Antimicrobial photodynamic therapy alone or in combination with antibiotic local administration against biofilms of Fusobacterium nucleatum and Porphyromonas gingivalis.

Antimicrobial photodynamic therapy (aPDT) kills several planktonic pathogens. However, the susceptibility of biofilm-derived anaerobic bacteria to aPDT is poorly characterized. Here, we evaluated the effect of Photodithazine (PDZ)-mediated aPDT on Fusobacterium nucleatum and Porphyromonas gingivalis biofilms. In addition, aPDT was tested with metronidazole (MTZ) to explore the potential antimicrobial effect of the treatment. The minimum inhibitory concentration (MIC) of MTZ was defined for each bacterial species. Single-species biofilms of each species were grown on polystyrene plates under anaerobic conditions for five days. aPDT was performed by applying PDZ at concentrations of 50, 75 and 100 mg/L, followed by exposure to 50 J/cm2 LED light (660 nm) with or without MTZ. aPDT exhibited a significant reduction in bacterial viability at a PDZ concentration of 100 mg/L, with 1.12 log10 and 2.66 log10 reductions for F. nucleatum and P. gingivalis in biofilms, respectively. However, the antimicrobial effect against F. nucleatum was achieved only when aPDT was combined with MTZ at 100× MIC. Regarding P. gingivalis, the combination of PDZ-mediated aPDT at 100 mg/L with MTZ 100× MIC resulted in a 5 log10 reduction in the bacterial population. The potential antimicrobial effects of aPDT in combination with MTZ for both single pathogenic biofilms were confirmed by live/dead staining. These results suggest that localized antibiotic administration may be an adjuvant to aPDT to control F. nucleatum and P. gingivalis biofilms.

Analyses of Biofilm on Implant Abutment Surfaces Coating with Diamond-Like Carbon and Biocompatibility.

The aim of this study was to evaluate the surface free energy (SFE), wetting and surface properties as well as antimicrobial, adhesion and biocompatibility properties of diamond-like carbon (DLC)-coated surfaces. In addition, the leakage of Escherichia coli through the abutment-dental implant interface was also calculated. SFE was calculated from contact angle values; R a was measured before and after DLC coating. Antimicrobial and adhesion properties against E. coli and cytotoxicity of DLC with human keratinocytes (HaCaT) were evaluated. Further, the ability of DLC-coated surfaces to prevent the migration of E. coli into the external hexagonal implant interface was also evaluated. A sterile technique was used for the semi-quantitative polymerase chain reaction (semi-quantitative PCR). The surfaces showed slight decreases in cell viability (p<0.05), while the SFE, R a, bacterial adhesion, antimicrobial, and bacterial infiltration tests showed no statistically significant differences (p>0.05). It was concluded that DLC was shown to be a biocompatible material with mild cytotoxicity that did not show changes in R a, SFE, bacterial adhesion or antimicrobial properties and did not inhibit the infiltration of E. coli into the abutment-dental implant interface.

Comparative effects of photodynamic therapy mediated by curcumin on standard and clinical isolate of Streptococcus mutans.

AIM: The aim of this study was investigate the effect of photodynamic therapy (PDT) using curcumin (C) as a photosensitizing agent irradiated with an LED (L) in the blue wavelength as a light source on a standard and clinical isolate of Streptococcus mutans (S. mutans) in a planktonic suspension model. MATERIALS AND METHODS: Suspensions of both strains were divided into 4 groups as follows: absence of C and L (control group: C-L-), with C and without L (C group: C+L-), absence of C with L (L group: C-L+) and presence of C and L (PDT group: C+L+). Three different concentrations of curcumin (0.75 mg/ml, 1.5 mg/ml and 3 mg/ml) and three light fluences of studied light source (24, 48 and 72 J cm(-2)) were tested. Aliquots of each studied group was plated in BHI agar and submitted to colony forming units counting (CFU/ml) and the data transformed into logarithmical scale. RESULTS: A high photoinactivation rate of more than 70% was verified to standard S. mutans strain submitted to PDT whereas the clinical isolate showed a lower sensitivity to all the associations of curcumin and LED. A slight bacterial reduction was verified to C+L- and C-L+, demonstrating no toxic effects to the isolated application of light and photosensitizer to both S. mutans strains tested. CONCLUSION: Photodynamic therapy using a combination of curcumin and blue LED presented a substantial antimicrobial effect on S. mutans standard strain in a planktonic suspension model with a less pronounced effect on its clinical isolate counterparts due to resistance to this alternative approach. CLINICAL SIGNIFICANCE: Alternative antimicrobial approaches, as photodynamic therapy, should be encouraged due to optimal results against cariogenic bacteria aiming to prevent or treat dental caries.

Detecção de Periodontopatógenos, Glicoproteína Emmprin (Cd-147) e sua correlação com MMP-2 e MMP-9 / Detection of Periodontopathogens, Glycoprotein Emmprin (CD-147) and its Correlation whith MMP-2 and MMP-9

A periodontite é uma doença infecciosa caracterizada pela secreção de uma variedade de mediadores inflamatórios que levam a destruição dos tecidos de suporte dental e possível perda dos dentes, em associação com a infecção por múltiplas espécies bacterianas. Estima-se que mais de 400 espécies colonizam o biofilme dental e algumas das espécies bucais relacionadas à doença periodontal estejam no biofilme subgengival como Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola. Entretanto, outros microrganismos podem estar relacionados a patologia desta doença, como Filifactor alocis e Prevotella tannerae. Esses microrganismos e seus subprodutos, como endotoxinas liberados o meio extracelular, levam ao estímulo da glicoproteína indutora de metaloproteinase (EMMPRIN, CD-147), que estimula a liberação de MMPs por fibroblastos e células endoteliais, levando a destruição do tecido. Com o objetivo de detectar F. alocis, P. tannerae e T. denticola, glicoproteina EMMPRIN (CD-147) e sua correlação com MMP-2 e MMP-9, amostras de fluido subgengival de pacientes com periodontite crônica, foram coletados de sítios sadios e doentes antes do tratamento periodontal básico e após 60 dias do tratamento. Os respectivos DNAs das bactérias foram extraídos e trechos do gene 16S foram amplificados e posteriormente realizados PCR convencional para a análise microbiológica dos microrganismos. Para a quantificação do EMMPRIN (CD-147), MMP-2 e MMP-9 foi usado ELISA-Sandwich. Resultados demonstraram que o grupo doente aumentou significantemente T. denticola, F. alocis e P. tannerae quando comparados com sítios saudáveis. MMP-2 e MMP-9 foram detectados em altas concentrações com redução estatisticamente significante após tratamento periodontal para MMP-2, mas não houve correlação com EMMPRIN.

Periodontitis is an infectious disease characterized by thesecretion of a variety of inflammatory mediators that lead todestruction of tooth supporting tissues, including the possibleloss of alveolar bone, in association with infection with multiplespecies of bacteria. It is estimated that more than 400 speciescolonize the biofilm and some oral species related to periodontaldisease is present in the subgingival including P. gingivalis, T.forsythia and T. denticola. However, other organisms may berelated of this disease, as Filifactor allocis and Prevotella tannerae.These microorganisms and subproducts such as endotoxinsreleased into the extracellular lead to the stimulation of metalloproteinaseinducer glycoprotein (EMMPRIN, CD-147), whichstimulates the release of MMPs by host cells, like fibroblasts andendothelial cells, thus leading to tissue destruction. The objectiveof this study was to detect F. allocis, P. tannerae, T. denticolaand the glycoprotein EMMPRIN (CD-147) and its correlationwith MMP-2 and MMP-9 in subgingival fluid samples of patientswith chronic periodontitis. Fluids were collected from healthyand disease subgingival sites of 20 healthy individuals beforebasic periodontal treatment and after of 60 days of treatment.Their DNAs were extracted and portions of the 16S gene wereamplified and performed conventional PCR. For immunologicalanalysis and quantification of EMMPRIN (CD-147), MMP-2 andMMP-9 was used ELISA-Sandwich. Results demonstrated thatthe disease group showed significantly high amounts of T. denticola,F. alocis and P. tannerae when compared with health sites.MMP-2 and MMP-9 were detected in high concentrations withstatistically significantly reduction after periodontal treatment toMMP-2, but without correlation with EMMPRIN.

Photodynamic potential of curcumin and blue LED against Streptococcus mutans in a planktonic culture.

BACKGROUND: The photodynamic therapy (PDT) involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent or dye in the presence of oxygen for eradication of target cells. In dentistry, this therapy is used to suppress the growth of microorganisms involved directly with dental decay and periodontitis process. There are evidences that curcumin dye is able to control microbial activity when illuminated with specific wavelength. The purpose of this study was to evaluate the in vitro efficacy of PDT using curcumin dye (Cur-C) in combination with a blue LED (L) device on a planktonic model of Streptococcus mutans (S. mutans). METHODS: Suspensions (0.5 mL) containing S. mutans at 1×10(7)CFU mL(-1) were prepared and divided into 4 groups: Group C-L- (control: no treatment and 1 experimental condition), Group C+L- (curcumin at 3 different concentrations: 2000; 4000 and 8000 µM and 3 experimental conditions), Group C-L+ (LED at 3 different dosages: 24, 48 and 72 Jcm(-2) and 3 experimental conditions), and Group C+L+ (PDT group: curcumin at respective concentrations combined to LED dosages and 9 experimental conditions). Samples of each experimental condition were cultured in Petri dishes of BHI agar. Incubation in micro-aerophilia at 37°C for 48 h was performed for subsequent visual counting of CFU/mL. Data were transformed into log10 and analyzed by two-way ANOVA and Tukey's test at p<0.05. RESULTS: Group C+L+, in specific experimental conditions, demonstrated a log bacterial reduction 70% higher than Group C-L-. Both groups C-L+ and C+L- presented a slight decrease in log bacterial counting. CONCLUSION: This in vitro method was able to reduce the number of S. mutans in a planktonic suspension.

Diretrizes para o tratamento periodontal e acompanhamento durante o tratamento ortodôntico / Guidelines for periodontal care and follow-up during orthodontic treatment

Objetivo deste trabalho foi, através de uma revisão da literatura, ressaltar os cuidados antes, durante e depois do tratamento ortodôntico em pacientes com doença periodontal. Diante da literatura exposta, foi possível verificar que o tratamento ortodôntico em pacientes saudáveis não traz nenhum risco ao periodonto, mas a presença de doença periodontal ativa contraindica a movimentação dentária. Por isso, é extremamente importante antes de iniciar a terapia ortodôntica, executar um diagnóstico correto das alterações periodontais e tratá-las; e durante toda a terapia ortodôntica, ter um controle periodontal com reavaliações periódicas. Além disso, ao final do tratamento ortodôntico, aconselha-se fazer uma nova orientação de higiene oral e estabelecer a manutenção de acordo com a exposição aos fatores de riscos do paciente a doença periodontal.

The aim of this paper was to search though a revision of the literature the cares before, during and after the orthodontic treatment in patients with a periodontal disease. The literature shows that the orthodontical treatment in healthy patients brings no risk to the periodontium, although the presence of an active periodontal disease counter indicates the dental movement. Thus, it is extremely important to execute a correct diagnosis of any periodontal alteration and treat them before the beginning of the orthodontical treatment. Besides, during the whole orthodontical treatment is also important to have a periodontal control with periodic reevaluations and at the end of the orthodontical treatment, a new oral hygiene orientation may be needed to finally establish the follow-up of the patient according to the risk of periodontal disease.

Streptococcus mutans adhesion to titanium after brushing with fluoride and fluoride-free toothpaste simulating 10 years of use.

PURPOSE: To assess the influence of fluoride on the adhesion of Streptococcus mutans to titanium using an experimental paradigm simulating 10 years of brushing. MATERIALS AND METHODS: Commercially pure titanium (cpTi) and titanium alloy (Ti-6Al-4V) disks (6 mm in diameter and 4 mm thick) were mirror-polished and randomly assigned to one of the following six groups (n = 6): immersion (I) or brushing (B) in deionized water (groups IW [control] and BW), fluoride-free toothpaste (groups IT and BT), or fluoridated toothpaste (groups IFT and BFT). Specimens subjected to immersion were statically submerged into the solutions without brushing. For the brushed specimens, a linear brushing machine with a soft-bristled toothbrush was used. The experiments lasted a total of 244 hours. Before and after treatment, the specimens were analyzed under an atomic force microscope to determine the mean roughness (Ra) and the mean of the maximum peak-to-valley heights of the profile (Rtm). The disks were contaminated with standard strains of S mutans in well plates with brain-heart infusion broth. Adhesion was analyzed based on the numbers of colony-forming units (CFU/mL) of adhered viable cells using scanning electronic microscopy. Differences in CFU/mL between the groups were analyzed by one-way analysis of variance. RESULTS: Immersion did not affect either surface. As suggested by Ra and Rtm, BW, BT, and BFT induced changes on the surface of cpTi, whereas only BT and BTF induced changes on the surface of Ti-6Al-4V. No significant differences were observed regarding CFU/mL among the cpTi or Ti-6Al-4V groups. S mutans adhesion was similar for all surfaces. CONCLUSIONS: The changes in titanium induced by 10 years of simulated brushing with fluoride toothpaste did not increase the adhesion of S mutans.

Expression of interferon-γ, interferon-α and related genes in individuals with Down syndrome and periodontitis.

BACKGROUND: Recently, attenuation of anti-inflammatory and increase of pro-inflammatory mediators was demonstrated in individuals with Down syndrome (DS) in comparison with euploid patients during periodontal disease (PD), suggesting a shift to a more aggressive inflammation in DS. AIM: To determine the influence of DS in the modulation of interferons (IFNs) signaling pathway in PD. MATERIALS AND METHODS: Clinical periodontal assessment was performed and gingival tissue samples obtained from a total of 51 subjects, including 19 DS individuals with PD, 20 euploid individuals with PD and 12 euploid individuals without PD. Expression levels of interferon-gamma (IFNG) and interferon-alpha (IFNA), and their receptors IFNGR1, IFNGR2, IFNAR1 and IFNAR2, the signaling intermediates Janus kinase 1 (JAK1), signal transducer and activator of transcription 1 (STAT1) and interferon regulatory factor 1 (IRF1) were determined using real time quantitative polymerase chain reaction (qPCR). RESULTS: Clinical signs of periodontal disease were markedly more severe in DS and euploid patients with PD in comparison to euploid and periodontally healthy patients. There was no difference on mRNA levels of IFNA, IFNG, INFGR2, IFNAR1 and IFNAR2 between DS and euploid individuals, even though some of these genes are located on chromosome 21. STAT1 and IRF1 mRNA levels were significantly lower in DS patients in comparison with euploid individuals with PD. In euploid individuals, PD was associated with an increased expression of IFNGR1, IFNGR2, IFNAR1, STAT1 and IRF1. CONCLUSIONS: Reduced expression of STAT1 and IRF1 genes indicate an impaired activation of IFNs signaling in individuals with DS and PD. Expression of IFNA, IFNG and IFN receptors was not altered in DS patients, indicating that indirect mechanisms are involved in the reduced activation of IFN signaling.

Effect of a calcium hydroxide/chlorhexidine paste as intracanal dressing in human primary teeth with necrotic pulp against Porphyromonas gingivalis and Enterococcus faecalis.

BACKGROUND: Intracanal medication is important for endodontic treatment success as it eliminates microorganisms that persist after biomechanical preparation. Aim. To evaluate the effect of two intracanal medications against Porphyromonas gingivalis and Enterococcus faecalis in the root canals of human primary teeth with necrotic pulp with and without furcal/periapical lesion, using quantitative real-time polymerase chain reaction (qRT-PCR). DESIGN: Thirty-two teeth with necrotic pulp were used. Twelve teeth did not present lesion, and 20 teeth presented radiographically visible furca/periapical lesion. Microbiological samples were collected after coronal access and biomechanical preparation. The teeth were medicated with calcium hydroxide pastes prepared with either polyethylene glycol or chlorhexidine. After 30days, the medication was removed and a third collection was performed. Microbiological samples were processed using qRT-PCR. Data were analysed by Wilcoxon and Mann-Whitney tests (α=0.05). RESULTS: There was no significant difference in the microbiota present in the primary teeth with and without furcal/periapical lesion. Biomechanical preparation was effective in reducing the number of microorganisms (P<0.05). The intracanal medications had similar antibacterial activity. CONCLUSION: The association of chlorhexidine with calcium hydroxide did not increase the antibacterial activity of the intracanal medication in the treatment of primary teeth with necrotic pulp with and without furcal/periapical lesion.

Mechanical and biological characterization of resin-modified glass-ionomer cement containing doxycycline hyclate.

OBJECTIVES: To characterize the mechanical and biological properties of a resin-modified glass ionomer cement (RMGIC) containing doxycycline hyclate. METHODS: The antibacterial effect of RMGIC containing 1.5, 3.0 and 4.5% doxycycline hyclate was assessed using two experiments - agar diffusion test for 24h and biofilm assay for 24h and 7 days - against some cariogenic bacteria. Briefly, base layers of BHI agar and 300µL of each inoculum were prepared in Petri dishes with 6 wells that were completely filled with materials. After 24h incubation, zones of bacterial growth inhibition were measured using a digital caliper. Biofilm assays were conducted using RMGIC specimens immersed in 24-well plates containing the inoculum in BHI broth. After 24h and 7 days, each specimen were removed, vortexed and the suspension diluted and inoculated in BHI plates for subsequent bacterial counting. Cytotoxicity tests used 50 specimens made in sterilized metal molds, including Vitrebond as positive control. Extracts from every specimen were applied on the MDPC-23 odontoblast-like cells for 24h. The MTT assay and SEM evaluation determined cell metabolism and morphology, respectively. 80 cylindrical specimens were made from the previously cited groups, and were submitted to testing with a universal testing machine (Instron 4411) using a crosshead speed of 1.0mm/min for compressive strength and 0.5mm/min for diametral tensile strength, respectively. Data from antibacterial and cytotoxic effects, and mechanical properties were submitted to appropriated statistical tests. RESULTS: All tested groups showed growth inhibition of all tested strains (p<0.05) in 24h for both microbiological tests, but only 4.5% doxycycline have antibacterial effect after 7 days. None of doxycycline concentrations caused toxic effect to the MDPC-23 cells or presenting alterations to mechanical properties. CONCLUSION: The incorporation of up to 4.5% doxycycline hyclate into RMGIC inhibits important oral microorganisms, without modifying biological and mechanical characteristics of the dental material, suggesting a new alternative for the treatment of dental caries.

In Vitro effect of low-level laser therapy on typical oral microbial biofilms.

The aim of this study was to evaluate the effect of specific parameters of low-level laser therapy (LLLT) on biofilms formed by Streptococcus mutans, Candida albicans or an association of both species. Single and dual-species biofilms--SSB and DSB--were exposed to laser doses of 5, 10 or 20 J/cm(2) from a near infrared InGaAsP diode laser prototype (LASERTable; 780 ± 3 nm, 0.04 W). After irradiation, the analysis of biobilm viability (MTT assay), biofilm growth (cfu/mL) and cell morphology (SEM) showed that LLLT reduced cell viability as well as the growth of biofilms. The response of S. mutans (SSB) to irradiation was similar for all laser doses and the biofilm growth was dose dependent. However, when associated with C. albicans (DSB), S. mutans was resistant to LLLT. For C. albicans, the association with S. mutans (DSB) caused a significant decrease in biofilm growth in a dose-dependent fashion. The morphology of the microorganisms in the SSB was not altered by LLLT, while the association of microbial species (DSB) promoted a reduction in the formation of C. albicans hyphae. LLLT had an inhibitory effect on the microorganisms, and this capacity can be altered according to the interactions between different microbial species.

The in vitro antimicrobial activity of natural infant fluoride-free toothpastes on oral micro-organisms.

PURPOSE: The objective of this study was to evaluate the antimicrobial activity of six toothpastes for infants: 3 fluoride-free experimental toothpastes--cashew-based, mango-based and without plant extract and fluoride compared with 2 commercially fluoride-free toothpastes and 1 fluoridated toothpastes. METHODS: Six toothpastes for infants were evaluated in this study: (1) experimental cashew-based toothpaste; (2) experimental mango-based toothpaste; (3) experimental toothpaste without plant extract and fluoride (negative control); (4) First Teeth brand toothpaste; (5) Weleda brand toothpaste; and (6) Tandy brand toothpaste (positive control). The antimicrobial activity was recorded against Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus, and Candida albicans using the agar plate diffusion test. RESULTS: First Teeth, Weleda, mango-based toothpaste, and toothpaste without plant extract presented no antimicrobial effect against any of the tested micro-organisms. Cashew toothpaste had antimicrobial activity against S mutans, S sobrinus, and L acidophilus, but it showed no antimicrobial activity against C albicans. There was no statistical difference between the inhibition halo of cashew and Tandy toothpastes against S mutans and L acidophilus. CONCLUSIONS: Cashew fluoride-free toothpaste had inhibitory activity against Streptococcus mutans and Lactobacillus acidophilus, and these results were similar to those obtained for fluoridated toothpaste.

Influence of antiplatelet drugs in the pathogenesis of experimental periodontitis and periodontal repair in rats.

BACKGROUND: Platelets contain an array of biologic mediators that can modulate inflammation and repair processes including proinflammatory mediators and growth factors. Previous studies have shown that periodontitis and periodontal repair are associated with platelet activation. We hypothesized that drug-induced platelet inactivation may interfere in the processes of inflammation and repair in experimental periodontitis in rats by suppressing the release of biologic mediators from platelets to the site of injury. METHODS: To measure the effects on periodontitis, ligatures were placed around first molars, and aspirin (Asp, 30 mg/kg) or clopidogrel (Clo, 75 mg/kg) was given intragastrically once daily for 15 days. Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and thromboxane A(2) levels were measured by enzyme-linked immunosorbent assay. To evaluate the effects of antiplatelet drugs on periodontal repair, ligatures were removed after 15 days of periodontitis induction, and Asp or Clo were administered beginning the following day for 15 days. Periodontal repair was assessed by microcomputed tomography. RESULTS: On periodontitis phase, Asp and Clo significantly reduced levels of TNF-α and Il-6 (P <0.05), but only Asp decreased thromboxane A(2) (P <0.05). Asp and Clo decreased inflammatory infiltration; however, this reduction was more pronounced with Clo treatment (P <0.05). Histometric analysis showed that Asp and Clo impaired alveolar bone resorption. During the repair phase and after removal of the ligatures, microcomputed tomography analysis demonstrated that treatment with Asp and Clo did not impair alveolar bone repair. CONCLUSION: Systemic administration of Asp and Clo attenuates the inflammation associated with periodontitis without affecting the repair process when stimulus is removed.

In Vitro effect of low-level laser therapy on typical oral microbial biofilms

The aim of this study was to evaluate the effect of specific parameters of low-level laser therapy (LLLT) on biofilms formed by Streptococcus mutans, Candida albicans or an association of both species. Single and dual-species biofilms - SSB and DSB - were exposed to laser doses of 5, 10 or 20 J/cm2 from a near infrared InGaAsP diode laser prototype (LASERTable; 780 ± 3 nm, 0.04 W). After irradiation, the analysis of biobilm viability (MTT assay), biofilm growth (cfu/mL) and cell morphology (SEM) showed that LLLT reduced cell viability as well as the growth of biofilms. The response of S. mutans (SSB) to irradiation was similar for all laser doses and the biofilm growth was dose dependent. However, when associated with C. albicans (DSB), S. mutans was resistant to LLLT. For C. albicans, the association with S. mutans (DSB) caused a significant decrease in biofilm growth in a dose-dependent fashion. The morphology of the microorganisms in the SSB was not altered by LLLT, while the association of microbial species (DSB) promoted a reduction in the formation of C. albicans hyphae. LLLT had an inhibitory effect on the microorganisms, and this capacity can be altered according to the interactions between different microbial species.

O objetivo deste estudo foi avaliar o efeito de parâmetros específicos de irradiação com laser de baixa intensidade sobre biofilmes formados por Streptococcus mutans (S. mutans), Candida albicans (C. albicans) ou associação de ambas as espécies. Biofilmes isolados ou associados destes microrganismos foram irradiados com um dispositivo laser infra-vermelho próximo de diodos InGaAsP (LaserTABLE 780 ±3 nm, 0,04W), utilizando-se para isto o dispositivo LASERTable. Quinze horas após a irradiação, foi demonstrado, por meio da avaliação da viabilidade celular (Teste de MTT), da morfologia das células (MEV) e do crescimento do biofilme (UFC/mL), que esta terapia foi capaz de reduzir o metabolismo celular, número de microrganismos presentes no biofilme, bem como seu crescimento no local. Quanto à viabilidade celular, a resposta à irradiação do biofilme de S. mutans (SSB) foi semelhante para todas as doses de energia, sendo que o crescimento do biofilme foi dose dependente. Porém, quando associado à C. albicans, este microrganismo apresentou resistência à fototerapia. Já a C. albicans associada ao S. mutans apresentou redução de crescimento significativa, sendo este resultado também foi dose dependente. A morfologia dos microrganismos não foi alterada pelas irradiações realizadas quando em biofilmes isolados. A associação entre os microrganismos promoveu redução na formação de hifas pela C. albicans. A laserterapia de baixa intensidade apresentou efeito inibitório sobre microrganismos, sendo que esta capacidade pode ser alterada de acordo com a interação entre diferentes microrganismos.

Patógenos periodontais: comparação entre cultura bacteriana e PCR em tempo real para teste diagnóstico / Periodontal pathogens: comparison between culture and real time PCR for diagnostic assay

A correta distinção dos microrganismos envolvidos na patogênese da doença periodontal, torna-se importante para o entendimento da sua progressão e adequado plano de tratamento. Métodos de identificação e quantificação foram desenvolvidos e são considerados extremamente sensíveis e precisos na caracterização das espécies bacterianas. Com isso a presente revisão mostra trabalhos existentes na literatura, os quais analisaram comparativamente os métodos de Reação em Cadeia da Polimerase em tempo real (qPCR) e cultura bacteriana com objetivo na identificação de periodontopatógenos. Através do método de cultura bacteriana é possível a identificação de novos microrganismos e realização de testes de sensibilidade a antibióticos. O qPCR é um teste microbiológico que identifica e quantifica espécies bacterianas, através da amplificação gênica de fragmentos de DNA pré-determinados, com alta sensibilidade, especificidade e dispendem menor tempo do operador quando comparados a cultura bacteriana. Assim para a escolha de um determinado teste diagnóstico deve-se levar em consideração não somente a sua precisão na identificação dos micro-organismos, mas também a relação custo-beneficio.

The correct distinguishment of microorganisms involved in the periodontal disease pathogen, it is important in the understanding of its progression and adequate treatment planning. Considering this fact, some molecular methods of identification and quantification were developed and are extremely sensitive and precise in the characterization of different bacteria species. The present study aimed to realize a literature review, including studies that realized a comparative analysis between bacterialculture and real time PCR methods in the identification of pathogens. The bacterial culture method can possibly identify new microorganisms and realize antibiotics sensitivity tests. The real time PCR is a microbiologic test that identifies and quantifies bacterial species, through gene amplification of predetermined DNA fragments, with high sensitivity and specificity, and need a shorter operation time of the operator when compared to thebacterial culture method. In this way, to determine a specific diagnostic test, should be considered not only its precision in the identification of microorganisms, but the cost-benefit relationship as well.

Efeito antimicrobiano e citotóxico do óleo essencial de cymbopogon citratus sobre células odontoblastóides / Antimicrobial and cytotoxic effects of the essential oil of cymbopogon citratus on odontoblast-like cells

O objetivo deste trabalho foi avaliar a atividade antimicrobiana e o efeito citotóxico do óleo essencial (OE) de capim-limão (Cymbopogon citratus). A partir do método de difusão em ágar, diferentes concentrações de OE (0,1%; 0,2% e 1%), e soluções controle (clorexidina (Chx), água destilada (Ad) e álcool de cereais (Ac) foram aplicados sobre culturas de Candida albicans (C.a), Streptococos mutans (S.m), Streptococos sobrinus (S.sob) e Lactobacilus acidoflus (L.a). Para C.a, S.m e S.sob, os maiores halos de inibição, em ordem decrescente foram: Chx, Ac e óleo 1%, sendo os dois últimos semelhantes estatisticamente (Mann-Whitney, p>0,05). Para L.a, o maior halo de inibição foi observado para a Chx, seguido do óleo a 1%, 0,2%, 0,1% e Ac. Para avaliação da citotoxicidade foram determinados os seguintes grupos: OE a 0,1%; G2: OE puro; G3 (controle positivo): H2O2; G4: álcool de cereais (Ac); e G5 (controle negativo): meio de cultura (DMEM). As soluções foram aplicadas sobre cultura de células MDPC-23 (30.000 células/cm2) semeadas em placas de 24 wells. O metabolismo celular foi avaliado pelo teste do MTT. Considerando G5 como 100% de metabolismo celular, foi observado para os grupos G1, G2, G3, e G4 uma redução percentual no metabolismo das células de 29,6%; 82%; 81,2%; e 33,4%, respectivamente. Concluiu-se que o OE a 0,1% foi capaz de inibir o crescimento das cepas avaliadas e de causar discreta citotoxicidade sobre células odontoblastóides MDPC-23.

The aim of this study was to evaluate the antimicrobial and cytotoxic efect of essential oil (EO) of lemon grass (Cymbo-pogon citratus). From the agar difusion method, diferent concentrations of EO (0.135%, 0.2% and 1%), and control solutions (chlorhexidine (Chx), distilled water (Ad) and cereal alcohol (Ac)) were applied on cultures of Candida albicans (C.a), Streptococcus mutans (S.m), Streptococcus sobrinus (S.sob) and Lacto-bacillus acidophilus (L.a). For C.a, S.m and S.sob, the largest inhibition zones in descending order were: Chx, Ac and EO 1%, while the later two were statistically similar (Mann-Whitney, p> 0.05). For L.a, the largest inhibition halo was observed for the Chx, followed by EO at 1%, 0.2%, 0.135% and Ac. For evaluation of cytotoxicity, the following groups were set: G1: 0,1% EO; G2: pure EO; G3 (positive control): H2O2; G4: cereal alcohol; and G5 (negative control): culture medium - DMEM. The solutions were applied on the cultured MDPC-23 cells, which were plated (30,000 cells/cm2) in wells of 24 well-dishes. Cell metabolism was evaluated by MTT assay. Considering G5 (negative control) as 100% of cell metabolism, it was observed for G1, G2, G3 and G4 a percentage reduction in cell metabolism of 29.6%, 82%, 81.2% and 33.4%, respectively. It was concluded that the low concentration of 0,1% OE (C. citratus) was able to inhibit the growth of the strains tested as well as caused mild cytotoxicity to the cultured MDPC-23 cells.

Intermittent therapy with 1,25 vitamin D and calcitonin prevents cyclosporin-induced alveolar bone loss in rats.

Bone loss associated with cyclosporin A (CsA) therapy can result in serious morbidity to patients. Intermittent administration of 1,25 Vitamin D and calcitonin reduces osteopenia in a murine model of postmenopausal osteoporosis. The purpose of this study was to evaluate the effects of this therapeutic approach on CsA-induced alveolar bone loss in rats. Forty male Wistar rats were allocated to four experimental groups according to the treatment received during 8 weeks: (1) CsA (10 mg/kg/day, s.c.); (2) 1,25 Vitamin D (2 microg/kg, p.o.; in weeks 1, 3, 5, and 7) plus calcitonin (2 microg/kg, i.p.; in weeks 2, 4, 6, and 8); (3) CsA concurrently with intermittent 1,25 Vitamin D and calcitonin administration; and (4) the control treatment group (vehicle). At the end of the 8-week treatment period, serum concentrations of bone-specific alkaline phosphatase, tartrate-resistant acid phosphatase (TRAP-5b), osteocalcin, interleukin (IL)-1 beta, IL-6, and tumor necrosis factor alpha (TNF-alpha) were measured and an analysis of bone volume, bone surface, number of osteoblasts, and osteoclasts was performed. CsA administration resulted in significant alveolar bone resorption, as assessed by a lower bone volume and an increased number of osteoclasts, and increased serum bone-specific alkaline phosphatase, TRAP-5b, IL-1 beta, IL-6, and TNF-alpha concentrations. The intermittent administration of calcitriol and calcitonin prevented the CsA-induced osteopenic changes and the increased serum concentrations of TRAP-5b and inflammatory cytokines. Intermittent calcitriol/calcitonin therapy prevents CsA-induced alveolar bone loss in rats and normalizes the production of associated inflammatory mediators.

Invasão microbiana: infecção focal e a relação com aterosclerose / Microbial Invasion: focal infection and relationship with atherosclerosis

Os extraordinários avanços no desempenho de técnicas laboratoriais corroboram na evolução do entendimento dos mecanismos das doenças de modo geral, facilitando o tratamento e/ou a prevenção. De fato, informações equilibradas, curadas e atuais estão colaborando de forma estimulante no estudo da relação entre doença periodontal e periapical crônica com o desenvolvimento ou estabelecimento de algumas doenças cardiovasculares. Dessa forma, o objetivo da presente trabalho foi descrever de forma sucinta e objetiva a relação entre doença periodontal crônica e doença periapical como fatores de risco para o desenvolvimento ou estabeleciomento da aterosclerose. Estudos epidemiológicos têm procurado demonstrar que indivíduos com doença periodontal ou periapical poderiam apresentar um aumento significativo do risco de desenvolver algumas doenças sistêmicas incluindo a aterosclerose.

Staphylococcus aureus contamination in a pediatric dental clinic.

UNLABELLED: Staphylococcus aureus strains can be disseminated during dental treatment and occasionally lead to contamination and infection of patients and dentists. THE OBJECTIVE of this study was to determine the frequency and compare the number of S. aureus colonies isolated from the nose, hands and tongue of students and patients, as well as from the clinical environment, before and after dental treatment. Staphylococcus species were isolated from the tongue, nose and hands of 30 students and 30 patients and from the environment of a Pediatric Dentistry Clinic. The samples were incubated in SMA plates at 37 degrees C for 48 hours. RESULTS: The colonies that showed the presence of mannitol fermentation were collected as identification for Staphylococcus aureus, using CHROMagar and the coagulase test. The highest amount of S. aureus was found in the nose and tongue of children. In relation to dental students, more contamination was observed on gloved hands, followed by the tongue and hands without gloves, before clinical attendance. At the end of dental treatment, S. aureus colonies isolated from the gloved hands of students decreased significantly. Considering the clinical environment, the most contaminated areas were the auxiliary table and the storeroom, which was located at the center of the clinic. CONCLUSION: The dental clinic can be considered an environment for S. aureus cross-transmission. Preventative measures should be used to avoid the dissemination of pathogenic microorganisms.

Myeloperoxidase as inflammatory marker of periodontal disease: experimental study in rats.

RATIONALE: Previous studies have used myeloperoxidase (MPO) as an inflammatory marker to estimate the accumulation of neutrophils in inflamed regions. OBJECTIVE: The aim of this experimental study was to quantify the levels of MPO related to experimental periodontal disease in rats. METHODS: Periodontal disease was induced in a group of rats using placement of a ligature around molar teeth. A group of rats without ligature placement served as a control. Measurements were made on the 3(rd), 7(th), 15(th) and 30(th) day from baseline. Gingival tissues were taken for quantification of MPO levels by ELISA. RESULTS: The rats with induced periodontal disease showed statistically higher MPO levels (p < 0.05) when compared to control rats. A significant increase in the levels of MPO released on days 7 and 30 was observed, with higher levels in the group with induced periodontitis. CONCLUSION: The levels of MPO were found to be higher in rats with induced periodontal disease, confirming the hypothesis that MPO may serve as an inflammatory marker for periodontitis.