What is the best way to fix the dent at the tip of my nose? (photos)

Your picture is not that clear. I cannot see the extent of the depression. Conceptually, yes you can have a depression corrected with a filler. You would really be best served with a face to face consultation. This would allow for the palpation of the skin and a direct examination of the depression. A good depends on the cause of the depression. You would also need to balance out if if want a permanent improvement. Hope this helps!
Sincerely,
Michael Kulick MD
ASAPS, ASPS member
San Francisco Ca.

You did not say what caused the 'dent" but it appears to be something that could be treated well with a filler. Make sure you see a plastic surgeon who is experienced in rhinoplasty (nasal surgery) as well as fillers.