If you have ever crossed a bridge, driven over a dam, or climbed the stairs of an arch, you have benefitted from the structural support of an abutment, though you likely never paused to consider what was holding these structures up as you made use of them. In engineering, an abutment is part of a complex support system designed to be both out of sight and out of mind. In many ways, they are hiding in plain sight off on the sidelines but doing incredibly important work!
What is an abutment?
An abutment is a key support element that provides a foundation upon which the structure itself rests. It must be capable of absorbing the weight and transferring it to the foundation itself; essentially, it serves as the primary connecting structural element between the base and superstructure.
In the engineering world, there are multiple types of abutments, including cantilever abutments, stub abutments, and spill-through abutments. They type of abutment used depends upon the type of structure it must hold and the foundational structure that it connects with.
Additionally, abutments can be man-made or existing. In the construction of bridges, for example, abutments are generally man-made. They can take the form of retaining walls as well as vertical supports, and they are constructed with the sole purpose of providing support for the bridge being built. Engineers oftentimes take advantage of naturally existing structures such as valleys or gorges, however, in the construction of other features like dams. In these cases, engineers take advantage of already strong and available supports nearby, both utilizing and modifying these structures as needed to benefit the structural integrity of the project at hand.
What do abutments have to do with dentistry?
While all this talk of bridges and dams and engineering design might seem incompatible with dentistry, the construction of these kinds of support systems is actually quite central to the design and installation of various dental appliances. These include dental implants, bridges, and even partial dentures. In fact, the supports that are created and installed by your dentist during these procedures are called abutments, as well.
Dental abutments are small fixtures that, similarly to the other kinds of abutments discussed earlier, provide support to the visible structure by both holding and transferring weight to the foundational support. In the case of a dental implant, for example, the dental abutment provides support for the implant crown – the replacement tooth that is visible to the eye – by providing a connection between it and the foundational support system, in this case the implant fixture that is embedded into the jawbone. While they are indeed created on a much smaller scale than the abutments that hold up bridges and dams, dental abutments must be able to transfer a great deal of force – more than you might think! The human jaw creates a great deal of force in the seemingly simple acts of biting and chewing – it is only with the aid of abutments that replacement teeth that can withstand this amount of pressure and be made to function inside the human mouth.