Ozone Therapy – Ozone Applicability in Various Dental Specialties

Ozone (O3) is an allotropic oxygen compound, found in abundance in the stratosphere and which, due to its antimicrobial, disinfectant and healing properties, provide therapeutic applications for more than 260 different pathologies. Ozone therapy is a technique that uses this gas, in its gaseous, aqueous and oily forms as a disinfection treatment option, being considered a safe, minimally invasive and conservative modality. This study aimed to review the literature on ozone therapy applied to dentistry, aiming to clarify its benefits and care during use as complementary therapy. For that, searches were carried out in databases addressing the theme proposed between 2007 and 2020, in three languages: Portuguese, English and Russian. It is concluded that Ozone therapy can be used safely and efficiently in dentistry as a complementary disinfection practice, without contraindications. Although laboratory studies have emerged as a promising potential for ozone in dentistry, more in-depth studies with standardized methodologies are needed to, in short, obtain more information about its applicability. Keywords— Ozone therapy, Dentistry, Application.


I. INTRODUCTION
Ozone (O3), an allotropic oxygen compound (O2) also known as triple oxygen or oxygen, is formed in the atmosphere through photochemical analyzes, that is, after generating an electrical discharge in the oxygen molecule, the same breakdown releasing atoms and binding to another oxygen molecule, forming O3. It contains a halflife of approximately 40 min at 20 ° C (AZARPAZHOOH, LIMEBACK, 2008). It is a dynamically unstable and oxidizing structure, being easily created and destroyed in O2 molecules (BOCCI, et al., 2011).
Found in the stratosphere at a concentration of 1 to 10 ppm, ozone is important due to its ability to filter out ultraviolet (UV) rays emitted by the sun. On the other hand, ozone in the atmosphere is considered toxic to the lung, since it is produced by chemicals that involve sunlight, car exhaust and oxygen, while the atmosphere can be caused by the action of ultraviolet rays or artificially with the aid of a generator (OLIVEIRA, MENDES, 2009).
It was discovered in 1785 by Martin Van Marum and substantiated in 1840 by the German researcher Christian Friedrich Schonbein, who already worked with water electrolysis when he included ozone in one of his experiments. According to or researcher, after performing an electric discharge in the water in a glass hood using oxygen, the use of gas that had a bluish color and a strong odor, calls it "Ozon", which derives from the Greek oil and means "what it smells. "He considers ozone to be a potent disinfectant (FERREIRA, 2011).
During the First World War, the use of ozone was reported for the first time in the German physician Albert Wolf, whose main objective was to treat post-traumatic ulcerations, infected wounds, burns and fistulas in German soldiers, obtaining satisfactory results that, soon after, created a technique for exporting blood directly to the gas mixture composed of oxygen-ozone (NOGALES, 2011).
In Dentistry, its first use was in the form of ozonized water by Dr. Edward A. Fisch (1899-1966) during a surgery on the German Dr. Erwin Payr (1871-1946), being the main objective in employment in the technical era for promote hemostasis, inhibiting the proliferation of bacteria and, thus, improving the local oxygen supply. Fisch was fascinated by the technique and went on to research deeply. In 1935, he published the work "On Ozone Treatment in Surgery" at the 59th Congress of the German Surgical Society in Berlin and then started Ozone therapy as it is known today. (FERREIRA, 2011).
Ozone therapy is a complementary technique that uses ozone (O3), in its gaseous, aqueous and oily forms, as a therapeutic option in the treatment of various pathologies, due to its biocompatibility generated by its bacteriological and immunostimulating power. In Brazil, a practice that Nesi (2018) relates that Ozone therapy can be performed in several dental practices, for example: Periodontics (prevention and treatment of infectious/inflammatory conditions); Surgery (assist in tissue repair); Temporomandibular joint pain and dysfunction (reduction of symptoms); Jaw necrosis (osteoradionecrosis, drug-induced necrosis and osteomyelitis); Stomatology (accelerated healing of ulcers, cold sores and other gum infections); Caries treatment; Endodontics (intensifying an antisepsis phase of the root canal system, acute and chronic infections); Biosafety (acting as a technique in the sterilization of dental materials).
Therefore, this objective work reviews the literature on the use of ozone in several dental specialties, helps to clarify its benefits and care when using complementary therapy.

II. MATERIALS AND METHODS
The type of study addressed was a literature review, whose bibliographic survey was guided by the question: Is there evidence of benefit from ozone therapy in dentistry? To ensure the relevance of the information contained in this work, searches were carried out on the PubMed electronic portals using the Health Sciences Descriptors (DeCS) "Ozone therapy" and "Dentistry" and "Application"; and Google Scholar searching for "Ozonioterapia na Odontologia". In the crossing of the adopted words, the expression of Boolean logic "AND" was used. As inclusion criteria, it was determined: articles available in the aforementioned databases that reported on the therapeutic use of ozone in dental specialties. All studies that did not address the proposed theme and also those that presented duality were excluded.
Initially, to check if there was a relationship with the theme of the present study, the articles were previously selected from reading the titles and abstracts. After a more in-depth analysis of the research content, publications that were in agreement with the guided question and with the pre-defined inclusion and exclusion criteria were inserted in this bibliographic review. Thus, a total of 30 articles were included in this literature review and presented in three languages: English (22), Portuguese (08) and Russian (01).

III. RESULTS AND DISCUSSION
Ozone therapy is proposed in dentistry due to its biocompatibility, curative properties, oxidizing, antimicrobial, fungicidal and bactericidal action ( irrigating agent throughout the procedure and, Oliveira, et al., (2018) add that, in the context of GUN, the ozonized oil was applied without a specific time interval. Regarding the concentration, it is known that the maximum allowed for the clinical application of the ozone-oxygen gas mixture is 5% or 100 µg / ml of ozone, where 1 µg / ml means that it contains 0.05% O3, and 100 µg / ml contains 5% (FERREIRA, 2011; NOGALES, 2011).
Nesi (2018) (2011), ozone (in gaseous and aqueous forms) does not eliminate microorganisms such as E. faecalis and S. mutans, and have antimicrobial activity similar to NaOCl 2,5% to 5% and CHX 2%. In contrast, for Noites, et al., (2014), the association of 2% chlorhexidine with ozone gas for 24 seconds, completely eliminates Candida albicans and Enterococcus faecalis. Ferreira (2011) believes that gas is more effective than ozonized water. Silva, et al., (2019) concluded that, for microbial reduction, ozonized water cannot replace or complement NaOCl, as it is less effective than conventional therapy. While Ferreira (2011) shows that patients who received ozonized oil as an intracanal medication had their recovery enhanced, Nogales (2011) states that there was no significant difference between him, calcium hydroxide associated with camphorated paramonochlorophenol and glycerin.
The author adds that, in situations where NaOCl cannot be used in high concentrations, ozone in gaseous form can be an equivalent substitute.

Systematic review
Data base:: Academic Google 2009.

Randomized Controlled Study
Ferreira. Effect on ozone therapy periapical bone repair as an adjunct to endodontic treatment: a radiographic clinical study. 2011.
-Evaluate in vitro the effects of ozone therapy and other root canal disinfectants infected with Enterococcus faecalis.
-Examine the effect of ozone as an intracanal medication.

Clinical and radiographic study
Data base:: Academic Google -In the other studies, it did not show significant results; -In three studies, ozone combined with other media completely inhibited pathogens and enhanced recovery.

IV. CONCLUSION
Ozone therapy is consolidated as a promising, safe and low cost complementary treatment option, generating benefits, especially for low-income patients. It is a widely known and used therapeutic modality due to the large number of bacteria and infectious diseases being sensitive to ozone.
Although laboratory studies advocate that ozone therapy is biologically effective and atraumatic for dental practices, there is still a discrepancy in the concentrations of therapeutic ozone levels, requiring more randomized, double-blind clinical trials with well-designed sample sizes and that present standardized measurement and analysis methods, in order to clarify the ideal concentrations and periods of ozone administration.