Dental Care ; Plasma Gases

In this paper, the generation of the plasma, its principle and its application in the sterilization of medical instruments are described. The relation between discharge voltage and air pressure, frequency, electrode distance is analysed and discussed in glow discharge so as to get a new formula of discharge voltage in the whole frequency range and a design has been made to produce a plasma RF power. The result of the study has a great significance to the application of plasma sterilization of medical instruments.
Equipment Design ; Plasma Gases ; Sterilization ; instrumentation

PURPOSE: The aim of this study was to evaluate the effects of atmospheric plasma (APL) versus conventional surface treatments on the adhesion of self-adhesive resin cement to Ti-6Al-4V alloy. MATERIALS AND METHODS: Sixty plates of machined titanium (Ti) discs were divided into five groups (n=12): 1) Untreated (CNT); 2) Sandblasted (SAB); 3) Tribochemically treated (ROC); 4) Tungsten CarbideBur (TCB); 5) APL treated (APL). SEM analysis and surface roughness (Ra) measurements were performed. Self-adhesive resin cement was bonded to the Ti surfaces and shear bond strength (SBS) tests, Ra and failure mode examinations were carried out. Data were analyzed by one-way analysis of variance and chi-squared test. RESULTS: The lowest SBS value was obtained with CNT and was significantly different from all other groups except for APL. The ROC showed the highest SBS and Ra values of all the groups. CONCLUSION: It was concluded that the effect of APL on SBS and Ra was not sufficient and it may not be a potential for promoting adhesion to titanium.
Alloys ; Plasma Gases ; Plasma* ; Resin Cements* ; Titanium* ; Tungsten

PURPOSE: To investigate the effect of non-thermal atmospheric pressure plasma (NTAPP) treatment on shear bond strength (SBS) between resin cement and colored zirconia made with metal chlorides. MATERIALS AND METHODS: 60 zirconia specimens were divided into 3 groups using coloring liquid. Each group was divided again into 2 sub-groups using plasma treatment; the experimental group was treated with plasma, and the control group was untreated. The sub-groups were: N (non-colored), C (0.1 wt% aqueous chromium chloride solution), M (0.1 wt% aqueous molybdenum chloride solution), NP (non-colored with plasma), CP (0.1 wt% aqueous chromium chloride solution with plasma), and MP (0.1 wt% aqueous molybdenum chloride solution with plasma). Composite resin cylinders were bonded to zirconia specimens with MDP-based resin cement, and SBS was measured using a universal testing machine. All data was analyzed statistically using a 2-way ANOVA test and a Tukey test. RESULTS: SBS significantly increased when specimens were treated with NTAPP regardless of coloring (P<.001). Colored zirconia containing molybdenum showed the highest value of SBS, regardless of NTAPP. The molybdenum group showed the highest SBS, whereas the chromium group showed the lowest. CONCLUSION: NTAPP may increase the SBS of colored zirconia and resin cement. The NTAPP effect on SBS is not influenced by the presence of zirconia coloring.
Chlorides ; Chromium ; Molybdenum ; Plasma Gases ; Plasma* ; Resin Cements*

The hydrogen peroxide low temperature plasma sterilization technology solved the problems of thermo-sensitive materials' disinfection and sterilization based on its development and unique characteristics. This paper introduced the researches of clinical application quality control, and showed the hydrogen peroxide low temperature plasma sterilizers were being widely used in hospitals and highly recognized. According to the clinical data and the literatures of the domestic equipment in preliminary application, it could be concluded that the technology maturity of domestic hydrogen peroxide low temperature plasma sterilizers was in a high level. The advantages of using domestic hydrogen peroxide low temperature plasma sterilizers to do disinfection and sterilization included lower cost, safer, faster and non-toxic, etc. Also the management system should be improved and the clinical staff should master the technical essentials, obey the procedures strictly, verify periodically and offer full monitoring to upgrade the quality of sterilization.
Cold Temperature ; Disinfection ; instrumentation ; Hydrogen Peroxide ; chemistry ; Plasma Gases ; chemistry

Biorefinery that utilizes renewable biomass for production of fuels, chemicals and bio-materials has become more and more important in chemical industry. Recently, steam explosion technology, acid and alkali treatment are the main biorefinery treatment technologies. Meanwhile, low temperature plasma technology has attracted extensive attention in biomass refining process due to its unique chemical activity and high energy. We systemically summarize the research progress of low temperature plasma technology for pretreatment, sugar platflow, selective modification, liquefaction and gasification in biomass refinery. Moreover, the mechanism of low temperature plasma in biorefinery and its further development were also discussed.
Biomass ; Biotechnology ; methods ; Biotransformation ; Chemical Industry ; Cold Temperature ; Plasma Gases

PURPOSE: The fourth state of matter, plasma is known as an ionized gas with electrons, radicals and ions. The use of non-thermal plasma (NTP) in cancer research became possible because of the progresses in plasma medicine. Previous studies on the potential NTP-mediated cancer therapy have mainly concentrated on cancer cell apoptosis. In the present study, we compared the inhibitory effect of NTP on cell migration and invasion in the oral squamous cancer cell lines. MATERIALS AND METHODS: We used oral squamous cancer cell lines (SCC1483, MSKQLL1) and different gases (N₂, He, and Ar). To investigate the mechanism of plasma treatment, using different gases (N₂, He, and Ar) which induces anti-migration and anti-invasion properties, we performed wound healing assay, invasion assay and gelatin zymography. RESULTS: The results showed that NTP inhibits cancer cell migration and invasion of oral squamous cancer cell. In addition, focal adhesion kinase expression and matrix metalloproteinase-2/9 activity were also inhibited. CONCLUSION: The suppression of cancer cell invasion by NTP varied depending on the type of gas. Comparison of the three gases revealed that N₂ NTP inhibited cell migration and invasion most potently via decreased expression of focal adhesion kinase and matrix metalloproteinase activity.
Apoptosis ; Cell Line ; Cell Movement ; Epithelial Cells* ; Focal Adhesion Protein-Tyrosine Kinases ; Gases ; Gelatin ; Ions ; Neoplasms, Squamous Cell* ; Paxillin ; Plasma ; Plasma Gases* ; Wound Healing

BACKGROUND: Platelets (PLTs) stored in platelet additive solution (PAS) presents potential benefits in clinical use by reducing the risk of several plasma-associated adverse transfusion reactions and more plasma may be recovered for fractionation. In this study, we compared in vitro characteristics of apheresis PLTs stored in CompoSol PS (Fenwal, Lake Zurich, IL, USA), InterSol (Fenwal, Lake Zurich, IL, USA), SSP+ (MacoPharma, Tourcoing, France), T-PAS+ (Terumo BCT, Lakewood, CO, USA), or plasma to evaluate the effectiveness of PAS. METHODS: PLTs were collected two times by apheresis from 12 healthy volunteers in a study comparing four kinds of PASs with 35% autologous plasma and 100% plasma-stored apheresis PLTs. The parameters of PLTs, including PLT counts, pH, PLT activation markers, blood gases, and metabolic variables were assessed up to 7-day. RESULTS: The results of in vitro assay including PLT concentration, mean PLT volume, pH, and blood gases for PLTs in four kinds of PASs were similar to those in 100% plasma PLTs. All units had Day 5 pH greater than 6.2. In vitro quality rating results, PLTs in T-PAS+ had a rating of 5, 4 for CompoSol PS, 2 for SSP+, 1 for InterSol, and 2 for plasma on Day 5. CONCLUSION: Partial replacement of plasma with CompoSol PS, SSP+, or T-PAS+ in PLTs showed better or equivalent quality and preservability of PLTs compared to PLTs in 100% plasma. The use of PAS for storage of PLTs in clinical practice may have an advantage as PAS-stored PLTs have a reduced volume of plasma.
Blood Component Removal* ; Blood Group Incompatibility ; Blood Platelets* ; Gases ; Healthy Volunteers ; Hydrogen-Ion Concentration ; Lakes ; Plasma

OBJECTIVETo compare the bactericidal efficacy of two different cold plasma (glow discharge and dielectric barrier discharge) treatments on root canal infected with Enterococcus faecalis biofilms in vitro.

METHODSOne hundred and twenty teeth infected with Enterococcus faecalis biofilm in the roots for seven days were divided into twelve groups randomly. Two served as negative control group (gas only, no discharge). Five were teeth treated by dielectric barrier discharge cold plasma and the other five were treated by glow discharge cold plasma. The treatment time in each five groups was 2, 4, 6, 8 and 10 min, respectively. The disinfection of Enterococcus faeccalis biofilm was evaluated by colony forming unit (CFU) counting. The plasma component produced by different devices was analyzed by optical emission spectroscopy (OES).

RESULTSComparing the two plasma treatments, the plasma produced by dielectric barrier discharge had better bactericidal effect than that produced by glow discharge at different treatment time (P < 0.05). The advantage was obvious with the time getting longer. The OES indicated that active components of the two type plasmas were similar. But the peak of excited Ar atom of dielectric barrier discharge was twice as that of glow discharge.

CONCLUSIONThe cold plasma produced by dielectric barrier discharge has more bactericidal efficiency in the treatment of root canal infected with Enterococcus faecalis biofilms.

As a convenient and effective surface modification approach, non-thermal atmospheric pressure plasma (NTAPP)can be used to improve dentin bonding, and has recently become a research focus. Studies have shown that NTAPP can alter dentin surface properties, improve the penetration and polymerization of adhesives, stimulate the cross-linking of collagen, and change the micro-morphology and element content of dentin surface, thus improve the dentin bonding quality. This article introduces the current research progress in the application of NTAPP in the field of dentin bonding, in order to provide innovative information for future research in optimization of the quality of dentin bonding.
Dental Bonding ; Dental Cements ; Dentin ; Dentin-Bonding Agents ; Materials Testing ; Plasma Gases ; Resin Cements ; Surface Properties