scholarly journals Light Energy Dose and Photosensitizer Concentration Are Determinants of Effective Photo-Killing against Caries-Related Biofilms

2020 ◽  
Vol 21 (20) ◽  
pp. 7612
Author(s):  
Abdulrahman A. Balhaddad ◽  
Mohammed S. AlQranei ◽  
Maria S. Ibrahim ◽  
Michael D. Weir ◽  
Frederico C. Martinho ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Red Light ◽  
In Vitro Study ◽  
Disease Recurrence ◽  
Light Energy ◽  
Chemical Components ◽  
Biofilm Inhibition ◽  
Log Reduction ◽  
Energy Dose

Caries-related biofilms and associated complications are significant threats in dentistry, especially when biofilms grow over dental restorations. The inhibition of cariogenic biofilm associated with the onset of carious lesions is crucial for preventing disease recurrence after treatment. This in vitro study defined optimized parameters for using a photosensitizer, toluidine blue O (TBO), activated via a red light-emitting diode (LED)-based wireless device to control the growth of cariogenic biofilms. The effect of TBO concentrations (50, 100, 150, and 200 μg/mL) exposed to light or incubated in the dark was investigated in successive cytotoxicity assays. Then, a mature Streptococcus mutans biofilm model under sucrose challenge was treated with different TBO concentrations (50, 100, and 150 μg/mL), different light energy doses (36, 108, and 180 J/cm2), and different incubation times before irradiation (1, 3, and 5 min). The untreated biofilm, irradiation with no TBO, and TBO incubation with no activation represented the controls. After treatments, biofilms were analyzed via S. mutans colony-forming units (CFUs) and live/dead assay. The percentage of cell viability was within the normal range compared to the control when 50 and 100 μg/mL of TBO were used. Increasing the TBO concentration and energy dose was associated with biofilm inhibition (p < 0.001), while increasing incubation time did not contribute to bacterial elimination (p > 0.05). Irradiating the S. mutans biofilm via 100 μg/mL of TBO and ≈180 J/cm2 energy dose resulted in ≈3-log reduction and a higher amount of dead/compromised S. mutans colonies in live/dead assay compared to the control (p < 0.001). The light energy dose and TBO concentration optimized the bacterial elimination of S. mutans biofilms. These results provide a perspective on the determining parameters for highly effective photo-killing of caries-related biofilms and display the limitations imposed by the toxicity of the antibacterial photodynamic therapy’s chemical components. Future studies should support investigations on new approaches to improve or overcome the constraints of opportunities offered by photodynamic inactivation of caries-related biofilms.

scholarly journals Effect of Gaseous Ozone on Listeria monocytogenes Planktonic Cells and Biofilm: An In Vitro Study

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1484
Author(s):  
Felice Panebianco ◽  
Selene Rubiola ◽  
Francesco Chiesa ◽  
Tiziana Civera ◽  
Pierluigi Aldo Di Ciccio
Keyword(s):  
Listeria Monocytogenes ◽  
In Vitro Study ◽  
Planktonic Cells ◽  
Free Living ◽  
Biofilm Inhibition ◽  
Additional Tool ◽  
Complete Inactivation ◽  
Gaseous Ozone ◽  
Food Borne

Among food-borne pathogens, Listeria monocytogenes continues to pose concerns to food business operators due to its capacity to form biofilm in processing environments. Ozone may be an eco-friendly technology to control microbial contaminations, but data concerning its effect on Listeria monocytogenes biofilm are still limited. In this study, the effect of gaseous ozone at 50 ppm on planktonic cells and biofilm of reference and food-related Listeria monocytogenes strains was evaluated. Ozone caused a reduction in microbial loads of 3.7 ± 0.4 and 3.9 ± 0.4 Log10 CFU/mL after 10 and 30 min, respectively. A complete inactivation of planktonic cells after 6 h of treatment was observed. Biofilm inhibition and eradication treatments (50 ppm, 6 h) resulted in a significant decrease of the biofilm biomass for 59% of the strains tested, whilst a slight dampening of live cell loads in the biofilm state was observed. In conclusion, gaseous ozone is not sufficient to completely counteract Listeria monocytogenes biofilm, but it may be useful as an additional tool to contrast Listeria monocytogenes free-living cells and to improve the existing sanitization procedures in food processing environments.

scholarly journals In vitro study of human osteoblast proliferation and morphology on orthodontic mini-implants

2015 ◽  
Vol 85 (6) ◽  
pp. 920-926 ◽  
Author(s):  
Ricardo Carvalho Bueno ◽  
Roberta Tarkany Basting
Keyword(s):  
Chemical Composition ◽  
In Vitro Study ◽  
Chemical Components ◽  
Control Group ◽  
Osteoblast Proliferation ◽  
Mini Implants ◽  
Significant Difference ◽  
Implant Anchorage ◽  
Positive Effect

ABSTRACT Objective:  To evaluate the proliferation and morphology of human osteoblasts cultured on two brands of mini-implants after 24, 48, and 72 hours, in addition to the chemical composition found on their surface. Materials and Methods:  Two brands of mini-implant (Morelli and Neodent) were evaluated; polystyrene was used as a control group (n  =  3). Osteoblasts were cultured on the surface of sterilized mini-implants in a CO2 incubator at different time periods (24, 48, and 72 hours). Osteoblast proliferation was quantified by scanning electron microscopy using up to 5000× magnification, and cell morphology was analyzed by a single observer. For the chemical analysis, spectroscopy X-ray fluorescence was used to identify and quantify chemical components on the surface of the mini-implants. Results:  Two-way ANOVA showed no significant interaction between the factors studied (P  =  0.686). A Tukey test revealed no significant difference in osteoblast proliferation between the mini-implants at all studied periods; however, a difference in cell proliferation was detected between the Neodent and the control group (P  =  .025). For all groups, time had a direct and positive effect on osteoblast proliferation (P &lt; .001). The significant elements present in both brands of mini-implants were titanium, aluminum, vanadium, and iron. Conclusions:  Osteoblast proliferation was present on the mini-implants studied, which increased over time; however, no significant difference between brands was observed. No difference was seen between the mini-implants evaluated in terms of chemical composition. Cell adhesion after 72 hours suggests that areas of bone remodeling can be achieved, thus initiating the process of mini-implant anchorage.

scholarly journals Evaluation of a Bioengineered Honey and Its Synthetic Equivalent as Novel Staphylococcus aureus Biofilm-Targeted Topical Therapies in Chronic Rhinosinusitis

2019 ◽  
Vol 34 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Dionyssia Papadopoulou ◽  
Alicja Dabrowska ◽  
Philip G. Harries ◽  
Jeremy S. Webb ◽  
Raymond N. Allan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Chronic Rhinosinusitis ◽  
In Vitro Study ◽  
Sinus Surgery ◽  
Bacterial Strains ◽  
Methicillin Resistant ◽  
Log Reduction ◽  
Lower Minimum Inhibitory Concentration

Background Chronic rhinosinusitis (CRS) is a common condition which affects the quality of life of millions of patients worldwide and has a significant impact on health-care resources. While Staphylococcus aureus bacterial biofilms play an important role in this disease, antimicrobial therapy is rarely effective and may promote antibiotic resistance. Thus, development of novel biofilm-targeting and antibiotic-sparing therapies is highly desirable and urgently required. Objective This in vitro study evaluated the antimicrobial activity of a novel synthetic honey-equivalent product which was designed to have the same reactive oxygen release profile as the engineered honey SurgihoneyRO™. Methods Treatment efficacy was investigated by assessment of planktonic growth, biofilm viability, thickness, and biomass using 12 CRS-related S. aureus mucosal bacterial strains. Results Both SurgihoneyRO™ and the synthetic honey-equivalent product inhibited growth of planktonic methicillin-resistant and methicillin-sensitive S. aureus strains, with the synthetic honey-equivalent product exhibiting a lower minimum inhibitory concentration. Treatment of established S. aureus biofilms reduced biofilm viability with 24-hour treatment resulting in a 2-log reduction in viability of biofilms formed by methicillin-resistant strains and a 1-log reduction in biofilms formed by methicillin-sensitive strains. Conclusions This preliminary study shows that the synthetic honey-equivalent product provides marked antimicrobial activity against S. aureus biofilms, with the potential for development in the clinical setting as an adjunctive biofilm-targeted therapy in CRS. The ultimate aim of such a product would be to reduce the need for antibiotics, steroids, and invasive surgical procedures in CRS patients as well as improving clinical outcomes following endoscopic sinus surgery.

scholarly journals Toluidine blue O and porphyrin-mediated photodynamic therapy on three main pathogenic bacteria of periodontitis using portable LED phototherapy device

2015 ◽  
Vol 08 (04) ◽  
pp. 1550017 ◽  
Author(s):  
Xuewei Jiang ◽  
Zhichao Fan ◽  
Yili Yu ◽  
Chenying Shao ◽  
Yuanzhen Suo ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Toluidine Blue ◽  
Pathogenic Bacteria ◽  
Light Emitting Diode ◽  
Red Light ◽  
In Vitro Screening ◽  
Light Emitting ◽  
Led Phototherapy ◽  
Prevotella Melaninogenica

Photodynamic therapy (PDT) has been commonly used in treating many diseases, such as cancer and infectious diseases. We investigated the different effects of PDT on three main pathogenic bacteria of periodontitis — Prevotella melaninogenica (P.m.), Porphyromonas gingivalis (P.g.) and Aggregatibacter actinomycetemcomitans (A.a.). The portable red light-emitting diode (LED) phototherapy device was used to assess the exogenous PDT effects with different light doses and photosensitizer concentrations (Toluidine blue O, TBO). The portable blue LED phototherapy device was used to assess the endogenous PDT effects with the use of endogenous photosensitizers (porphyrin) under different light doses. We found out that both exogenous and endogenous PDT were able to restrict the growth of all the three bacteria significantly. Moreover, the optimal PDT conditions for these bacteria were obtained through this in vitro screening and could guide the clinical PDT on periodontitis.

scholarly journals Evaluation of Different Light-Curing Units—Light-Emitting Diodes and Quartz–Tungsten–Halogen-Based Light-Curing Units in Polymerization of Posterior Composite: An In Vitro Study

2018 ◽  
Vol 6 (02/03) ◽  
pp. 060-064
Author(s):  
R. Bansal ◽  
M. Bansal ◽  
S. Walia ◽  
C. Gupta ◽  
L. Bansal ◽  
...  
Keyword(s):  
Composite Resin ◽  
Light Emitting Diode ◽  
In Vitro Study ◽  
Hardness Test ◽  
Acrylic Resin ◽  
Halogen Lamp ◽  
Light Emitting ◽  
Quartz Tungsten Halogen ◽  
Light Curing

Abstract Objective To assess the adequacy of various light-curing units to polymerize the posterior composite resin. Materials and Methods Specimens were prepared by placing a single increment of posterior composite resin in split cylindrical metallic mold of dimension (6.0 mm in diameter and 5 mm in depth). Polymerization was done by utilizing one quartz-tungsten-halogen and three light-emitting diode light-curing units of different powers. The specimens of composite resin were then mounted on metallic molds utilizing autopolymerizing acrylic resin. After polishing, the complete setting of composite resin material was analyzed using Vickers hardness test. Results Showed in each group, hardness reduced as we moved from upper to lower surface of composite resin. Furthermore, hardness increased as intensity of light was increased. The maximum hardness was detected when light-emitting diode light-curing unit having intensity of 1,250 mW/cm2 was utilized and least hardness was detected when halogen lamp having intensity 418 mW/cm2 was utilized and results were found to be highly significant (p < 0.01). Conclusion It was concluded that increased top and bottom hardness can be accomplished by utilizing the light-curing unit of high intensity.

PHOTOTHERAPY OF GINGIVITIS: PILOT CLINICAL STUDY

2011 ◽  
Vol 04 (04) ◽  
pp. 437-446 ◽  
Author(s):  
ELINA A. GENINA ◽  
VLADIMIR A. TITORENKO ◽  
VALERY V. TUCHIN ◽  
GEORGY V. SIMONENKO ◽  
ALEXEY N. BASHKATOV ◽  
...  
Keyword(s):  
Clinical Study ◽  
Treatment Group ◽  
Red Light ◽  
In Vitro Study ◽  
Control Group ◽  
Mechanical Removal ◽  
Pilot Clinical Study ◽  
Photodynamic Reaction ◽  
Microbial Action

The goal of this work was to evaluate the safety and efficacy of the Red Light Emitted Toothbrush (R-LETB) emitting at wavelength of 663 nm with power density of 3.3 mW/cm2 in combination with 0.1%-methylene blue (MB) solution for the reduction of plaque and treatment of gingivitis. A microbiological in vitro study and a pilot clinical study were conducted. The microbiological study has shown total suppression of pathogenic flora after a 3-min exposure to the dye solution followed by a 20-sec treatment with the R-LETB. For the clinical study, 37 subjects of both sexes with gingivitis were enrolled and randomly assigned to one of two groups. Subjects in the first (treatment) group were instructed to rinse their mouth with MB solution provided for 1 min and then brush the teeth with the R-LETB and standardized toothpaste. The second (control) group used only the toothpaste and a regular toothbrush. Subjects in both groups followed their respective procedures 2 times a day (morning and evening) for 30 days. Indices of plaque, gingival bleeding, and inflammation were evaluated at 14-day and 30-day timepoints. In the both groups, all indices improved in comparison with baseline. However, the treatment group demonstrated more pronounced improvement of the studied indices that was attributed to additional anti-microbial action of red light and MB on gum tissue. Thus, the use of R-LETB with MB appears to have a multifactor therapeutic action on oral pathological microflora: mechanical removal of the bacteria and suppressing action on microorganisms due to photodynamic reaction.

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