Inside Dentistry
January 2008
Volume 4, Issue 1

Clinical reversal of root caries using ozone: 6-month results

Howard E. Strassler, DMD

Commentary by Howard E. Strassler, DMD

Baysan A, Lynch E.  Am J Dent. 2007;20:203-208.


Purpose: To assess the safety and efficacy of ozone either with or without a root sealant, for the management of leathery root caries. Methods: 79 subjects with 200 root caries lesions were recruited into four study groups in this randomized, controlled trial. At baseline and after 1, 3, and 6 months, the ECM III and DIAGNOdent were employed. Subsequently, the root caries lesions were clinically assessed for color, hardness, cavitation, dimensions, distance from the gingival margin and severity index. Modified USPHS criteria were also performed after 1, 3, and 6 months. These groups were as follows: Group 1: Ozone application was performed for a period of 10 seconds on caries lesions; Group 2: There was neither ozone nor root sealant application on root caries; Group 3: Ozone treatment and a root sealer were applied to root caries lesions; and Group 4: Only root caries sealer was applied to root caries. Results: At the 6 month recall, 78 subjects were examined. There were no observed adverse events. 38.1% of lesions became hard in the ozone only group, while none of the lesions became hard in the control group (P < .0001). Noncavitated lesions were more likely to reverse than cavitated lesions. 38.4% on the noncavitated lesions became hard, while only 5.7% of cavitated lesions became hard in the ozone only group. Modified USPHS criteria revealed that there were 66.6% intact sealants in the ozone and sealant group and 45.5% intact sealants in the sealant only group (P < .05). After 1, 3, and 6 months, the ECM and DIAGNOdent readings showed improvements in the ozone only group when compared to the control group (P < .001). The ozone and sealant group also had greater improvements in the ECM and DIAGNOdent values when compared to the sealant only group (P < .05).


Ozone has been shown to be an effective treatment of root caries when used with remineralization solutions. It has been suggested that the application of ozone to the root surface disrupts the acidogenic and aciduric microorganisms responsible for root caries with an additional preventive effect decreasing the regrowth of the organisms over the next 6 months. While ozone treatment may soon be available for use in the United States, it is important to note that, at the time of this commentary, ozone treatment is under review for approval by the FDA.

These two abstracts represent opposite ends of the spectrum for the use of ozone therapy in the treatment of caries. Baysan and Lynch is one of many studies demonstrating the success of ozone treatment for the reversal of root caries. It must be noted that case selection is important. Brazzelli et al is a systematic review that questions the effectiveness of ozone therapy for both occlusal and root caries. A search of the literature produced two additional systematic reviews of ozone therapy that concluded that there was no reliable evidence that ozone gas stops or reverses tooth decay.1,2 In fact, one of the authors of the root caries study reported in another article that ozone treatment of non-cavitated occlusal lesions for 40 seconds failed to significantly reduce the numbers of viable bacteria in infected dentin beneath the demineralized enamel.3 

For the treatment of pit-and-fissure caries, the use of minimally invasive restorations and sealants is a clinically proven treatment technique. Ozone is currently not the answer. For the treatment of root caries alone, ozone therapy may be an adjunctive treatment that is worth looking at, but again, this treatment is not the complete answer in the treatment of root caries. Patient compliance with at-home remineralization therapies and future restorative interventions will still be necessary. There should be concern that ozone therapy may be used to “sterilize” cavity preparations without any clinical evidence that there will be an improvement in outcome from that of a well-sealed restoration.


1. McComb D. No reliable evidence that ozone gas stops or reversed tooth decay. Evid Based Dent. 2005;6(2):34.

2. Rickard GD, Richardson R, Johnson T, et al. Ozone therapy for the treatment of dental caries. Cochrane Database Syst Rev. 2004(3):CD004153.

3. Baysan A, Beighton D. Assesssment of the ozone-mediated killing of bacteria in infected dentine associated with non-cavitated occlusal carious lesions. Caries Res. 2007;41(5):337-341.

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

© 2021 AEGIS Communications | Privacy Policy