dentist here. Don’t remember if I ever learned a rate of dentin growth but I can’t give one off the top of my head. It isn’t fast but I’d have to say that it is quite variable. Usually on deep decay the dentist will place a layer of calcium hydroxide under the filling to stimulate dentin growth. It doesn’t always work but usually(in my 29 years experience)if it is going to work it takes 3 to 6 months. Sometimes the tooth lays down dentin fast enough that even though the cavity is deep, one never gets any sensation from it.
Without knowing more I’d say if you are tolerating the sensitivity give it more time as you have nothing to loose. If it is worsening it is probably a lost cause.
Not exactly an answer to you question but hope it helps.
“odontoblasts” are the cells that form the dentin, the process in dentinogenisis.