There are two major approaches when cleaning resin cement as part of seating indirect all ceramic restorations. Each method has pros and cons and places where we can introduce challenges or encounter issues. As a foundation to bonding restorations we etch the tooth and apply a dentin adhesive. Despite the fact that many of our new dentin adhesives have very low values for film thickness I am still hesitant to cure prior to placing the restoration. Leaving the dentin adhesive uncured reduces the surface tension and increases the ability of the resin cement to flow when seated. It also eliminates the possibility of the thickness of the dentin adhesive preventing the restoration from seating and a resulting wide resin interface.
Once we have the restoration in place we can either clean all of the excess cement prior to any curing or we can tack cure and then begin to clean the excess away. If you chose to leave the resin uncured clean the excess away always wiping from the porcelain to the tooth structure and never int he reverse direction. Moving from the tooth onto the restoration can pull cement out of the margin leaving it open. Alternatively you can clean along the margin interface, parallel to it. There are many ways to clean the excess from a rubber tip stimulator to micro-brushes. The interproximal spaces need to be flossed, pulling down toward the papilla and out the facial, careful not to initiate bleeding. Alternatively you can isolate the tooth interproximally using plumbers tape or matrices. Finally all of the margins must be covered with an oxygen barrier like de-ox or glycerin and then cured. The risk of this method is moving or displacing the restoration during the cleaning process. If the restoration gets lifted off and reseated you can introduce air and a void int he bonded interface.
Alternatively, you can seat the restoration and tack sure to create a gel phase prior to cleaning the cement. In this method using a tack tip and closely following the recommended time you cure at the beginning of the process. The resin is now in a gel phase and can be cleaned with an explorer or other hand instrument. Similarly, to the above the interproximal contacts ,must be protected or flossed avoiding injury to the tissue. The last step is again to cover all of the margins with an oxygen barrier. The risk of this approach is pulling partially cured resin cement and opening the margins. Another challenge is over curing the resin and moving beyond a gel phase which makes the clean up process laborious.