What can I do till I see a dentist , I bought the dentek kit and was thinking of using the temp filling to seal the root but I didn't save the crown , would this be OK to do ?

Did the molar break because of decay? If there was a large cavity in it there could be an abscess. If you close the top off you could end up in +++pain. If the tooth isn't sensitive just keep the area clean, if it is, you could place a thin layer of the temporary material over it but get to the dentist ASAP.