Inside Dentistry
October 2008
Volume 4, Issue 9

Placebo-Controlled Clinical Trial with Combined Whitening Strips and Dentifrice

Howard E. Strassler, DMD

Gerlach RW, Barker ML, Booker DL, et al. J Dent Res. 2008;87(Spec Iss B): 1769.


Objectives: A clinical study was conducted to evaluate the combined use of hydrogen peroxide whitening strips and a sodium hexametaphosphate whitening dentifrice on tooth color.

Methods: A randomized, placebo-controlled clinical study was conducted to evaluate tooth color with a whitening strip–paste combination versus control. The combination group (Crest® Healthy Radiance™) was assigned 10% hydrogen peroxide whitening strips and sodium hexametaphosphate dentifrice, while the control group was assigned a placebo strip (0% hydrogen peroxide) and pyrophosphate whitening dentifrice. Subjects received a manual toothbrush; strip use was 30 minutes once weekly on the maxillary arch, and brushing was twice daily beginning at baseline. Standard digital images were collected over a 3-week period to assess L*a*b* color change.

Results: A total of 57 subjects were randomized, attended all visits, and completed the study. Mean (SD) baseline tooth color was 17.9 (1.1) for b*, and 71.4 (1.4) for L*. Relative to baseline, the combination peroxide strip–dentifrice group exhibited significant (P < .05) b*L* color improvement beginning at Week 1 and continuing through Week 3. Most (89%) subjects in the peroxide strip–dentifrice group experienced two-parameter (Δb* & ΔL*) color improvement of 1+ unit, with groups differing (P < .001) on Δb*, ΔL* and Δa* at end-of-treatment, favoring the peroxide combination group. Oral irritation (4%) and tooth sensitivity (2%) were uncommon overall.

Conclusion: A placebo-controlled clinical trial demonstrated that a combination weekly 10% hydrogen peroxide whitening strip with a daily anticavity sodium hexametaphosphate dentifrice provided significant tooth whitening without meaningful or unexpected adverse events.


People are delaying their regular check-ups and are not as quick to accept costly esthetic treatment plans, but they still want a beautiful white smile. Tooth whitening has made a resurgence and our patients are pursuing less expensive over-the-counter (OTC) options. For some people, the idea of only 1 or 2 weeks with an OTC product is cost-effective.

Patients are going to ask about OTC products for tooth whitening and oral health. As clinicians, we need to make recommendations based on the evidence of oral health. Recently, a combined toothpaste–whitening strip product, Crest Healthy Radiance, was introduced. I have had several patients ask me if this product would not only improve their oral health but also whiten their teeth. This well-done clinical research study demonstrated that a combined toothpaste–whitening strip product with the strip used only once a week, in fact, can provide a patient with color improvement and whitening with minimal adverse effects. There should be little concern for adverse intraoral effects with long-term use of this family of products. For overall gingival health, use of a carbamide or hydrogen peroxide whitening agent can provide improvements in gingival health.1,2 When a patient asks about OTC products, we can feel comfortable making a cost-effective recommendation to fulfill his or her oral health and whitening needs.


1. Scherer W, Palat M, Hittlemen E, et al. At-home bleaching system: effect on gingival tissue. J Esthet Dent. 1992;4(3): 86-89.

2. Almas K, Al-Harbi M, Al-Gunaim M. The effect of 10% carbamide peroxide home bleaching system on the gingival health. J Comtemp Dent Pract. 2003;4(1): 32-41.

About the Author

Howard E. Strassler, DMD
Professor and Director of Operative Dentistry
Department of Endodontics, Prosthodontics and Operative Dentistry
University of Maryland Dental School
Baltimore, Maryland

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