I like to use no more than 11% Carbamide Peroxide. I don't remember how
much H2O2 this ends up being... We still have a few kits made by
American Dental Hygienics, and I like them because the stuff is very
viscous. I don't know if that company is still in buisness.

How to make a locking tray:

You take good and accurate impressions of the teeth and gums. Pour them
up in a hard stone, not plaster. Then, you take a 1/2 size round bur on
the high-speed drill and trace around the buccal gum line making a score
exactly where the gum line is. This 'trough' should be at least the same
depth as the diameter of the bur. Next, you take a extra-fine red
permanent felt tipped marker (Ex: Stadtler) and trace in this trough,
all the way around the buccal, to make it visible. Now, take a
laboratory composite and paint a composite bubble onto the middle 1/2 of
each tooth surface that you want to bleach. This bubble will create a
reservoir of material in the tray. Ignore the molars.

Now, put this on the vaccuform and pull down a tray acetate or send the
model to your lab to have them make the tray.  Carefully liberate the
tray by cutting the excess away from beneath the trough area. (Don't cut
away the trough area; leave it in the tray.) Now look closely  at the
internal side of the tray: you'll see an indented line that traces the
gum line all around on the buccal side. If you don't see that
indentation, do another acetate, and this time, heat it up some more to
make it really hot and soft. The idea is that the hot acetate must mold
into that trough. NOW, LET IT COOL COMPLETELY. Now, put on your
magnifying glasses and carefully cut the excess tray material away,
leaving about a one millimeter extension outside the trough. This
trough/indentation is what seals the material into the pocket and keeps
it on the tooth surface, not allowing it to leak onto the gums.
Therefore, don't cut it away when you trim the excess material away from
the tray. Pull the excess acetate material DOWNWARDS and not outwards.

Use a viscous bleaching material to keep leaking to a minimum.

Re, sensitivity: Have your hygienist do a NEUTRAL fluoride treatment for
a couple of minutes. DON'T use acidulated fluoride. If sensitivity
persists, apply Duraflour or other paste type fluoride balm.

????? But, really, Jochen, I'm confused: Aren't you a HealOzone user? I
was told that the HealOzone can relieve sensitivities in teeth after
only a few second's exposure. Is this not true?

Further, I was also told that the HealOzone can bleach teeth after a few
more seconds' worth of exposure. In fact, they said that you can bleach
and soothe sensitive teeth all at the same time.

Again, I'm interested in knowing whether this is true or not.
Choos
SP