[otab111]

It's tough to imagine finding qualified employees who will tolerate a split shift like that, or who want to only work part time and take one shift or the other. So the dental practice would, almost by definition, be made up largely employees who couldn't secure employment in a business with traditional working hours - maybe even making it the least skilled dental practice in the area. In order to attract workers who can work at 9-5 dental practices, you'd have to pay more than those businesses, given the awkward opening hours. And then you'd hope you got enough patients out of the shift in hours to make some extra money. But a little extra money wouldn't be enough to go through all the trouble... there's no point opening weird hours and then doing "about as well as other dentists" because the weird hours introduce various overhead. So you have to somehow figure out how much more profitable the weird-hours business needs to be in order to deliver a profit that's significantly more than a traditional dentist. And if that profit difference is worth the extra hassle (in its various forms) to you as the owner of the business, sure go ahead.