Some things never change even after nearly 20 years as a man caught posing as a dentist here back in 1994 has been arrested again on the same charge in Columbia.The suspect, Michael Richardson, 54, and his wife, Lana Richardson, 51, were arrested recently at their business, Amazing Smiles, in Columbia. They are charged with impersonating a licensed professional.Their charges come after an undercover agent discovered Richardson was portraying himself as a licensed dentist as part of his practice. When officers served a search warrant on their business, police say they encountered customers who wrongly believed they were being serviced by a dentist.