A space maintainer is a dental device used to maintain the space for the permanent to erupt when a baby tooth is pulled prematurely on a child. Space maintainers are used to prevent the other teeth from crowding into the extraction site and causing problems when the permanent tooth finally comes in to replace the missing baby tooth.
Most of the time, the space maintainer is constructed with a metal band that is cemented to the 1st permanent molar and has a wire extended across the space where the baby tooth was extracted and resting on the tooth on the other side of the space. If baby teeth have been lost on both sides of the mouth, two of these cemented space maintainers may be used, or a retainer-like removeable space maintainer can be made to wear until the permanent teeth erupt.
The biggest problem with the cemented, or fixed space maintainer is that they can be pulled off when the child eats sticky foods or candy. If they do come off, they can and should be recemented as soon as possible. The main problem with removeable space maintainers is that they can be easily lost or broken by the child.
A bridge is used to replace missing permanent teeth when there are remaining teeth on both sides of the space where the teeth are missing. It consists of crowns on the teeth on both sides of the the space where the teeth are missing and false teeth attached to the crowns with a connecting metal framework. The bridge is constructed with a solid metal framework that extends from the crowned teeth on one side of the space where the teeth are missing to the other side. It is also sometimes called a fixed partial.
Bridges can be made of different materials. They can be all metal, porcelain fused to metal, or all porcelain. The type of material used depends on where the bridge is located, esthetics ( how the bridge looks), function, and other criteria. You should ask your dentist which type of material they would suggest for your particular situation.
The main advantages of bridges are: 1) they are permanently cemented in place, 2) they are attached to natural teeth, which allows for normal function and support, 3) they are none invasive ( no surgery needed), 4) they are usually very esthetic, look natural and can match the color of your natural teeth. The disadvantages are: 1) the teeth on both sides of the space where the teeth are missing must be prepped for crowns and 2) they require use of a floss threader to floss underneath to maintain good oral hygiene. If you have any questions, please contact me at firstname.lastname@example.org.