Third trip to dentist reveals progress

Almost a month to the date from the dental work, I still have a numb tongue and no feeling in the area of my mouth (the "valley") under the tongue and just below the toothline. The dentist repeats the procedure that he had done on two prior visits: using what I presume to be the dental scaler, or pick, he moves along the surface of my tongue and asks if I can feel anything. Later he uses a dry cloth and has me describe what I'm feeling. Afterwards, he says he's compared his analysis to the previous trips and says the feeling is returning, albeit slightly.