Ozone in Clinical Care, Caries Prevention, Feature Article

Another protective benefit for adults is the prevention of root decay. Studies have demonstrated that fluoride is incorporated into the structure of the root surface, making it more resistant to decay.42,43,44,45,46 A Swedish study investigating decay activity among adults in optimal- and low-fluoride areas revealed that not only was decay significantly lower in the optimal fluoride area, but also the discrepancy could not be explained by differences in oral bacteria, buffer capacity of saliva, or salivary flow. The fluoride concentration in the drinking water was solely responsible for decreased decay rates.47

Lower socioeconomic status: Of most concern was the high decay rate among young children from low-income families. Specifically, children whose families were lifetime residents of non-fluoridated communities and whose income was more than 200% below the U.S. Federal Poverty Level had 39% more decay in their baby teeth when compared to counterparts who were lifetime residents of optimally fluoridated areas.18 Using data from the dental surveys in 1991-1992 and 1993-1994, a British study demonstrated that children with the greatest dental need benefit the most from water fluoridation.40 Top

For patients to whom fluoride treatments have been administered, or who drink fluoridated water, has fluoride affected a change in the characteristics of caries progression altering the behavior of the mineralized tissue during the acid attack?
Answer: Maximum decay reduction is realized when fluoride is incorporated systemically during all stages of tooth formation and applied topically after eruption.48 Systemic fluorides that are ingested regularly while teeth are developing are deposited throughout the entire tooth surface and provide longer-lasting protection than fluorides applied topically.48 Additionally, the presence of systemic fluoride in saliva provides a reservoir of fluoride ions that can be incorporated into the tooth surface to prevent decay.49 Systemic fluorides also can give topical protection because ingested fluoride is present in saliva, which continually bathes the teeth providing a reservoir of fluoride that can be incorporated into the tooth surface to prevent decay. Fluoride also becomes incorporated into dental plaque and facilitates further remineralization.50 However, topical fluoride applied to teeth in an adult's mouth during the initial formation of decay not only stops the decay process, but also makes the enamel surface more resistant to future acid attacks. Researchers have observed fluoride’s decay preventive effects through three specific mechanisms:51,52

Fluoride ions in and at the enamel surface convert the mineral component (hydroxyapatite) into a less soluble form (fluorapatite), resulting in fortified enamel that is more resistant to the acid.

Fluoride exerts an influence directly on dental plaque by reducing the ability of plaque organisms to produce acid. Fluoride has well been established as a potent inhibitor of the enzyme enolase, a key enzyme for bacterial metabolism. This is thought to reduce the amount of acid produced in the plaque by decay-causing bacteria. Other effects could include less binding of bacteria and the reduction of plaque growth and thickness.

Fluoride promotes the remineralization or repair of tooth enamel in areas that have been demineralized by acids and in which early decay does not enlarge.

The theory is that fluoride is concentrated in the surface of the mineralized tissues and then is released to the plaque biomass as the acids demineralize the tooth surface. The remineralization effect of fluoride is of prime importance, allowing enamel to repair, or remineralize, early dental decay caused by acids from decay-causing bacteria.48,54,55,56,57,58,59

However, enamel-forming pits and fissures do not receive the same level of caries protection from fluoride as does smooth surface enamel. It also may partially explain why occlusal caries is responsible for almost 60% of the total caries experienced even though occlusal surfaces account for only 12.5% of the total number of tooth surfaces exposed to cariogenic challenges. If caries occurring in pits and fissures on buccal and lingual surfaces are considered, then pit and fissure caries would account for at least 80% of the total caries experienced in all children and adolescents. Over 90% of dental caries occurs in occlusal and buccal-lingual surfaces in fluoridated communities and comprise, almost exclusively, pit and fissure caries.59

This particular problem can be explained by the presence of fluoride.60,61,62 Referred to as “the fluoride syndrome,” the increased fluoride intake causes the highly caries-resistant occlusal enamel to obscure a spreading dentinal lesion. So the lesion progresses and undermines the intact enamel reaching the dentin without cavitation.

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What research on methods to manage carious lesions is currently being conducted at Queens University?
Answer: We are currently researching the use of ozone (O3) to manage dental caries as well as to treat dental unit waterlines.

In our research we are using the most advanced technologies to measure objectively the various aspects of dental caries behavior with ozone treatment. For the clinical diagnosis, we are applying the clinical criteria developed by Kim Ekstrand, one of the foremost experts on fissure caries classification. This was further tested at the school and was found to be a valid method for diagnosing caries.68

For the subjective quantification of the lesions, we are using the Diagnodent caries detection laser from Kavo as well as the Electrical Caries Monitor (ECM) from Lode B.V. These devices allow us to see the lesions, measure them numerically, and then periodically monitor them over the period of our study measuring any remineralization (lesion reversal) or further demineralization (lesion progression).

The Diagnodent was found to be highly correlated with the histological true extent of caries.68 Ozone treatment had an immediate effect on these readings, lowering them significantly. 68 Any progression of the caries leading to cavitation undetected by the eye can be detected with an advanced laser scanning device that scans the surface of teeth or oral tissue in a matter of seconds and then sends the resultant image to a computer system. Complex calculations and procedures from the image produce data that accurately measures the surface.

Another application of this scanning device is to measure the fissure sealant applied over the occlusal surface. (Figs. 2a,2b,2c) It can measure sealant volume and depth as well as detect any change in volume due to retention loss or wear.69

Altering the organic substance in the plaque70, saliva71 and in the lesion72 by the application of ozone was tested by use of high-resolution proton spectroscopy (1H NMR). With the help of 1H NMR, examination of the organic acid status of primary root carious lesions has added information about the molecular profile and concentrations of microbial-derived organic acids in carious dentin as demineralization parameters involved in the induction, development, and progression of dental caries.73 Finally the disinfection of microorganisms within the lesions is tested microbiologically. This was done in-vitro to check its activity against various cariogenic bacteria and was proven to dramatically reduce them in root caries. 74,75

Preliminary results from the first study conducted on root caries,76 which is the most prevalent form of caries in elderly patients, was very positive and shown to reverse the lesions clinically as well as to be safe for both patient and dentist.77

New products on the market, The Ozi-cure from O3, South Africa and the HealOzone unit, manufactured by CurOzone in the U.S. can successfully treat dental unit waterlines with ozone to easily and very effectively control microorganisms using current dental unit designs.78 Once more it was tested with the 1H NMR and shown to alter the organic substance in water with bacterial contamination.79

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How does ozone work and affect the carious lesions?
Answer: Ozone is a powerful agent that disinfects by destroying, neutralizing, or inhibiting the growth of pathogenic microorganisms. It has been found to be an effective alternative biocide to chlorine and possesses the added advantages of acting rapidly in lower concentrations and of having no side effects such as taste and odor, which are characteristic of other disinfecting agents.

Ozone also decomposes to a harmless, non-toxic, environmentally safe material (oxygen). An old-new methodology, ozone was first suggested as a disinfectant for drinking water in the 19th century because of its powerful ability to inactivate microorganisms, but medical applications for it are relatively new. The use of ozone for managing caries is considered a breakthrough that is expected to be a cornerstone of dental care in the near future. Ozone can not only halt decay by killing the main acid-producing bacteria but also reverse dental caries by allowing the natural remineralization process to take place without the use of anaesthesia, drilling, or filling.