# Application of Ozone Therapy in Paediatric Density
## 3 Clinical Use in Paediatric Density
### Pulpectomy  
Caries in primary teeth progresses rapidly and the complete elimination of all soft, demineralized carious dentin in asymptomatic teeth with deep caries may result in pulp exposure [14; 44; 45]. The pulpal damage is caused directly by bacteria and or by their derived toxins. The contamination of the tissue could be consequently irreversible, so endodontic treatment is indicated. As already mentioned in the previous paragraph, the elimination of the pulp organ causes an additional weakening of the dental structure and a consequent risk of fracture or reinfection. Early loss of primary teeth should be avoided; it can cause several problems, including space loss for successor permanent teeth as well as aesthetic, functional, or phonetic complications [14]. Control of infection is of fundamental importance because the ample medullary bone spaces favour dissemination of infection, and the developing permanent tooth germ is very close to the roots of the primary teeth and could be affected [15; 16]. A successful primary root canal treatment depends on proper shaping and cleaning of the root canal system followed by obturation with hermetic root canal filling. However, the complex internal nature of primary teeth makes it difficult to achieve correct tooth shaping. Therefore, ideal irrigation and root canal disinfection are rising in importance with the current evidence in the literature [17]. Current practice suggests using a decreased concentration of 2.5% sodium hypochlorite (NaOCI) in paediatric dentistry to avoid complications, which may occur depending on the pathological resorption areas on the primary root. The primary disadvantage of NaOCI irrigation, besides its taste and foul smell, is its cytotoxicity, especially when injected into periradicular tissues [17]. Furthermore, when co-operation is limited, such as in very young children or patients with special needs, control over all procedures may be reduced. Ozone advantages are as follows: its oxidation power; lack of mutagenicity and biocompatibility; rapid microbicidal effects, especially against anaerobes and _E. faecalis_; and ease of handling [13]. Ozone presents a neutral taste, no cytotoxicity, and higher biocompatible compared with other antiseptics such as sodium hypochlorite (NaOCI is not as biocompatible as ozone in the aqueous phase for human oral epithelial cells, periodontal cells, and gingival fibroblast cells). Recent literature points toward better acceptance of this irrigant in gasouse or water form in paediatric patients [11; 17; 18; 19; 20; 46]. [PERSON] et al. [14] compared the antibacterial effect of gaseous ozone with other antimicrobial techniques. They obtained positive results on the reduction of the E. _facalis_ bacterial load. They suggest the use of ozone therapy to aid NaOCI 2.5% in endodontic treatment of primary teeth and recommend the application at the end of instrumentation. In the study, gaseous ozone, applied with an ozone device (HealOzone, KaVo, Biberach, Germany) with a 4 g/m\({}^{3}\) ozone concentration, was activated in dried root canals for 150 s using a hand piece, silicone caps (for sealing), and endodontic cannulas. This instrumentation avoids gas dissipation and guarantees the expected concentration even in root canals and endodontic space. [PERSON] et al. [19] evaluated in primary teeth the antimicrobial efficacy of aqueous ozone as an irrigant in pulpectomy procedures. They concluded that ozonated water can be used as an irrigant, owing to its neutral taste and powerful antimicrobial efficacy, especially against anaerobes. The proposed protocol starts with the anaesthesia and isolation with a rubber dam. Under strict aseptic conditions, the procedural tooth root canal access was performed with a high-speed air-rotor hand-piece and a round bur. Working length determination and biomechanical preparation were carried out with files three sizes beyond the first instrument. During instrumentation, the root canal was alternately irrigated with 2 mL of irrigant after every step of instrumentation.