In comparison, the comparable laser procedure runs about $750 - $2,000. That is a significant difference. The patient needs to decide whether the gained justify the extra cost. But to avoid that dreaded drill whine, it may just be worth it.