The Implant Was Fine. The Screw Had Come Loose.

Quick answer: An implant crown that has started to move is usually a loosened retaining screw, not a failing implant. It is fixable, often in one short appointment — but it must not be left, because chewing on a loose screw can fracture it inside the implant, which is a far bigger problem.

The call

Menashe, 63, from Nofei Aviv, had an implant crown replacing a lower molar, placed five years earlier. He had noticed over about three weeks that it moved slightly when he pressed it with his tongue, and had started clicking when he chewed.

He assumed the implant was failing and phoned expecting bad news.

What we found

The crown rotated very slightly under finger pressure. Crucially, the implant itself did not move.

That distinction is everything, and it is one patients cannot make themselves.

A loose screw means the small screw holding the crown onto the implant has unwound slightly. The crown moves; the implant is solid. Common, fixable, not serious if dealt with promptly.

A failing implant means the implant itself has lost its bond with the bone. The whole unit moves. That is a much more serious situation and usually means the implant has to be removed.

We tested carefully. The gum around it was healthy, with no bleeding on probing, pocket depths of 3mm, and no pus. The x-ray showed normal bone levels right up to the implant shoulder, with no dark halo around it — and, visible on the film, a tiny gap between the crown assembly and the implant, which is the radiographic signature of a loosened screw.

Why screws loosen. Every implant crown is held by a screw torqued to a specific value. Over years of chewing, micro-movements can gradually unwind it. Contributing factors include a bite that loads the crown off-axis, grinding, a crown that is slightly too wide so food wedges and levers it, and a screw that was never torqued to the correct value at the outset.

Menashe ground his teeth and had no night guard. That was almost certainly the driver.

Why it must not be left. A loose screw is subject to bending forces it was not designed for. It can fracture inside the implant. Retrieving a fractured screw fragment from inside an implant is difficult, sometimes impossible, and occasionally means the implant has to be removed and replaced. A twenty-minute appointment prevents all of that.

What we did

Removed the crown by unscrewing it through the access hole in the biting surface — the hole having been sealed with composite, which is why patients rarely realise it is there.

Inspected the screw. It was intact, not fractured, but had unwound noticeably. We replaced it with a new one — standard practice, since a screw that has loosened has been stretched.

Cleaned the internal surfaces, reseated the crown, torqued the new screw to the manufacturer's specified value with a calibrated torque wrench, waited ten minutes and retorqued, which allows for settling.

Then the important part: adjusted the bite so the crown was not taking a heavy load in side-to-side movements. And made him a night guard.

The outcome

No further loosening in two years. The night guard is worn nightly and shows the wear to prove it.

What to do if this happens to you

1. Do not chew on it. That is what fractures the screw.
2. Be seen within a day or two. This is a short appointment now, or a serious problem later.
3. Say exactly what you notice — movement, clicking, food packing, a change in the bite.
4. Ask whether the implant or just the crown is loose. They are different problems.
5. Ask about your bite and about grinding. Recurrent loosening usually has a mechanical cause.
6. Keep implants under review with x-rays and probing at least yearly.

Implant crown feeling loose? Ramat Beit Shemesh Urgent Dental Care can tell you whether it is the screw or the implant. 055-985-8845 · WhatsApp https://wa.me/972559858845 · Harav Kook 28/1, Beit Shemesh.

Based on real cases treated at the clinic. Names have been changed.