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How does Tooth Whitening work?

July 18th, 2017

Before we get into the details of tooth-whitening, let's take a minute to meet the enemy. What are tooth stains anyway?

Each of your teeth is made up of an inner dentin layer and a hard outer enamel layer, which protects the teeth. When you put stuff in your mouth -- food, cigarette smoke, coffee, etc. -- another layer gradually forms on top of the enamel layer. Basically, the foreign material accumulates to form a pellicle film over the enamel layer.

A dentist can clean away this film, through scraping and chemical treatments. Even brushing your teeth can knock out some of it -- brushing with the abrasive toothpaste cleans the tooth in the same sort of way scrubbing with an abrasive pad cleans a dish. "Whitening toothpastes" are designed to work even harder on this layer.

The problem is, as this pellicle layer sits on your teeth for years and years, the foreign material gets into the enamel. The enamel layer is made up of hydroxyapatite crystals, which form microscopic hexagonal "rods." Simply put, enamel is porous, which means staining agents can work their way down into the tooth, where you can't simply scour them away. The deeper stains are basically harmless, but many people find them unattractive.

This is where true tooth whiteners come in. Basically, the whiteners use bleaching chemicals to get down into the tooth enamel and set off a chemical reaction (specifically, an oxidation reaction) that breaks apart the staining compounds.

Most tooth whiteners use one of two chemical agents: carbamide peroxide or hydrogen peroxide (the same stuff that will bleach your hair). When used in the mouth, carbamide peroxide breaks down into hydrogen peroxide and urea, with hydrogen peroxide being the active whitening ingredient.

Dentist Supervised Whitening- In Office versus Home

Dentist-supervised tooth whitening involves the controlled use of carbamide or hydrogen peroxide, tailored to a particular patient. Dentists may administer in-office treatments or at-home treatments. Before the tooth whitening treatment, most dentists clean the teeth, fill any cavities, and make sure the patient's gums are healthy.

Most in-office systems use 15 to 35 percent hydrogen peroxide gels, sometimes coupled with a high intensity light or warming to expedite the bleaching chemical reaction. The in-office procedure involves the dentist gently cleaning your teeth with pumice and then putting a protective barrier on the gums. The dentist then places hydrogen peroxide paste on the teeth for several minutes, rinses it off, and usually reapplies it several times. The procedure can achieve about four to six shades of whitening after only one 40-minute treatment.

At-home, dentist provided systems will often use 10 to 20 percent carbamide peroxide gels that also contain glycerin, carbomer, sodium hydroxide, water, and flavoring agents. Some gels that contain more than 10 percent carbamide peroxide will also include sodium fluoride to reduce sensitivity.

To begin the at-home procedure, the dentist takes impressions (molds) of your mouth, and then has soft, custom mouth trays made. Dr Donohue no longer takes goopy impressions, but rather she can scan your teeth with a small camera to make the custom trays. To administer the treatment at home, you put a thin ribbon of the gel into the tray and wear it during the day, or while sleeping. Most whitening occurs in one to two weeks. In difficult cases, trays may need to be worn for up to six weeks.  Dr Donohue advocates wearing the trays every other day, rather than everyday, to minimize discomfort.

Dentist supervised systems have advantages when compared to over-the-counter tooth whitening products. The main advantage of the dentist supervised system is that the dentist can help determine if tooth whitening should be performed and if it will be effective for the patient. Patients with decayed teeth, infected gums, white spots on their teeth, and multiple tooth colored fillings or crowns (caps) on the front teeth may not be good candidates for tooth whitening.

Dr Donohue can also help you decide what type of tooth whitening is required (in-office, at-home or both) and the concentration of the whitening gels.  She can monitor and treat patients who experience sensitivity to the whitening agents and modify the procedure for those who are having difficulty getting optimal results. Finally, she can help you explore other cosmetic dental options such as porcelain or resin veneers, tooth colored fillings, gum lifts and tooth shaping used with or without tooth whitening.

Higher cost is really the only disadvantage of dentist provided whitening systems (versus over the counter).  The old adage applies here: is that "you get what you pay for".  If you are looking for something that can take more time and may not do quite as effective a job, but prefer the lower cost, then over the counter is fine.

Often patients will express concern whether or not tooth whitening is safe.  The short answer is: yes.  The bleaching solution is cleaning out existing "pores" in your teeth.  While it may be uncomfortable for some, it is not harming your tooth's vitality or nerve in any way.  The sensitivity is temporary and will go away.

Dr Donohue's office uses the GLO Tooth Whitening System which is known for reduced patient sensitivity after its use.  Call and speak with Ashley or Angelica to find out more about tooth whitening at Sunshine Dentists.  You will love your teeth whiter and cleaner looking.

The cool photo above is a scanning electron microscope of the dentin tubules that exist on the root surface of your tooth that can inadvertently get coated with the whitening gel and become sensitive.  Fortunately, it's a temporary discomfort.  As you can see there are clearly spaces for stains to become trapped.

-Dr Donohue

The Importance of Your Oral Microbiome

November 22nd, 2016

The most important part of oral health is attending to your oral microbiome. Achieving oral health is really about promoting balance among the bacteria in your mouth. And contrary to popular belief, antimicrobial agents and alcohol mouthwashes designed to "kill bad bacteria" may actually do far more harm than good.

The oral microbiome, while connected to the gut microbiome, is quite unique. Most importantly, it has a protective component that protects you from deadly viruses and bacteria in the environment. The second function of the oral microbiome is the beginning of digestion. When we look at the oral microbiome, it's an essential component of the salivary immune system; it aids in digestion, and it even makes vitamins. We are looking at ways to promote oral microbiome homeostasis.

Interestingly, probiotics do not work in the mouth, so it's not as simple as adding more beneficial microbes. As an initial step, you need to cease killing all the microbes in your mouth with alcohol mouthwashes. In the mouth, you don't want to have a 'scorched earth policy' or nuking all the bacteria and hoping the good bugs come back.

Instead, we recommend *effective removal* of the "food source" of these bacteria: plaque and food particles.  This involves careful home care each day and regular dental cleanings to clean beneath the gums.  Brushing of the tongue to remove the film can also aid in the balance of good and harmful bacteria. Plant based diets and lean proteins aid in the minimization of harmful mouth bacteria.  Avoidance of processed food, which contain vastly more sugars, is also an important goal.

From a systemic point of view, minimizing the use of systemic antibiotics can help improve the gut and oral microbiome.  Unless there is a clear diagnosis of infection, routine use of antibiotics may also kill off many of the beneficial bacteria in a person's mouth.

The secondary benefit from improved oral microbiome health is less odors and halitosis. The very products we are using to improve our breath, by masking the odor or killing all the bacteria in our mouths, may not be as effective as better daily home care to manually remove the food particles and film from our mouths.

Instead of banishing bacteria in our mouths, which is impossible anyway, let's think of it as limiting the buffet of food that we provide when we forget to floss or brush our teeth, or put off professional cleanings.

Come see Hasiba and Brooke for the "best cleaning of your life".  It's a comment we often hear and we thought you should know.

-Dr Donohue

Is an implant just for cosmetics?

June 8th, 2016

I have often had the conversation with my patients whether or not a dental implant is necessary.  Too often, people believe that an implant to replace a missing tooth, is frivolous or just for cosmetics.  This belief couldn't be further from the truth.  Teeth, all 28-32 of them, are designed to function as a whole.  When there are teeth missing, besides the wisdom teeth, changes may occur that weaken the other remaining teeth.  Besides the obvious extra chewing forces that would be placed on the teeth adjacent to the missing tooth, these teeth will often shift and move into the newly formed space.  As the teeth shift- and depending on the number of teeth missing- this can result in a collapse of a patient's bite.  In other words, the teeth move and the jaw now "over closes" to accommodate to the new shifted tooth position.  This can lead to jaw pain and problems with the TemporoMandibular joint (TMJ).

Shifting of teeth into the space of a missing tooth  can also lead to irregular gums that become difficult to clean and can often develop into periodontal disease.  Once this occurs, the bone becomes diseased and can lead to more tooth loss.  As more and more teeth are lost, it becomes a slippery slope of dental problems that can result in more tooth loss.  Therefore, replacing a tooth, whether with an implant or a bridge or a partial denture, depending on the situation,  is important to stopping the progress of these problems.

All forms of tooth replacement have their pros and cons, but dental implants have proven to be the most predictable, long term tooth replacement option in healthy, non-smokers.  The value of knowing that there are no "missing teeth" can improve one's self esteem and of course, make a smile look great, but there are other important reasons to replace a missing tooth.  Implants are just one way to do this.

-Dr Donohue

Comprehensive Dentistry: a New Paradigm

May 3rd, 2016

Dentistry is an art.  As with any art, it takes training to see the nuances of a person's teeth, gums, lips, nose and eyes.  I enjoy looking at proportions and symmetry, and comparing that to what our society considers to be a "pretty smile".  When patients ask me about cosmetic dental procedures, I don't just look inside their mouths, but consider the whole picture.  Sometimes, it can be as simple as some tooth whitening and replacing an old silver filling, but sometimes great care can take multiple steps.

I am proud to be a comprehensive dentist that can deliver this care.  This is often when I discuss  phasing of treatment with my patients.  Phasing is when you take a step by step approach, with the overall goal in mind.   Phasing allows dentistry to become more predictable and affordable.  Setting goals, which are unique to each patient, is the most important step.  I let patients co-diagnose with me and take ownership of their care.

For example, a patient might have crooked teeth with old, mismatched dental work.  The first phase would be to straighten the teeth with Invisalign.  Later, the old fillings or veneers could be replaced to make the teeth look brighter and more natural.  When teeth have been crooked for many years, often the gums are irregular.  Laser gum sculpting could balance the smile and frame the teeth.

Nothing makes me happier than to see a patient with a huge smile and speaking with confidence.  I also love to empower patients and let them help design their smiles, so we can both work toward this common goal over several months, or even years.  Comprehensive dental care is something we can all smile about!

Dr Kristen Donohue

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