There are two schools of thought about dentin adhesive when seating indirect restorations. One school of thought treats the technique much like a direct resin and places and cures the dentin adhesive prior to placing the final restoration. The other group leaves the dentin adhesive uncured until after the restoration is placed and the resin cement is in place. Most manufacturers recommend curing the dentin adhesive layer, so why did the other technique develop?
All dentin adhesives have a film thickness when cured, and in some of the fourth generation total etch systems even with air drying the resin and thinning it is a significant thickness. The technique came about of leaving the dentin adhesive uncured until after placement of the restoration to avoid open margins and a resin interface that was larger and could stain and break down more easily. Many of today’s dentin adhesives have much lower film thicknesses, however even with air drying and thinning a small amount of pooling could create an open margin. Unless you know the film thickness of the particular material you are using, and are willing to confirm this if you decide to switch dentin adhesives it is most predictable to leave the material uncured. In this technique you are now depending on the penetration of light all the way to the dentin adhesive layer for adequate curing.
In posterior restorations such as inlays and onlays light penetration to the depth of the restoration can be a concern so utilizing a dual cure resin cement system will be required. One note is that when you utilize a dual cure resin cement you either need to make sure that the dentin adhesive system is compatible.