Caries means demineralization with the formation of cavities and pulp symptoms and necrosis as an end result. The acids in the mouth are mainly produced by oral bacteria like Streptococcus mutans from bacterial biofilms adhering to the tooth. Ozone has been shown to have a very strong bactericidal effect on bacteria causing dental caries. Baysan et al reported that there was a statistically significant reduction of streptococci in root caries lesions and saliva samples after ozone application. The positive clinical effect of ozone with respect to arresting caries progression and the remineralization of caries has been shown in vitro and in vivo. In an in vivo study, Baysan and Lynch found that the application of ozone resulted in a significant reduction of bacterial contamination as well as a reduction in size and severity of root caries lesions. In a subsequent study, Baysan and Lynch reported that the severity of root caries lesions was significantly reduced after ozone application as measured by electrical conductance and laser fluorescence. In several studies, the caries reducing effect of ozone was measured with biochemical methods in root surface caries lesions, the biofilm and saliva after ozone application. See Citation section for references.

The objectives of this multi-center clinical study were to determine: (1) the effectiveness of the HealOzone in stopping the progression of fissure caries; and (2) the oral soft tissue safety of the ozone system.

The proposed study was designed as a twelve-month, multi-center, double-blind, randomized controlled clinical study involving 394 subjects with 788 lesions. There were three sites participating in this trial: Indiana University School of Dentistry (lead site), Tufts University School of Dental Medicine, and SUNY School of Dental Medicine. Each site submitted a version of the protocol to their respective Institutional Review Board ("IRB") that incorporated the specific institutional and state guidelines and regulations applicable to that site.

The two treatment regimens were: (a) placebo treatment and (b) experimental ozone treatment. Selected subjects had to have at least two teeth with similar stages of early active fissure caries. The selection of the study teeth was determined by a review of the visual examination, including the ICDAS severity score and the caries lesion activity score, conducted at the screening visit, in conjunction with the bitewing radiographs. The decision whether a tooth was to be treated with ozone or receive placebo treatment was made randomly.

All clinical personnel involved in the clinical examinations and treatment application were trained at the primary site prior to the initiation of the trial both in the use of the device, and in how to identify the signs and symptoms of ozone toxicity and in how to provide the appropriate medical response should any of these signs or symptoms be observed.

All qualified subjects received the following:

1. Professional dental cleaning and scaling at the Screening Visit (or separate visit prior to baseline visit and after completing the study at 12 months.

2. Diagnostic procedures:

   1. Clinical visual examination (utilizing the International Caries Detection and Assessment System [ICDAS] severity scoring)
   2. Clinical visual/tactile assessment of caries lesion activity
   3. Bitewing x-rays
   4. Laser fluorescence measurement (utilizing the DIAGNOdent, KaVo)

3. Treatment Regimen:

Using a split-mouth design, the assigned investigational treatment regimen was administered on the two selected study teeth at the baseline, and at the three-, six- and nine-month appointments.

After three, six, nine and twelve months, the diagnostic procedures were repeated with the exception of bitewing x-rays, which were only repeated at the twelve-month exam (unless the examining dentist determined that x-rays also were needed at the six- or nine-month visit to confirm whether dentinal caries were present). In addition, optional digital photographs were taken at the Boston site of selected study teeth to document clinical changes over the study period.

If a selected study tooth progressed from an initial caries lesion to a more advanced lesion, which in the judgment of the examining dentist required restorative intervention, the tooth was restored at no cost to the subject and the lesion was recorded as 'progression from baseline' at any remaining examinations. The subject was eligible to remain in the study.

Subjects received a thorough dental cleaning and scaling and topical fluoride treatment at the conclusion of the twelve-month examination.

The primary efficacy parameter will be the ICDAS severity value. The severity criteria used in the ICDAS diagnostic system are as follows:

0 = Sound tooth surface.

1. = First visual change in enamel.
2. = Distinct visual change in enamel.
3. = Localized enamel breakdown due to caries with no visible dentin.
4. = Underlying dark shadow from dentin, with or without localized enamel breakdown.
5. = Distinct cavity with visible dentin.
6. = Extensive distinct cavity with visible dentin.

The secondary efficacy parameters will be measured by:

Caries Lesion Activity score:

1. = Inactive - surface of enamel appears whitish, brownish or black. Enamel may be shiny and feels hard and smooth when the tip of the probe is moved gently across the surface.
2. = Active lesion - surface of enamel appears whitish/yellowish opaque with loss of luster. The surface feels rough when the tip of the probe is moved gently across the surface.

Radiographic Changes:

The occlusal surface of study teeth will be evaluated using the following scale:

Lesion presence: yes /no

Lesion depth:

E1 = outer half of enamel E2 = inner half of enamel D1 = outer third of dentin D2 = middle third of dentin D3 = inner third of dentin or greater/pulpal exposure

Laser fluorescence measurement:

DIAGNOdent reading using a scale from 00 to 99, with 00 indicating no caries activity and 99 indicating a high level of activity.

Inclusion Criteria:

To be eligible for study participation, subjects had to:

1. provide written informed consent, HIPAA authorization and medical history information prior to their participation; 2. be between the ages of 10 and 40 years of age; 3. if female and of childbearing potential, agree to:

• a urine pregnancy test, which must be negative;
• use one form of medically accepted contraceptive measures which include oral contraceptives, condom, or diaphragm with spermicide, Intra Uterine Device (IUD), Depo-Provera, Norplant during the study and for at least 30 days after the last treatment. (Females who are post menopausal, i.e. amenorrhea for the previous 12 months, or surgically sterile may be included.) 4. be in good general health as evidenced by a review of the medical history; 5. have good oral health; 6. agree to comply with all subjects' responsibilities as stated in the protocol (e.g. attendance at appointments, turning off of cell phone during appointment, etc.); and 7. have two posterior (molar or premolar) teeth with active fissure caries as defined by ICDAS severity score between 1 and 4, a caries lesion activity score of 2, and with radiographic evidence indicating that there is no extension past the dentinal enamel junction. Lesions within the same subject ideally should have the same ICDAS criterion; however, the following deviations will be acceptable - teeth with ICDAS criterion 1 paired with a 2, and a 3 paired with a 4.

Exclusion Criteria:

Any of the following excluded subjects from participating:

1. a medical condition that requires antibiotic therapy prior to dental work;
2. any medical condition that could be expected to interfere with the subject's safety, such as a pacemaker or similar powered implant;
3. selected study teeth with occlusal restorations, sealants, carious lesions extending into dentin, hypomineralization or fluorosis;
4. generalized severe gingivitis or gross unrestored caries;
5. orthodontic appliances that interfere with access to selected study teeth;
6. pregnant or nursing.

The adverse events were collected during the one-year period of the trial.

Study length may have been too brief to permit progression of early stage caries; Low caries increment in study population; Difficult to establish that lesions were truly active at baseline.