Your wood floor may be in excellent condition as long as you take good care of it. In most cases, after sanding, the floor can stay in great condition for about 5-7 years. But, it depends on the room type, what's the finishing, and do you use carpet. Sometimes, it's good to make seasonal maintenance for scratch removal, polishing, or something else.
If you're interested in taking care of your floor, we can advise you after the job is done.