The antimicrobial effect and pain control of ozonized gel versus gaseous ozone in the management of primary molars caries: randomized clinical trial with in vivo microbiological evaluation

Background: Pediatric dentistry has been radically revolutionized in recent years with the atraumatic approach (atraumatic restorative treatment (ART)), which is able to preserve the vitality of the tooth, with a higher attention to the child’s well-being and emotional comfort. In this scenario, the use of ozone with its decontaminating power and bacterial load reduction, can play a decisive role in the application of the principles of selective caries removal (SCR). The aim of this study was to evaluate and compare the efficacy of ozonized gel (GeliO3) and gaseous ozone (healOzone X4) by analysing colony forming unit (CFU) microbial load of Streptococcus mutans (S. mutans) after caries removal, together with patient sensitivity and compliance. Methods: 16 patients aged 4–12 years were enrolled and randomly assigned to gel or gas treatment. Baseline dental and periodontal indices, such as Gingival Index (GI), Plaque Index (PI), International Caries Detection and Assessment System (ICDAS), and Basic Erosive Wear Examination, were assessed. After manual caries removal with an excavator, microbiological samples were collected with a sterile paper cone at T0 (before treatment), T1 (after ozone application for 30 seconds), and T2 (after an additional 30 seconds application). Schiff Air Index (SAI) and Face, Legs, Activity, Cry and Consolability (FLACC) were recorded at T0 and at T2 to evaluate patients’ compliance and dental sensitivity of the clinical procedure. Data underwent statistical analysis (significance: p < 0.05). Results: Significantly lower microbial loads were found after treatment in both groups (p < 0.05) with no significant between-group differences (p > 0.05). SAI and FLACC showed no significant inter-and intragroup differences at any time point (p > 0.05). Conclusions: GeliO3 and healOzone X4 demonstrated comparable antimicrobial effect against S. mutans. The procedures had no emotional impact on paediatric patients. Clinical Trial Registration: clinicaltrials.gov (NCT06641323).