CAMPANELLIProgrammed Death 1 (PD-1) and PD-1 Ligand (PD-L1) Expression in Chronic Apical Periodontitis.

OBJECTIVE: This study aimed to examine programmed death protein 1 (PD-1) and programmed death lig-and 1 (PD-L1) expression on leukocytes from chronic apical periodontitis, and to determine the levels of cytokines in the apical periodontitis lesions. METHODS: Leukocytes from healthy gingival tissue (n=16) and chronic apical periodontitis (n=10) were eval-uated using flow cytometry. The PD-1 and PDL-1 expressions were evaluated using flow cytometry. The cy-tokine levels were evaluated by enzyme-linked immunosorbent assay. Data were analyzed using one-way ANOVA. The statistical significance level was set at P<0.05. RESULTS: Results showed that the apical periodontitis lesions are more infiltrated by PD-1+ and PDL1+ lym-phocytes than the control samples. In addition, the PDL-1 expression was detected on macrophages in the apical periodontitis lesions, and was significantly higher compared to leukocytes from healthy gingival tis-sue. The IFN-γ, TGF-ß, IL-10, and TNF-α levels were significantly higher in the apical periodontitis lesions com-pared to control samples. CONCLUSION: The PD-1, PD-L1, and CTLA-4 molecules are evident in apical periodontitis, and can be an impor-tant immune checkpoint in chronic periapical periodontitis.

Sealing ability of MTA, CPM, and MBPc as root-end filling materials: a bacterial leakage study.

Objectives To evaluate the sealing ability of three root-end filling materials (white MTA, CPM, and MBPc) using an Enterococcus faecalis leakage model. Material and Methods Seventy single-root extracted human teeth were instrumented and root-ends were resected to prepare 3 mm depth cavities. Root-end preparations were filled with white MTA, CPM, and MBPc cements. Enterococcus faecalis was coronally introduced and the apical portion was immersed in BHI culture medium with phenol red indicator. The bacterial leakage was monitored every 24 h for 4 weeks. The statistical analysis was performed using the Wilcoxon-Gehan test (p<0.05). Results All cements showed bacterial leakage after 24 hours, except for the negative control group. The MBPc showed significantly less bacterial leakage compared with the MTA group (p<0.05). No significant differences were found between the CPM and the other groups. Conclusions The epoxy resin-based cement MBPc had lower bacterial leakage compared with the calcium silicate-based cements MTA and CPM.

Sealing ability of MTA, CPM, and MBPc as root-end filling materials: a bacterial leakage study

ABSTRACT Objectives To evaluate the sealing ability of three root-end filling materials (white MTA, CPM, and MBPc) using an Enterococcus faecalis leakage model. Material and Methods Seventy single-root extracted human teeth were instrumented and root-ends were resected to prepare 3 mm depth cavities. Root-end preparations were filled with white MTA, CPM, and MBPc cements. Enterococcus faecalis was coronally introduced and the apical portion was immersed in BHI culture medium with phenol red indicator. The bacterial leakage was monitored every 24 h for 4 weeks. The statistical analysis was performed using the Wilcoxon-Gehan test (p<0.05). Results All cements showed bacterial leakage after 24 hours, except for the negative control group. The MBPc showed significantly less bacterial leakage compared with the MTA group (p<0.05). No significant differences were found between the CPM and the other groups. Conclusions The epoxy resin-based cement MBPc had lower bacterial leakage compared with the calcium silicate-based cements MTA and CPM.

PD-1 blockage delays murine squamous cell carcinoma development.

Engagement of programmed death-1 (PD-1) with its two ligands [programmed death ligand-1 (PD-L1) and PD-L2] has been associated with the suppression of tumor-reactive T cells; however, the underlying mechanism for this T-cell dysfunction is not clear. We hypothesized that PD-1 and PD-L1 signals are, in part, responsible for squamous cell carcinoma (SCC) escape from immune antitumor regulation by modulation of the tumor environment. In the present study, we used a multistage model of SCC to examine the role of PD-1/PD-L1 activation during tumor development. Tumor sites presented an increased percentage of CD4(+) and CD8(+) T cells expressing PD-1 when compared with non-tumorigenic control mice, whereas the expression of PD-L1 was particularly increased in F4/80(+) macrophages in tumor sites. Further, the systemic immune neutralization of PD-1 resulted in a decreased number and delayed incidence rate of papillomas followed by a differential expression of cytokeratins, suggesting that the PD-1-PD-L1 interaction contributes to the progression of SCC by downregulation of antitumor responses. In fact, blocking PD-1 increased the percentage of CD8(+) and CD4(+) T cells, and the levels of interferon-γ in the tumor sites. Our results indicated involvement of PD-1(+) T cells in SCC development and in the modulation of the inflammatory immune response.

Antimicrobial activity of calcium hydroxide and chlorhexidine on intratubular Candida albicans.

This study investigated the efficacy of calcium hydroxide and chlorhexidine gel for the elimination of intratubular Candida albicans (C. albicans). Human single-rooted teeth contaminated with C. albicans were treated with calcium hydroxide, 2% chlorhexidine gel, calcium hydroxide plus 2% chlorhexidine gel, or saline (0.9% sodium chloride) as a positive control. The samples obtained at depths of 0-100 and 100-200 µm from the root canal system were analyzed for C. albicans load by counting the number of colony forming units and for the percentage of viable C. albicans using fluorescence microscopy. First, the antimicrobial activity of calcium hydroxide and the 2% chlorhexidine gel was evaluated by counting the number of colony forming units. After 14 days of intracanal medication, there was a significant decrease in the number of C. albicans colony forming units at a depth of 0-100 µm with chlorhexidine treatment either with or without calcium hydroxide compared with the calcium hydroxide only treatment. However, there were no differences in the number of colony forming units at the 100-200 µm depth for any of the medications investigated. C. albicans viability was also evaluated by vital staining techniques and fluorescence microscopy analysis. Antifungal activity against C. albicans significantly increased at both depths in the chlorhexidine groups with and without calcium hydroxide compared with the groups treated with calcium hydroxide only. Treatments with only chlorhexidine or chlorhexidine in combination with calcium hydroxide were effective for elimination of C. albicans.

Avaliação in vitro da atividade antimicrobiana de enxaguatórios bucais / In vitro evaluation of antimicrobial activity of mouthrinses

O potencial antimicrobiano dos seguintes enxaguatórios bucais: Periogard®, Plax®, Oral-B®, Flogoral ® e Listerine® foram avaliados in vitro, frente às seguintes cepas: Pseudomonas aeroginosa, Escherichiacoli, Cândida albicans, Staphilococcus áureos, Staphilococcus epidermidi e Enterococcus faecallis, por meio do método de difusão em Agar Muller Hinton, o qual foi distribuído em alíquotas de 25 ml, em placas de Pétri estéreis. Cinco discos de papel filtro foram colocados em pontos equidistantes e foram embebidos com 20 μl dos enxaguatórios testados. As leituras dos halos foram realizadas após 48 horas. Os melhores resultados médios foram obtidos pelo Periogard® e pelo Plax®.

Periodontal parameters and BANA test in patients with chronic renal failure undergoing hemodialysis.

OBJECTIVES: The aim of this study was to analyze the periodontal parameters of patients with chronic renal failure. MATERIAL AND METHODS: The periodontal status of 16 Brazilian patients aged 29 to 53 (41.7 ± 7.2) years with chronic renal failure (CRF) and another matched group of 14 healthy controls with periodontitis was assessed clinically and microbiologically. Probing pocket depth (PPD), gingival recession (GR), dental plaque index (PLI), gingival index (GI), and dental calculus index (CI) were the clinical parameters recorded for the entire dentition (at least 19 teeth), while the anaerobic periodontopathogen colonization in four sites with the highest PPD was evaluated using the BANA test ("PerioScan"; Oral B). RESULTS: The results for the CRF group and control group, respectively were: PPD: 1.77 ± 0.32 and 2.65 ± 0.53; GR: 0.58 ± 0.56 and 0.51 ± 0.36; PLI: 1.64 ± 0.56 and 1.24 ± 0.67; GI: 0.64 ± 0.42 and 0.93 ± 0.50; CI: 1.17 ± 0.54 and 0.87 ± 0.52. Comparison between groups using the "t" test revealed a significantly increased PPD (p<0.001) in the control group. Comparison of the other clinicial parameters by the Mann-Whitney test showed differences only for PLI, which was significantly higher (p<0.05) in the CRF group. Spearman's test applied to each group showed a positive correlation among all clinical parameters, except for GR (p<0.05). None of the groups showed any correlation between GR and GI, while a significant negative correlation between GR and PPD was observed for the CRF group. The percentage of BANA-positive sites was 35.9% for the CRF group and 35.7% for the control group. The BANA test correlated positively with PPD only in the control group and with GR only in the CRF group. CONCLUSIONS: In spite of a higher PLI and dense anaerobic microbial population even in shallow PPD, patients with CRF exhibited better periodontal conditions than periodontitis patients, which is an evidence of altered response to local irritants.

Periodontal parameters and BANA test in patents with chronic renal failure undergoing hemodialysis

OBJECTIVES: The aim of this study was to analyze the periodontal parameters of patients with chronic renal failure. MATERIAL AND METHODS: The periodontal status of 16 Brazilian patients aged 29 to 53 (41.7±7.2) years with chronic renal failure (CRF) and another matched group of 14 healthy controls with periodontitis was assessed clinically and microbiologically. Probing pocket depth (PPD), gingival recession (GR), dental plaque index (PLI), gingival index (GI), and dental calculus index (CI) were the clinical parameters recorded for the entire dentition (at least 19 teeth), while the anaerobic periodontopathogen colonization in four sites with the highest PPD was evaluated using the BANA test ("PerioScan"; Oral B). RESULTS: The results for the CRF group and control group, respectively were: PPD: 1.77±0.32 and 2.65±0.53; GR: 0.58±0.56 and 0.51±0.36; PLI: 1.64±0.56 and 1.24±0.67; GI: 0.64±0.42 and 0.93±0.50; CI: 1.17±0.54 and 0.87±0.52. Comparison between groups using the "t" test revealed a significantly increased PPD (p<0.001) in the control group. Comparison of the other clincial parameters by the Mann-Whitney test showed differences only for PLI, which was significantly higher (p<0.05) in the CRF group. Spearman's test applied to each group showed a positive correlation among all clinical parameters, except for GR (p<0.05). None of the groups showed any correlation between GR and GI, while a significant negative correlation between GR and PPD was observed for the CRF group. The percentage of BANA-positive sites was 35.9 percent for the CRF group and 35.7 percent for the control group. The BANA test correlated positively with PPD only in the control group and with GR only in the CRF group. CONCLUSIONS: In spite of a higher PLI and dense anaerobic microbial population even in shallow PPD, patients with CRF exhibited better periodontal conditions than periodontitis patients, which is an evidence of altered response to local irritants.

Absence of functional TLR4 impairs response of macrophages after Candida albicans infection.

Candida albicans is recognized by phagocytic cells through a set of recognition receptors patterns. Recently, we showed the importance of TLR2 in the regulation of neutrophil survival after C. albicans infection. In the present work, we analyzed the involvement of TLR4 in the recognition of C. albicans by neutrophils and macrophages. Our results show that the absence of functional TLR4 resulted in lower chemotaxis of neutrophils to the site of infection, lower levels of TNF-α, CXCL1 and nitric oxide, and dissemination and persistence of the pathogen in lymph nodes and spleen. In vitro, the phagocytic activity, nitric oxide production and myeloperoxidase activity, CXCL1, IL-1ß production by neutrophils from TLR4-defective mice were not changed. In contrast, macrophages from TLR4-defective mice demonstrated lower phagocytosis and lower levels of CXCL1, IL-1ß and TNF-α. Together, these data demonstrate that TLR4 signals are important for the recognition of C. albicans by macrophages and their absence allows persistence of the infection.

Bacterial leakage in obturated root canals-part 2: a comparative histologic and microbiologic analyses.

OBJECTIVE: In this study, presence of dentin infection in root canals, obturated with 4 techniques submitted to the bacterial leakage test, was evaluated using histologic methods. STUDY DESIGN: The canals of palatal roots of 160 molars were instrumented and divided into different groups, according to the obturation technique used (lateral condensation, MicroSeal system, Touch 'n Heat + Ultrafil, and Tagger's hybrid technique) and extent of the remaining obturation material (5 mm and 10 mm). Ten additional roots were used as control samples. The roots were sterilized in ethylene oxide and mounted on a device for evaluation of bacterial leakage using the bacteria Enterococcus faecalis for 120 days. After the leakage test, roots were microscopically analyzed for the presence of dentin infection in the root canals and dentinal tubules. RESULTS: A total of 154 specimens were analyzed using both methodologies in the experimental groups; 50 root canals (32.4%) showed bacterial leakage at the end of the experimental period, and 118 (76.6%) showed the presence of bacteria in the root canals using the histologic criteria. The lateral condensation technique allowed lower penetration of bacteria in the root canals and dentinal tubules, followed by Touch 'n Heat + Ultrafil, MicroSeal, and Tagger's hybrid technique, which allowed significantly greater penetration of bacteria. Root canals with 10 mm of remaining obturation material presented similar bacterial penetration as root canals with 5 mm. CONCLUSIONS: Even when an adequate seal of the apical foramen was shown by the absence of turbidity in the bacterial leakage test, E. faecalis dentin infection was present in a high percentage of the root canals after 120 days of root filling exposure to the bacteria. Tagger's hybrid technique presented greater quantity of bacteria in histologic sections than root canals obturated with the other techniques.

The essential role of toll like receptor-4 in the control of Aggregatibacter actinomycetemcomitans infection in mice.

OBJECTIVE: Aggregatibacter actinomycetemcomitans is an oral Gram-negative bacterium that contributes to periodontitis progression. Isolated antigens from A. actinomycetemcomitans could be activating innate immune cells through Toll-like receptors (TLRs). In this study, we evaluated the role of TLR4 in the control of A. actinomycetemcomitans infection. MATERIAL AND METHODS: We examined the mechanisms that modulate the outcome of A. actinomycetemcomitans-induced periodontal disease in TLR4(-/-) mice. The production of cytokines was evaluated by ELISA. The bacterial load was determined by counting the number of colony-forming units per gram of tissue. RESULTS: The results showed that TLR4-deficient mice developed less severe periodontitis after A. actinomycetemcomitans infection, characterized by significantly lower bone loss and inflammatory cell migration to periodontal tissues. However, the absence of TLR4 facilitated the A. actinomycetemcomitans dissemination. Myeloperoxidase activity was diminished in the periodontal tissue of TLR4(-/-) mice. We observed a significant reduction in the production of tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1beta in the periodontal tissue of TLR4(-/-) mice. CONCLUSION: The results of this study highlighted the role of TLR4 in controlling A. actinomycetemcomitans infection.

Absence of TLR2 influences survival of neutrophils after infection with Candida albicans.

Candida albicans is an opportunistic pathogen, which causes local and/or disseminated diseases in immunosuppressed humans. Phagocytic cells play a critical role in the immune response against C. albicans. Toll like receptors (TLR) are important in the identification of invading microorganisms and in the regulation of neutrophil survival. TLR2 has been shown to participate in the response against pathogenic yeasts and to increase the functional life span of neutrophils. In view of these observations, we studied the involvement of TLR2 in neutrophil function after C. albicans infection. The absence of TLR2 resulted in lower chemotaxis of neutrophils to the site of infection. This in turn was associated with lower levels of chemokines from neutrophils, facilitating the dissemination of the pathogen to the lymph nodes and spleen. A high frequency of apoptotic neutrophils and macrophages in the inflammatory exudates from TLR2(-/-) mice was found. In addition, the phagocytic activity of neutrophils and macrophages, nitric oxide production and myeloperoxidase activity were diminished in cells from TLR2(-/-) mice. Together, these data demonstrate the importance of TLR2 signals for neutrophils activation and survival after C. albicans infection.

Avaliação in vitro da infiltração e da atividade antimicrobiana de cimentos endodônticos resinosos / In vitro evaluation of the infiltration and antimicrobial activity of endodontic cements resins

São características ideais para os cimentos endodônticos: selar os canais radiculares, prevenir a infiltração de bactérias ou de toxinas para os tecidos periapicais, tornar o ambiente impróprio à vida dos microrganismos. Avaliar in vitro a atividade antimicrobiana e a capacidade de selar os canais radiculares que os cimentos: Acroseal, AH Plus, EndoREZ, Epiphany e Sealer 26, para uma melhor indicação destes materiais para o uso clínico e para o desenvolvimento e melhorias de novas propriedades. Os cimentos foram avaliados frente aos microrganismos: Enterococcus faecalis, Cândida albicans, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis e Pseudomonas aeruginosa; através do teste de difiusão em ágar (TDA). Os cimentos Fill Canal, Sealer 26 e Epiphany com e sem a adição do “Epiphany Thinning Resin”, foram efetivos contra todas as cepas; o EndoREZ não apresentou nenhuma atividade antimicrobiana e os cimentos Acroseal e AH Plus não atuaram sobre a Cândida albicans e Pseudomonas aeroginosa, respectivamente. A capacidade de selar os canais radiculares foi avaliada pelo teste de infiltração pelo sistema de transporte de fluído (TISTF) e pelo microrganismo Enterococcus faecalis (TIM). O cimento AH Plus apresentou menor índice de infiltração quando comparado aos demais através da TISTF enquanto o Epiphany apresentou infiltração bacteriana em 7/20 (35%) raízes, o AH Plus em 8/20 (40%), o Acroseal em 9/19 (47,4%), o Sealer 26 em 11/20 (55%), o maior número foi observado para o EndoREZ em 9/15 (73,3%) pelo TIM. O emprego do TODA, TISTF e TIM, possibilitou comparar e indicar quais cimentos seriam seguros e efetivos para os pacientes.

Characteristics are ideal for endodontic sealer: seal the root canals to prevent leakage of bacteria or toxins to the periapical tissues, making the environment unsuitable for life of microorganisms. Evaluating in vitro antimicrobial activity and ability to seal the root canals that sealers: Acroseal, AH Plus, EndoREZ, Epiphany Sealer 26 with a target state or the redesign these clinical materials. The sealers were evaluated against the microorganisms: Enterococcus faecalis, Cândida albicans, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa, by the agar diffusion method (ADM). The sealer Fill Canal, Sealer 26 and Epiphany with and without the addition of the “Epiphany Thinning Resin”, were effective against all strains; the EndoREZ not had any antimicrobial activity and the AH Plus and Acroseal sealer not acted on Cândida albicans and Pseudomonas aeruginosa, respectively. The ability to seal the root canal was evaluated by test of infiltration by the fluid transport system (TIFTS) and by the microorganism Enterococcus faecalis (TIM). The AH Plus sealer showed lower rate of infiltration when compared to the others; through the Epiphany TIFTS as presented bacterial infiltration in 7/20 (35%) roots, AH Plus in 8/20 (40%), the Acroseal on 9/19 (47.4%), the Sealer 26 in 11/20 (55%), the largest number was observed for EndoREZ on 9/15 (73.3%) for the TIM. The use of the ADM, TISTF and TIM, has compared and indicate sealers were safe and effective for patients.

Inhibitory signals mediated by programmed death-1 are involved with T-cell function in chronic periodontitis.

BACKGROUND: Inhibitory signals mediated via molecules such as programmed death-1 (PD-1) play a critical role in downmodulating immune responses and maintaining peripheral tolerance. We investigated the involvement of cytokines and PD-1 engagement in mediating the T-cell unresponsiveness to bacterial and ubiquitous antigens in periodontal diseases. METHODS: Gingival and peripheral blood samples from healthy individuals and patients with chronic periodontitis were collected and used for the subsequent assays. Leukocytes in the lesion site and blood were evaluated using flow cytometry. The production of interferon-gamma, interleukin-10, and transforming growth factor-beta proteins was evaluated by enzyme-linked immunosorbent assay (ELISA), and the presence of PD-1+ cells in the inflamed gingiva was confirmed by immunofluorescence confocal microscopy for CD4 and PD-1 colocalization. RESULTS: T cells from patients with chronic periodontitis proliferated poorly in response to Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) antigen. T-cell unresponsiveness was not associated with imbalanced cytokine production. However, T cells from patients with chronic periodontitis expressed significantly higher levels of PD-1 either upon isolation or after culture with antigens. Moreover, PD-1 blocking did not result in significant T-cell proliferation in cells cultured with phytohemagglutinin or bacterial antigens. The blockade of PD-1 resulted in the increased production of IFN-gamma. In addition, CD4+ and CD8+ T cells expressing PD-1 accumulated in lesions with chronic periodontitis. CONCLUSION: These data show that PD-1 engagement could be involved in the modulation of IFN-gamma production by T cells in patients with chronic periodontitis.

Bacterial leakage in root canals obturated by different techniques. Part 1: microbiologic evaluation.

OBJECTIVE: This study compared the coronal bacterial leakage of root canals obturated by different techniques and with different lengths of obturation. STUDY DESIGN: The canals of palatal roots of 160 maxillary molars were instrumented and divided into different groups according to the obturation technique used (lateral condensation, Microseal system, Touch 'n Heat + Ultrafil system, or Tagger's hybrid technique) and the length of obturation (5 mm or 10 mm). The roots were impermeabilized, sterilized in ethylene oxide, and mounted on a device for evaluation of the bacterial leakage. RESULTS: Tagger's hybrid technique produced a statistically greater number of specimens with coronal leakage than the other techniques. There was no statistically significant difference between the lateral condensation, Touch 'n Heat + Ultrafil, and Microseal groups. Root canals with 10 mm of obturation produced a statistically significantly smaller number of specimens with leakage than root canals with 5 mm of obturation. CONCLUSION: Tagger's hybrid technique produced a greater number of specimens with coronal leakage than the other techniques, and a greater number of root canals with 5 mm of obturation leaked than root canals with 10 mm of obturation.

Antimicrobial effect of propolis and other substances against selected endodontic pathogens.

OBJECTIVE: The aim of this study was to determine the antimicrobial effect of ethanol extract of propolis (EEP) and intracanal medicaments calcium hydroxide, camphorated paramonochlorophenol, and formocresol by means of the macrodilution method using the reinforced clostridial medium (RCM) and brucella and brain heart infusion media. STUDY DESIGN: The antimicrobial agents were sequentially diluted and tested against anaerobic bacteria Prevotella nigrescens, Fusobacterium nucleatum, Actinomyces israelii, and Clostridium perfringens and against Enterococcus faecalis, with the 5 x 10(5) CFU/mL standardized inocula. The tubes were anaerobically incubated and the minimum inhibitory concentration was detected. Blood agar RCM subcultures were performed to provide minimum bactericidal concentration. The results were analyzed by analysis of variance test. RESULTS: All drugs were effective against all tested strains, without statistical differences. E. faecalis was the less susceptible strain, and RCM broth promoted faster bacterial growth, but there were no significant differences in these results. Ethanol did not influence the antimicrobial effect of EEP.

Periodontopathogens in the saliva and subgingival dental plaque of a group of mothers

Procurou-se avaliar a condiçäo periodontal e a presença de periodontopatógenos em 30 mäes brasileiras, com idades entre 21-40 anos (28,4ñ4,49anos) e seus filhos, com 5-6 anos de idade, considerando que elas possam ser fonte de transmissäo para seus filhos e influenciar suas condiçöes clínicas e bacteriológicas. Além de determinar o índice de placa (IP), índice gengival (IG) de mäes e filhos, e a profundidade de sondagem periodontal (PS), apenas das mäes, avaliaram-se quatro amostras de placa dental subgengival de mäes e filhos e uma amostra de saliva total estimulada das mäes para a presença de Actinobacillus actinomycetemcomitans (A.a.), Prevotella nigrescens (P.n.), Porphyromonas gingivalis (P.g.) e Treponema denticola (T.d.), pela técnica de "slot immunoblot" (SIB). As médias e desvios-padräo para as variáveis clínicas em mäes e filhos foram, respectivamente: 1,86ñ0,67 e 1,64ñ0,68, para o IP e 1,24ñ0,67 e 0,82ñ0,37, para o IG, enquanto apenas nas mäes, a PS total foi 1,81ñ0,69 e a PS dos 4 sítios, 4,03ñ1,40. O teste de Wilcoxon revelou diferença significante (p<0,05) entre mäes e filhos apenas para o IG. As bactérias mais prevalentes nas mäes, em ordem decrescente, foram, A.a., P.n., P.g. and T.d. As crianças demonstraram padräo de higiene oral e de ocorrência bacteriana semelhante aos de suas mäes, apesar da maioria delas näo apresentar quantidade suficiente de placa subgengival. A comparaçäo entre amostras revelou diferença estatisticamente significante (p<0,05), com a saliva sempre exibindo os maiores valores e maior positividade, demonstrando ser um indicador de colonizaçäo oral e poder funcionar como veículo para a transmissäo de periodontopatógenos de mäes para filhos

Activity of endodontic antibacterial agents against selected anaerobic bacteria.

The antimicrobial activity of substances used as antibacterial agents (solutions of 10% calcium hydroxide, camphorated paramonochlorophenol - PMCC, 2% chlorhexidine digluconate and 10% castor oil plant detergent) on anaerobic bacteria (Fusobacterium nucleatum ATCC 25586, Prevotella nigrescens ATCC 33563, Clostridium perfringens ATCC 13124 and Bacteroidesfragilis ATCC 25285), using a broth dilution technique, was evaluated in vitro. For determination of minimum inhibitory and minimum bactericide concentrations (MIC and MBC), two culture broths, Reinforced Clostridial Medium (RCM) and supplemented Brucella, standardized inoculum and serially diluted solutions were used. All antibacterial agents presented antimicrobial activity that varied for different bacteria. There were no differences in the performance of the two broths. Chlorhexidine digluconate was the most effective, with the lowest MICs, followed by castor oil detergent, PMCC and calcium hydroxide. C. perfringens and B. fragilis were the most resistant bacteria to all agents.

In vitro effect of intracanal medicaments on strict anaerobes by means of the broth dilution method.

The determination of bacterial susceptibility to intracanal medicaments is a necessity. Nevertheless, few studies utilize the proper methodology to carry out that evaluation with anaerobes. In this study, the steps of a broth dilution method, carried out in microplates (microdilution) and tubes (macrodilution), to test the effect of traditional intracanal medicaments on anaerobic bacteria are described. The results are presented as values of minimal inhibitory and bactericidal concentrations (MIC and MBC). Standardized inocula of the anaerobic bacteria Prevotella nigrescens (ATCC 33563), Fusobacterium nucleatum (ATCC 25586) and Clostridium perfringens (ATCC 13124), in reinforced Clostridium medium (RCM) and supplemented Brucella broth, were submitted to different concentrations of calcium hydroxide, chlorhexidine digluconate, camphorated paramonochlorophenol and formocresol solutions. The drugs were diluted in the same culture broths, in microplates and tubes, and were then incubated in anaerobiosis jars at 37 degrees C for 48 or 96 hours. The determination of MICs was carried out through visual and spectrophotometric readings, and the determination of MBCs, through the plating of aliquots on RCM-blood agar. For that kind of study, the macromethod with spectrophotometric reading should be the natural choice. MICs and MBCs obtained with the macromethod were compatible with the known clinical performance of the studied medications, and the values varied according to the bacteria and culture media employed. RCM was the most effective medium and C. perfringens, the most resistant microorganism.

In vitro effect of intracanal medicaments on strict anaerobes by means of the broth dilution method

A determinaçäo da suscetibilidade bacteriana aos medicamentos intracanal é uma necessidade, mas säo poucos os estudos que utilizam metodologia própria para anaeróbios estritos nessa avaliaçäo. Neste estudo, säo descritos os passos de um método de diluiçäo em caldo, feito em microplacas (microdiluiçäo) e em tubo (macrodiluiçäo), para testar a açäo de medicamentos intracanal tradicionais sobre bactérias anaeróbias estritas, com apresentaçäo dos resultados em Concentraçöes Inibitória e Bactericida Mínimas (CIM e CBM). Inóculos padronizados dos anaeróbios Prevotella nigrescens (ATCC 33563), Fusobacterium nucleatum (ATCC 25586) e Clostridium perfringens (ATCC 13124), em caldo Reinforced Clostridium Medium (RCM) e caldo Brucella suplementado, foram submetidos a diferentes concentraçöes de soluçöes de hidróxido de cálcio, digluconato de clorexidina, paramonoclorofenol canforado e formocresol, diluídas nos mesmos caldos de cultura, em microplacas e tubos, e depois incubados em jarras de anaerobiose a 37ºC por 48h ou 96h. A determinaçäo das CIMs foi feita através de leituras visual e em espectrofotômetro, e das CBMs, pela semeadura de alíquotas em ágar RCM-sangue. Para esse tipo de estudo, o macrométodo com leitura em espectrofotômetro deve ser a escolha natural. As CIMs e CBMs do macrométodo foram compatíveis com seu conhecido desempenho clínico, variando com as bactérias e meios de cultura empregados. O caldo RCM foi o mais efetivo e o C. perfringens, o microrganismo mais resistente