How long should my appliance last?
Gumshields/Mouthguards 3-6 months
What happens if the appliance doesn't fit?
If the appliance doesn't fit in most cases it will be because of the original impression.
Struggling to get an accurate impression due to patient gagging?
There are a couple of ways you can take a more accurate impression for patient with a high gag reflex.
The first would be to load the alginate/putty anteriorly ensuring there is enough to get sufficient sulcus depth, push up anteriorly and allow the alginate/putty to flow round the tray before pressing up posteriorly.
The next method is to use a lower tray for an upper impression. This is normally the most effective as it reduces the amount of putty in the palate.