Implant is the best treatment modality to replace missing teeth. They generally last life long.

They last long if you don't have systemic problem then go ahead with it

There won't be any warranty for any treatment. Longevity of any treatment depends on multiple factors. For your age the neighbouring teeth will also be worn out .so bridge system of tooth replace ment will be better as the neighbouring teeth will also be capped. If you don't want to disturb the neighbouring teeth then go for implants.

Implants are always a good option, as they doesn't require to grind the adjacent teeth, where as fixed teeth or a bridge require support from adjcent  teeth and also in future if adjecent teeth are mobile entire bridge needs to be removed and a new one has to be fabricated. implants are little expensive but good option. There are lot of varieties, visit a prosthodontist for detailed explanation