Cement Retained Restoration

Cement-retained implant-supported prosthesis are very similar to traditional cemented restorations on natural teeth. In some cases, this type of restoration is essential to ensure a suitable esthetic result, especially in the anterior region with an implant axis on the buccal surface. It should be noted that a minimum height of 6 mm between the implant head and the opposite occlusal surface is required for the restoration to be built up correctly. Cement-retained implant-supported restorations are suitable for simple situations (single implants) and more complex ones (partial or full bridges on implants). Another advantage of this type of restoration is that it is not necessary to position the implant with a high degree of precision to achieve a successful result. By using an abutment, a diverging implant axis can be accomodated.

Unless temporary cement is used, the main disadvantage of this cement-retained restoration is that it is difficult to remove it. The prosthesis may have to be cut away to regain access to the abutment again, which is not the case with screw-retained restorations. The range of restorative materials that can be used for such prostheses is extensive: from full gold to porcelain fused to metal to ceramic.

In this procedure, the crown is cemented to a natural tooth as any other conventional restoration cemented onto a natural tooth, after the abutment is installed on the patient's implant. To avoid cement flares in the sulcus, it is recommended to use a temporary luting cement applied with a brush on the inside of the prosthesis. Excess cement should be avoided to prevent the resorption phenomena at the implant neck described in the literature.

Adjusting the proximal and occlusal contacts may take more time. Usually, no temporary restoration is fabricated and the adjacent teeth may have moved during the interim phase of impression taking and placement.

In addition, the occlusal contact must be very light and just outside the occlusion. Unlike dental implants, the periodontal ligament of the remaining natural teeth allows them to superficially sink into their bone sockets during masticatory movements. It is therefore recommended that only occlusal contact is made directly on the implant.