In Office vs. Over the Counter Bleaching

What is the difference between getting your teeth bleached in a dental office and using the over the counter bleaching products? I get asked this all the time. Is it worth the additional cost and time? Let’s look at the two options and you can decide for yourself.

First let’s learn how teeth bleach or lighten. The active ingredient in all bleaching or tooth whitening products are hydrogen peroxide or carbamide peroxide. It does not matter if you are getting your teeth bleached through a dental office or using an over the counter product like crest strips. The higher the concentration of the active ingredient and the longer it is in contact with the teeth the whiter the teeth will get. Thus, time and concentration are the key factors.

Over the counter products are convenient to buy and much less expensive. They use the same core chemicals as in office treatment just at a substantially lower concentration. The concentration is very low so that the public cannot hurt themselves even if used incorrectly. Thus their effectiveness or ability to lighten teeth is less the professionally supervised systems. The differences in the over the counter systems is primarily the delivery system, how the solution is applied to the teeth. The concept of impregnating an adhesive material with bleaching solution to keep the bleaching solution in contact with the tooth like Crest White strips is ideal as it enables the solution to stay in contact with the tooth longer. Over the counter systems battles the problems of low concentration and short contact times with the tooth. The problem with Crest White strips is it does not conform to the irregular surfaces and shapes of teeth and you can get unbleached areas of the tooth.

There are a variety of systems to pick from in the in office bleaching category, varying in cost, time and effort on the part of the patient. The professional dental offices can use much higher concentrations, have much better delivery systems and overcome obstacles like sensitivity. The simplest and least expensive is the Treswhite system by Ultradent. This is a manufactured set of trays which has the bleaching solution impregnated in a thin membrane that adapts over the whole arch of teeth. It differs from crest white strips as the concentration of bleaching solution is much greater and it fits the teeth much more precisely. It does not work as well as other professional systems, but very easy and convenient.
The next category is the take home tray system and has been around since the mid 1990’s. This is where the dentist takes impressions of your teeth and makes a custom tray to fit over your teeth. This allows a lot of versatility as with it you can use different concentration of bleaching solutions as well as fluoride to remineralize the teeth and desensitizers to make the patient more comfortable.
Different concentrations of active bleaching solutions are used in the trays to meet the individual patient’s needs. For example a 10% solution of carbamide peroxide can be used for patients with sensitive teeth and although it will take longer to bleach the patients teeth it can be used over night for longer exposure time or 16% solution is available for the average person or 22% carbamide peroxide which is used usual for day time use for a couple of hours, but if the patient does not have sensitive teeth it can be used for nighttime as well. Each concentration comes with potassium nitrate to decrease sensitivity and fluoride to seal the surface. Sound sleepers usually like night time trays and light sleepers usually like day time tray usage. Often sensitivity to teeth from bleaching is a result of having exposed root surfaces in your mouth as the root has no enamel to insulate them and the root often more sensitive. The dentist can apply dentinal bonding agents to your roots to protect them allowing people with very sensitive roots to bleach successfully. Additionally, there are desensitizing agents which can be placed in the bleaching trays for 5-10 minutes after bleach to eliminate cold sensitivity after each session, which allows patients to use the more effective higher concentration of bleaching solutions. This system is more versatile and effective than the previously mentioned systems and usually takes 1-2 weeks to get a good result for the average patient. Patients with difficult tetracycline staining will take longer. Bleaching affects the outer enamel and in tetracycline staining the color is coming from the deeper layers of dentin in the teeth.

The next category of bleaching is in-office. The is the most efficient and quickest way to get immediate gratification. In 45-60 minutes of bleaching in the office the patient has been completely bleached. This method is the most expensive due the labor, material and facility costs, but it is like coming in for an hour to relax in the comfortable message chair. Everything is done for you in a competent professional setting and what ever is needed it is right their in the office. In our office this is done with the Zoom Advanced Power. In this process we are using the strongest concentration of bleaching solution up to 40% carbamide peroxide and this cannot get on your gums or tissues, only your teeth so we must seal off your teeth from your gums. This is called an isolation which takes on average about 15 minutes. The light is used to increase the activity of the solution as we have a short exposure time for the bleaching solution to lighten the tooth. Personally I like this form of tooth lightening when we are using it in combination with cosmetic procedures as the patient does not have to do anything except show up for the appointment whereas take home systems require the patient to complete treatment in a specific amount of time before cosmetic procedures. After bleaching the teeth will rehydrate and gain some color. Seven to 10 days after bleaching the final new color of the teeth has settled in and the teeth can be bonded again for cosmetic procedures. Thus we want to complete home bleaching or in office bleaching 7-10 days before we match a new shade or bond to a tooth. Sometimes the evening after in office home bleaching the patient will experience cold sensitivity or zingers but it is always gone by the next day.

Unfortunately bleaching fades with time as pigmentation from the foods we eat penetrates into the enamel surface. The duration depends on the porosity or density of each person’s teeth. Some people with less porosity in their enamel will go a year before they see a change in the color of their teeth. On the other end of the scale people with more porosity will see their teeth darken in 3 months. It is sort of like sun bathing, some people get a nice bronze tan and hold the color along time, others mostly turn red and loose their color quickly. Thus you must “touch up” your bleaching every 3-12 months depending on your tooth surface porosity. For this reason we make take home trays for our in-office bleaching patients while they are under the Zoom Power Plus Lamp. Then every 3-12 months they can use the bleaching solution we send them home with for 2-3 nights or days to touch-up and revitalize their smile. This allows then to keep their results a long time without having to come in for retreatment. The solution kits are sold at our office for around $50 and will last you 1-2 years for touch ups. Also, for difficult to bleach teeth like tetracycline stained teeth which take more exposure time, they can use the take home trays to continue to bleach the teeth a home getting the best possible result offered from bleaching. This combination technique gives the best results and insures long term stability of the new whiter smile.

Another product offered in our office is the Zoom whitening pen which is like an over the counter product but at higher concentration and can be carried in your purse or pocket and can be applied before a date, picture, public event or whenever you want your smile to look its best. You just apply it by rubbing the applicator on your teeth, and in 20 minutes you have brightened your smile without a tray. It is great for people on the go, thus you are always prepared to look your best.

In general the average patient can expect a 2-3 shade change with the in office and take home combo system in our office. Each of the others systems will result is progressively less whitening results as the concentration and time of exposure goes down. You will hear or read advertisements claiming 6-8 shade changes. This is misleading; they are just saying the same thing by reading or interpreting the shade guide in a different way. It just sounds better in an advertisement to say 6-8 shade changes. I am referring to a shift from A-4 to A-1 or A-2 on the Vita Classic Shade guide. Both are claiming the same results, one just sounds better.

In summary the main difference between the over the counter and in office systems are results and cost. It is my experience that patients often want even better results than what the combination in office system will offer, as bleaching will lighten teeth, but not take out all the different colors within a tooth or from tooth to tooth. The only way to meet these patients’ expectations is with bonded veneers.