Screw-retained vs. Cement-retained Prosthetics on Implants

The decision between a screw-retained and a cement-retained restoration depends on the patient's anatomy, esthetic zone, and treatment plan – not on habit. Below, we've gathered data from laboratory practice that will help you make an informed decision.

How the two systems differ

Screw-retained restorations are secured with a screw passing through the crown or abutment directly into the implant. Cement-retained restorations are seated on an abutment with cement – analogous to crowns on natural teeth.

Both systems have over 30 years of clinical documentation. The choice depends on the specific case's conditions.

Screw-retained restorations – indications and limitations

Indications for screw-retained restorations:

• Patient with limited hygiene – the restoration is removable, allowing for cleaning
• Multi-implant restorations – screws allow for precise fit
• Need for revision – full reversibility
• Implant in a correct axis – the screw access channel can be masked with composite

Limitations:

• Screw access channel visible with unfavorable implant axis (above 15°)
• Risk of screw loosening (first 6 months – recommended check-up)
• Higher laboratory requirements for fitting

Cement-retained restorations – indications and limitations

Indications for cement-retained restorations:

• Esthetic zone with unfavorable implant axis – no visible channel
• Single implants in patients with good hygiene
• Cases where screw placement is technologically difficult

Limitations:

• Cannot be removed without destroying the restoration
• Risk of leaving excess cement subgingivally – the main cause of peri-implantitis with cementation
• Requires perfect cementation technique (light-body cement, marginal control)

Detailed comparison

Feature	Screw-retained	Cement-retained
Reversibility	Full	None / Destruction
Esthetics with unfavorable axis	Screw channel visible	No channel
Risk of peri-implantitis	Low	Elevated (excess cement)
Hygiene	Possible after removal	Standard
Laboratory realization	Higher requirements	Simpler execution
Resistance to loosening	Controlled (Ncm value)	No parameter

How to choose in a specific case

Esthetic zone with unfavorable implant axis → cement-retained (abutment masks the axis).

Esthetic zone with favorable axis → screw-retained (composite masks the channel).

Multiple implants or a bridge → screw-retained (precision of fit).

Patient with hygiene difficulties → screw-retained (removable).

Single implant, good hygiene, esthetics secondary → both systems work.

Clinical errors and how to avoid them

Excess cement subgingivally – the most common error in cementation. Any excess below the gingival margin is a potential source of inflammation. Use light-body cement and probe the margin after seating.

Screw loosening without check-up – 2-4 weeks after seating a screw-retained restoration, a torque check is recommended. Manufacturer-recommended values: 15–35 Ncm for abutments, 10–15 Ncm for crown screws (vary by system – check manufacturer's instructions).

Incorrect system decision – changing systems after seating is costly. The screw-retained/cement-retained decision should be made before implant planning, not after exposure.

Can the system be changed after the restoration is seated?

For screw-retained restorations, yes, after unscrewing. For cement-retained, changing requires destroying the restoration and usually replacing the abutment.

Which system is more durable long-term?

Both methods have comparable results in 10-year observations with correct execution and proper case selection (Journal of Prosthetic Dentistry, meta-analyses of implant systems).

Does permanent cement dissolve?

Cement designed for permanent seating (e.g., RMGIC, zinc phosphate cement) does not dissolve under normal conditions. Temporary deformation is possible with excessive occlusal forces.