scholarly journals Influence of Curing Time on the Microbiological Behavior of Bulk-Fill Nanohybrid Resin Composites

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2948
Author(s):  
Andrei C. Ionescu ◽  
Allegra Comba ◽  
Eugenio Brambilla ◽  
Nicoleta Ilie ◽  
Lorenzo Breschi ◽  
...  

This in vitro study aimed to evaluate the influence of curing time on surface characteristics and microbiological behavior of three bulk-fill resin-based composites (RBCs). Materials were light-cured for either 10 s or 80 s, then finished using a standard clinical procedure. They were characterized by surface morphology (SEM), surface elemental composition (EDS), surface roughness (SR), and surface free energy (SFE). Microbiological behavior was assessed as S. mutans adherence (2 h) and biofilm formation (24 h) using a continuous-flow bioreactor. Statistical analysis included a two-way ANOVA and Tukey’s test (p < 0.05). Materials differed substantially as filler shape, dimension, elemental composition and resin matrix composition. Significant differences between materials were found for SR, SFE, and microbiological behavior. Such differences were less pronounced or disappeared after prolonged photocuring. The latter yielded significantly lower adherence and biofilm formation on all tested materials, similar to conventional RBCs. Improved photoinitiators and UDMA-based resin matrix composition may explain these results. No correlation between surface characteristics and microbiological behavior can explain the similar microbiological behavior of bulk-fill materials after prolonged photocuring. This different performance of bulk-fill materials compared with conventional RBCs, where surface characteristics, especially surface chemistry, influence microbiological behavior, may have important implications for secondary caries occurrence and restoration longevity.

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1758
Author(s):  
Urszula Wójcik-Bojek ◽  
Joanna Rywaniak ◽  
Przemysław Bernat ◽  
Anna Podsędek ◽  
Dominika Kajszczak ◽  
...  

Staphylococcus aureus is still one of the leading causes of both hospital- and community-acquired infections. Due to the very high percentage of drug-resistant strains, the participation of drug-tolerant biofilms in pathological changes, and thus the limited number of effective antibiotics, there is an urgent need to search for alternative methods of prevention or treatment for S. aureus infections. In the present study, biochemically characterized (HPLC/UPLC–QTOF–MS) acetonic, ethanolic, and water extracts from fruits and bark of Viburnum opulus L. were tested in vitro as diet additives that potentially prevent staphylococcal infections. The impacts of V. opulus extracts on sortase A (SrtA) activity (Fluorimetric Assay), staphylococcal protein A (SpA) expression (FITC-labelled specific antibodies), the lipid composition of bacterial cell membranes (LC-MS/MS, GC/MS), and biofilm formation (LIVE/DEAD BacLight) were assessed. The cytotoxicity of V. opulus extracts to the human fibroblast line HFF-1 was also tested (MTT reduction). V. opulus extracts strongly inhibited SrtA activity and SpA expression, caused modifications of S. aureus cell membrane, limited biofilm formation by staphylococci, and were non-cytotoxic. Therefore, they have pro-health potential. Nevertheless, their usefulness as diet supplements that are beneficial for the prevention of staphylococcal infections should be confirmed in animal models in the future.


PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e107588 ◽  
Author(s):  
Hironobu Koseki ◽  
Akihiko Yonekura ◽  
Takayuki Shida ◽  
Itaru Yoda ◽  
Hidehiko Horiuchi ◽  
...  

Author(s):  
María Consuelo Latorre ◽  
María Jesús Pérez-Granda ◽  
Paul B Savage ◽  
Beatriz Alonso ◽  
Pablo Martín-Rabadán ◽  
...  

Abstract Background Ventilator-associated pneumonia is one of the most common nosocomial infections, caused mainly by bacterial/fungal biofilm. Therefore, it is necessary to develop preventive strategies to avoid biofilm formation based on new compounds. Objectives We performed an in vitro study to compare the efficacy of endotracheal tubes (ETTs) coated with the ceragenin CSA-131 and that of uncoated ETTs against the biofilm of clinical strains of Pseudomonas aeruginosa (PA), Escherichia coli (EC) and Staphylococcus aureus (SA). Methods We applied an in vitro bench top model using coated and uncoated ETTs that were treated with three different clinical strains of PA, EC and SA for 5 days. After exposure to biofilm, ETTs were analysed for cfu count by culture of sonicate and total number of cells by confocal laser scanning microscopy. Results The median (IQR) cfu/mL counts of PA, EC and SA in coated and uncoated ETTs were, respectively, as follows: 1.00 × 101 (0.0–3.3 × 102) versus 3.32 × 109 (6.6 × 108–3.8 × 109), P &lt; 0.001; 0.0 (0.0–5.4 × 103) versus 1.32 × 106 (2.3 × 103–5.0 × 107), P &lt; 0.001; and 8.1 × 105 (8.5 × 101–1.4 × 109) versus 2.7 × 108 (8.6 × 106–1.6 × 1011), P = 0.058. The median (IQR) total number of cells of PA, EC and SA in coated and non-coated ETTs were, respectively, as follows: 11.0 [5.5–not applicable (NA)] versus 87.9 (60.5–NA), P = 0.05; 9.1 (6.7–NA) versus 62.6 (42.0–NA), P = 0.05; and 97.7 (94.6–NA) versus 187.3 (43.9–NA), P = 0.827. Conclusions We demonstrated significantly reduced biofilm formation in coated ETTs. However, the difference for SA was not statistically significant. Future clinical studies are needed to support our findings.


2020 ◽  
Vol 15 (4) ◽  
pp. 493-499
Author(s):  
Aylin Pasaoglu Bozkurt ◽  
Özge Ünlü ◽  
Mehmet Demirci

2020 ◽  
Vol 54 (4) ◽  
pp. 311-320
Author(s):  
Neeraj E Kolge ◽  
Vivek J Patni ◽  
Girish Karandikar ◽  
Ravindranath VK ◽  
Prateek Daga ◽  
...  

Aims & Objectives: The aim of the study was to evaluate and compare dimensional accuracy, surface characteristics and load deflection attributes of SS wires sourced from six different commercial houses. Materials & Methods: 0.019” x 0.025” SS wire samples were divided into 6 groups and evaluated and compared for the aforementioned properties. Dimensional accuracy, surface roughness, frictional resistance, load deflection rate and ultimate tensile strength were evaluated and compared. Results: Dimensional accuracy did not vary significantly. Surface Profilometry proved 3M Unitek (Group 1) to be the wire with least irregularities. According to SEM, Modern Orthodontics (Group 6) and 3M Unitek (Group 1) in terms of ‘Sa’ and ‘Sq’ respectively had the smoothest surface finish. SS wires sourced from G&H Orthodontics (Group 2) exhibited least frictional resistance. Load deflection rates varied for all the groups for all three parameters under the study. UTS was best for SS wires sourced from Rabbit Force Orthodontics (Group 5). Conclusion: No wire from a single commercial house excels in all the parameters that were evaluated, each one having its aces and minuses.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2458 ◽  
Author(s):  
Bruna Raquel Zancopé ◽  
Vanessa B. Dainezi ◽  
Marinês Nobre-dos-Santos ◽  
Sillas Duarte ◽  
Vanessa Pardi ◽  
...  

BackgroundA carbon dioxide (CO2) laser has been used to morphologically and chemically modify the dental enamel surface as well as to make it more resistant to demineralization. Despite a variety of experiments demonstrating the inhibitory effect of a CO2laser in reduce enamel demineralization, little is known about the effect of surface irradiated on bacterial growth. Thus, this in vitro study was preformed to evaluate the biofilm formation on enamel previously irradiated with a CO2laser (λ = 10.6 µM).MethodsFor this in vitro study, 96 specimens of bovine enamel were employed, which were divided into two groups (n = 48): 1) Control-non-irradiated surface and 2) Irradiated enamel surface. Biofilms were grown on the enamel specimens by one, three and five days under intermittent cariogenic condition in the irradiated and non-irradiated surface. In each assessment time, the biofilm were evaluated by dry weigh, counting the number of viable colonies and, in fifth day, were evaluated by polysaccharides analysis, quantitative real time Polymerase Chain Reaction (PCR) as well as by contact angle. In addition, the morphology of biofilms was characterized by fluorescence microscopy and field emission scanning electron microscopy (FESEM). Initially, the assumptions of equal variances and normal distribution of errors were conferred and the results are analyzed statistically by t-test and Mann Whitney test.ResultsThe mean of log CFU/mL obtained for the one-day biofilm evaluation showed that there is statistical difference between the experimental groups. When biofilms were exposed to the CO2laser, CFU/mL and CFU/dry weight in three day was reduced significantly compared with control group. The difference in the genes expression (Glucosyltransferases (gtfB) and Glucan-binding protein (gbpB)) and polysaccharides was not statically significant. Contact angle was increased relative to control when the surface was irradiated with the CO2laser. Similar morphology was also visible with both treatments; however, the irradiated group revealed evidence of melting and fusion in the specimens.ConclusionIn conclusion, CO2laser irradiation modifies the energy surface and disrupts the initial biofilm formation.


2010 ◽  
Vol 124 (6) ◽  
pp. 594-598 ◽  
Author(s):  
C H Jang ◽  
H Park ◽  
Y B Cho ◽  
C H Choi

AbstractBackground and objective:Bacterial biofilm formation has been implicated in the high incidence of persistent otorrhoea after tympanostomy tube insertion. It has been suggested that the tube material may be an important factor in the persistence of such otorrhoea. Development of methicillin-resistant Staphylococcus aureus otorrhoea after tympanostomy tube placement is a growing concern. We evaluated the effect of using vancomycin and chitosan coated tympanostomy tubes on the incidence of methicillin-resistant Staphylococcus aureus biofilm formation in vitro.Materials and methods:Three sets each of vancomycin-coated silicone tubes (n = 5), commercial silver oxide coated silicone tubes (n = 5) and uncoated tympanostomy tubes (as controls; n = 5) were compared as regards resistance to methicillin-resistant Staphylococcus aureus biofilm formation after in vitro incubation.Results:Scanning electron microscopy showed that the surfaces of the silver oxide coated tubes supported the formation of thick biofilms with crusts, comparable to the appearance of the uncoated tubes. In contrast, the surface of the vancomycin-coated tympanostomy tubes was virtually devoid of methicillin-resistant Staphylococcus aureus biofilm.Conclusion:Vancomycin-coated tympanostomy tubes resist methicillin-resistant Staphylococcus aureus biofilm formation. Pending further study, such tubes show promise in assisting the control of methicillin-resistant Staphylococcus aureus biofilm formation.


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