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Klapcsik K. GPU accelerated numerical investigation of the spherical stability of an acoustic cavitation bubble excited by dual-frequency. ULTRASONICS SONOCHEMISTRY 2021; 77:105684. [PMID: 34358882 PMCID: PMC8350425 DOI: 10.1016/j.ultsonch.2021.105684] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 05/03/2023]
Abstract
The spherical stability of an acoustic cavitation bubble under dual-frequency excitation is investigated numerically. The radial dynamics is described by the Keller-Miksis equation, which is a second-order ordinary differential equation. The surface dynamics is modelled by a set of linear ordinary differential equation according to Hao and Prosperetti (1999), which takes into account the effect of vorticity by boundary layer approximation. Due to the large amount of investigated parameter combinations, the numerical computations were carried out on graphics processing units. The results showed that for bubble size between RE=2μm and 4μm, the combination of a low and a high frequency, and the combination of two close but not equal frequencies are important to prevent the bubble losing its shape stability, while reaching the chemical threshold (Rmax/RE=3) (Kalmár et al., 2020). The phase shift between harmonic components of dual-frequency excitation has no effect on the shape stability.
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Affiliation(s)
- Kálmán Klapcsik
- Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Hydrodynamic Systems, P.O. Box 91, 1521 Budapest, Hungary.
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Villalta-Briones N, Baca P, Bravo M, Solana C, Aguado-Pérez B, Ruiz-Linares M, Arias-Moliz MT. A laboratory study of root canal and isthmus disinfection in extracted teeth using various activation methods with a mixture of sodium hypochlorite and etidronic acid. Int Endod J 2020; 54:268-278. [PMID: 32970865 DOI: 10.1111/iej.13417] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 09/10/2020] [Accepted: 09/17/2020] [Indexed: 12/29/2022]
Abstract
AIM To evaluate in a laboratory setting the antibiofilm activity of several irrigating protocols including conventional irrigation, ultrasonic activation and XP-endo Finisher, with a mixture of sodium hypochlorite and etidronic acid in infected isthmuses and root canals of extracted human mandibular molar teeth. METHODOLOGY Fifty-six mesial roots of mandibular molars, half of them with a continuous isthmus from the cervical to the apical third between the two root canals (type 1), and the other half with a continuous isthmus from the cervical to the middle third and one canal in the apical third (type 2), were included. The root canals were contaminated for 7 days with an Enterococcus faecalis suspension. There were three experimental groups plus a control group (n = 7 per type of root canal anatomy). All the root canals, except for the control group that was not treated, were chemomechanically prepared and then assigned to one of the experimental groups according to the final adjunctive procedure: conventional irrigation, ultrasonic activation or XP-endo Finisher activation. The irrigating solution used was a combination of 2.5% sodium hypochlorite and 9% etidronic acid, and the final protocols were applied for three cycles of 30 s with a 3 mL volume. The antibiofilm activity was evaluated at each location (root canal and isthmus) and third (cervical, middle and apical) using confocal laser scanning microscopy and the live/dead technique. Statistical analysis was performed using SPSS (descriptive statistics) and SUDAAN (P-value calculations). RESULTS Root canals had significantly lower biovolume values than the isthmuses (P < 0.05). The biovolume in the root canals was significantly reduced in all the experimental groups in all the thirds except for conventional irrigation in the apical third (P > 0.05). In the cervical and middle thirds, ultrasonic activation was associated with the lowest biovolumes (P < 0.05), followed by XP-endo Finisher. In the isthmus, disinfection was similar in all the thirds for all the protocols. Conventional irrigation was associated with intermediate values with no significant differences from the control group or from the activated protocols (P > 0.05), although the latter were significantly different from the control group (P < 0.05). No differences were found between ultrasonic activation and XP-endo Finisher in the middle and apical thirds (P > 0.05) in the isthmuses. CONCLUSIONS In this laboratory study on extracted teeth, the isthmus was more difficult to disinfect than root canals. In the root canals, ultrasonic activation and XP-endo Finisher had a greater effectiveness than conventional irrigation. In the isthmuses, no differences were observed between the two activation techniques and conventional irrigation.
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Affiliation(s)
- N Villalta-Briones
- Department of Stomatology, School of Dentistry, University of Granada, Granada, Spain
| | - P Baca
- Department of Stomatology, School of Dentistry, University of Granada, Granada, Spain
| | - M Bravo
- Department of Stomatology, School of Dentistry, University of Granada, Granada, Spain
| | - C Solana
- Department of Stomatology, School of Dentistry, University of Granada, Granada, Spain
| | - B Aguado-Pérez
- Department of Stomatology, School of Dentistry, University of Granada, Granada, Spain
| | - M Ruiz-Linares
- Department of Stomatology, School of Dentistry, University of Granada, Granada, Spain
| | - M T Arias-Moliz
- Department of Microbiology, School of Dentistry, University of Granada, Granada, Spain
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Seo Y, Leong J, Park JD, Hong YT, Chu SH, Park C, Kim DH, Deng YH, Dushnov V, Soh J, Rogers S, Yang YY, Kong H. Diatom Microbubbler for Active Biofilm Removal in Confined Spaces. ACS APPLIED MATERIALS & INTERFACES 2018; 10:35685-35692. [PMID: 30107112 PMCID: PMC8216637 DOI: 10.1021/acsami.8b08643] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Bacterial biofilms form on and within many living tissues, medical devices, and engineered materials, threatening human health and sustainability. Removing biofilms remains a grand challenge despite tremendous efforts made so far, particularly when they are formed in confined spaces. One primary cause is the limited transport of antibacterial agents into extracellular polymeric substances (EPS) of the biofilm. In this study, we hypothesized that a microparticle engineered to be self-locomotive with microbubbles would clean a structure fouled by biofilm by fracturing the EPS and subsequently improving transports of the antiseptic reagent. We examined this hypothesis by doping a hollow cylinder-shaped diatom biosilica with manganese oxide (MnO2) nanosheets. In an antiseptic H2O2 solution, the diatoms doped by MnO2 nanosheets, denoted as diatom bubbler, discharged oxygen gas bubbles continuously and became self-motile. Subsequently, the diatoms infiltrated the bacterial biofilm formed on either flat or microgrooved silicon substrates and continued to generate microbubbles. The resulting microbubbles merged and converted surface energy to mechanical energy high enough to fracture the matrix of biofilm. Consequently, H2O2 molecules diffused into the biofilm and killed most bacterial cells. Overall, this study provides a unique and powerful tool that can significantly impact current efforts to clean a wide array of biofouled products and devices.
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Affiliation(s)
- Yongbeom Seo
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Jiayu Leong
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore
| | - Jun Dong Park
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yu-Tong Hong
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Sang-Hyon Chu
- National Institute of Aerospace, 100 Exploration Way, Hampton, Virginia 23666, United States
| | - Cheol Park
- Advanced Materials and Processing Branch, NASA Langley Research Center, Hampton, Virginia 23681, United States
| | - Dong Hyun Kim
- Department of Human and Culture Convergence Technology R&BD Group, Korea Institute of Industrial Technology, Ansan-si, Gyeonggi-do 426-910, South Korea
| | - Yu-Heng Deng
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Vitaliy Dushnov
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Joonghui Soh
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Simon Rogers
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yi Yan Yang
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore
| | - Hyunjoon Kong
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Carle Illinois College of Medicine, Department of Bioengineering, Department of Pathobiology, Carl R. Woese Institute for Genomic Biology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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