The Whitening Effect and Histological Safety of Nonthermal Atmospheric Plasma Inducing Tooth Bleaching

Abstract

Various light sources have been applied to enhance the bleaching effect. This study was to identify the histological evaluation in oral soft tissues, as well as tooth color change after tooth bleaching by nonthermal atmospheric pressure plasma (NAPP). Nine New Zealand adult female rabbits were randomly divided into three groups (n = 3): group 1 received no treatment; group 2 was treated with NAPP and 15% carbamide peroxide (CP), which contains 5.4% H2O2, and group 3 was treated with 15% CP without NAPP. Color change (ΔE) was measured using the Shade Eye NCC colorimeter. Animals were euthanized one day later to analyze the histological responses occurring in oral soft tissues, including pulp, gingiva, tongue, buccal mucosa, and hard and soft palates. Changes in all samples were analyzed by hematoxylin and eosin staining and Masson’s trichrome. Teeth treated with plasma showed higher ΔE than that obtained with bleaching agents alone. Overall, the histological characteristics observed no appreciable changes. The combinational treatment of plasma had not indicated inflammatory responses as well as thermal damages. NAPP did not cause histological damage in oral soft tissues during tooth bleaching. We suggest that NAPP could be a novel alternative energy source to conventional light sources for tooth bleaching.

The Effect of Natural Antioxidants on Free Radicals Clearance after Tooth Bleaching

“…Tukey's post hoc test indicated a statistical substantial variation between control group and each of the other groups. Table (1) and figure (2,3). (0.202±0.011), with the least value recorded in ascorbic acid group (0.029±0.008).…”

“…The mechanism of tooth whitening using peroxides occurs by penetration of peroxide through the porosities of enamel prism to the dentin. Oxidation and formation of free radicals lead to lighten of colored species and achieve rapid aesthetic results (1) .…”

Low-Temperature Plasma for Biology, Hygiene, and Medicine: Perspective and Roadmap

“…The RONS produced by LTP has been considered playing important roles in antimicrobial processes and surface modification, and also known to cause oxidative and nitrosative stress to cells and tissue. Nam et al recently conducted a histological safety study in a rabbit model using an LTP for tooth bleaching [183]. The LTP was based on a DBD configuration, powered by 15 kHz ac at 10-kV peak voltage.…”

“…The working gas was Ar. The gap temperature was about 35 • C. The study concluded that the combinational treatment of plasma and 15% carbamide peroxide (CP) resulted in the most color change compared with 15% CP treatment alone, and the combination treatment did not indicate inflammatory responses nor thermal damages [183]. Nam et al also noted that the plasma did not cause histological damage in oral soft tissues during tooth bleaching [183].…”

“…The gap temperature was about 35 • C. The study concluded that the combinational treatment of plasma and 15% carbamide peroxide (CP) resulted in the most color change compared with 15% CP treatment alone, and the combination treatment did not indicate inflammatory responses nor thermal damages [183]. Nam et al also noted that the plasma did not cause histological damage in oral soft tissues during tooth bleaching [183]. Another recent in vivo study conducted by Yao et al [167] demonstrated the antimicrobial effectiveness of an NTAP against apical periodontitis in a beagle model, comparable to that of 2% CHX irrigation, with no detected structural damage in dentin or tissue necrosis at the periapical region.…”