Full Circle Back to Screw Retained Implant Crowns

Last week at the Seattle Study Club Symposium I was talking with a group of the other presenters and we were all remarking how implant restorations have come full circle back to screw retained. It is funny if you think about the fact that in the early years everything we did was screw retained. Then over the years the pendulum swung to people doing almost exclusively cement retained. Now we have the option to choose between these two alternatives and the pendulum is swinging back as we realize that a large number of implant failures are due to cement that was left behind. As with anything in dentistry there are risks and benefits of each option. One of the primary things to realize is that this is a treatment planning decision and needs to be discussed ahead of time between the restoring dentist and the surgeon. The position of the implant is a key factor in choosing between screw retained and cement retained. In a screw retained restoration, especially in the anterior the screw access has to be placed in a position where it does not compromise esthetics and allows for adequate thickness of the restorative materials to avoid premature fracture. In the posterior I have moved back to screw retained primarily, and only utilize cement retained in select situations driven by esthetics or mesial to distal space concerns. In the anterior often the overriding factor is implant placement and management of the facial free gingival margin, which can be easier to manipulate with a cement retained restoration. If utilizing a cement retained restoration it is imperative to clean all of the excess cement.

Screw Retained Implant Crowns

Advantages:

• Ability to be used with limited inter-occlusal distance
• Absence of cement under the gingival tissues as a potential irritant
• Predictable retention
• Retrievability

Disadvantages:

• Screw access compromise of occlusal function
• Esthetics of access hole

Cement Retained Implant Crowns

Advantages:

• Passive Fit of the Implant Crown
• Esthetics
• Ideal occlusal form
• Flexibility of fixture placement

Disadvantages:

• Subgingival Cement Line
• Cleaning of Excess Cement
• Crown Retention