Sam Mellor, from Bedminster, said he arrived outside the practice after 07:00 and managed to get to the reception shortly after 11:00.
Having spoken to frustrated patients who had just paid the £69 for the hygienist, Mr Mellor said he asked the receptionist if this was in fact the case.
He said that she responded by telling him if he wanted to be registered as an NHS patient, he needed to book a hygienist appointment.
She advised that he could pay for it at a later date, before the appointment, but that he would have to book it and would not be registered as an NHS patient until he had paid.
Mr Mellor said he paid for the appointment and subsequently complained in an email about the service offered and being forced to sign up to the hygienist.
Lodge Causeway Dental Practice replied to Mr Mellor in an email seen by the BBC, claiming that the hygienist’s appointment was “just an offer”.
But Mr Mellor insists this was not the case for him and many others, describing it as an “ultimatum”.