Implant or bridge?

What is the fundamental difference?

With an implant, a titanium screw is placed into the jawbone and a crown is made on it once it has integrated. The gap gets its own root; the neighbouring teeth are not touched.

With a bridge, the teeth on either side of the gap are reduced and a three-unit span sitting on them closes the space. The middle unit does not touch bone; it rests on the gum.

That difference explains why the decision is irreversible: choose the implant and the neighbouring teeth stay as they are; choose the bridge and two sound teeth have been permanently reduced.

How many teeth are reduced for a bridge?

A standard bridge for one missing tooth has three units: the teeth on either side are used as abutments. So one missing tooth means two sound teeth are reduced.

The amount removed is 1.0–1.5 mm depending on the surface, and it goes all the way round the tooth. That figure is set by the minimum thickness the crown needs to sit properly.

Where two missing teeth sit side by side, the bridge can extend to five units and the number of abutments rises. The more abutments, the more sound teeth are reduced.

Which one causes bone loss?

After a tooth is removed, the alveolar bone in that area loses volume because it is no longer loaded. The fastest loss is in the first 12 months after extraction.

An implant transmits chewing load directly into the bone, stimulating it and slowing that loss. The pontic of a bridge does not touch bone; the bone beneath it stays unloaded and continues to resorb.

Over time a space opens between the bridge pontic and the gum above the resorbing bone. That space traps food and produces a visible dark gap.

Which lasts longer?

A bridge is typically replaced at 10–15 years. What determines its life is the health of the abutment teeth; decay at the crown margin means the whole bridge has to come off.

The body of an implant inside the bone is permanent. The crown on it may be replaced at 10–15 years for wear or colour match, which is not the same as replacing the implant.

In both methods the shared determinant is gum health and regular review. Inflammation progressing around an implant — peri-implantitis — causes bone loss and can cost you the implant.

Which is better at what?

Superiority varies from mouth to mouth. The two methods solve different problems at different costs.

• Implant better — neighbouring teeth: sound teeth are not touched at all.
• Implant better — bone: it transmits chewing load into the bone and slows local resorption.
• Implant better — replacing a single tooth: if a problem arises later, only that site is dealt with.
• Bridge better — time: completed in one trip, typically 5–7 days.
• Bridge better — no bone required: it can be done where there is not enough bone to carry an implant.
• Bridge better — where the neighbouring teeth are already compromised: using root-treated or heavily filled teeth as abutments costs nothing extra.
• Equal — chewing function: correctly planned, both restore the ability to chew.

How much difference is there in time and travel?

A bridge is completed in one trip and typically takes 5–7 days: preparation and impressions, try-in, cementation.

An implant needs two trips. On the first the implant is placed (2–3 days), then 2–3 months of integration in the lower jaw and 3–4 months in the upper. On the second the restoration is completed (4–5 days).

If bone grafting or a sinus lift is needed, the total extends by a further 3–6 months. That need is identified by 3D scan before treatment, and it is the commonest reason a travel plan changes.

When is an implant deferred or not done?

Implants are not for every mouth. In the situations below, either preparation is done first or other options — including a bridge — are considered.

• Patients whose jaw growth is incomplete — implants are generally not planned before 18.
• Uncontrolled diabetes — no placement until blood glucose is controlled.
• Untreated gum disease — periodontal treatment is completed first.
• Heavy smoking — it lowers integration success, so reducing or stopping is asked for.
• Patients on bone density medicines (bisphosphonates and similar) — not planned without consulting the doctor managing that treatment.
• A history of radiotherapy to the head and neck — requires a separate assessment.