Q. I am currently undertaking home whitening with bleach supplied by the denist in tailor made dental trays. 1 hour a day. How long after treatment should I avoid ingesting food/drink with staining potential. Any further during and aftercare advice would be greatly appreciated. I have post operative hypthyroidism and hypoparathyroidisim for which I am on total replacement thyroxin and Sandocal (effervescent calcium) and one alpha to maintain my calcium levels. I am an ex nurse and just thought I’d run this by you though I don’t think my condition would have an adverse or corrosive effect when teeth whitening as I can’t maintain serum calcium levels due to no parathyroid hormone. So can’t extract calcium from bone when needed have to absorp for GI tract to maintain levels. Love my teeth and as just enhancing them as hit 40 want to be sure I am not damaging them. Any advice appreciated. Know I am rare but thought I’d just ask incase you’d encountered anyone like me (a consequence of surgical error). Thanks,