Can roots of a tooth fuse to the bone?

I've been told recently that statistics say after the age of 26, the probability of being able to retrieve an impacted tooth such as the "I tooth" and pull it into place are very slim. The tooth has moved considerably and has maybe 5mm left from the front of the mouth. Just an educated guess, does this sound like the roots of the tooth have fused to the bone or a hopeful case?