Clinical applications:
Prevention and management of dental caries: The application of Ozone therapy in the management of dental caries is widely studied. Most of the child patients have fear and anxiety towards dental treatment. Dahnhart JE et al4 evaluated the anxiety level of children (and their parents) treated with ozone and found that all children & parents reported significant anxiety prior to ozone treatment. However, following the treatment, the children reported they would be pleased to return for future treatments. Also, 80% of the parents said they would be willing to pay more for this therapy compared with traditional drilling and filling. Huth et al5 ran a split mouth clinical trial to assess the effect of a single 40 second application of gaseous ozone on non cavitated fissure caries in permanent molars. The ozone-treated teeth showed reduced caries progression when compared to the untreated control lesions in these same patients. Kronusova M6 found that Ozone treatment either alone or combined with a remineralizing solution was found to be effective for remineralization of initial fissure caries lesions. Ozone has been shown to reverse pit and fissures caries in deciduous teeth7. Ozone is also found to be effective against the microflora associated with primary root caries lesion8.It also oxides volatile sulphur compounds precursor methionine to its corresponding sulphoxide and thus prevents malodor associated with root caries. The mechanism of action is due to its antimicrobial properties and its ability to oxidize the bacterial cell wall. Pyruvic acid that is produced by bacteria and implicated in the progression of caries is oxidized by Ozone to acetate and carbon dioxide. Ozone generating equipment converts oxygen to ozone. The ozone is thereafter led to a hand piece fitted with a silicone cup. Differently shaped silicone cups are available that correspond to the form of various teeth and their surfaces. This ensures close contact between the silicone cup and the carious area of the tooth so that the ozone does not escape. The ozone is led through the silicone cup over the tooth for a minimum of 10 seconds. The ozone in the silicone cup is collected again and reconverted to oxygen by the apparatus.
Management of Periodontal diseases: Studies found that ozonated water strongly inhibited the formation of dental plaque and was highly effective in killing of both gram positive and gram negative microorganisms9. Ozonated water can be used in the ultrasonic water reservoir, also as a pre treatment rinse before scaling, root planning and the sulci, pockets are irrigated using syringe and canula in non surgical pocket curettage. This process will reduce the initial pathogenic load on the patient locally and systemically. After treatment, each pocket & sulcus is insufflated with ozone gas which directly goes into tissues, sterilizing the area. The patients are also given ozonated oil to apply topically to the soft tissue. Huth et al10 in their study declared that the aqueous form of ozone, as a potential antiseptic agent, showed less cytotoxicity than gaseous ozone or established antimicrobials under most conditions. Dhingra et al11 proposed that subgingival ozone irrigation can be performed during monthly visits on orthodontic patients to reduce subgingival inflammation because of plaque retentive orthodontic appliances.
Disinfection of the infected root canals: Ozone was found to be effective against endodontic pathogenic microorganisms like E.Faecalis, Candida albicans, Peptostreptococcus micros and Pseudomonas aeruginosa disinfecting of root canals and dentinal tubules12. Ozone will also penetrate through the apical foramen and enter into the surrounding and supportive bone tissue encouraging healing & regeneration of bone. In infected necrotic canals, ozonized oils can be used as an intra-canal dressing. In periapical infections ozone therapy can increase the scope of non-surgical management of these lesions. Ozone also eliminates the distinctive anaerobic odor associated with some chronically infected teeth. Before the obturation of the canals, the files are coated with ozonated olive oil for lubrication and disinfection and the canals are prepared and then irrigated with ozonated water and dried followed by slow insufflations into each canal with moderate/high concentration of ozone gas. Insufflations of ozone electrochemically travel into the lateral canals and dentinal tubules killing the microbes13.
Bleaching of discolored teeth: Crown discoloration is one of the major aesthetic problem in root canal treated teeth. Teeth whitening can be done using ozone gas due to its strong oxidizing properties. The bleaching effect with ozone is seen when the bleaching agent is placed in the access cavity and crown is exposed to ozone for a minimum of 3 to 4 minutes14. For bleaching of entire dentition, tray technique can be used.
Desensitization of sensitive teeth: Ozone removes smear layer, opens up the dentinal tubules, broadens their diameter and then calcium and fluoride ions flow into the tubules easily, deeply and effectively to plug the dentinal tubules, preventing the fluid exchange through these tubules followed by mineral wash onto the exposed dentine in a repetitive manner. Thus, ozone can be used effectively for desensitization of dentine and also lasts longer than those by conventional methods15.
Wound healing: The influence of ozonized water on the epithelial wound healing process in the oral cavity was observed by Filippi16. Ozone has been reported to accelerate the healing of soft tissue conditions i.e.: aphthous ulcers, herpes labialis, ANUG and other gingival infections because ozone encourages physiological healing rate as well as control opportunistic infections. It also reduces the post extraction healing time by forming a pseudo membrane over the socket and protecting it from any physical and mechanical insults. In alveolitis, there is accelerated healing by irrigation with ozonated water after removal of the necrotic plug and debris under antibiotic coverage.
Decontamination of avulsed teeth before reimplantation: Ebensberger et al17 observed that 2 minutes irrigation of the avulsed teeth with non-isotonic ozonated water provides mechanical cleansing and decontaminate the root surface.
Decontamination of toothbrush: Ozone application was found to remove the toothbrushes bristles microbiota following conventional brushing.
Dental unit water lines disinfection: Ozone can be used for Dental unit water lines purification and to minimize cross infection due to its antimicrobial efficiency and lack of side effects. Wirthlin et al8 concluded that controlling Dental unit water line biofilm would have beneficial effects on nosocomial infections.
Contraindications:
Ozone is contraindicated in certain medical conditions like pregnancy, glucose-6-phosphatedehydrogenase deficiency (favism), recent myocardial infarction, hyperthyroidism,severe anemia, severe myasthenia, hemorrhage, acute alcohol intoxication and ozone allergy3.