Occasionally a tooth may have a defect or cavity that is too large to fix with a standard filling, and too small for a crown to be indicated. In this scenario, an inlay or onlay may be a good option. Inlays and Onlays are similar to a crown in that they are fabricated outside the mouth by either CAD/CAM technology or in a dental lab, and therefore typically take 2 visits to complete, but are a conservative way to treat a tooth in situations that apply.