Firstly have you had a look on the NHS website to see which practices are accepting patients? You may want to ring your local NHS Trust and talk to them regarding dental patients, they'll be able to tell you which ones are good or not plus their individual "preferences."
I initially registered at the Dentist in my village when I moved over, got charged £25 just for a 5 minute check and was told come back in a year. Went back they'd changed hands and were claiming to be taking on NHS patients, but in fact weren't and booked me in, I got into the dentists seat and was told (after dentist had me open my mouth) that I would be charged as a private patient. Told them where to get off (not before said dentist told me I needed x, y & z doing in a whole 5 second looksie).

Called my local NHS trust and got a list of a couple practices, one of which being about a 10 minute drive from home (and told that they were really really good and I could've had a next day appointment when I first called them up!). I love my dental practice (I've been with them now for a year and a half). I've never had a clean while being here in the UK, except for a spot clean on a couple teeth because I had a specific issue that I asked them to sort, which the Dentist did himself. DH & my dentists are in the same village, however separate practices and our appointments are supposed to be in the same month, so we try and book appointments on the same day if possible. (I tried to get into the same practice as DH, but its fully booked & not accepting new NHS or otherwise or having a waiting list.)
Good luck Jewlz! By any chance have you looked into going closer to your work, if the trust will allow it if you're wanting to go NHS?