of the abrasive material for a given
number of revolutions, and the weight loss of the screen measured. The
higher the loss, the more abrasive the particles used in the slurry. Three
of Specialty Minerals Inc. (SMI) calcium carbonates were tested by this
method with the following results:
The larger, ground carbonate resulted in the largest metal loss, while the
fine particle-sized PCC showed the least.
When formulating a toothpaste with calcium carbonate as the abrasive, the
strongest cleaning action will result when using a GCC. For products for
everyday use, a GCC or a larger-particled PCC is fine.
Some dentifrices are designed for bridgework, dentures and other forms of
artificial teeth which are made from polymers much softer than natural
tooth enamel. If a highly abrasive material like silica is used on these
synthetic teeth, then they can be worn away too quickly. Here, a
smaller-particled PCC would be necessary. The same is true for toothpastes
for people with sensitive teeth. Abrasion of the remaining tooth enamel
must be minimized, so a small PCC would be the best choice.
Specialty Minerals Calcium Carbonates for Toothpastes
* Mildest abrasion applications: ViCALity Albafil® PCC, a 0.7
micron-sized PCC, will be the mildest, yet effective abrasive. ViCALity
Albaglos® PCC, a mixture of 85 percent ViCALity Albafil® PCC and 15 percent
3-micron ViCALity® Heavy PCC, will be slightly more abrasive because of the
presence of the larger particle in the blend. The small particle size, and
resulting higher surface areas, will provide body or thicken the toothpaste
formulation potentially reducing the amount of more expensive thickeners.
* Moderate abrasion applications: We recommend ViCALity® Heavy (3
microns) or Extra Heavy (4.5 microns) PCCs made in the U.S. or Sturcal L
PCC (6 microns) made in the U.K.
* Moderate abrasion with thickening: The ViCALity® Extra Light,
Calopake® Extra Light, and Sturcal F and H PCC products have needle
shaped, open structures which result in higher surface areas. With particle
sizes ranging from 2 to 4 microns, they function effectively as moderate
abrasives and the high surface areas will add thickening. The chart below
shows an example of viscosities achieved in slurries of ViCALity® Extra
Light PCC:
Calcium Carbonate: The Moderate to Mild Abrasive
The abrasivity of a mineral particle depends on two factorsits particle
size and the basic hardness of the mineral.
Within a given mineral type, the smaller a particle, the less abrasive it
will be; the larger, the more abrasive. Calcium carbonates used in various
toothpastes range from 0.7 to 10 microns with the grade chosen partially
depending on the degree of abrasiveness desired for the product.
The basic abrasivity of a mineral can be indicated by giving its Mohs
Hardness number. The Mohs Hardness Scale runs from 1 to 10. The hardness of
talc, the softest mineral, is defined as 1. The hardness of a diamond, the
hardest mineral, is defined as 10.
Moderately high abrasion applications: Food grade Vicron® ground
limestones such as 25-11 (5.5 microns) or 41-8 (8 microns) grades are
typically used. These GCCs are a bit larger than the PCCs and a bit harder.
They are excellent in opaque toothpastes for the general population.
As you can see from the graph, it is not a linear scale, but more
exponential. Therefore, a mineral with a hardness of 6 is not twice as
abrasive as a mineral with a hardness of 3, but is about 8 times as hard.
Calcite is the pure mineral form of calcium carbonate. While the pure
mineral itself has a Mohs Hardness of 3, the limestone rocks in which it is
found also contain some quartz, or silica, giving ground limestones or GCCs
Mohs values around 4. PCCs have silica removed during manufacturing, so its
Mohs value is closer to 3. For comparison, silica has a Mohs value of 6.
Calcium carbonates are considered moderately abrasive, less abrasive than
precipitated silicas, but abrasive enough to provide good cleaning.
At 04:05 PM 6/18/2010 -0700, you wrote:
What is a good source of calcium carbonate for teeth? I use oyster shell
flour in the garden - that is 95% calcium carbonate. I am not sure I want
to brush my teeth with it.
Gayla
- Original Message - From: Norton, Steve stephen.nor...@ngc.com
To: silver-list@eskimo.com
Sent: Friday, June 18, 2010 8:17 AM
Subject: RE: CStooth remedy
Here is the comment by Bodhi:
Fluoride does nothing for sensitivity, most likely it would be something
like the calcium carbonate or something else in the paste filling the
vestibiles. The way to correct this is easy, mix calcium carbonate and
arginine, brush with it once a month to fill the vestibiles.
Sensitivity will be virtually corrected in a single dosage of that - at
least for a few weeks. As a former dental technician, I can tell you this
works in 99% of the cases, and the cost is slight. I haven't used
fluoride
