Influence Of Non-thermal Atmospheric Pressure Plasma On The Rat Dental Pulp

In recent years, Non-thermal Atmospheric Pressure Plasma (NAPP)has attracted increased attention in dentistry, such as Surface modifications of dental implants, Surface disinfection,Root canal disinfection, Tooth whitening and Peri-implantitis. In Tooth whitening, Non-thermal Atmospheric Pressure Plasma has the potential to serve as an effective augmentation for tooth-whitening procedure, but there is rarely report about the influence of Non-thermal Atmospheric Pressure Plasma on the rat dental pulp after being treated by it.In this study, by choosing different tooth bleaching treatment (include plasma, plasma +blank gel and 35%H2O2gel)to observe the effect on dental pulp tissue of rats. In order to provide a solid foundation for the further clinical application.The present study including two sections:1. The histopathological study of Non-thermal Atmospheric Pressure Plasma on rat pulp tissues.This study was divided into four groups:control group, plasma group, plasma+blank gel group and 35%H2O2 gel group. Each group was divided into continuous and intermittent manner. Observe the pathological changes of rat dental pulp during the bleaching treatment and comparison the pulp situation with control group. The results showed that the plasma+blank gel group have no visible effect on the pulp tissue and the intermittent group have the same performance with the control group. Most of the specimens showed moderate inflammatory infiltration of the pulp in plasma group and 35%H2O2gel group.2. The Immunohistochemistry study of Non-thermal Atmospheric Pressure Plasma on rat pulp tissues.Four groups:control group, plasma group, plasma+blank gel group and 35%H2O2 gel group were set up in this study. Each group was divided into continuous and intermittent manner. Immunohistochemistry of HSP70, MMP-2, MMP-9 were observed in the process of the different performance of the pulp tissue. The results showed that most of the specimens showed no expression of the pulp in control group. The expression of HSP70 in plasma group was higher than that in 35% hydrogen peroxide gel group, while The expression of MMP-2, MMP-9 was higher than that in 35% hydrogen peroxide gel group. HSP70, MMP-2, MMP-9 were lower expression or no expression in plasma+blank gel group. HSP70. MP-2, MMP-9 were showed strong expression in 35% hydrogen peroxide gel group. Different time groups showed different expression in experimental group except control group.Study on tooth bleaching by the Non-thermal Atmospheric Pressure Plasma, minimal impact on pulp tissues in the plasma+blank gel group.We want to suggest these experiments as a possible safety standard for upcoming plasma devices where an application on tooth is targeted.