My crown lengthening took 1 visit, 1 hour. 2 follow ups, 5 minutes each. If crown buildup is the same as crown lengthening, sounds like your wife got scammed. I was quoted the price over the phone before my first appointment, @ $650 of which I got @ $425 back. They also told me what to expect with the 1 visit and 2 follow ups and never deviated from what they told me on the initial call.