The parts of a fixed bridge
These terms appear whenever a bridge is planned, and they explain why a bridge is counted in units rather than in teeth replaced.
- Abutment teeth and retainers
- The natural teeth on either side of the gap carry the bridge. They are prepared for crowns, which are called retainers, and from then on they carry their own chewing load plus a share of the load from the missing tooth.
- Pontic
- The false tooth that fills the gap. It rests against the gum without being attached to it and does not enter the bone. A modified ridge lap design touches the gum only on the cheek side, so it looks natural and can still be cleaned underneath.
- Connectors and span
- The joins between the units are solid, which is why floss cannot pass between the teeth of a bridge. A three-unit bridge is two abutments and one pontic. Longer spans flex more and place more load on the abutment teeth.
What a bridge requires of the neighboring teeth
This is the real cost of a bridge, and it should be understood before you decide. To carry the pontic, the teeth on either side are shaped to receive crowns. Enamel that is removed does not grow back, and those teeth are committed to being crowned from that point on. Preparing a tooth also carries some risk to the nerve, and some prepared teeth need root canal treatment later.
Two roots then carry the load of three teeth. If one abutment decays under its crown or fractures, the whole bridge usually has to be removed, and the resulting gap is wider than the original one. The calculation changes when those teeth already have large fillings or crowns, because they need coverage in any case and the bridge costs no additional tooth structure.
The work runs over two visits a few weeks apart, much like having two crowns made at once, with a temporary bridge in between.
Cleaning under the bridge
A bridge is joined together, so floss cannot pass between the units. The pontic sits against the gum and plaque collects beneath it, and problems with a bridge often begin there.
- A floss threader. A stiff plastic loop that carries floss under the pontic, so that you can work it against the abutment teeth and the underside of the false tooth.
- Superfloss. A single strand with a stiff threading end and a spongy middle section that cleans the underside of the pontic. It is easier than a threader and floss used separately.
- An interdental brush. A small tapered brush that passes under the pontic where there is room, and for many people this is what makes cleaning a bridge quick enough to do daily. A water flosser helps, though it does not replace the brush or the floss.
- Make it part of the daily routine. Plaque under a pontic can cause bleeding gums and decay at the crown margins, and neither one causes pain until it is well advanced.
Cleaning under a bridge takes an extra minute each day. If you would prefer not to take that on, a removable partial denture or an implant may suit you better, and that discussion belongs in the planning stage. See periodontal care.
Cantilever, Maryland and implant-supported variations
The traditional bridge, with an abutment tooth at each end, is the standard design. Three variations appear often enough to describe here.
- Cantilever bridge
- A bridge supported at one end only, with the pontic extending from a single abutment tooth. That places leverage on the tooth, so it is limited to situations with light forces, such as a small upper lateral incisor.
- Maryland or resin-bonded bridge
- A pontic with thin wings bonded to the back of the neighboring teeth. Very little tooth structure is removed, so it is a conservative option, and it is often used at the front for a younger patient whose jaw is still growing. The limitation is that the bond can fail.
- Implant-supported bridge
- Two or more implants carrying a bridge, with no natural teeth involved, which suits several missing teeth in a row.
A fixed bridge compared with a removable partial denture
When an implant is not an option, this is usually the choice, and each one has real advantages.
| Consideration | Fixed bridge | Removable partial denture |
|---|---|---|
| In the mouth | Cemented in place and never removed. It feels closest to natural teeth. | Removed for cleaning and overnight. It is bulkier, and adapting to it takes time. |
| Tooth structure | The abutment teeth are shaped to receive crowns. | Little or none is removed, beyond small rest seats in the supporting teeth. |
| How many teeth it replaces | A short span, with sound teeth at both ends of the gap. | Several gaps at once, including gaps with no tooth behind them. |
| Cleaning and appearance | Floss is threaded under the pontic every day. No metal is visible. | It is removed and brushed, which is easier, though clasps can show and the teeth holding them need careful cleaning. |
Bridge questions
How long does a dental bridge last?
Bridges commonly serve for many years, and many last beyond a decade. What usually ends a bridge is a problem in an abutment tooth underneath, through decay at a margin or a fracture. Daily cleaning under the pontic is the part within your control.
How many teeth can a bridge replace?
It depends on the length of the span and on the bone support of the abutment teeth. One missing tooth between two sound teeth is straightforward, and two in a row is often workable. Beyond that, the load on the abutment teeth becomes the limiting factor.
Which costs more, a bridge or an implant?
A bridge generally costs less at the outset and is finished in weeks rather than months. Over a longer period the comparison narrows, because a bridge involves two crowns that may need replacing. We will review the fees for either option with you before treatment begins. See insurance and financing.
What are the alternatives to a bridge?
A single dental implant, which leaves the neighboring teeth untouched, or a removable partial denture. Leaving the gap is also a choice, though the drifting described under restorative dentistry can make it a costly one over time.