Is it possible to repair a dent on an aluminium frame? I have Centurion Cyclo Cross 4000 bike. Recently I got into an accident with a car door. As a result I have a significant dent on my frame(see the photos below).

I have two questions:


Is it possible to repair the frame? 
Is it safe to ride the bike after this?
In the near term it's reasonably safe -- the dent is not sufficiently deep to seriously weaken the tube (though one does need to be concerned about the integrity of the welds on the rest of the bike, given it's been in an accident).  In the far term (10s of thousands of miles) there's danger that the tube will fatigue and become weakened at the dent.  (The thing to watch out for is growing cracks in the paint around the dent, or at frame joints, though some paints will hide cracks more than others.)

As to repair, about the only thing I can think of is to have an experienced frame builder cut out the section and weld in a new one, or fashion some sort of sleeve over the dent.  But those solutions would also be subject to long-term fatigue issues.