The Alphabet Blog: D is for Dentin

The Alphabet Blog: D is for Dentin

Dentin is the layer of tooth beneath the outer enamel layer and is important for a few reasons:

The color of dentin shows through the enamel and imparts color to the tooth.

In this photo, the dentin is the darker inner layer:

The next two pictures are great examples of what acid in plaque does as it works its way through the outer enamel into the dentin.  It turns the enamel frosty white, as acid does to glass, and turns the inner dentin dark brown. 

Dentin is flexible and helps prevent fracture of the brittle overlying enamel.

Dentin contains tubules that transmit painful stimuli like cold and sweet.  Are your teeth sensitive?  Blame it on the dentin.

Dentin allows faster spread of bacteria from the outside of the tooth to the inner nerve (pulp).

That’s dentin in a nutshell.

Love your smile,

Dr. Cook

The Floss Blog

Brushing cannot clean between your teeth, but bacteria certainly can live there quite happily, creating enamel-destroying acid 24/7.  Rinsing does not remove plaque anywhere, so flossing is a must.   Here is an x-ray of a cavity between teeth:


Dr. Cook

Sensitive teeth? Like hard bristles?

Last time I discussed correct brushing and showed a photo of the type of toothbrush abrasion dentists see all day. Here are before and after photos of toothbrush abrasion that was very sensitive and our restoration.



Last time I discussed correct brushing and showed a photo of the type of toothbrush abrasion dentists see all day. Here are before and after photos of toothbrush abrasion that was very sensitive and our restoration.



Brush gently in circles twice a day with the softest brush you can find.

-Dr. Cook

Brush up on brushing

By this time, toothbrushing is so mundane that you don’t know how you’re doing it or for how long, much less how effective your technique is. Maybe your only reasons for brushing are to freshen your breath and because you were told to do it ever since you can remember. Yes, we know that brushing helps prevent cavities.

Here’s the skinny on Safe, effective plaque removal:

    Use a soft or extra-soft-bristled brush
    Brush at least 2x a day: morning and night
    Angle the bristles 45 degrees so that they are directed into the gum line.
    If using a manual toothbrush, brush in a circular motion.
    If using an electric toothbrush, gently hold the moving bristles at the gum    

    Brush each quadrant of your mouth for 30seconds.
    Remember to brush the cheek side, tongue side and biting surfaces.
    Gums, cheeks, and tongue harbor bacteria; brush them, too.

Back-and-forth brushing results in heavy, irreversible wear of the tooth, forming grooves that are sensitive and decay easily.  These teeth have been abraded by back-and-forth scrubbing.

In my office, I give patients the tongue cleaner by Discus Dental to remove plaque that forms on the surface of the tongue, which is a reservoir of bacteria.  Try brushing your tongue with a toothbrush then using a tongue cleaner.  You won’t believe the amount of debris left behind by a toothbrush.

Brushing removes sticky, acidic plaque that cannot be rinsed away.

Best times to brush: first thing in the morning and right before bed.
Bacteria are present everywhere in the mouth constantly. They require simple sugar to proliferate. When we feed ourselves, we also feed them. They produce acidic plaque between meals.

Proper brushing begins with a soft or extra-soft toothbrush. Extra-soft toothbrushes are often marketed to people with sensitive teeth, but they’re good for everyone. Do not use a medium or hard bristled brush. I checked my local Safeway and was sad to see that Colgate, Reach, and Safeway brands all sell Medium bristled brushes. Shame on them!! Enamel may be the hardest substance in the body, but it certainly is not immune to abrasion or erosion.

Electric toothbrushes clean better than manual toothbrushes because there is more movement in the bristles.

Find a head that is small enough to reach the cheek side of your upper back teeth and the tongue side of your lower back teeth. Often, the jaw joint and tongue make it difficult to fit a toothbrush into those areas. These are areas that dental hygienists constantly find heavier plaque deposits, and where dentists often find cavities.

Brush twice and floss daily.

Dr. Cook

How Cavities Form

Cavities are holes in our teeth that are created by acid. The acid in our mouths is created by the bacteria that live in our mouths.  We are not born with oral bacteria;  we pick them up as soon as we are born.  Generally, mothers, because of their close contact with their babies, transmit their own oral bacteria to their babies.  One major strain that causes tooth decay is Streptococcus Mutans.  Once we contract them, we cannot get rid of them.

Oral bacteria require glucose to live.  We provide them plenty of glucose in the form of sugary foods and grain-based foods (simple carbohydrates).  Examples of foods that cause cavities are crackers, pretzels, bread, rice, pasta, and cereals.  Unlike healthy complex carbs in fruits and vegetables, simple carbs begin their breakdown in our mouths.  Oral amylase (an enzyme) in our saliva breaks grain-based carbohydrates into glucose, feeding our oral bacteria.  Bacteria eat the glucose, metabolize it, store some for later (like when we’re sleeping), and excrete the waste.  Bacterial waste is plaque.  Plaque is that creamy white coating that develops on our teeth (even between meals and after we brush).  Plaque is very sticky and very acidic.  Bacteria have evolved to live very happily in an acidic environment.  Plaque CANNOT be rinsed off.  It must be mechanically removed by brushing and flossing.

For more info, visit the Centers for Disease Control:


Dr. Amy Cook

Facts about Fluoride

Hello to a special population who take interest in and ownership of their own oral health.  To those in this world who trust the pure and beautiful thing that is science (ie, testing theories to confirm truth), I salute you!  For those who still fear or mistrust science, I wish you an open mind and the oral health benefits of fluoride that have been proven safe and effective only with the agonizing labor of scientific method over decades and thousands of studies.  Enjoy this:

*Water fluoridation is recognized as a major public health achievement of the 20th Century by the Centers for Disease Control and Prevention (CDC)

*Although dental caries (decay process)  is largely preventable, it remains the most common chronic disease of children ages 5-17 years.

*Studies have demonstrated that people in communities with fluoridated water have 20-40% less tooth decay than those without.  (above facts from the Washington State Dept of Health)

*Fluoride occurs naturally in the earth’s water and is the 13th most prevalent element in the earth’s crust. (US Dept of Health/Human Svcs.  Oral Health in America, 2000 p. 158)

*Enamel is dynamic, like bones.  It gains and loses minerals.  (Have you heard of bones losing density (ie osteoprosis)?   Fluoride, because of its chemical properties, remineralizes enamel to make it stronger.

*Fluoride taken internally via water, tablets, or drops, strengthens developing teeth that are still under the gums.  Fluoride applied topically, as with toothpaste, soaks into the enamel and strengthens teeth that are exposed to harmful bacteria that cause cavities.

*Fluoride can be removed from water through reverse osmosis or distillation.

*Fluoridation of community water supplies is supported by the American Dental Association, the U.S. Public Health Service, the American Medical Association and the World Health Organization.

Want more?  Check this out:

Alain Tressaud, Günter Haufe
Fluorine and Health presents a critical multidisciplinary overview on the contribution of fluorinated compounds to resolve the important global issue of medicinal monitoring and health care. The involved subjects are organized in three thematic parts devoted to Molecular Imaging, Biomedical Materials and Pharmaceuticals.

Initially the key-position of partially fluorinated low molecular weight compounds labelled either with the natural 19F-isotope for Magnetic Resonance Imaging (MRI) or labelled with the radioactive [18F]-isotope for Positron Emission Tomography (PET) is highlighted. Both non-invasive methods belong to the most challenging in vivo imaging techniques in oncology, neurology and in cardiology for the diagnosis of diseases having the highest mortality in the industrialized countries.
The manifold facets of fluorinated biomaterials range from inorganic ceramics to perfluorinated organic molecules. Liquid perfluorocarbons are suitable for oxygen transport and as potential respiratory gas carriers, while fluorinated polymers are connected to the pathology of blood vessels. Another important issue concerns the application of highly fluorinated liquids in ophthalmology. Moreover, fluorine is an essential trace element in bone mineral, dentine and tooth enamel and is applied for the prophylaxis and treatment of dental caries. The various origins of human exposure to fluoride species is detailed to promote a better understanding of the effect of fluoride species on living organisms.
Medicinally relevant fluorinated molecules and their interactions with native proteins are the main focus of the third part. New molecules fluorinated in strategic position are crucial for the development of pharmaceuticals with desired action and optimal pharmacological profile. Among the hundreds of marketed active drug components there are more than 150 fluorinated compounds. The chapters will illustrate how the presence of fluorine atoms alters properties of bioactive compounds at various biochemical steps, and possibly facilitate its emergence as pharmaceuticals. Finally the synthetic potential of a fluorinase, the first C-F bond forming enzyme, is summarized.

– New approach of topics involving chemistry, biology and medicinal techniques
– Transdisciplinar papers on fluoride products
– Importance of fluoride products in health
– Updated data on specific topics

Brush.  Floss.  Fluoride.
Dr. Cook
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