Dr Knowlton was my dentist for several years. He was a competent dentist, but not much of a businessman. For years, he billed me for visits and was always paid promptly. Then he started instructing staff to call me before a visit, tell me how much the charges would be and telling me to bring the money. I was so irritated that I dumped him and went elsewhere. This is probably the reason he is no longer in business.