I would think that 23% is too high perhaps 23% of respondents? If the line in the sand is 20 dentists, there aren't many laboratories that can handle that kind of volume. You would need the technicians and the space to support the customer and you would face constant pricing pressures. Large practices aren't interested in relationships and cost is paramount buying power is why they became a large practice in the first place. Labs and other vendors would be hammered on price and the balance of power shifts heavily to the dentist. To me, it only makes sense for a lab to do work for a large group practice if they are built to compete on price and have capacity. They also need to be able to react quickly and absorb the loss when the practice eventually leaves. It also de-values a business to have a single customer be a large percentage of the revenue.