30% Safe for At-Home

A study by Robert M. Drosman, D.D.S., "Whitening the Dentition with 30% Urea Peroxide" can be summarized as follows:

• 2,800 arches were tested from 1989 to 1999 with profound whitening and no detrimental effects.
• Multiple shade shifts were achieved in 93% to 97% of cases using two 20-30 minute treatments within 7 to 10 days.
• 30% carbamide peroxide has been tested in-vivo and has shown no soft tissue aberrations in accordance with the A.D.A. protocol for safety.
• 30% carbamide peroxide had no deleterious effects on oral tissue or body systems in accordance with the A.D.A. safety standards for in-vivo soft tissue tests.
• Undesirable one-shift color change and temporary dental sensitivity occurred at a frequency of less than 5%.
• Even 5 years after the initial treat- ment, only 4% of the cases displayed a color reversion of 2 shades.
• Uniform, predictable whitening of the dentition is safely attainable by increasing the bleaching agent 50%-100% over that whiach is presently commercially available (15% to 22% concentrations) with the added benefit of substantially quicker results.

Can whitening cause pulpal damage? A series of studies on pulpal damage indicate that some in-office procedures can damage the pulp, identifies the culprits, and points the way to avoiding the risks.

At risk are the in-office procedures that combine H2O2 and heat. H2O2 is absorbed more quickly than carba-mide peroxide allowing the peroxide to reach the pulp more quickly and in greater quantity. Pulpal enzymes are significantly inhibited by H2O2. Heat alone can cause pulpal damage. However, the combination of H2O2 and heat is the real problem! The hydrodynamic pressures of a H2O2 exposed pulp under heat can disrupt the metabolic pathway or damage biological membrane. It can evoke an inflammatory response that may result in pulpal necrosis and the need for future endodontic treatment.1

Heat can come from such a source as a resin curing lamp. Lamps are good for sizzle but are at risk of pulpal damage and do little for the actual in-office procedure. The heat does accelerate the whitening process but only a few minutes of time is actually saved over in-office non-heat chemical whitening.

There are other risks besides actual pulpal necrosis. Acute pulpal sensitivity is common during and/or after treatment when heat and H2O2 are combined. Why subject your patients to pain and pulpal risk?

How do you protect the patient and still have the ability to deliver the fast, in-office results patients demand? Using high-concentration carbamide peroxide is safe as less peroxide reaches the pulp. Use a waiting room carbamide peroxide (i.e. 44%) in a maxillary bleaching tray as a booster and send the patient home with a high-concentration (30% CP) at-home bleaching gel. It will deliver the fast, predictable, and safe results your patients deserve.

The fact is, it takes multiple in-office treatments, regardless of technique employed to achieve the equivalent of at-home whitening. If your treatment plan is strictly in-office, use 35% H2O2 without the lamp and keep the treatment time to multiple 3-minute paintings. This way, the patient will see the results without the risk of potential necrosis or post-op pain.

1. Bowles WH, Thompson LR, Vital bleaching: the effect of heat and hydrogen peroxide on pulpal enzymes. J Endodon 1986;12:108-12.

2. Bowles WH, Ugwuneri Z, Pulp chamber penetration by hydrogen peroxide following vital bleaching procedures. J Endodon 1986:13:375-77.

In a business climate where patients can sue their dentists over a toothbrush, thoughts of limiting liability are prudent. What kind of exposure do you have regarding the use of bleach- ing gel? How do you play it safe? What are acceptable risks? Only you can answer these questions for your- self, but these are some of the issues on the table to consider:

• The ADA has accepted only 10% carbamide peroxide for at-home use.
• Because a company has an ADA approved product does not mean their products with KNO3 in them or their higher concentrations of carbamide peroxide (11%, 13%, 15%, 16%, 20%, 22%, 30%) have been ADA accepted.
• In my experience, most dentists are not postponing the use of higher concentrations until the ADA finally gives their blessing, but have already moved to the efficacy and predictability of the higher concentrations.
• Higher concentrations of carbamide peroxide have been used successfully for a decade and, to my knowledge, without a single lawsuit.
• After ten years of whitening, there are no studies indicating that higher concentrations of carbamide peroxide have a negative effect on enamel or the pulp.
• The FDA classifies carbamide peroxide for teeth whitening as a cosmetic, which limits the testing requirements and regulations.
• The ADA traditionally takes a relatively long period of time to sort out such seemingly conflicting issues.

Dentists are left to make their own product selection decisions. Based on what we now know, the acceptance of higher concentrations looks good - as they are backed by years of safety and success.

1. Oral Health Care Drug Products for OTC Human Use..., Federal Register Vol. 56, No. 185, 21 CFR Parts 356 & 369, Sep. 24, 1991, 48302:48347

On November 14, 1999 a panel of tooth whitening professionals gathered at Loma Linda University for a discussion on "The State of the Art 2000."

Loma Linda was the first national symposium on the subject of tooth whitening and served to eliminate bleaching myths and bring out the truths of Bleaching Science.

The panelists included:

• Van Haywood, DMD, Medical College of Georgia
• Rella Christiansen, PhD, Clinical Research Assoc.
• Chakwan Siew, PhD, ADA
• Yiming Li, DDS, MSD, PhD, Past ADA, now at Loma Linda University
• Ralph Leonard, DDS, Chapel Hills, NC
• James Dunn, DDS, Loma Linda University
• Bruce Matis, DDS, Indiana University
• Carlos Munoz, DDS, Loma Linda University

Some KEY ISSUES raised by the panel include:

• Lack of data to support the contention that reservoirs whiten better
• The assertion that all tooth whitening products work
• Skepticism for the curing light/35% H2O2 modality due to lack of data and an increase in post-op pain
• Questions about whether activators do or do not whiten better
• Concerns that heat can damage the pulp
• Recognition that canines are more difficult to whiten and can best be addressed with higher concentrations.

Patient compliance is the biggest barrier to bleaching success.

Here's a tip to give your patients that will help assure their whitening success:

Tell your patients to simply work the treatments into their daily bathroom routines, morning and night, using 30% carbamide peroxide with the fast and easy 20-30 minute bleaching modality.

Here's how it works:

The patient goes into the bathroom, brushes, puts a small amount of gel (10-12 drops) into a non-reservoir stent, inserts the tray, and then goes on with the usual bathroom routine (shower, shave, preparing hair and makeup). The patient then removes the tray, expectorates, rinses the mouth and tray, and is finished.

This way, the patient doesn't have to find a special or separate TIME for bleaching each day. Instead, the bleaching session just becomes an additional part of his/her daily bathroom routine. Try it yourself and see how easy it is to take whitening out of the bedroom and put it into the bathroom -- where it really belongs.