Can repair be done to chipped/decayed teeth at the gum line? (photos)

No Need for shame--these are cavities from the heavy sugar exposure--like many kids and some adults do--most likely it will be a simple repair--a good cosmetic dentist can make your teeth look perfect again--typically this is not a big expense like crowns or root canals or implants --$2-300 each. Congratulations and good luck! Your pretty and confident smile will return. 

Without an x-ray of the tooth and some vitality testing there really is no way to tell.If all looks ok then the fix would be a simple filling and relatively inexpensive however, if the cavity has gone into the nerve or there is not enough tooth structure to support a filling then you may need a crown or possibly a root canal as well.