Share Hub — Methods and Techniques to Prevent Residual Cement in Cement-Retained Crowns
To prevent cement remnants from remaining around cemented crowns, various methods and techniques have been proposed:
∆ First
Using a subgingival cord below the finishing line of the abutment, so that after cementation, by removing it, we can be sure the cement has escaped.
It is worth considering as an option, but in practical terms it has many limitations.
∆ Second
Where possible, using a rubber dam, so that during cementation of the restoration, the abutment-and-crown assembly is isolated from the oral environment.
∆ Third
Using a silicone replica. The silicone replica, or silicone die, is made by placing putty inside the implant crown; before cementing the implant crown in the mouth, the crown is seated on this silicone die so that the excess cement is expressed.
∆ Fourth
Using a vent on the crown, so that the escape of cement through this vent on the occlusal surface is further assisted
∆ Fifth
A very effective solution is using a limited, measured volume of cement, so that there is essentially no excess cement, or it is very minimal. The suggested volume in crowns is approximately 3 to 5 percent of the internal volume of the crown. This amount of cement is placed only on the lateral walls of the crown using a brush or an explorer.
∆ Sixth
Before cementation, when covering the screw head and filling the inside of the abutment with Teflon, only a limited coverage of the screw head is used, so that the cavity inside the abutment remains empty. In fact, this empty space will be a place for any potential excess cement to collect.
∆ Seventh
Using screw-cemented–type restorations, so that after cementation the crown can be removed and the excess cement cleaned. Interestingly, in these crowns, usually very limited excess cement is observed below the gingiva, the reason being that the screw access hole functions as a vent.