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To see all the teeth and surrounding structures on one large film, your dentist may use a panoramic X-ray machine, which makes a complete circle around your head. In just a few seconds, all your teeth and gums are photographed on hypersensitive film.
Panoramic radiography is invaluable for examining unerupted teeth in children and investigating suspected cysts or bone abnormalities in adults. But when detail is necessary, such as in detecting cavities or gingival problems, the conventional X ray is still necessary.
Fillings and flaws. Thanks to fluoridation and growing awareness of nutrition and oral hygiene, severe dental problems are decreasing. Observes Winnipeg dentist Ralph Crawford, editor of the Journal of the Canadian Dental Association, "Today’s average 17-year-old may have only one filling in his mouth; a person his age a generation ago would have had a dozen."
Nevertheless, due to accident or inheritance, many of us have teeth that are discoloured, chipped, crooked or badly spaced. And a new emphasis in dental practice is being placed on repairing these flaws. "An attractive smile is a personal asset," says Toronto dentist Edward Philips. "We can now create that smile."
Resin bonding is a painless and inexpensive method of correcting minor problems in a single office visit. The dentist paints your tooth with a weak solution of phosphoric acid, which etches a network of tiny crevices on the enamel surface and on the underlying tissue, dentin. This provides an effective clinging surface for the pastelike bonding material that he then brushes on. The bonding material – a tough composite of resin, glass and plastic – is hardened on the tooth by exposing it to intense light for 20 to 30 seconds. The process of applying thin layers of the resin and then hardening them by light exposure is repeated until the tooth is built up to the desired shape and size. After the last coat, the dentist applies finishing touches and polishes the tooth. For more serious defects, a thin, porcelain laminate veneer can be bonded over the entire tooth.
If you are considering cosmetic work, a cosmetic imager can show you the potential results. In only a few minutes, Vancouver dentist Ken Neuman can produce an edited picture of his patient’s smile, simulating possible cosmetic changes – from reshaping the teeth to closing gaps between teeth. Armed with "before and after" views, the patient can decide whether to go ahead with the changes.
Fillings nowadays are commonly made of porcelain or a durable plastic composite. They require smaller holes than amalgam, the traditional silver-coloured material, because they’re cemented in with resin bonding, which also seals out bacteria. Dentists may still use amalgam in back teeth because it’s cheaper than porcelain and stronger than plastic.
Amalgam has several drawbacks. Because it is held in mechanically, the dentist has to drill a hole larger at the bottom than at the top, and the fit is never precise enough to seal the filling completely. As the amalgam suffers wear and tear, decay-causing bacteria seep in.
Implants and replants. Synthetic implants now provide an alternative to cumbersome bridgework or dentures, once the only means of replacing lost teeth. At the site of the missing tooth, the dentist freezes the gum and bone, drills a conical hole into the bone and fits into it a cylinder made of titanium, a material that resists erosion and co-exists happily with oral tissue. The gum is sewn up, and, within three to six months, the cylinder becomes so firmly embedded by the growth of fresh bone around it that, says one dentist, "it’s stronger than natural teeth."
At this point the gum is cut open over the cylinder, and a porcelain tooth is cemented into it. A complete upper or lower plate can similarly be anchored with three or four titanium cylinders. Follow-up studies indicate a success rate of 75 to 90 percent for the implants, which cost about $2000 per tooth.
When an otherwise sound tooth is knocked out as a result of accident or injury, in many cases it can be replanted if tended to promptly. The dentist seals off the small hole at the end of the tooth where the nerve emerged, fits the tooth into its original socket and, with resin bonding, joins it to the adjacent teeth for support. In four or five months, new bone grows around the base of the tooth, and it becomes firmly attached.
Pain reduction. Along with new methods and devices, your dentist also has access to drugs that can make almost any treatment painless while you are in his chair. Some are so powerful they can be administered only by dentists certified in anesthesia. For example, midazolam, a potent intravenous sedative used in cases where the patient prefers being asleep, puts the patient into a trancelike state in which he can respond to directions. Upon awakening he may not remember anything about the treatment.
For the many patients who request a general anesthetic during stressful procedures, propofol is one of several drugs of choice. Administered by injection at ten-minute intervals and in very small quantities, this drug will keep a patient asleep, allowing the dentist to complete in one appointment extensive treatment that would otherwise have required many appointments. When the drug is stopped, consciousness returns quickly, and the side effects are minimal. Its use requires that an additional trained person also be present to monitor the patient.
Bone and tissue treatment. An early-warning test for periodontal disease, the leading cause of adult tooth loss, has been devised by biochemist Jaro Sodek and periodontist Christopher A. G. McCulloch of the University of Toronto. The patient rinses his mouth, and the rinse water is then analyzed. An above-normal enzyme count indicates trouble in the tissues around the teeth.
Another new technique actually restores bone loss caused by periodontal disease, a condition previously thought irreparable. At the site of a bone deficiency, a small, gauze- like package made of filaments of human bone is sewn inside the gum. In time the implant fuses with the existing bone and enhances it. "It’s incredible," says Edward Philips. "In most cases we are now able to halt the advance of periodontal disease and lessen the chances of patients ever losing their teeth."
Indeed, so many dental problems are now preventable that today’s children can look forward to a lifetime with healthy teeth. And for those of us who grew up without the advantages of fluoride and flossing, thankfully the new dentistry is there to keep our teeth in better shape than we ever expected.
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