I am currently halfway through my invisalign process. I had IPR done in four different spots on my top teeth approximately 8 weeks ago. The gap between my front two teeth started to close but now I have a very visible black triangle. My front two teeth appear to meet at the bottom but there is a triangular gap on top. What caused the black triangle to appear and is there a chance that this black triangle will disappear? If not how can it be fixed?