An Investigation into the effect of ozone (HealOzone) pre-treatment and the addition of CPP-ACP (Tooth Mousse) on the effectiveness of carbamide peroxide bleaching of teeth

The research project, presented as a table clinic at the ADA/Dentsply Student Clinician Program 2007 was titled, 'Effect of Ozone and Tooth Mousse on efficacy of Carbamide Peroxide Bleaching'. The research was done at the University of Melbourne's Cooperative Research Centre with the assistance of an ADRF summer student project grant under the supervision of Dr David Manton, Dr Matthew Hopcraft and Prof. Eric Reynolds.

Background

The demand for dental bleaching is rising. Tooth sensitivity is a common side effect of vital tooth bleaching with one study reporting an incidence of hypersensitivity as high as 38-78% with 6 weeks of 10% carbamide peroxide (CP) bleaching. So the question that we can ask is - "is there a way to improve the effectiveness of bleaching yet reduce these side effects?"

Ozone (O3) is a powerful oxidant and is widely used as a bleaching agent and germicide in industry. It has been suggested that ozone may be able to increase the oxidative capability of the bleaching agent with concomitant use. However, there is no published research as yet to support this suggestion. This is the question that our study has addressed - "Can ozone, which is a far more powerful oxidant than hydrogen peroxide, be used to enhance bleaching effectiveness?"

Tooth Mousse contains the active ingredient CPP-ACP (Casein Phosphopeptide- Amorphous Calcium Phosphate) at a concentration of 10% w/v. It has been shown that this nanocomplex is able to reduce demineralization and enhance remineralization of enamel. It has also been reported to reduce tooth sensitivity and improve the aesthetics of hypomineralised and stained enamel.

There are anecdotal reports of clinicians mixing Tooth Mousse and carbamide peroxide and using this as a bleaching preparation. So far, there are no published reports regarding the effect of mixing Tooth Mousse and CP on bleaching effectiveness.

Therefore, in this study, our aim was to investigate the effect of:

1. Addition of Tooth Mousse (containing CPP-ACP); and
2. Ozone treatment on the efficacy of carbamide peroxide bleaching.

Method

A controlled in-vitro study was set up. 60 enamel slabs were stained in tea solution and then divided into 6 groups to receive treatment by various combinations of bleach, ozone and Tooth Mousse. Data was collected through digital photography and analysed using Photoshop and SPSS.

Results - Ozone

The results indicate that the concomitant application of ozone according to the protocol we used (a 40-second application of ozone every 4 hours over a layer of carbamide peroxide) did not significantly increase or decrease the bleaching effectiveness of 52 hours of CP bleaching.

Results - Tooth Mousse

TM application does not significantly increase or decrease bleaching effectiveness of carbamide peroxide.

Clinical significance

The results of the study do not support the notion that application of ozone may be able to increase bleaching effectiveness of carbamide peroxide when used concomitantly. The study indicates that mixing Tooth Mousse and carbamide peroxide does not reduce the bleaching effectiveness and is able to increase the aesthetics of the enamel. Therefore, this may be important in future development of a more efficacious product or clinical technique with reduced side effects.

Comments/Afterthoughts

The opportunity to carry out a research project at the Cooperative Research Centre Oral Health Science, The University of Melbourne and to be supervised by such experienced researchers has been a real privilege. And then to be able to take the project to Sydney as part of the ADA/Dentsply Student Clinician Program 2007 was a thrilling experience on its own. It was great to meet final year students from the other states and share stories from our own university lives, what the research program had meant for us and how we could not wait to graduate. It made for an exciting Congress weekend. Reflecting on the results of the competition, I think that any one of us could have been up on the stage that day and I feel very honoured to be chosen to accept the award for all of us. I would again like to thank the ADA, Dentsply and all the organizers for their support of students and the program. It has been a most memorable experience.