Low-Temperature Plasma Short-Exposure to Decontaminate Peri-Implantitis-Related Multispecies Biofilms on Titanium Surfaces

Abstract Peri-implantitis is a bacteria-initiated infection that as yet has no effective treatment. A novel approach to treat peri-implantitis is the use of low-temperature plasma (LTP). LTP disrupts the biofilm while conditioning the surrounding host environment for bone growth around the infected implant. The goal of this study was to evaluate the antimicrobial properties of LTP on newly formed (24-h) and mature (7-days) peri-implant-related biofilms. Biofilm was composed of Actinomyces naeslundii (ATCC 12104), Porphyromonas gingivalis (W83), Streptococcus oralis (ATCC 35037), and Veillonella dispar (ATCC 17748). They were cultivated in brain heart infusion supplemented with 1% yeast extract, hemin (0.5 mg/mL), and menadione (5 mg/mL) and kept at 37⁰C in anaerobic conditions for 24-h. The species were mixed for a final concentration of ~105 colony forming units (CFU)/mL (OD=0.01), and the bacterial suspension was transferred to 24-well plates containing titanium specimens. Biofilms were treated with LTP for 1, 3, and 5 min at 3 or 10 mm from plasma-tip to sample. Controls were no treatment (Negative control=NC) and argon-flow at the same LTP conditions. Positive controls were 14 g/mL amoxicillin and 140 µg/mL metronidazole individually or combined, and 0.12% chlorhexidine. Biofilms were evaluated by CFU, confocal laser scanning microscopy (CLSM), and Fluorescence in situ Hybridization (FISH). Wilcoxon Signed-Rank and Wilcoxon Rank Sum tests were applied (α = 0.05). Bacterial growth was observed in all no-treatment groups corroborated by FISH. LTP treatment significantly reduced all bacteria species when compared to the NC in both tested periods and in all treatment combinations (p≤0.016), these results were corroborated by CLSM. There were no significant differences during biofilm development, between 24-h, 3, and 7 days within each LTP treatment, or among the bacteria within each LTP treatment (p≥0.05). LTP application is effective to reduce peri-implantitis-related multispecies biofilms on titanium surfaces.

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Low-Temperature Plasma as an Approach for Inhibiting a Multi-Species Cariogenic Biofilm

Applied Sciences ◽

10.3390/app11020570 ◽

2021 ◽

Vol 11 (2) ◽

pp. 570

Author(s):

Leandro W. Figueira ◽

Beatriz H. D. Panariello ◽

Cristiane Y. Koga-Ito ◽

Simone Duarte

Keyword(s):

Low Temperature ◽

Laser Scanning ◽

Single Species ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Low Temperature Plasma ◽

Temperature Plasma ◽

Plasma Device ◽

Negative Controls ◽

Promising Source

This study aimed to determine how low-temperature plasma (LTP) treatment affects single- and multi-species biofilms formed by Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii formed on hydroxyapatite discs. LTP was produced by argon gas using the kINPen09™ (Leibniz Institute for Plasma Science and Technology, INP, Greifswald, Germany). Biofilms were treated at a 10 mm distance from the nozzle of the plasma device to the surface of the biofilm per 30 s, 60 s, and 120 s. A 0.89% saline solution and a 0.12% chlorhexidine solution were used as negative and positive controls, respectively. Argon flow at three exposure times (30 s, 60 s, and 120 s) was also used as control. Biofilm viability was analyzed by colony-forming units (CFU) recovery and confocal laser scanning microscopy. Multispecies biofilms presented a reduction in viability (log10 CFU/mL) for all plasma-treated samples when compared to both positive and negative controls (p < 0.0001). In single-species biofilms formed by either S. mutans or S. sanguinis, a significant reduction in all exposure times was observed when compared to both positive and negative controls (p < 0.0001). For single-species biofilms formed by S. gordonii, the results indicate total elimination of S. gordonii for all exposure times. Low exposure times of LTP affects single- and multi-species cariogenic biofilms, which indicates that the treatment is a promising source for the development of new protocols for the control of dental caries.

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Development of a methodology for measuring the evolution of duplex stainless-steel low-temperature plasma nitrided phases expansion using confocal laser scanning microscopy

Revista Brasileira de Aplicações de Vácuo ◽

10.17563/rbav.v40.1194 ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Carlos Eduardo Alves Feitosa ◽

Rodrigo Perito Cardoso ◽

Silvio Francisco Brunatto

Keyword(s):

Stainless Steel ◽

Low Temperature ◽

Duplex Stainless Steel ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Low Temperature Plasma ◽

Temperature Plasma ◽

Innovative Methodology ◽

Different Response

Samples of duplex stainless steel SAF 2507 were low-temperature plasma nitrided to characterize separately, on the surface, the behavior of its ferrite and austenite phases in relation to two competing processes, that is, one caused by enrichment by nitrogen, resulting in possible expansion, and the other caused by the removal of superficial atoms via sputtering, which may lead to the retraction of the studied phases. Since these phases have different different compositions and crystalline structures, of which the diffusivity and solubility of nitrogen in them are dependent, a different response for each type of phase can be expected. In this article, an innovative methodology has been developed to quantify and clarify which effects are predominant in the course of nitriding for each of these phases. The results indicate that phase expansion prevails over sputtering.

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Improvement in the Biological Properties of Titanium Surfaces with Low-Temperature Plasma

Metals ◽

10.3390/met9090943 ◽

2019 ◽

Vol 9 (9) ◽

pp. 943

Author(s):

Yu-Hwa Pan ◽

Wan-Ling Yao ◽

Jerry Chin Yi Lin ◽

Eisner Salamanca ◽

Pei-Yo Tsai ◽

...

Keyword(s):

Low Temperature ◽

Surface Properties ◽

Surface Composition ◽

Titanium Implants ◽

Control Group ◽

Osteoblastic Cell ◽

Low Temperature Plasma ◽

Temperature Plasma ◽

X Ray ◽

Titanium Surfaces

Peri-implantitis has become a common complication, accompanied by soft tissue inflammation. Porphyromonas gingivalis infection is the major cause of inflammation and progressive bone loss in the jaws. The surface property of titanium implants is a key factor in the alteration of osseointegration and P. gingivalis adhesion. However, the interplay between P. gingivalis and the surface properties of implants, subjected to different treatments, is not well described. Therefore, we focused on the surface properties of titanium implants; titanium disks that were autoclaved alone were used as controls. Those that were autoclaved and then subjected to low-temperature plasma (LTP) at 85 W and 13.56 MHz and with 100 mTorr of argon gas at room temperature for 15 min formed the experimental group. LTP-treated disks had smoother surfaces than the control group disks. The physical properties, such as scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDX), and X-ray photoelectron spectroscopy (XPS), demonstrated the surface composition was changed after LTP treatment. Further, osteoblastic cell proliferation enhancement was observed in the LTP-treated titanium surfaces. The results also revealed relatively less P. gingivalis adhesion to the LTP-treated disks than on the control disks on spectrophotometry and SEM. These findings clarified that P. gingivalis adhesion is reduced in implants subjected to LTP treatment. Thus, LTP treatment of peri-implantitis with the settings used in the present study is an option that needs further investigation.

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