The pulp becomes necrotic because of tooth trauma or tooth decay, and the tooth will appear greyish-black. Endodontic treatment must be done to treat the discoloured tooth which has pulp necrosis. If teeth still appear greyish-black, dentist can treat the discolored teeth by bleaching , laminate veneer or crown .
Reasoning, as a way of proving arguments, comes in many different forms. Different forms of reasoning are accepted in different fields and contexts. Arguing with family members generally relies on different methods of reasoning than arguing with professors.
Logic (from the Greek logos, which has a variety of meanings including word, thought, idea, argument, account, reason or principle) is the study of reasoning, or the study of the principles and criteria of valid inference and demonstration.