Stains between teeth after Invisalign

Based on what you've reported, its more likely that you are just having some slight accumulation liquids, food or debris in these areas that is causing the appearance of stains.  If you were my patient, I would highly suggest asking your dentist for whitening gel that you may add to your Invisalign trays each day for the next 2-3 weeks.  This gel will really help make your teeth whiter and brighter.  This is standard procedure in my office, so that my patients always love the whiteness of their teeth after Invislaign.  Good luck and I hope this helps. Follow me if you have more questions.Sarah Thompson, DMD

Would need to SEE what you describe, so be sure to ask at your next aligner appointment.  It is possible that the original alignment allowed some minor decalcification that could not be seen, and with the new positions they are more visible.  It could be "tartar" and scraped off by the dentist.  It is likely NOT a big deal and can be easily fixed when the case is done.