I went to him shortly after moving to DC from NY.
He seemed ok at first, albeit extremely young looking,but unfortunately he was working in the office of a horrible dentist (dr. seiden (sp?)) who advised him to drop me as a patient because I was 10 min. late to an appt. (I kid you not -- there was nothing more cited than that) I have great dental insurance and it was only my 2nd visit so there wasn't even time to build up some kind of bad rapport with the office.
Dr. Ellis at first seemd embarrassed and said of course he would treat me (I was having a lot of dental problems and didn't want to have to find another dentist at spur of the moment)
But when I called later the extremely disgusting Dr. Seiden got on the phone and literally SCREAMED at me and said they wouldn't see me ... absolutely no sane reason was given.
of course, they did me a favor b/c why would i want to go there after this treatment? but it also is very confusing, hurtful, etc.
I would stay far away.
out of 
