After eating, if you make a habit of using your tongue to clean gums and teeth, no cold and hot cycle of drinks or food, and no hard biting, there will be no need to visit a dentist.
Focus of cleaning should be particularly front bottom row and upper middle and rear molars.
If you have cracked a tooth, and go yo the dentist, he or she would extract it. You can save the tooth by not using that side of the affected tooth and giving a rest. Avoid cold and hot drinks. Nature would heal it.
An old root canal tooth, may get get infected because of inflamation around the gum, where food particles get stuck. If you go to the dentist, he or she may ask you to extract the tooth. But by cleaning the infected gum, you may save the tooth. I have done it for 5 years though twice the dentist told me to do so.
If tooth pains, use clove and eucalyptus oil to reduce pain.
If gums are inflamed and swollen, use salt and olive or mustard oil mixture and apply as paste. The salt will suck the fluids and oil will act like a thin film of protective skin or gum layer. If gums bleed, use turmeric powder and rub it.