Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 83
Filtrar
1.
Braz Oral Res ; 35: e030, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33729275

RESUMEN

The present study evaluated the ability of Bifidobacterium and Lactobacillus species associated with streptococci to increase insoluble extracellular polysaccharide (EPS) production and initial caries lesion progression. Bovine enamel blocks (n = 190; 4 mm x 4 mm) were prepared, selected according to initial surface hardness (SH), and divided into two groups: a) double combinations: S. mutans with Bifidobacterium or Lactobacillus, and b) triple combinations: S. mutans and S. sobrinus with Bifidobacterium or Lactobacillus species. The blocks were exposed to the bacterial associations for 7 days. Subsequently, quantity of EPS from biofilms and caries lesion depth were determined by means of colorimetric and cross-sectional enamel hardness (ΔKHN) analysis. The data were submitted to one-way analysis of variance, followed by the Bonferroni test (p < 0.05). S. mutans with B. animalis or B. dentium produced a higher quantity of EPS; S. mutans + B. animalis led to the highest ∆KHN. S. mutans + S. sobrinus + B. longum induced greater EPS and ∆KHN values. In conclusion, associations of B. animalis and B. longum with streptococci promoted EPS production and caries lesion progression.


Asunto(s)
Caries Dental , Desmineralización Dental , Animales , Biopelículas , Bovinos , Estudios Transversales , Esmalte Dental , Streptococcus mutans
2.
Braz. oral res. (Online) ; 35: e030, 2021. tab
Artículo en Inglés | LILACS-Express | LILACS, BBO - Odontología | ID: biblio-1153618

RESUMEN

Abstract The present study evaluated the ability of Bifidobacterium and Lactobacillus species associated with streptococci to increase insoluble extracellular polysaccharide (EPS) production and initial caries lesion progression. Bovine enamel blocks (n = 190; 4 mm x 4 mm) were prepared, selected according to initial surface hardness (SH), and divided into two groups: a) double combinations: S. mutans with Bifidobacterium or Lactobacillus, and b) triple combinations: S. mutans and S. sobrinus with Bifidobacterium or Lactobacillus species. The blocks were exposed to the bacterial associations for 7 days. Subsequently, quantity of EPS from biofilms and caries lesion depth were determined by means of colorimetric and cross-sectional enamel hardness (ΔKHN) analysis. The data were submitted to one-way analysis of variance, followed by the Bonferroni test (p < 0.05). S. mutans with B. animalis or B. dentium produced a higher quantity of EPS; S. mutans + B. animalis led to the highest ∆KHN. S. mutans + S. sobrinus + B. longum induced greater EPS and ∆KHN values. In conclusion, associations of B. animalis and B. longum with streptococci promoted EPS production and caries lesion progression.

3.
Microb Pathog ; : 104657, 2020 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-33278515

RESUMEN

The in vitro antagonist growth effect of bifidobacteria were evaluated on periodontal bacteria. Bifidobacterium longum, Bifidobacterium lactis and Bifidobacterium infantis biofilms were grown in single, double or triple combinations with putative periodontal pathogens P. gingivalis and F. nucleatum or beneficial bacteria S. oralis for 24, 72 and 168 h and the total counts were analyzed by checkerboard DNA-DNA hybridization. The results showed that B. infantis and B. lactis, as single species, demonstrated the best antagonist effect on F. nucleatum and P. gingivalis and no influence on S. oralis growth at 168h. All the double combinations of bifidobacteria tested demonstrated an inhibitory effect on F. nucleatum (72h) and P. gingivalis (168h) and did not affect S. oralis counts at any time. In conclusion, B. lactis and B. infantis alone or in double combinations have antagonist effect on periodontopathogens biofilms, at different times points, and minimal influence on S. oralis growth.

4.
Microb Pathog ; : 104669, 2020 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-33278519

RESUMEN

Streptococcus mutans is the main etiological agent of dental caries because of its capacity to adhere to enamel structure and form biofilms. This study aimed to evaluate the effects of the anticariogenic agents - sodium fluoride (NaF) and chlorhexidine (CHX) - at levels below minimum inhibitory concentrations (sub-MICs) on the growth of planktonic cells and biofilms and on the expression of vicR and covR genes associated with the regulation of biofilm formation. MICs and minimum bactericidal concentrations (MBCs) of NaF and CHX were determined for S. mutans strains ATCC25175, UA159 and 3VF2. Growth curves were constructed for planktonic cells cultured in brain heart infusion (BHI) broth supplemented with NaF (0.125-0.75MIC) or CHX (0.25-0.75MIC). Biofilm formation assays were performed in microplates containing CHX or NaF at 0.5-1.0MIC and stained with violet crystal. Quantitative polymerase chain reaction determined the alterations in covR and vicR expression in cells exposed to antimicrobials at sub-MIC levels. NaF and CHX at sub-MIC levels affected the growth of planktonic cells of all three S. mutans strains, depending on the concentration tested. The biofilm formation in UA159 and 3VF2 was reduced by NaF at concentrations ≥0.5 MIC, while that of ATCC 25175 was reduced significantly irrespective of dose. In contrast, UA159 and 3VF2 biofilms were not affected by CHX at these levels, whereas those of ATCC 25175 were reduced significantly at all concentrations tested. Under sub-MIC conditions, CHX and (to a lesser degree) NaF increased vicR and covR expression in all three strains, although there were large differences between strains and treatment conditions employed. CHX and NaF at sub-MIC levels exert influence on the growth of S. mutans in planktonic and biofilm conditions and up regulate biofilm-associated genes vicR and covR, in a dose-dependent manner.

5.
J Prosthet Dent ; 2020 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-33250196

RESUMEN

STATEMENT OF PROBLEM: Biofilms can be retained on dental prostheses leading to the development of infections. The indiscriminate use of antifungal drugs can result in the development of microorganisms that are resistant to these antimicrobial agents. Whether probiotics are a suitable alternative for reducing the prevalence of oral candidiasis is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the influence of 6 different live strains of probiotics and 2 commercially available probiotic supplements used for inhibiting the growth of Candida albicans biofilm in heat-polymerized acrylic resin denture base material and to determine whether biofilm byproducts modify the surface of specimens. MATERIAL AND METHODS: Biofilms of C. albicans were formed on acrylic resin specimens in the presence of probiotics and quantified by colony-forming units (CFUs), and the surface roughness (Ra) of the specimens was assessed before and after the formation of biofilms. The CFU and roughness data were analyzed by analysis of variance and the Tukey HSD test (α=.05). RESULTS: A significant decrease in the number (CFU/mL) of C. albicans cells was found when they were cultured with 4 probiotics: B. lactis (P=.045), B. longum (P<.001), L. casei (P<.001), and L. helveticus (P<.001) and with the commercially available probiotic Prolive (P=.05). The Ra of specimens decreased after exposure to different microbial biofilms (P≤.05) except in 3 experimental groups. CONCLUSIONS: In general, the tested probiotics had an antagonistic effect on the growth of C. albicans, and the surface of acrylic resin was altered after exposure to biofilm byproducts.

6.
J Biomed Nanotechnol ; 16(3): 390-397, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32493549

RESUMEN

KSL-W peptide has demonstrated antibacterial and antifungal activity and inhibitory effects against oral biofilm. This study aimed to check out the effect of chlorhexidine (CLX) or KSL-W peptide-loaded poloxamer 407-based microemulsions for buccal delivery on Fusobacterium nucleatum (F. nucleatum) biofilm. The formulation (F) containing 10% copolymer poloxamer 407 dispersion (1%), 40% oleic acid and 50% PPG-5-CETETH-20 was characterized by polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), rheology, bioadhesive and syringeability; and in the treatment of a biofilm produced by F. nucleatum. The darkfield images obtained by PLM and the SAXS curves with an extended peak indicated that the system was characteristic of microemulsions. In a continuous analysis, microemulsions exhibited Newtonian behavior. In frequency, the oscillatory analysis profile presented predominantly viscous behavior. Bioadhesive force detected in the analysis of F (7.4 ± 1.81 mN˙ s) and syringeability (17.83± 5.97 N · mm) being adequate values for buccal administration. After 4 h, KSL-W-loaded F shown over 20% higher effectiveness than chlorhexidine-loaded microemulsions. In conclusion, the KSL-W-loaded microemulsions showed a considerable reduction in F. nucleatum biofilm formation and presented promising structural properties for buccal drug delivery.


Asunto(s)
Fusobacterium nucleatum , Péptidos Catiónicos Antimicrobianos , Biopelículas , Poloxámero , Dispersión del Ángulo Pequeño , Difracción de Rayos X
8.
Rev. ciênc. farm. básica apl ; 41: [10], 01/01/2020.
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1147075

RESUMEN

Herbal medicines have been studied as potential antimicrobial agents, emerging as treatments against oral diseases. The current study evaluated the antimicrobial activity of the crude extract and fractions of Mikania laevigata SchultzBip. ex Baker (ML) and Varronia curassavicaJacq (VC) against oral pathogens associated with persistent dental root infections, under planktonic and biofilm conditions. Minimal inhibitory concentrations and minimal bactericidal/fungicidal concentrations were determined for the ML and VC fractions/extracts against Enterococcus faecalis, Actinomyces israelii, Pseudomonas aeruginosa, and Candida albicans using the microdilution method. The best results were chosen for subsequent biofilm assays. All tested ML and VC extracts/fractions demonstrated inhibitory activity against E. faecalis and A. israelii. The ML ethyl acetate fraction affected the growth of all microorganisms tested. C. albicans and P. aeruginosawere not affected by any VC extract/fractions. The ML ethyl acetate fraction eliminated E. faecalis, A.israelii, and P. aeruginosa biofilms after 24h. A similar result was observed for ML crude hydroethanolic extract and its hexane fraction for A. israelii. The VC hexane fraction was able to eliminate A. israelli biofilms. None of the tested extracts or fractions eliminated C. albicans biofilm. The Mikania laevigata ethyl acetate fraction is an efficient antimicrobial agent against oral pathogens and could be indicated for the treatment of persistent dental infections.

9.
Arch Oral Biol ; 109: 104577, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31606567

RESUMEN

Although the effectiveness of some mouthwashes has been proven, phytotherapy is still a field to be explored as an alternative to commercial products. OBJECTIVE: To evaluate, in vitro, the cytotoxicity and efficacy of two solutions based on citronella oil (CN), on S. aureus and C. albicans biofilms (in formation-adhesion phase and 24 h-biofilm formation) on acrylic resin and nickel-chromium alloy samples (one trademark of each material), compared to two alcohol-free commercial mouthwashes. MATERIAL AND METHODS: Two solutions containing CN at concentrations of 5x and 10x the minimum bactericidal/fungicidal concentration (MBC/MFC) were prepared by microdilution. After contamination of the samples surfaces with these microorganisms, the mouthwashes (CN - 5x and 10x; CHX - 0,12% alcohol-free chlorhexidine and LT - alcohol-free essential oils) were evaluated. Mouthwash simulation was performed for 1 min at two moments, the first simulation after 4 h of microbial adhesion and 24 h-biofilm formation, and the second simulation, 6 h after the first simulation. For biofilm quantification, the number of cultured cells was evaluated by CFUs. The cytotoxicity assay was performed on HaCat epithelial cells and quantified by the MTT method. RESULTS: Tested solutions completely inhibited the growth of both microorganisms in the adhesion phase. All solutions showed inhibitory activity against 24 h-biofilm formation. However, CN led to greater microbial reduction, regardless of the surface of the sample. All solutions demonstrated a toxic effect. However, after serial dilution, CN presented the lowest cytotoxic effect. CONCLUSION: Citronella had a lower cytotoxic effect and a higher action compared to commercial solutions.


Asunto(s)
Biopelículas/efectos de los fármacos , Cymbopogon/química , Prótesis Dental/microbiología , Antisépticos Bucales/farmacología , Aceites Vegetales/farmacología , Antiinfecciosos/farmacología , Candida albicans/efectos de los fármacos , Línea Celular , Humanos , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus/efectos de los fármacos
10.
PLoS One ; 14(10): e0223148, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31639129

RESUMEN

The aim of this research was to evaluate the efficacy of a commercial sealing agent at the abutment/implant interface against microleakage of single and dual-species biofilms of Candida albicans and Enterococcus faecalis into external hexagon (EH) and Morse taper (MT) prosthetic connections. A total of 216 samples of implants and their abutments were tested. Six groups (n = 36) were evaluated based on biofilm and period of incubation (7 and 14 days). The implant connections EH and MT (n = 18) were divided according to the use of the material (n = 9) (EH-T and MT-T: with the sealing agent; EH-C and MT-C: control). The biofilms were analyzed by microbial counting (CFU/mL) and SEM analysis and photographs of the material in the screw joints were also taken. Data were analyzed by Student t test, two-way ANOVA and Bonferroni test. For the single-species biofilms, there was a significant reduction in the growth of E. faecalis when compared MT-C and MT-T or EH-C and EH-T at 7 and 14 days. The same was observed for C. albicans biofilms. For dual-species biofilms of E. faecalis and C. albicans, the sealing agent was more effective in preventing microbial infiltration into the MT connection at 14 days, while microbial infiltration did not occur into EH connections even in absence of the sealing agent for both periods of evaluation. Overall, these data suggest that the presence of the sealing agent reduces or eliminates the microleakage of E. faecalis and C. albicans biofilms into the implants regardless of the period of incubation.


Asunto(s)
Tornillos Óseos/microbiología , Candida albicans/efectos de los fármacos , Materiales Dentales/farmacología , Enterococcus faecalis/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Tornillos Óseos/efectos adversos , Candida albicans/crecimiento & desarrollo , Candida albicans/patogenicidad , Pilares Dentales/microbiología , Implantes Dentales/microbiología , Análisis del Estrés Dental , Enterococcus faecalis/crecimiento & desarrollo , Humanos , Ensayo de Materiales/métodos , Titanio/química , Titanio/uso terapéutico
11.
Bioorg Chem ; 90: 103031, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31238181

RESUMEN

Curcumin is a plant diphenylheptanoid and has been investigated for its antibacterial activity. However, the therapeutic uses of this compound are limited due to its chemical instability. In this work, we evaluated the antimicrobial activity of diphenylheptanoids derived from curcumin against Gram-positive and Gram-negative bacteria, and also against Mycobacterium tuberculosis in terms of MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) values. 3,3'-Dihydroxycurcumin (DHC) displayed activity against Enterococcus faecalis, Staphylococcus aureus and M. tuberculosis, demonstrating MIC values of 78 and 156 µg/mL. In addition, DHC was more stable than curcumin in acetate buffer (pH 5.0) and phosphate buffer (pH 7.4) for 24 h at 37 °C. We proposed that membrane and the cell division protein FtsZ could be the targets for DHC due to that fact that curcumin exhibits this mode of antibacterial action. Fluorescence microscopy of Bacillus subtilis stained with SYTO9 and propidium iodide fluorophores indicated that DHC has the ability to perturb the bacterial membrane. On the other hand, DHC showed a weak inhibition of the GTPase activity of B. subtilis FtsZ. Toxicity assay using human cells indicated that DHC has moderate capacity to reduce viability of liver cells (HepG2 line) and lung cells (MRC-5 and A549 lines) when compared with doxorubicin. Alkaline comet assay indicated that DHC was not able to induce DNA damage in A549 cell line. These results indicated that DHC is promising compound with antibacterial and antitubercular activities.


Asunto(s)
Antituberculosos/farmacología , Membrana Celular/efectos de los fármacos , Curcumina/análogos & derivados , Curcumina/farmacología , Antituberculosos/síntesis química , Antituberculosos/toxicidad , Bacterias/efectos de los fármacos , Proteínas Bacterianas/antagonistas & inhibidores , Línea Celular Tumoral , Curcumina/toxicidad , Proteínas del Citoesqueleto/antagonistas & inhibidores , ADN/efectos de los fármacos , Estabilidad de Medicamentos , GTP Fosfohidrolasas/antagonistas & inhibidores , Humanos , Pruebas de Sensibilidad Microbiana
12.
Arch Oral Biol ; 103: 19-25, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31112936

RESUMEN

OBJECTIVES: To evaluate the effect of analogues of cationic peptides on the viability and the expression of phenotypic and genotypic markers of dentin mineralization in MDPC-23 odontoblast-like cells. MATERIALS AND METHODS: Cells were exposed to serial dilutions of analogues of cationic peptides hBD-3-1CV and KR-12-a5 compared to peptide LL-37 and their viability was assessed by methyltetrazolium assay. Next, peptides (0.78-62.5 µg/mL) were applied on the MDPC-23 cells for evaluating the total protein (TP) production, alkaline phosphatase (ALP) activity and mineralized nodule deposition. Gene expression of mineralization markers (DSPP and DMP-1) was also determined by quantitative PCR. RESULTS: LL-37 and hBD-3-1CV treatment did not affect cellular viability at concentrations below 62.5 µg/mL. KR-12-a5 reduced cell viability above 31.25 µg/mL. TP production was similar for all groups compared with the control group, except by hBD-3-1CV (at 15.62 µg/mL). LL-37 (at 62.5 µg/mL) induced higher ALP activity than control and other experimental groups. LL-37 and hBD-3-1CV, at 62.5 µg/mL and KR-12-a5 at 31.25 µg/mL stimulated the highest deposition of mineralized nodule. Overall, no statistical differences were observed between the groups for DSPP-1 and DMP-1 expressions. CONCLUSIONS: LL-37 was the only peptide that induced both ALP activity and mineralized nodules deposition, without affecting cell viability. None of peptides tested induced the expression of DSPP or DMP-1, genes commonly involved in active dentin mineralization.


Asunto(s)
Péptidos Catiónicos Antimicrobianos , Catelicidinas , Dentinogénesis , Proteínas de la Matriz Extracelular , Odontoblastos , Fragmentos de Péptidos , Fosfoproteínas , Sialoglicoproteínas , beta-Defensinas , Animales , Células Cultivadas , Dentina , Dentinogénesis/genética , Proteínas de la Matriz Extracelular/genética , Humanos , Ratones , Péptidos , Fosfoproteínas/genética , Sialoglicoproteínas/genética
13.
J Appl Oral Sci ; 27: e20180205, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30994772

RESUMEN

Porphyromonas gingivalis is one of the most important Gram-negative anaerobe bacteria involved in the pathogenesis of periodontitis. P. gingivalis has an arsenal of specialized virulence factors that contribute to its pathogenicity. Among them, fimbriae play a role in the initial attachment and organization of biofilms. Different genotypes of fimA have been related to length of fimbriae and pathogenicity of the bacterium. OBJECTIVES: The aim of this study was to identify 5 types of fimA genotype strains in smokers and nonsmokers with periodontitis, before and after periodontal therapy. MATERIAL AND METHODS: Thirty-one patients with periodontitis harboring P. gingivalis were selected: 16 nonsmokers (NS) and 15 smokers (SM). Clinical and microbiological parameters were evaluated at baseline and 3 months after periodontal treatment, namely: plaque index, bleeding on probe, probing depth, gingival recession and clinical attachment level. The frequency of P. gingivalis and fimA genotype strains were determined by polymerase chain reaction. RESULTS: Type I fimA was detected in the majority of SM and NS at baseline, and the frequency did not diminish after 3 months of treatment. The frequency of type II genotype was higher in SM than NS at baseline. After 3 months, statistical reduction was observed only for types II and V fimA genotypes in SM. The highest association was found between types I and II at baseline for NS (37.5%) and SM (53.3%). CONCLUSION: The most prevalent P. gingivalis fimA genotypes detected in periodontal and smoker patients were genotypes I and II. However, the presence of fimA genotype II was higher in SM. Periodontal treatment was effective in controlling periodontal disease and reducing type II and V P. gingivalis fimA.


Asunto(s)
Proteínas Fimbrias/aislamiento & purificación , Periodontitis/microbiología , Periodontitis/terapia , Porphyromonas gingivalis/aislamiento & purificación , Fumar/efectos adversos , Adulto , Anciano , ADN Bacteriano , Femenino , Proteínas Fimbrias/genética , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Índice Periodontal , Periodontitis/patología , Reacción en Cadena de la Polimerasa , Porphyromonas gingivalis/genética , Estadísticas no Paramétricas , Factores de Tiempo
14.
J Dent ; 84: 81-88, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30953673

RESUMEN

OBJECTIVE: To evaluate the antimicrobial/antibiofilm and mechanical properties, and the effect on enamel demineralization of a resin-modified GIC (RMGIC) containing CHX and nano-sized sodium trimetaphosphate (TMP). METHODS: RMGIC was associated with CHX (1.25 or 2.5%) and/or TMP (7 or 14%). Antimicrobial and antibiofilm activity were assessed using agar diffusion test and evaluation of biofilm metabolism, respectively. In addition, fluoride (F) and TMP releases as well as the diametral tensile (DTS) and compressive (CS) strength were determined. The percentage of mineral loss (%SH), integrated loss of subsurface hardness (ΔKHN) and enamel F concentrations were also evaluated. RESULTS: RMGICs containing CHX associated or not with TMP presented higher inhibition zones and effect on S. mutans biofilm. A reduction on CS was observed only for RMGIC + 2.5%CHX and on DTS for RMGIC + 2.5%CHX + 14%TMP. The highest F and TMP releases and lowest %SH and ΔKHN values were detected for RMGIC + 1.25%CHX + 14%TMP and RMGIC + 2.5%CHX + 14%TMP. Higher enamel F concentrations were observed for TMP groups. CONCLUSION: 1.25%CHX and 14%TMP increased antimicrobial/antibiofilm action and the ability to prevent enamel demineralization, with minimal effect on the mechanical properties of RMGIC. CLINICAL SIGNIFICANCE: RMGIC containing CHX and TMP is an alternative material for patients at high risk for dental caries and can be indicated for low-stress regions or provisional restorations.


Asunto(s)
Clorhexidina , Caries Dental , Cementos de Ionómero Vitreo , Polifosfatos , Esmalte Dental , Humanos
15.
Photodiagnosis Photodyn Ther ; 25: 92-102, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30468900

RESUMEN

BACKGROUND: The aim of this study was to evaluate the effect of multiple sessions of antimicrobial photodynamic therapy (aPDT) on the treatment of experimental periodontitis (EP) in rats treated with chemotherapy. METHODS: Chemotherapy using 5-fluorouracil (5-FU) consisted of intraperitoneal administration of 60 and 40 mg/kg of 5-FU. 120 rats were subjected to chemotherapy with 5-FU and divided into groups: PT (periodontal treatment); PT+1aPDT (PT and single aPDT session); PT+4aPDT(PT and 4 sessions of aPDT); 1aPDT (single aPDT session); 4aPDT(4 sessions of aPDT). EP was induced in the mandibular molars via ligature placement. The alveolar bone loss (ABL) area in the furcation region was analysed histometrically. Proliferating cell nuclear antigen (PCNA), tartrate-resistant acid phosphatase (TRAP), receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG) and cleaved caspase-3 (CC3) were analysed by immunohistochemistry. Prostaglandin E2 was quantified using an ELISA, tumor necrosis factor (TNF)-α and interleukin (IL)-6 were assessed using a multiplex method. The prevalence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella nigrescens, Prevotella intermedia and Fusobacterium nucleatum was assessed using PCR. The data were statistically analysed (P < 0.05). RESULTS: The PT+4aPDT group showed lower ABL than the PT or 1aPDT groups on day 7. Rats treated with aPDT showed a higher number of PCNA-positive cells with reduced immunolabeling of RANKL. Significant reductions in Prevotella nigrescens were observed in the PT+4aPDT group and in Aggregatibacter actinomycetemcomitans for the 1aPDT and 4aPDT groups. CONCLUSION: Repeated sessions of aPDT as an adjunct or alternative therapy were effective at reducing ABL, regulating bone metabolism, and reducing Prevotella nigrescens and Aggregatibacter actinomycetemcomitans.


Asunto(s)
Fluorouracilo/farmacología , Periodontitis/tratamiento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/farmacología , Aggregatibacter actinomycetemcomitans/efectos de los fármacos , Pérdida de Hueso Alveolar/terapia , Animales , Raspado Dental/métodos , Modelos Animales de Enfermedad , Interleucina-6/biosíntesis , Masculino , Enfermedades Mandibulares , Periodontitis/terapia , Prevotella nigrescens/efectos de los fármacos , Ratas , Factor de Necrosis Tumoral alfa/biosíntesis
16.
Lasers Med Sci ; 34(3): 465-471, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30121722

RESUMEN

The aim of this preliminary study was to compare the effects of different energy densities from red and infrared low-level laser (LLL) on viability and proliferation of stem cells from human exfoliated deciduous teeth (SHED). SHED were irradiated with red laser (R) or infrared laser (IR) set with the following dosimetry: 1.2 J/cm2 (0.05 J), 2.5 J/cm2 (0.1 J), 5.0 J/cm2 (0.2 J), and 7.5 J/cm2 (0.3 J). Positive (C+) and negative (C-) control groups comprised non-irradiated cells. Data were analyzed by two-way ANOVA followed by Tukey's test (P < 0.05). At 24- and 48-h period, group R5.0 showed significantly higher cell viability rates than R1.2 and R2.5. At 48 h, R2.5 also revealed lower proliferation than R5.0. Comparing to the C+ group, R2.5 exhibited lower viability at 72 h, and proliferation at 24 and 48 h. Groups R1.2, IR1.2, and IR5.0 were less viable at 24 h, while R1.2, IR2.5, and IR5.0 revealed lower proliferative capacity at 48 h. Overall, our results showed that LLL can favor viability and proliferation of SHED, especially when cells receive red laser irradiation at 5.0 J/cm2. Therefore, according to this preliminary investigation, 5 J/cm2 applied by red LLL induced high rates of cell viability and proliferation, while the same irradiation dose using infrared laser led to negative effects. LLL irradiation with 1.2 and 2.5 J/cm2 was deleterious to metabolic activity and proliferation of SHED regardless of the type of laser. Further studies are necessary to gain in-depth knowledge about the effects of different wavelengths of LLL on SHED viability and proliferation.


Asunto(s)
Rayos Infrarrojos , Rayos Láser , Células Madre/citología , Células Madre/efectos de la radiación , Exfoliación Dental/radioterapia , Diente Primario/efectos de la radiación , Proliferación Celular/efectos de la radiación , Supervivencia Celular/efectos de la radiación , Humanos
17.
Lasers Med Sci ; 34(1): 15-21, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29980944

RESUMEN

This study aimed to analyze the effects of laser irradiation on the membrane integrity and viability of stem cells from human exfoliated deciduous teeth (SHED) that were kept in serum starvation. Nutritional deficit was used to mimic the cellular stress conditions of SHED isolation for regenerative dental approaches, where laser therapy could be beneficial. SHED were cultured under serum starvation (MEMα + 1%FBS) for 1 or 24 h pre-irradiation (protocols A and B, respectively). Then, cells received low-level laser therapy (LLLT; 660 nm) at 2.5 J/cm2 (0.10 W; groups I and V), 5.0 J/cm2 (0.20 W; groups II and VI), 7.5 J/cm2 (0.30 W; groups III and VII), or remained non-irradiated (groups IV and VIII). During irradiation, cells were maintained in 1% FBS (groups I-IV) or 10% FBS (normal culture conditions; groups V-VIII). Membrane integrity was evaluated by quantifying lactate dehydrogenase (LDH) release (immediately after irradiation), and cell viability was assessed by the MTT assay (24, 48, and 72 h post-irradiation). Serum starvation did not alter LDH release by non-irradiated SHED, while LDH release decreased significantly in groups irradiated in 1% FBS (I and III), but not in groups irradiated in 10% FBS (V-VII), regardless the pre-irradiation conditions (protocols A/B). Cell viability was significantly higher 24 h after irradiation, in most protocol A groups. In contrast, cell viability remained mostly unaltered in protocol B groups. LLLT contributed to maintain membrane integrity in SHED subjected to nutritional deficit before and during irradiation with 0.10 or 0.30 W. Short serum starvation before irradiation improved SHED viability at 24 h post-irradiation.


Asunto(s)
Membrana Celular/metabolismo , Rayos Láser , Fenómenos Fisiológicos de la Nutrición , Células Madre/patología , Células Madre/efectos de la radiación , Exfoliación Dental/patología , Diente Primario/efectos de la radiación , Membrana Celular/patología , Membrana Celular/efectos de la radiación , Proliferación Celular/efectos de la radiación , Supervivencia Celular/efectos de la radiación , Células Cultivadas , Humanos , L-Lactato Deshidrogenasa/metabolismo , Suero
18.
Clin Oral Investig ; 23(5): 2345-2354, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30298451

RESUMEN

OBJECTIVES: To evaluate the effects of hexametaphosphate microparticles (mHMP) or nanoparticles (nHMP) incorporated in glass ionomer cement (GIC) on antimicrobial and physico-mechanical properties, fluoride (F) release, and enamel demineralization. MATERIAL AND METHODS: HMP solutions were obtained at concentrations of 1, 3, 6, 9, and 12%, for screening of antimicrobial activity. Next, mHMP or nHMP at 6, 9, and 12% were incorporated into a resin-modified GIC and the antibacterial activity was evaluated. The resistance to diametral tensile and compressive strength, surface hardness, and degree of monomer conversion as well as F and HMP releases of GICs were determined. Furthermore, specimens were attached to enamel blocks and submitted to pH-cycling, and mineral loss was determined. Parametric and non-parametric tests were performed, after checking data homoscedasticity (p < 0.05). RESULTS: HMP solutions at 6, 9, and 12% demonstrated the best antibacterial activity. GIC containing HMP showed better antibacterial effects at 9 and 12% for nHMP. Regarding F and HMP releases, the highest levels of release occurred for groups containing 9 and 12% nHMP. With the increase in HMP concentration, there was lower mineral loss. However, the incorporation of mHMP or nHMP in GIC reduced values of physico-mechanical properties when compared to the control GIC. CONCLUSIONS: nHMP improves antimicrobial activity and fluoride release, and decreases enamel demineralization, but reduces the physico-mechanical properties of GIC. CLINICAL RELEVANCE: The association of GIC/HMP could be an alternative material for patients at high risk for dental caries and could be indicated for low-stress regions or provisional restorations.


Asunto(s)
Antibacterianos/química , Esmalte Dental/efectos de los fármacos , Cementos de Ionómero Vitreo/química , Fosfatos/química , Animales , Bovinos , Caries Dental , Fluoruros/química , Concentración de Iones de Hidrógeno , Ensayo de Materiales , Desmineralización Dental/prevención & control
19.
J. appl. oral sci ; 27: e20180205, 2019. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1002408

RESUMEN

Abstract Porphyromonas gingivalis is one of the most important Gram-negative anaerobe bacteria involved in the pathogenesis of periodontitis. P. gingivalis has an arsenal of specialized virulence factors that contribute to its pathogenicity. Among them, fimbriae play a role in the initial attachment and organization of biofilms. Different genotypes of fimA have been related to length of fimbriae and pathogenicity of the bacterium. Objectives The aim of this study was to identify 5 types of fimA genotype strains in smokers and nonsmokers with periodontitis, before and after periodontal therapy. Material and Methods Thirty-one patients with periodontitis harboring P. gingivalis were selected: 16 nonsmokers (NS) and 15 smokers (SM). Clinical and microbiological parameters were evaluated at baseline and 3 months after periodontal treatment, namely: plaque index, bleeding on probe, probing depth, gingival recession and clinical attachment level. The frequency of P. gingivalis and fimA genotype strains were determined by polymerase chain reaction. Results Type I fimA was detected in the majority of SM and NS at baseline, and the frequency did not diminish after 3 months of treatment. The frequency of type II genotype was higher in SM than NS at baseline. After 3 months, statistical reduction was observed only for types II and V fimA genotypes in SM. The highest association was found between types I and II at baseline for NS (37.5%) and SM (53.3%). Conclusion The most prevalent P. gingivalis fimA genotypes detected in periodontal and smoker patients were genotypes I and II. However, the presence of fimA genotype II was higher in SM. Periodontal treatment was effective in controlling periodontal disease and reducing type II and V P. gingivalis fimA.

20.
Eur J Dent ; 12(2): 176-183, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29988209

RESUMEN

Objective: The purpose of this study was to evaluate the influence of surface roughness in biofilm formation of four microorganisms (Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis, and Candida albicans) on acrylic resin surface of ocular prostheses. Materials and Methods: Acrylic resin samples were divided into six groups according to polishing: Group 1200S (1200 grit + silica solution); Group 1200; Group 800; Group 400; Group 120 and Group unpolished. Surface roughness was measured using a profilometer and surface images obtained with atomic force microscopy. Microbial growth was evaluated after 4, 24, and 48 hours of incubation by counting colony-forming units. Statistical Analysis Used: For roughness, it was performed 1-way ANOVA and parametric Tukey test α5% (P ≤ 0.05). For CFU data found, it was applied Kruskal-Wallis and Mann-Whitney tests. Results: Group 120 and 400 presented the highest roughness values. For S. epidermidis and S. aureus, Group 1200S presented the lowest values of microbial growth. For E. faecalis at 4 hour, microbial growth was not observed. C. albicans did not adhere to the acrylic resin. Except for Group 1200S, different surface roughnesses did not statistically interfere with microbial adhesion and growth on acrylic surfaces of ocular prostheses. Conclusions: The roughness did not interfere with the microbial adhesion of the microorganisms evaluated. The use of silica decreases significantly microbial growth.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...