Investigation of the effects of ozonation of irrigating solutions on their physical properties

The aim of this study was to investigate the effects of ozonation of irrigating solutions on their physical properties and dentinal tubule penetration. Sodium hypochlorite (5%, 2.5%, 1%), EDTA (17%), chlorhexidine digluconate (2%), and saline solutions, along with their ozonated counterparts, were used Ozonation was performed using an Ozonette Ozone Generator (SEDECAL, Madrid, Spain) set to a gas-phase ozone concentration of 80 µg/NmL, with a gas flow rate of 30 L/h and a contact time of 5 min. The pH, density, and viscosity values of the solutions were determined using a pH meter, pycnometer, and Ostwald viscometer, respectively. For the evaluation of dentinal tubule penetration, the solutions were labeled with Rhodamine B, applied to extracted human teeth, and analyzed using confocal laser scanning microscopy (CLSM) following irrigation. Mean and maximum penetration depths as well as spread areas were measured. Ozonation significantly altered the density and viscosity of NaOCl and EDTA solutions. CLSM analyses revealed that dentinal tubule penetration increased after ozonation in NaOCl groups, whereas it decreased in the EDTA group. Particularly in the NaOCl groups, the effect of ozonation on penetration capacity varied depending on the concentration. Ozonation influences both the physical properties of irrigating solutions and their penetration behavior into dentinal tubules. This effect is dependent on the type and concentration of the solution. The findings provide new insights that should be considered regarding the clinical use of ozonated irrigants.