PLLC= is a Professional Limited Liability Company. Which is a LLC that
provides professional services. Doctors, Lawyers, Accountants etc..
fall under professionals and are stuck with a higher tax liability for
being professionals. Hence the added "P" which is a requirement in some
states. Regardless of whether you have the "P" or not the taxes follow
certain rules applicable to professional entities. The limited
liability blocks claims against personnal assets of the company's
owners in the event that malpractice insurance coverage is not
sufficient for the claim. The professional also implies that the
individual must be at least 51% owner of the company.
Currently there is no regulation preventing professionals including
dentists from operationg as professional business trust organizations
(having at least 51% of the benificial interest) and since this type of
entity is not very popular it is considered to be in the grey area of
the law and open to state board scrutiny.