Your teeth need to be properly assessed to decide which aresavable and which need to be removed.  Once this is done you have 4 options:
1. do nothing – not a great option usually
2. Have a denture – can often produce a good result but the appliance is obvious to your tongue and is removable
3. provided there are enough teeth present and they are healthy with good bone support bridges are possible
4. Implants are the final solution – implant bridges are often used rather than individual implants to replace each tooth.