I went to a dentist here in Deltebre, no English spoken, 50.00€ for filling. Same price as the one in Tortosa near Lidl without the bother of Driving to Torosa.  I also had a boken crown replaced here about three years ago with another dentist.  They said they could not say how long it would stay in place...it's still there.
Dentistry here is generally superior to that of the N.H.S.