Thank you for writing.
The scheduler should automatically reflect the any changes. Also better place to update the database will be the CollectionChanged event of the Appointments collection. Or you can use any other suitable for your case event.
However if you want to you can subscribe to the EditRecurrenceDialog.Closed event and update your database there. I have prepared a small sample where you can see how you can subscribe to this event and how to replace the default form with the custom one.
Do not hesitate to contact us if you have other questions.