applied sciences  
1.1 _Article_ Ozone Therapy for Early Childhood Caries (ECC) Treatment: An In Vivo Prospective Study  
[PERSON] **1**, [PERSON] **2**, [PERSON] **1**, **[PERSON] **1** and [PERSON] **1,3,*(c)**  
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Footnote  
Depending on the severity of the pathology, several significant consequences of ECC (pain, infections, etc.) may have a negative impact on a child's health and quality of life [2; 6; 7].  
ECC management is complex and may require treatments under general anesthesia, especially in very young, severely affected children uncooperative with traditional dental treatments [2; 8; 9; 10].  
Prevention and early diagnosis are essential to avoid the most frequent consequences related to ECC and allow a non-invasive or minimally invasive therapeutic approach, gaining patients' cooperation and reducing the care burden for both families and the National Health Service [1; 2; 5; 10].  
Among minimally invasive treatments of ECC, ozone therapy is a health-safe, simple, painless, and ultra-conservative approach that might be useful for controlling caries progression in children uncooperative with traditional dental treatments until appropriate cooperation and compliance are achieved [11; 12; 13; 14].  
Thanks to its high oxidizing power, ozone (O\({}_{3}\)) can oxidize the bacterial cell wall, causing its lysis, and the pyruvate acid produced by bacteria, turning it into acetic acid and carbon dioxide, arresting or reversing caries progression.  
If the antimicrobial properties of ozone are well known [13; 15; 16; 17; 18; 19], its remineralizing and desensitizing activities are controversial: by increasing the patency of dental tubules, ozone seems to enhance the diffusion of salivary ions to the surface of the decayed dentin, thus promoting its remineralization and reducing hypersensitivity [12; 13; 14; 15; 16; 20; 21; 22].  
The potential of the combined use of ozone with disinfect agents, i.e., chlorheximide (CHX), and remineralizing products i.e., sodium fluoride (NaF), nano-hydroxapatite [13; 23; 24; 25; 26] and/or glass ionomer cements (GICs) [27], in halting or slowing down caries progression in ECC-affected children is positively described in the literature, while its efficacy when used alone, as well as its ideal concentration and the time needed to reach a full antimicrobial effect, remain controversial [13; 23; 24; 25; 26; 27].  
Given the data available so far, the present in vivo study aimed to deepen the knowledge on ozone therapy's effects in treating ECC-affected children uncooperative with traditional restorative treatments. The goal was to increase the decayed dentin's compactness and reduce the salivary bacterial count and dentin hypersensitivity, improving the patients' and their families' quality of life. The primary null hypothesis tested was that the use of ozone therapy on ECC-affected teeth would not modify the compactness of the affected dentin. The secondary null hypotheses tested were that ozone would not reduce the dentin hypersensitivity and salivary bacterial count and would not influence the quality of life in ECC-affected children during a 3-month follow-up.