To Compare Cemented Versus Screw-retained Implant-supported Single Crowns With Customized Zirconia Abutments

The final lithium disilicate crowns will be cemented with an adhesive cement after tightening the abutments with the torque indicated by the manufacturer and closing the screw access hole with white guttapercha. The abutment will be cleaned with ethanol. A retraction cord will be placed for cementation if indicated. The crown will be etched with hydrofluoric acid and subsequently silanized. A sufficient amount of cement will be filled in the crown without creating major excesses. When the crown is seated correctly, the cement will be light-cured for a few seconds to facilitate the removal of the now hard excess cement. \- Excess cement will be meticulously removed with a carbon scaler. The removal of all excess cement will be checked with an X-ray and by visual and tactile inspection.

The screw-retained crowns will be inserted and tightened with the torque indicated by the manufacturer. The screw access hole will to be closed with white guttapercha and a composite filling (Filtek, 3M ESPE).