Hi Varsha, if your teeth are in good condition,even if 2-3 teeth are there they can be saved and only missing teeth can be replaced.however wether teeth can be saved or extracted will be decided after assessing your gums and bone surrounding the teeth.
Implant is always best compared to removable dentures. Before implants some tests are mandatory to get them done.
Next Steps
Visit specialist like Periodontist and Implantologist