Browsing by Author "Duarte, Simone"
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Item Antibacterial Activities of Cannabidiol Against Two Major Oral Pathogens(2024-05) Azabi, Asma A.; Windsor, L. Jack; Gregory, Richard L.; Platt, Jeffrey A.; Duarte, Simone; Goodpaster, JohnDespite advances in oral health research, biofilm-mediated oral diseases continue to pose a health challenge. Preventive measures against biofilm-mediated disease aim to inhibit pathogenic biofilm formation on tooth surfaces. Cannabidiol (CBD), a Cannabis sativa L. L. extract, has shown antibacterial properties against various bacterial species, especially gram-positive cocci. This dissertation aimed to evaluate the antibacterial efficacy of CBD against Streptococcus mutans and Porphyromonas gingivalis bacterial growth and virulence factors. The effects of CBD on the planktonic, biofilm, and total growth of S. mutans with or without nicotine and P. gingivalis, were evaluated. The minimal inhibitory concentration (MIC), minimal biofilm inhibitory concentrations (MBIC), and minimal bactericidal concentrations (MBC) of CBD were assessed. CBD concentrations ≥ 2.5 μg/ml exhibited significant inhibition (p<0.001) against S. mutans biofilm growth, as well as, biofilm metabolic activity, lactate dehydrogenase (LDH) activity, and extracellular polysaccharides (EPS) production. In the presence of nicotine, which upregulates biofilm formation, CBD demonstrated the same inhibitory effects on S. mutans growth and activities. CBD concentrations ≥ 0.47 μg/ml exhibited significant inhibition (p<0.003) against P. gingivalis biofilm growth. CBD reduced the hemagglutination activities of P. gingivalis and reduced the overall proteolytic activity. Concentrations of CBD ≥ 0.63 μg/ml provided an inhibitory effect on lysine-specific gingipain. The results of these studies demonstrate that CBD has antibacterial activities against S. mutans and P. gingivalis growth and virulence factors related to caries and periodontal diseases, respectively.Item Bioactive Compounds Enhance the Biocompatibility and the Physical Properties of a Glass Ionomer Cement(MDPI, 2024-11-07) de Castilho, Aline Rogéria Freire; Rosalen, Pedro Luiz; Oliveira, Marina Yasbeck; Burga-Sánchez, Jonny; Duarte, Simone; Murata, Ramiro Mendonça; Puppin Rontani, Regina Maria; Pediatric Dentistry, School of DentistryIn order to characterize a novel restorative material, knowledge about the toxicological effect on human cells and the physical behavior of a glass ionomer cement (GIC) containing flavonoids was established. The flavonoids apigenin, naringenin, quercetin, and liquiritigenin were manually incorporated into a GIC. In the control group, no incorporation was performed. Two cell culture assays evaluated the toxicity of GICs: SRB and MTT. For both assays, the keratinocyte cell line (HaCaT) was exposed to GIC (n = 3/group) for 24 h. The physical properties of the GICs were evaluated by compressive strength (n = 10), surface roughness (n = 10), and hardness (n = 10) tests. Cell viability by SRB ranged from 103% to 97%. The control revealed a significant decrease in the metabolism of cells (61%) by MTT, while the GIC+apigenin slightly increased the succinic dehydrogenase activity (105%; p > 0.05), also confirmed microscopically. The compressive strength and roughness values were similar among groups, but the hardness increased after the incorporation of naringenin and quercetin into GIC (p < 0.05). The incorporation of flavonoids positively altered the biological and physical properties of the GICs.Item Comprehensive biomedical applications of low temperature plasmas(Elsevier, 2020-08-26) Duarte, Simone; Panariello, Beatriz H.D.; Cariology, Operative Dentistry and Dental Public Health, School of DentistryThe main component of plasma medicine is the use of low-temperature plasma (LTP) as a powerful tool for biomedical applications. LTP generates high reactivity at low temperatures and can be activated with noble gases with molecular mixtures or compressed air. LTP reactive species are quickly produced, and are a remarkably good source of reactive oxygen and nitrogen species including singlet oxygen (O2), ozone (O3), hydroxyl radicals (OH), nitrous oxide (NO), and nitrogen dioxide (NO2). Its low gas temperature and highly reactive non-equilibrium chemistry make it appropriate for the alteration of inorganic surfaces and delicate biological systems. Treatment of oral biofilm-related infections, treatment of wounds and skin diseases, assistance in cancer treatment, treatment of viruses’ infections (e.g. herpes simplex), and optimization of implants surfaces are included among the extensive plasma medicine applications. Each of these applications will be discussed in this review article.Item Daily Phototherapy with Red Light to Regulate Candida albicans Biofilm Growth(JoVE, 2019) Panariello, Beatriz H. D.; Garcia, Bruna A.; Duarte, Simone; Cariology, Operative Dentistry and Dental Public Health, School of DentistryHere, we present a protocol to assess the outcomes of per diem red light treatment on the growth of Candida albicans biofilm. To increase the planktonic growth of C. albicans SN425, the inoculums grew on Yeast Nitrogen Base media. For biofilm formation, RPMI 1640 media, which have high concentrations of amino acids, were applied to help biofilm growth. Biofilms of 48 h were treated twice a day for a period of 1 min with a non-coherent light device (red light; wavelength = 635 nm; energy density = 87.6 J·cm-2). As a positive control (PC), 0.12% chlorhexidine (CHX) was applied, and as a negative control (NC), 0.89% NaCl was applied to the biofilms. Colony forming units (CFU), dry-weight, soluble and insoluble exopolysaccharides were quantified after treatments. Briefly, the protocol presented here is simple, reproducible and provides answers regarding viability, dry-weight and extracellular polysaccharide amounts after red light treatment.Item Effect of a chlorhexidine-encapsulated nanotube modified pit-and-fissure sealant on oral biofilm(J-STAGE, 2021-05) Feitosa, Sabrina; Carreiro, Adriana F. P.; Martins, Victor M.; Platt, Jeffrey A.; Duarte, Simone; Biomedical Sciences and Comprehensive Care, School of DentistryThe purpose of this study was to characterize a chlorhexidine-encapsulated nanotube modified pit-and-fissure sealant for biofilm development prevention. HS (commercial control); HNT (HS+15wt%Halloysite®-clay-nanotube); CHX10% (HS+15wt% HNT-encapsulated with chlorhexidine 10%); and CHX20% (HS+15wt% HNT-encapsulated with CHX20%) were tested. Degree-of-conversion (DC%), Knoop hardness (KHN), and viscosity were analyzed. The ability of the sealant to wet the fissures was evaluated. Specimens were tested for zones of inhibition of microbial growth. S. mutans biofilm was tested by measuring recovered viability. Data were statistically analyzed (p<0.05). DC% was significantly higher for the HNT-CHX groups. For KHN, CHX10% presented a lower mean value than the other groups. Adding HNT resulted in higher viscosity values. The biofilm on CHX10% and CHX20% sealants presented remarkable CFU/mL reduction in comparison to the HS. The experimental material was able to reduce the biofilm development in S. mutans biofilm without compromising the sealant properties.Item Effect of Curcumin-loaded Photoactivatable Polymeric Nanoparticle on peri-implantitis-related biofilm(2022) Tonon, Caroline Coradi; Panariello, Beatriz; Chorilli, Marlus; Spolidorio, Denise Madalena Palomari; Duarte, Simone; Biomedical and Applied Sciences, School of DentistryCurcumin has been used as a photosensitizer (PS) for antimicrobial photodynamic chemotherapy (PACT). However, its low solubility, instability and poor bioavailability are a challenge for its in vivo application. This study aimed to synthesize curcumin-loaded polymeric nanoparticles (curcumin-NP) and to determine their antimicrobial and cytotoxic effects. Nanoparticles (NP) were synthesized by the nanoprecipitation method using polyprolactone as a polymer. Curcumin-NP was characterized by particle size, polydispersity index and zeta potential, scanning electron microscopy and curcumin encapsulation efficiency (EE). Curcumin-NP was compared to free curcumin solubilized in 10% DMSO as photosensitizers for PACT in single and multi-species Porphyromonas gingivalis, Fusobacterium nucleatum and Streptococcus oralis biofilms. Chlorhexidine 0.12% (CHX) and ultrapure water were used as positive and negative controls, respectively. The cytotoxic effect of curcumin-NP was evaluated on human periodontal ligament fibroblast cells (HPLF). Data were analyzed by ANOVA (α=0.05). Curcumin-NP exhibited homogeneity and stability in solution, small particle size and 67.5% EE of curcumin. Curcumin-NP presented antibiofilm activity at 500 µg/ml when photoactivated. Curcumin-NP and curcumin with and without photoactivation were not cytotoxic to HPLF cells. Curcumin-NP has antimicrobial and antibiofilm properties, with better effects when associated with blue-light, being a promising therapy for preventing and treating peri-implant diseases.Item Effect of titanium dioxide on Streptococcus mutans biofilm(Sage, 2023) Sanders, Molly K.; Duarte, Simone; Ayoub, Hadeel M.; Scully, Allison C.; Vinson, LaQuia A.; Gregory, Richard L.; Pediatric Dentistry, School of DentistryBackground: Streptococcus mutans (S. mutans) participates in the dental caries process. Titanium dioxide (TiO2) nanoparticles produce reactive oxygen species capable of disrupting bacterial DNA synthesis by creating pores in cell walls and membranes. Objective: The objective of this study was to determine the effect of TiO2 on the disruption of S. mutans biofilm. Methods: This study was conducted in four phases involving a TiO2-containing toothbrush and TiO2 nanoparticles. Each phase was completed using 24 h established S. mutans biofilm growth. Phase one data was collected through a bacterial plating study, assessing biofilm viability. Biofilm mass was evaluated in phase two of the study by measuring S. mutans biofilm grown on microtiter plates following crystal violet staining. The third phase of the study involved a generalized oxygen radical assay to determine the relative amount of oxygen radicals released intracellularly. Phase four of the study included the measurement of insoluble glucan/extracellular polysaccharide (EPS) synthesis using a phenol-sulfuric acid assay. Results: Both exposure time and time intervals had a significant effect on bacterial viability counts (p = 0.0323 and p = 0.0014, respectively). Bacterial counts after 6 min of exposure were significantly lower than after 2 min (p = 0.034), compared to the no treatment control (p = 0.0056). As exposure time increased, the amount of remaining biofilm mass was statistically lower than the no treatment control. Exposure time had a significant effect on oxygen radical production. Both the 30 and 100 nm TiO2 nanoparticles had a significant effect on bacterial mass. The silver nanoparticles and the 30 and 100 nm TiO2 nanoparticles significantly inhibited EPS production. Conclusion: The TiO2-containing toothbrush kills, disrupts, and produces oxygen radicals that disrupt established S. mutans biofilm. TiO2 and silver nanoparticles inhibit EPS production and reduce biofilm mass. The addition of TiO2 to dental products may be effective in reducing cariogenic dental biofilm.Item Effectiveness of ozonated water irrigation against an established Enterococcus faecalis biofilm in root canal treated teeth in vitro(2020) Broady, Adam B.; Spolnik, Kenneth J.; Duarte, Simone; Gossweiler, Ana; Bringas, Josef S.; Ehrlich, YgalIntroduction: One of the main objectives of endodontic therapy is to reduce microbes and remove inflamed pulpal tissue within the root canal system (RCS). This is accomplished through chemomechanical debridement of the RCS using hand and rotary instrumentation along with an antimicrobial irrigant. Today, the most commonly used irrigant is sodium hypochlorite (NaOCl), often at concentrations toxic to human cells. The use of ozone as an endodontic irrigant is a novel technique that has been proven to be antimicrobial against several microorganisms. However, independent research is lacking on ozone’s efficacy against an established endodontic biofilm. If ozone’s efficacy against biofilms is confirmed, the use of toxic and potentially dangerous sodium hypochlorite could be replaced in some clinical situations (i.e., regeneration, immature teeth, resorption) with a safer and effective alternative. Objective: The aim of the current study was to evaluate the anti-biofilm activity of different concentrations of ozonated water compared to various concentrations of NaOCl against an established endodontic biofilm of Enterococcus faecalis in root canal treated teeth in vitro. Materials and Methods: The crowns of similarly sized, maxillary anterior teeth were removed, and the roots cut to a standard length (12 mm). All root canals were instrumented to a standard size. Specimens were sterilized and then inoculated with E. faecalis, which were allowed to grow for two weeks to form an established biofilm. There were six treatment groups: 1) 6% NaOCl; 2) 1.5% NaOCl; 3) 16µg/mL ozonated water; 4) 25µg/mL ozonated water; 5) 50µg/mL ozonated water, and 6) saline. Following treatment, samples were collected, plated, and incubated for two days. The number of CFU/mL were determined, and samples visualized using confocal imaging. The effect of treatment group on bacterial counts was made using one-way ANOVA followed by pair-wise comparisons. Null Hypothesis: Endodontically treated teeth irrigated with ozonated water will not demonstrate a statistically significant decrease in the E. faecalis biofilm compared to those treated with sodium hypochlorite Results: CFUs were converted to log10 and compared using Fisher’s Exact tests or one-way ANOVA followed by pair-wise tests. In all observations utilizing NaOCl irrigation, no colonies formed following treatment. The two NaOCl groups, with 0 CFU/mL, were significantly different than the other four groups (p=0.009). Saline showed a trend towards higher CFU/mL than 50 µg/ml O3 (p=0.068). None of the other comparisons approached statistical significance (p=0.453 25 µg/ml O3, p=0.606 16 µg/ml O3, p=0.999 25 µg/ml O3 vs 50 µg/ml O3, p=0.990 16 µg/ml O3 vs 50 µg/ml O3, p=1.000 16 µg/ml O3 vs 25 µg/ml O3). Confocal imaging helped illustrate effects of irrigation and confirm CFU findings. Conclusion: The results of this study failed to reject the null hypothesis. There was a statistically significant difference in the E. faecalis biofilm remaining in the groups treated with ozonated water compared to those treated with NaOCl. However, there was a trend towards higher CFU/mL in the saline group compared to the 50µg/mL ozonated water group. According to this finding, future studies should evaluate the effects of higher concentrations of ozonated water against an established E. faecalis biofilm. In addition, other follow-up studies might include ozonated water’s effect on human cells, such as the stem cells of the apical papilla that are so critical to the success of regenerative endodontic procedures. Due to university and laboratory closures caused by the COVID-19 pandemic, this project was stopped short and an insufficient sample size did not allow for proper statistical power. Additional occasions should be run upon the university’s re-opening to allow for proper statistical power.Item Enhancing Root Caries Lesion Prevention By Combining Two American Dental Association-Recommended Preventive Agents(2022) Almudahi, Abdulellah; Duarte, Simone; Hara, Anderson; Cook, N.BlainePurpose: This in vitro study aims to analyze the effect of combining two ADA-recommended professionally applied 1:1 Chlorhexidine/Thymol varnish ((Cervitec Plus)) and professionally prescribed 5,000 ppm fluoride toothpaste ((PreviDent 5000 Plus)) on reducing lesion depth and increasing mineral content Materials & Methods: Forty-eight dentin specimens were randomly distributed into four treatment groups (n=12 per treatment). Biofilms of Streptococcus mutans and Candida albicans were created on the polished surfaces of bovine root dentin specimens (n=12 per treatment). 1:1 Chlorhexidine/Thymol varnish was applied once then the tested 5,000 ppm fluoride toothpaste was applied for 120 seconds twice daily over the course of 2 days. Tested groups were: (1) 1:1 Chlorhexidine/Thymol varnish ((Cervitec Plus)) (C/T). (2) 5,000 ppm F toothpaste ((PreviDent 5000 Plus)) (F). (3) Combination of 1:1 Chlorhexidine/Thymol varnish ((Cervitec Plus)) & 5000 ppm F toothpaste ((PreviDent 5000 Plus)) (C/T+F). (4) Deionized water (DIW) as control group. Biofilms were analyzed for biofilm dry weight. Dentin specimens were analyzed using transversal microradiography (TMR) for mineral content change and lesion depth. PH data was analyzed using two-way ANOVA. Total biofilm dry weight data was analyzed using one-way ANOVA. Integrated mineral loss and lesion depth data was analyzed using two-way ANOVA All pair-wise comparisons from ANOVA analysis were made using Fisher’s Protected Least Significant Differences to control the overall significance level at 5%. Results: Treatment with (C/T+F) resulted in higher mean pH values compared to the control group (DIW) and (F) group. The average pH values of group (C/T) were not statistically different than group (C/T+F). the biomass of the combined S. mutans & C. albicans biofilm among all the groups were not significantly different. (DIW) presented significantly deeper lesions for both surfaces (sound &demineralized) when compared to (F) (P=0.0118), (C/T) (P=0.0002), and (C/T+F) (P<.0001). The sound surfaces for the specimens for group (C/T) and Group (F) showed superficial lesion depth. However, the sound surfaces of specimens treated with (C/T+F) showed the most superficial depth. Due to mineral gain, the demineralized surfaces of the specimens of both (C/T) & (C/T+F) showed a decrease in the lesion depth. Conclusion: Within the limitations of our study. The combination of 5,000 ppm fluoride toothpaste and CHX/Thymol had no significant effect on mineral content. However, the combination had a considerable effect on lesion depth reduction.Item Impact of curcumin loading on the physicochemical, mechanical and antimicrobial properties of a methacrylate-based experimental dental resin(Springer Nature, 2022-11-04) Comeau, Patricia; Panariello, Beatriz; Duarte, Simone; Manso, Adriana; Cariology, Operative Dentistry and Dental Public Health, School of DentistryOral biofilms are directly linked to one of the most common chronic human diseases, dental caries. Resin-based dental materials have significant potential to replace amalgam, however they lack sufficient antimicrobial power. This innovative study investigates a curcumin-loaded dental resin which can be utilized in an antimicrobial photodynamic therapy (aPDT) approach. The study evaluated the effects of curcumin loading on resin physicochemical, mechanical, and adhesive properties, as well as the antimicrobial response associated with blue light activation. Preliminary tests involving degree of conversion (DC) and sample integrity determined the optimal loading of curcumin to be restricted to 0.05 and 0.10 wt%. These optimal loadings were tested for flexural strength (FS), water sorption (WS) and solubility (SL), shear bond strength to dentin (SBS), and viability of Streptococcus mutans under 14.6 J/cm2 blue light or dark conditions, in 6 h and 24 h biofilms. The results demonstrated that 0.10 wt% curcumin had minimal impact on either FS or SBS, but detectably increased WS and SL. A 2 log10 (CFU/mL) reduction in S. mutans after light application in both 6 h and 24 h biofilms were corroborated by CLSM imaging and highlighted the significant potential of this novel aPDT approach with resin-based dental materials.