Hello sir.. A properly built up post and core of the front teeth will last for fifteen years....The only thing is you need not to be bite in the front teeth....the crown will gets loosen as the years passes....as it gets loosen you need to re cement that crown by visiting nearby dentists

No prediction for life span of the treatment but if customized post is made and good crown is made it will go long. 3mm structure above gum line for customized post is good enough to give the support. A good treatment also needs good patient maintaince for long term prognosis. So keep in mind you have post and core with crown and prevent sudden bitting on hard food with front teeth and maintain hygiene then life of tooth will be long enough.