THE SCIENCE OF TEETH WHITENING
June 7th, 2017 by Dr. Slate
What is the biology behind natural tooth color?
Your tooth has several layers that contribute to its color. Enamel is the characteristically white outer layer of your tooth that is visible to the eye. Dentin is the layer below the enamel which is naturally yellow in appearance. The inner chamber of the tooth is the pulp chamber which contains blood vessels, nutrients, and nerve fibers. The combination of these layers is what gives your tooth its natural color.
What causes discoloration of teeth?
A tooth’s color is a result of the convergence of anatomy and genetics of a tooth, environmental factors, and oral hygiene.
External stains are a result of stain molecules attaching to a bacterial biofilm on the tooth. This biofilm is the initial phase of plaque build-up and calculus build-up on your teeth. This biofilm is relatively easy to remove with good personal home care. Some areas of the tooth may be inaccessible at home, and your dental hygienist will scrape away the plaque and calculus build-up which is the basis for these external stains. The teeth can discolor by the external stain penetrating the outer layer of the enamel. These discolorations are relatively easy to treat.
Internal stains aren’t a result of your diet and home hygiene, but are caused by genetics, aging, systemic conditions, environment, medications, and even trauma. These stains develop from the pulp layer and outward toward the dentin.
As you age, the pulp chamber shrinks and the dentin layer thickens, causing a more yellow appearance to the teeth due increased color from dentin. Medications can alter the color of teeth during development. Tetracycline is a drug used to treat bacterial infections, but when taken during tooth development, it can cause a gray or yellow stain deep within the tooth. Trauma can cause damage within the pulp of the tooth, which can cause shrinkage of the pulp or even death of the nerve and vessels. The shrinkage of the pulp has the same effect of aging, where the colored dentin layer thickens. Death of the vessels and nerve chamber can cause darker staining of the dentin due to discolored remnants of the vessels and nerves.
What causes sensitivity when whitening?
There are several reasons that patients experience sensitivity after whitening such as:
- Contact of the surrounding gums and tissues with the whitening solutions
- Aggressive and improper use of heat causing reversible inflammation of the pulp
- Glycerine, ammonia, and acidic byproducts from the breakdown of carbamide peroxide (a common whitening solution)
Whitening Treatment Options
There are several types of whitening options available to patients including in-office whitening, take-home, and over the counter. The two key factors that influence whitening are concentration and exposure time. An increase in either of these factors will increase the effects of the whitening gel to a certain degree.
Both in-office and take-home whitening are supervised by your dentist, starting with an initial consultation to determine initial shades of your teeth and followed by either in-office whitening, or dispensing take-home whitening with instructions.
- During in-office whitening procedures, we treat the teeth with a high concentration hydrogen peroxide material (24% or greater) while applying consistent heat in a controlled environment. The controlled environment isolates the whitening material to the teeth only, preventing leakage to the surrounding gums and tissues, thereby preventing sensitivity. Temperature accelerates the reaction process leading shorter whitening treatment time (~30 minutes.) With shorter treatment times, there is less contact of the whitening material leading to less sensitivity. In-office whitening is able to achieve results in a very short period of time due to the highly concentrated materials and the utilization of heat.
- Take-home whitening utilizes custom fit trays which hold the whitening material against the tooth for extended periods of time (2 hours or more). The whitening material used to treat is a low concentration hydrogen peroxide (9%) or carbamide peroxide (10% - ⅓ of the strength of hydrogen peroxide) Take-home whitening takes advantage of exposure time, bathing the teeth in whitening gel for hours at a time. However, increased exposure time increases the likelihood sensitivity and for leakage to surrounding tissues. However, take-home whitening is still effective with the disadvantages of sensitivity and increased treatment times.
- Over the counter (OTC)
- OTC treatments are available almost anywhere including the pharmacy, malls, and spas with no dental professional oversight. Extrinsic stains are not removed beforehand, concentrations are low, there is no customized whitening regimen, and the application of the material is not distributed equally among all teeth.
Despite the various treatment options, the safest and most effective treatment is the “dual whitening” system which is dentist-prescribed and utilizes a combination of in-office whitening and take-home whitening.
Caring For Your Dental Implant
April 24th, 2017 by Dr. Johnathan Slate
What is a dental implant?
Dental implant therapy is the most common and predicable treatment option for the replacement of missing teeth. Teeth may be removed for a number of reasons, such as a fracture, a deep cavity, or periodontal disease (gum/bone disease.) Localized bacteria and plaque surrounding teeth for an extended period of time can cause damage to the gum and underlying bone. If the destruction is extensive enough to cause severe mobility, the tooth/teeth will ultimately need to be removed.
The most predictable treatment modality for replacement of the tooth is with an implant and implant-crown. The first step in treatment is to control the periodontal disease. The subsequent steps in treatment are implant placement, followed by the implant-crown placement.
Prevention of Peri-Implant Mucositis and Peri-Implantitis
Although the implant is titanium, and the crown is porcelain, the surrounding gums and bone still need to be protected. The following factors can contribute to damage of the gums and bone (peri-implant mucositis and peri-implantitis):
- Poor oral hygiene
- Regular brushing is a must, while angulating the bristles of the toothbrush toward the gum line. We recommend the use of electric toothbrushes.
- When flossing, create a c-shape with the floss, wrap around the tooth, and gently floss below the gum-line.
- A great adjunct to your hygiene routine is the addition of a proxy brush, to brush between the teeth, as well as a rubber tip to massage the gums.
- Irregular professional cleanings
- During your regular 3-6 month hygiene appointments, the hygienist will use a teflon coated instruments to clean the implant site.
- Ill-fitting crown
- The implant-crown should be designed such that the accumulation of plaque and bacteria at the gum line is minimized.
- There is a statistically significant difference in complications and failure rates between smokers and non-smokers. Smoking directly inhibits the body’s natural defense against bacteria, plaque, and inflammation.
Treatment of Peri-Implant Mucositis and Peri-Implantitis
If plaque and bacteria accumulate surrounding an implant, the gums and bone can become damaged through the same periodontal disease process that affects natural teeth. The initial stage of infection of the implant site is called Peri-Implant Mucositis, which is swelling/inflammation of the surrounding gums and tissues. This can cause sensitivity and irritation of the gums. Treatment involves a localized cleansing of the implant site, with the addition of bacteria-killing rinses and anti-biotics.
If left untreated, the disease can advance to Peri-Implantitis. Peri-implantitis involves destruction of the supporting bone that surrounds and stabilizes the implant. This can cause loss of gum tissue and exposure of the implant, which can be seen visually. Worst case scenario is mobility of the implant, leading to removal of the implant.
Several methods of treating peri-implantitis involve both non-surgical and surgical intervention. Non-surgical treatments often aim at the removal of the contaminating agent, but they remain highly unpredictable. There are two dental specialties which are formally trained in the surgical treatment of failing implants: periodontists and oral surgeons. Once the condition has been identified by your dentist, your surgeon and dentists will consult to formulate a treatment plan to restore the health and function of your implant.
*Photos courtesy of Spear Education
Managing White Spot Lesions
April 7th, 2017 by Dr. Johnathan Slate
What are white spot lesions?
White Spot Lesions (WSL) are common following orthodontic treatment and the management of these lesions can be difficult. Most studies report an incidence of new WSLs occurring during orthodontic treatment between a range of 30-70% of patients. WSLs develop from poor oral hygiene and an accumulation of bacteria and plaque surrounding the orthodontic brackets. When bacteria and plaque is present on the surface of a tooth for an extended period of time, the byproduct of the bacteria, lactic acid, demineralizes the surface of the tooth. Essentially, the tooth’s surface becomes more porous and reflects light differently than natural tooth structure giving the WSL a dull white appearance.
Prevention of White Spot Lesions
Remineralization and treatment of WSLs are possible, but the primary strategy is prevention of the WSLs from developing.
- Oral Hygiene
- Effective home hygiene habits as well as the use of an electric toothbrush are the key to plaque control.
- Foods and drinks that contain sugar and carbohydrates (which break down into sugar through an enzyme in our saliva) are the fuel for bacteria and plaque. We recommend limiting the amount of sugar in your diet, but when that cannot be avoided, it is best to brush and floss afterwards. If you don’t have the ability to brush, simply rinse with mouthwash or fresh water.
- Without getting too much into the science of the chemical structure of enamel (the visible outer layer of tooth structure), Fluoride substitutes part of the chemical structure of the tooth. Fluoride treated teeth are more acid resistant (think of the lactic acid described above) than normal teeth.
- In office fluoride treatments and prescription strength fluoride tooth pastes have proven to be effective in the prevention of white spot lesions. We recommend fluoride varnish every 6 weeks during orthodontic treatment.
- We often recommend ACT fluoride rinse as an adjunct to your hygiene routine
Treatment of White Spot Lesions
We have treatment options that can be as conservative as professional whitening. Other simple treatments are available such as infiltration of materials into the porous tooth structure to revitalize the natural appearance. However, the deeper the porosity, the more comprehensive that the treatment needs to be, such as microabrasion or veneering. Each tooth is unique and your treatment will be customized in order to obtain optimal results.