ALMOST anyone who is missing a front tooth wants it replaced especially if the loss is recent. But what if it is a back tooth? Would it be necessary to replace it? The answer depends on how many teeth are missing and whether or not the empty space presents a problem.

In general dental “quacks” fill missing spaces while dentists replace missing teeth bearing in mind function. If only one molar tooth is missing, for example, there is little if any benefit in its replacement if it does not participate actively in mastication. Often, it also depends on the patient’s finances.

Replacement of missing teeth can be relatively expensive and provides a major source of income to dentists. Because people are conditioned to pay for appliances and mechanical devices, it is customary to charge fees for prostheses that generate higher hourly income than for fillings. To be sure, crowns, bridges, and dentures are expensive because of the time involved and the added cost of laboratory construction, including the labour of the technician and the costs of materials. Nonetheless, when these costs are deducted from the total fee for the appliance, dentists earn more per hour for this kind of work than for most other services.

Because fees vary, reflecting the competitive dental marketplace, it is not a bad idea to obtain a few estimates whether a lot of expensive bridgework is required. But price should never be the only determinant. As John Ruskin is quoted on the nineteenth-century marketplace: There is hardly anything in this world that one man cannot make worse and sell for less. The person who considers price only is this man’s lawful prey.

One way to “make worse and sell for less” is to rush through treatment. Good dental technique requires careful attention to details, which takes more time and not infrequently, repetition of a procedure or an impression until the correct result is achieved. The less time a dentist spends on a procedure for which a fee has been established, the higher the hourly income; therefore, the lowest priced dentist may be less able to resist the temptation to cut corners.

On the other hand, there is no guarantee that a high-priced dentist will be more conscientious. The goal, then, is to locate a dentist who is competent in technique and reasonable in his or her charges. This requires that the consumer have at least a basic understanding of the basis for treatment.

Fixed bridges are virtually indistinguishable from the natural teeth, in contrast to a partial denture that is bulkier and must be removed to clean around the metal-plastic base and clasps. Yet if the larger expenditure of multiple fixed bridges is beyond one’s means, a properly designed partial denture can be as comfortable as fixed bridges.

If nothing is known of a dentist’s skills, a removable bridge is the safest way to replace missing teeth. After all, if the fit is poor, it can always be thrown away. Not so with a fixed bridge that is cemented onto adjacent teeth that have been cut down for artificial crowns to which the missing teeth are attached. If the crowns are poorly done, the bridge will be lost in a few years along with the teeth.

A good fixed bridge will last a decade or longer, many for over 20 years. When a bridge fails within a few years of placement, the reason is almost always poor care, not bad dental work. Much less expensive removable bridges or partial dentures, as they are more commonly known, last long as good fixed bridges if they are properly constructed and cared for. Patients who have resisted persuasive arguments to replace well-functioning partial dentures with fixed bridges have been known to wear the same appliance for 15 to 20 more years. An experienced dentist knows not to tinker with success and does not recommend replacements in the absence of obvious need.

Some fixed bridges, however, rival the Demerara Harbour Bridge in span, stretching from a back molar on one side to the last molar on the other side with too few supporting teeth in between. An “ear to ear” or “roundhouse” bridge costs thousands of dollars more than a removable bridge and seldom lasts longer. Too often these great bridges are monuments to the ambitions of the dentists but end up as disasters to their patients when they come loose and have to be removed along with the teeth that have decayed extensively underneath.

Nevertheless, if enough strong teeth remain, if good oral hygiene is maintained, and if the dentist is experienced and conscientious, and there is a legitimate need, fixed bridges, large and small, are well worth the effort and money.

Restorations seem to last longer when there is no dental insurance to pay for replacement. Willing patients and those with insurance may be receptive to suggestions that they replace crowns and bridges even when all that is required is a small gum line filling to repair a decayed margin. Most insurance plans limit coverage for crowns, bridges, and dentures to once in five years. This seems like an arbitrary limitation, but it does help prevent the worst abuses.