Screw-Retained or Cemented: How an Implant Crown Is Attached

A single dental implant has three parts: the fixture in the bone, the abutment that emerges through the gum, and the crown you see. Most discussion focuses on the fixture, but how the crown is joined to what is underneath has more practical consequences over the years than patients tend to expect.

There are two methods. The crown is either held by a small screw passing through it into the implant, or it is cemented onto an abutment much as a conventional crown is cemented onto a prepared tooth.

The distinction that matters is retrievability — whether the crown can be taken off and put back without destroying it.

The crown and abutment are made as one piece, or the crown is made with a channel through it. A screw passes through and engages a thread inside the implant. The access hole is then sealed with a soft filling material and covered with composite.

No cement is used below the gum. This is the primary clinical advantage, and it is a larger one than it sounds.

The crown is retrievable. Unscrew, remove, work on it, replace. If the screw loosens it can be retightened. If the ceramic chips it can be sent to the laboratory for repair rather than cut off and remade. If the gum around the implant needs treatment, access is straightforward.

The constraint is the screw channel. It has to emerge somewhere, and it must not emerge through the biting surface of an incisor edge or the working part of a cusp. That requires the implant to have been placed at an angle that allows the channel to exit in an acceptable position — usually the cingulum of an upper front tooth or the central fossa of a molar.

Angulated screw channel systems have widened what is possible, allowing the screwdriver to engage at an angle of up to around 25 degrees from the implant axis. This has made screw retention feasible in many cases that would previously have required cement.

The visible access hole. Sealed with composite, and usually unobtrusive, but on an upper front tooth it can occasionally be perceptible under certain lighting.

An abutment is screwed into the implant, then the crown is cemented onto it — a process identical in principle to cementing a crown onto a natural tooth.

The advantage is freedom of design. There is no screw channel to accommodate, so the occlusal and incisal surfaces are uninterrupted. Where the implant angle is unfavourable, cementation allows the abutment to correct the emergence direction and the crown to be made in the correct position regardless.

The disadvantage is cement. This is not a minor point. Excess cement extruded below the gum margin during seating is difficult to detect and difficult to remove. Retained subgingival cement is a well-documented cause of peri-implant inflammation, and in some cases of progressive bone loss around the implant. The deeper the crown margin sits below the gum, the harder the cement is to find and the more likely it is to be left behind.

The profession's response has been threefold: keep margins as close to the gum level as possible, use techniques that limit excess before the crown is seated, and — increasingly — prefer screw retention where the geometry allows.

Retrievability is limited. If the crown needs to come off, it usually has to be cut off and remade.

The abutment connection. Most contemporary implants use an internal connection, often conical, which provides mechanical stability and helps seal the interface. Our article on managing biological width around implants covers the tissue relationship at this junction.

The abutment screw. Tightened to a defined torque specified by the manufacturer, using a calibrated torque wrench. Under-tightening leaves the joint prone to loosening; over-tightening risks fracturing the screw. This is not a matter of feel.

The emergence profile. The shape of the abutment and crown as they pass through the gum determines how the soft tissue is supported. A contour that is too bulky compresses the tissue and makes cleaning difficult; one that is too thin leaves a hollow that collects plaque. Our article on implant crown design and long-term maintenance covers this.

Materials. Titanium abutments are strong and well tolerated. Zirconia and hybrid titanium-base abutments are used where the tissue is thin and a metal colour might show through. Our article on gum shape and implant results covers the aesthetic considerations, and shade matching an implant crown covers the crown itself.

Implant angulation. The dominant factor. If the screw channel would exit in an unacceptable position and cannot be corrected with an angulated channel system, cementation may be the only option.

Where the crown margin would sit. A deeply subgingival margin argues strongly for screw retention, because cement cannot be reliably removed from that depth.

Available height. Where there is limited space between the implant and the opposing tooth, a screw-retained crown avoids the additional cement layer and abutment height.

Aesthetic demands. An upper front tooth may occasionally favour cementation for an uninterrupted facial surface, though modern access-hole sealing makes this less often decisive.

Anticipated maintenance. Patients with a history of gum disease, or with risk factors for peri-implantitis, benefit from a retrievable restoration. Our article on early signs of peri-implantitis explains why access matters.

Bruxism. Grinding raises the likelihood of screw loosening and ceramic chipping, both of which are easier to manage on a retrievable crown. Our article on implants and bruxism covers the risks.

Contemporary practice leans towards screw retention where the geometry allows, principally because of the cement problem. Both methods, properly executed, perform well.

• Clean around it daily, including interdentally — an implant cannot decay, but the tissue around it can become inflamed and bone can be lost

• Use interdental brushes sized to the space, or a water flosser. Our article on cleaning an implant compared with a natural tooth covers technique

• Report any looseness or clicking promptly — a loosening screw caught early is retightened; one left in place can fracture. Our article on a loose implant crown covers what to do

• Report bleeding, swelling or tenderness around the crown without waiting

• Wear a night guard if you grind

• Attend maintenance appointments at the intervals advised, which include probing and periodic radiographs

• The essential difference is retrievability: screw-retained crowns come off, cemented crowns usually do not.

• Retained subgingival cement is a documented cause of peri-implant inflammation and bone loss.

• Screw retention requires an implant angle that allows the channel to emerge acceptably.

• Angulated screw channel systems have widened the range of cases suited to screw retention.

• Cementation offers freedom of design where the implant angle is unfavourable.

• Abutment screws are tightened to a specified torque with a calibrated wrench.

• Both approaches work well when properly executed and maintained.

Which type of implant crown is better?

Neither is universally better. Screw retention is often preferred because it avoids subgingival cement and allows the crown to be removed for maintenance. Cementation may be necessary where the implant angle would place the screw channel in an unacceptable position.

Can you see the screw hole on a screw-retained crown?

It is sealed with composite matched to the crown. On back teeth it is not noticeable. On an upper front tooth it may occasionally be perceptible in certain light, which is one factor in the planning discussion.

What happens if the screw comes loose?

The crown feels slightly mobile or may click. It should be assessed promptly — a screw can usually be retightened, but a loose joint left in function may fracture the screw, which is a more involved problem to resolve.

Is cement around an implant really a problem?

Excess cement left below the gum is associated with peri-implant inflammation and, in some cases, bone loss. This is why crown margins are kept as shallow as possible and why screw retention is often preferred when the geometry allows.

Can a cemented crown be removed if needed?

Sometimes, with specialised instruments, but often it must be cut off and remade. This lack of retrievability is the main practical drawback of cementation.

Does the choice affect how long the implant lasts?

The implant's longevity depends far more on bone quality, gum health, bite forces and maintenance than on the retention method. Retrievability does, however, make managing problems around the implant more straightforward if they arise.

If you are planning implant treatment, the restoration type is worth discussing at the planning stage, since implant position determines which options remain available later.

You can contact our team at our Wimpole Street practice, or read about dental implants and dental crowns.

This article provides general information about implant crown retention and does not constitute individual dental advice. Which method is appropriate depends on implant position and angulation, soft tissue depth, aesthetic demands and maintenance considerations, all of which require clinical assessment. Wimpole Dental is regulated by the Care Quality Commission, and our clinicians are registered with the General Dental Council.

Next review due: 18 September 2027