Dentist left part of my tooth exposed with new crown, are they responsible to replace it?

If you replace those old posts and crowns we need to check how is the condition of the bone/teeth underneath. Dental implant are an option, an other option is to make a new bridge from canine to canine, but, it means that we would have to grind both canines and the bridge would be a bit longer....

Although for an accurate answer a clinical and radiographic analysis would be necessary, from what you tell us, there is presence of plaque and possibly periodontal disease. So the first step in this patient would be to achieve a healthy periodontal tissue and after that analyze if it is...

A crown would be a better solutıon because may take up to 20 years, however your teeth must to be prepared (shaved),in your case wont be a problem since your tooth is already broken. The bonding is a cheaper procedure and can take up to 10 years, however the color change and can chip easily.