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Whangarei Dental Bridges



Is it necessary to replace a missing tooth?

Teeth that are lost between teeth should be replaced to avoid future complications. Like a stone arch in a building, if one of the stones is removed, the arch crumbles. A missing tooth has the same effect on the arrangement of your teeth. As teeth shift in the dental arch, gaps develop between the remaining teeth as they shift toward the missing tooth space. These gaps lead to decay as food gets trapped between teeth.

The upper or lower opposing tooth of the missing tooth will continue to erupt as it is needs the biting force of the lost tooth. When this happens, the teeth in the opposing arch also shift. The raised or lowered opposing tooth then becomes an obstacle for the natural jaw movements during chewing, which causes jaw problems. (see TMJ FAQ)

If the missing tooth is the last tooth in the dental arch, teeth will not shift in the same arch, but the opposing tooth will continue to erupt. Once back teeth (molars) are lost, the entire dental complex (teeth, jaw, tongue) starts to fail. Teeth toward the front of your mouth are not designed to withstand the chewing forces of the jaw by themselves. Without back teeth, front teeth usually start to fail by loosening or breaking.

Missing front teeth are obviously unsightly, but your speech is also affected. Certain speech sounds rely on the full compliment of front teeth to position your tongue and lip against. Try making the “v”or “f” sound and notice the position of your lower lip. Next, try making the “the” sound and notice the position of your tongue. These are obvious examples of how your teeth are used to make sounds, but almost every speech sound made is a functional variation of your tongue, lips and teeth.

What is a bridge?

A bridge is a permanent fixture designed to replace a missing tooth when there are teeth on either side of the missing tooth with sound bone structure. It is essentially three or more crowns made into one piece that is cemented over the prepared teeth on either side of the gap. The part of the bridge that is anchored to the teeth is called an abutment. The part of the bridge that takes the place of the missing tooth (the fake tooth part) is called a pontic.

The process of making a bridge is similar to a crown, where the adjacent teeth are prepared, an impression is taken and sent to a lab for fabrication, a temporary bridge is inserted while the bridge is being made, and then the bridge is cemented at another appointment 2-3 weeks later.

Bridges can also be placed on implants where, instead of the bridge being fitted to teeth on either side of the gap, the bridge is placed on implants. Unfortunately, a bridge cannot be placed on a combination of natural teeth and implants. The bridge has to be placed on all natural teeth or all implants.

Keeping a bridge healthy requires the use of special devices to clean the abutment teeth on either side of the pontic area. This is because the bridge is all one unit and cannot be flossed where the bridge is connected. Therefore the use of “bridge aids” are needed which allow you to thread floss under the pontic and then clean under it. There are many types of bridge aids and your dentist or hygienist can direct you to the one most suitable for your situation.

Is there more than ONE type of bridge?

Actually, there are four main types of bridges: Traditional; Cantilever; Maryland; and Implant-Supported. Each type has its advantages and criteria for use.

A traditional bridge can be used when you have natural teeth on both sides of a missing tooth. Traditional bridges can be made from metal, ceramics (porcelain or zirconium), plastic material or a combination of these materials. These types of bridges are preferred when the adjacent teeth to the missing tooth (or teeth) are in need of repair but are not affected by gum problems. This way, the adjacent teeth are restored and the missing tooth is replaced, all in one go.

A cantilever bridge is like a traditional bridge except the supporting tooth (or teeth) are on one side of the missing tooth to be replaced. In other words, the pontic (false tooth) hangs off of one side of the abutment (the part of the bridge connected to the tooth). Cantelever bridges are successful in very few situations where the tooth to be replaced is a small, low force tooth and the supporting tooth is very sturdy. The advantage to a cantilever bridge is that it is very easy to maintain since no special devices are required to clean under the false tooth (pontic).

A Maryland bridge is a very conservative alternative to traditional bridges. The false tooth is supported with “wings” that are cemented to the adjacent teeth. The wings (retainers) require very little, if any, tooth structure to be removed on the abutment teeth and thus are considered more conservative. While conservative, Maryland bridges rely on the strength of the cement to hold the bridge in place. Unfortunately, the glue often fails and requires the bridge to be re-cemented when dislodged.

Implant supported bridges are used when there are too few or no natural teeth in an area where teeth need to be replaced. Usually, a dental implant is placed for every tooth that needs to be replaced, but often two implants are placed to support three or more teeth to be replaced using a bridge. Implant supported teeth or bridges are a great way to add teeth when the natural teeth are lost. However, the process takes time, sometimes up to a year, before your implant teeth can be fully functional. Your dentist or implantologist will determine how many implants would be required to restore an area without teeth.

Are teeth with root canals ok for bridges?

Teeth with root canals generally make good supports for bridges. However, teeth with root canals are not quite as strong as those without root canals and require a “post” to be placed in the root system to provide additional strength.

The forces applied to teeth on bridges are more concentrated than if all teeth were present. If a bridge is replacing one tooth, then the biting forces are directed to two teeth instead of three. This means each supporting tooth of a bridge is enduring 50% more applied force than it would endure alone.

Many bridges placed are on teeth with root canals and are usually successful. However, there is a risk as a tooth with a root canal is not as strong and is more brittle and can possibly fracture.

Are there alternatives to bridges?

There are several options to replace missing teeth other than dental bridges. A missing tooth or teeth can be replaced with dental implants or removable appliances such as a partial or full denture. There are benefits and drawbacks to each option.

A removable appliance, also known as a “partial” can be made of acrylic, or a combination of acrylic and metal. The appliance has hooks or clasps that anchor the partial to the remaining teeth with the artificial teeth embedded into the acrylic replacing the missing teeth.

Removable appliances are a cost effective way of occupying the space of a missing tooth or teeth but there are some disadvantages. The most prevalent complaint about removable partials is comfort. Some people just cannot tolerate the bulk of a partial in their mouth which makes them feel like gagging when they wear the partial. Although metal partials are much thinner than all-acrylic partials, they still notice the appliance in their mouth. If you think about it, if you have ever had a hair in your mouth, it can feel like a rope!

Speech is also affected by wearing partial or full dentures as the appliance changes the natural position of the tongue against the roof of your mouth. The “s” sound is commonly affected by people who wear removable appliances.

Partial dentures just don’t feel like teeth when chewing. This is because the partial denture is not securely fixed to the supporting teeth and moves when forces are applied. In areas where many teeth are replaced with a partial denture, the support is dependant on the gum tissue under the appliance. The gum tissue has “give” to it and does not feel like natural teeth when chewing.

Decay and bad breath is another common side affect when wearing a removable appliance. The appliance contacts the gums and teeth under the device which traps bacteria. This buildup of bacteria causes increased risk of decay on the supporting teeth as well as emitting a foul odour.

Appearance is another factor that may influence the tooth replacement option. Removable appliances often have metal clasps or wires that hold the partial onto the remaining teeth. These can be visible in the smile and fall short of the optimum aesthetic result. Also, the gum coloured acrylic can often be seen when front teeth are involved.

Implants as a tooth replacement option are covered under implant services. You will discover why implants are almost always the best tooth replacement system available today!

Which type of bridge is best?

The best type of bridge depends on many factors. When choosing a bridge type, aesthetics, function, location, budget and the anatomy of your mouth are considered to find the best solution for your needs.

The most natural looking bridge is a traditional bridge constructed of all ceramics - porcelain and zirconium. However, these bridges are not ideal for high stress loads, such as back teeth, and they do require a significant amount of tooth preparation to make room for the bridge.

The strongest type of bridge is an implant supported bridge which is ideal for replacing lost back teeth. However, implant supported bridges can be expensive and do take time to construct. They also require the most maintenance and home care to ensure long term success.