Method and device for measuring dentin permeability

1. A method of visually recording the hydraulic conductance of a dentin section, comprising:

a) preparing a dentin section;

b) providing a test cell having a bottom component with an inner chamber;

c) providing a washer having a washer first surface and a washer second surface;

d) applying adhesive to washer first surface and washer second surface;

e) contacting adhesive and washer first surface with the bottom component;

f) positioning at least a portion of the dentin section on the adhesive and washer second surface;

g) providing a fluid under pressure to the inner chamber of the bottom component; and

h) visually recording hydraulic conductance of fluid through the dentin section, by visually recording images of liquid droplets coalescing on the dentin section surface;

i) distinguishing individual droplets from the dentin surface using at least one of reflective lighting or magnification;

wherein the washer forms a liquid-tight seal between the bottom component and dentin section establishing fluid communication between the bottom component and denting section.

2. A method of visually comparing the effect of two or more oral care compositions on the hydraulic conductance of dentin sections, comprising:

a) preparing a first dentin section;

b) providing a test cell having a bottom component with an inner chamber;

c) providing a washer having a washer first surface and a washer second surface;

d) applying adhesive to washer first surface and washer second surface;

e) contacting adhesive and washer first surface with the bottom component;

f) positioning at least a portion of the first dentin section on the adhesive and washer second surface,

g) providing a fluid under pressure to the inner chamber of the bottom component;

h) treating at least a portion of the first dentin section with a first oral care composition;

i) visually recording hydraulic conductance of fluid through the first dentin section, by visually recording images of liquid droplets coalescing on the dentin section surface;

j) distinguishing individual droplets from the dentin surface using at least one of reflective lighting or magnification;

k) preparing a second dentin section;

l) providing a test cell having a bottom component with an inner chamber;

m) providing a washer having a washer first surface and a washer second surface;

n) applying adhesive to washer first surface and washer second surface;

o) contacting adhesive and washer first surface with the bottom component;

p) positioning at least a portion of the second dentin section on the adhesive and washer second surface;

q) providing a fluid under pressure to the inner chamber of the bottom component;

r) treating at least a portion of the second dentin section with a second oral care composition;

s) visually recording hydraulic conductance of fluid through the second dentin section, by visually recording images of liquid droplets coalescing on the dentin section surface;

i) distinguishing individual droplets from the dentin surface using at least one of reflective lighting or magnification;

t) comparing the visually recorded hydraulic conductance of the denting section treated with the first oral care composition and the second dentin section treated with the second oral care composition

wherein the washer forms a liquid-tight seal between the bottom component and dentin section establishing fluid communication between the bottom component and denting section.

3. The method of claim 2 , wherein a camera is used to visually record hydraulic conductance.

4. The method of claim 3 , wherein the camera visually records hydraulic conductance of fluid through the first dentin section and second dentin section.

5. The method of claim 4 , wherein the images captured by the camera during recording hydraulic conductance of fluid through the first and second dentin section are cropped to enable side-by-side comparisons.