How to get rid of stomach dent from liposuction? (Photo)

You are encouraged to consult a board certified plastic surgeon. That being said, this may be corrected using high defintion VASER liposuction. The definitive correction for liposuction deformities requires the advanced technology of ultrasound assisted VASER liposuction. As an official trainer of VASER liposuction, I encounter suboptimal liposuction outcome referrals weekly. VASER liposuction has been the only modality that has consistently corrected liposuction caused deformities. VASER liposuction ensures a smooth contour regardless of severity of contour irregularities by virtue of being able to remove any and all remaining fat comprehensively and uniformly. Finally, when skin redundancy irregularities are observed, Renuvion technology can be simultaneously applied to tighten your skin to optimize your overall contour outcome. A Skype or FaceTime consultation with a VASER specialist will help you get an accurate recommendation and pricing. 
Respectfully, 
Arian Mowlavi MD, FACS
Realself 100 Hall of Fame Inductee

Correcting poor outcome from previous Liposuction can be difficult especially if someone has been over treated.
I’m curious if your previous provider intended to do etching or create six pack definition?  The indentation may have been done on purpose to mimic one of the Hemi-inscription  lines for muscle definition. 
If that’s the case it may be much more difficult to improve the contour.
Treatment options generally come down to revision Liposuction, fat transfer or converting your procedure to a skin tightening procedure such as a full tummy tuck.
All of the treatments are limited in what they can deliver but usually some improvements can be had.
Which of these options should be employed will absolutely require an in person consultation.
In someways revision Liposuction is pouring gasoline on the fire. Fat transfer may seem appealing but often fail because because over treated areas now lack host tissue to support that graft.
In your case converting this to a full tummy tech probably doesn’t make sense.
I suggest having a few in person consultations with experienced local board-certified plastic surgeons who have a solid track record of doing high-quality liposuction and fat transfer work.
Best, 
Mats Hagstrom MD