A patient is on hemodialysis every Monday and Thursday. On which day is it best to schedule dental treatment?

Dental treatment is best scheduled on the day AFTER a dialysis session, when the patient's fluid/electrolyte balance has been freshly optimized and any heparin used during dialysis (which has a short half-life) has worn off, reducing bleeding risk — for a Monday/Thursday dialysis schedule, that would be Friday (the day after Thursday's session).