Prevalence of Candida albicans in primary endodontic infections associated with a higher frequency of apical periodontitis in type two diabetes mellitus patients.

To identify the prevalence of C. albicans in primary endodontic infections of type two diabetes mellitus (T2DM) patients and compare their clinical and radiographical characteristics with a non-diabetic control group, establishing the possible relationship between primary endodontic infection, T2DM, and C. albicans, since diabetes mellitus (DM), influences the development, course, and response to the treatment of apical periodontitis, but the presence of Candida albicans (C. albicans) has not been considered before. A total of 120 patients were selected and divided into two groups: 60 T2DM diagnosed patients and 60 non-diabetic controls. A clinical examination and radiographic analysis were performed to establish a periapical index score (PAI). Root canal samples were taken. Deoxyribonucleic acid (DNA) was extracted, and specific primers were used to identify C. albicans by polymerase chain reaction (PCR). A twofold increase in the prevalence of C. albicans in T2DM patients was observed in contrast to control patients (p = 0.0251). Sixty-five percent of T2DM patients with positive C. albicans scored a ≥ 3 PAI, while only 27% of the patients without C. albicans had a ≥ 3 PAI score (p = 0.0065). Long-term DM patients presented C. albicans more frequently (p < 0.0001). In this study, long-term T2DM patients carried C. albicans in their root canals more frequently when having a primary endodontic infection. Furthermore, this C. albicans presence seems to be related to a higher frequency of apical periodontitis.

Kaurenoic acid and its sodium salt derivative: antibacterial activity against Porphyromonas gingivalis and their mechanism of action.

AIM: To evaluate the antibacterial activity of 12 kaurane-type diterpenes against a panel of bacteria that cause endodontic infection. METHODS & MATERIALS: We conducted tests against bacteria in the planktonic or in the sessile mode, cytotoxic assays for the most promising compounds against human normal lung fibroblast cells, and Porphyromonas gingivalis (ATCC 33277) proteomic analysis. RESULTS & CONCLUSION: Kaurenoic acid and its salt exhibited satisfactory antibacterial action against the evaluated bacteria. Proteomic analysis suggested that these compounds might interfere in bacterial metabolism and virulence factor expression. Kaurane-type diterpenes are an important class of natural products and should be considered in the search for new irrigating solutions to treat endodontic infections.

Comparative Molecular Analysis of Gram-Negative Bacteria in Primary Teeth with Irreversible Pulpitis or Periapical Pathology.

Purpose: The purpose of this study was to compare the Gram-negative pathogens identified in the root canals of primary teeth with irreversible inflammatory pulpitis and in teeth showing apical periodontitis. Methods: Samples were collected from 123 root canals of primary teeth from three- to seven-year-old patients. Root canals were assigned to either group one (irreversible inflammatory pulpitis; n equals 63) or group two (pulp necrosis and apical periodontitis; n equals 60). Total number of cells of selected Gram-negative microorganisms was determined by the checkerboard DNA-DNA hybridization technique. Demographic data were compared using either chi-squared or t tests. Total numbers of microorganisms were compared using the Mann-Whitney test (α equals 0.05). Results: There were no significant intergroup differences in gender, age, and tooth group distribution (P>0.05). Among the 123 samples, 17 were discarded due to salivary contamination. The total numbers of Prevotella nigrescens, Treponema denticola, Fusobacterium nucleatum polymorphum, Fusobacterium nucleatum spp nucleatum, Aggregatibacter actinomycetemcomitans serotype a, Aggregatibacter actinomycetemcomitans serotype b, Porphyromonas gingivalis, Prevotella intermedia, and Prevotella melaninogenica were higher in teeth with apical periodontitis compared to those with irreversible inflammatory pulpitis (P<0.05). Conclusion: Higher numbers of Gram-negative bacteria were found in teeth with apical periodontitis compared to teeth with irreversible in- flammatory pulpitis.

Microbial analysis of root canal and periradicular lesion associated to teeth with endodontic failure.

The quantification of ten microorganisms at the root ends and in the surrounding periradicular lesions was performed. Thirty 3 mm samples root ends and 30 samples of the surrounding chronic periapical infection were collected during apical microsurgery. Samples were triturated, and the bacterial DNA was obtained. The bacterial quantification was performed by using the SYBR Green system. At least one microorganism was detected in all patients. In both the root end and periapical samples, Fusobacterium nucleatum (71.6%), Dialister pneumosintes (58.3%) and Tannerella forsythia (48.3%) were the most prevalent species. Dialister pneumosintes showed statistically significant values in the root end, and F. nucleatum was also significant in the apical periodontitis samples. A statistically significant association between T. forsythia and Porphyromonas gingivalis in the root ends was observed. Bacterial associations from 2 to 7 species were observed in most samples. Extra-radicular and/or intra-radicular infections were present in all teeth with failed endodontic treatment, and showed polymicrobial infection in most cases, with a predominance of F. nucleatum, D. pneumosintes and T. forsythia. When present, Enterococcus faecalis was never found to be the most prevalent species. The presence of a microbial diversity in post-treatment apical periodontitis confirms the polymicrobial and synergistic characteristic of this process. Our results show that the bacterial array associated with the 3 mm root ends and periradicular lesions in post-treatment apical periodontitis are complex and with a high inter-individual variability. These results might be useful to delineate treatment strategies for microbial elimination in apical periodontitis. Further studies are necessary to elucidate the role of these microorganisms in endodontic treatment failures.

Mikania glomerata Sprengel extract and its major compound ent-kaurenoic acid display activity against bacteria present in endodontic infections.

The search for new, effective and safe antimicrobial compounds from plant sources has continued to play an important role in the maintenance of human health since ancient times. Such compounds can be used to help to eradicate microorganisms from the root canal system, preventing/healing periapical diseases. Mikania glomerata (Spreng.), commonly known as "guaco," is a native climbing plant from Brazil that displays a wide range of pharmacological properties. Many of its activities have been attributed to its phytochemical composition, which is mainly composed of diterpenes, such as ent-kaurenoic acid (KA). The present study evaluated the potential activity of an ent-kaurenoic-rich (KA) extract from Mikania glomerata (i.e. Mikania glomerata extract/MGE) and its major compound KA against bacteria that can cause endodontic infections. Time-kill assays were conducted and the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), anti-biofilm activity, and synergistic antimicrobial activity of MGE and KA were determined. The MGE exhibited MIC and MBC values, which ranged from 6.25 to 100 µg/mL and 12.5 to 200 µg/mL respectively. The MIC and MBC results obtained for the KA, ranged from 3.12 to 100 µg/mL and 3.12 to 200 µg/mL respectively. Time-kill and anti-biofilm activity assays conducted for KA at concentrations between 3.12 and 12.5 µg/mL exhibited bactericidal activity between 6 and 72 h of incubation and 50% inhibition of biofilm formation for Porphyromonas gingivalis (clinical isolate), Propionibacterium acnes (ATCC 6919), Prevotella nigrescens (ATCC 33563), P. melaninogenica (ATCC 25845), Aggregatibacter actinomycetemcomitans (ATCC 43717). For synergistic antimicrobial activity, KA combined with chlorhexidine dichlorohydrate (CHD) had an additive effect with increased efficacy against P. gingivalis (clinical isolate) compared to CHD alone. It was concluded that M. glomerata extract and its major compound ent-kaurenoic acid (KA) showed in vitro antibacterial activity, the latter being a potential biofilm inhibitory agent. They may play important roles in the search for novel sources of agents that can act against bacteria present in endodontic infections.

Estudo comparativo de sistemas rotatório, reciprocante e híbrido no preparo de canais radiculares em dentes com infecção endodôntica primária: perfil microbiano e quantificação de endotoxinas / Comparative estudy of rotatory, reciprocating and hybrid systems on the instrumentation of root canals in teeth with primary endodontic infection: microbiological profile and endotoxin quantification

Os objetivos deste trabalho são: 1) Quantificar por checkerboard a carga microbiana e pelo método de LAL endotoxinas (EU/mL) nas infecções endodônticas primárias; 2) Realizar o monitoramento dos níveis de endotoxinas (EU/mL) e de carga microbiana antes do tratamento, após o preparo biomecânico com sistemas de instrumentação rotatória, reciprocante e híbrida e após o uso da medicação intracanal; 3) Relacionar sinais e sintomas clínicos com níveis de endotoxinas, micro-orgnismos e com complexos bacterianos; 4) Relacionar volumetria dos canais radiculares por meio de TCFC com níveis de endotoxina, micro-organismos e complexos bacterianos. Trinta dentes com infecção endodôntica primária e presença de lesão periapical foram submetidos a TCFC antes do tratamento e avaliados quanto a presença de sinais e sintomas clínicos. Após abertura coronária, foi realizada a coleta inicial nos canais radiculares, e em seguida, procedeu-se com o tratamento endodôntico, sendo os dentes divididos em diferentes grupos experimentais de acordo com o sistema de instrumentação utilizado (n=10): rotatório Mtwo (MTWO), reciprocante Reciproc (REC), e híbrido Genius (GEN). Durante o preparo biomecânico, os canais foram irrigados com 24 mL de NaOCl 2,5%. Foram realizadas coletas do conteúdo dos canais radiculares: logo após a abertura coronária (1 col), após a instrumentação (2 col), e após a MIC por 14 dias, realizada com pasta de hidróxido de cálcio associada a solução salina fisiológica (3 col). A detecção de micro-organimos foi realizada pelo teste checkerboard DNA-DNA hybridization. A quantificação de endotoxinas foi realizada pelo teste cinético cromogênio do lisado de amebócito de Limulus. As volumetrias dos canais radiculares foram realizadas com auxílio do software Nemotec®. Todos os dados foram analisados estatisticamente. Os resultados mostraram a detecção de micro-organismos e endotoxinas em 100% das amostras iniciais, sendo as bactérias C. ochracea e F. nucleatum as mais prevalentes (53%). Após o PBM, os micro-organismos mais encontrados foram F. nucleatum e L. buccalis (50%); e após a MIC C. gracilis (53,3%). Não houve diferença estatística entre os grupos quanto à redução da carga microbiana. Quanto as endotoxinas, logo após o PBM, o grupo que mais reduziu foi o MTWO, seguido por GEN e REC; após a MIC, o grupo que mais reduziu foi o GEN, seguido pelo MTWO e REC, porém todos os grupos se comportaram de maneira semelhante. Dor espontânea foi relacionada com P. nigrescens; dor a percussão com P. gingivalis, V. parvula, S. sputigena, P. nigrescens e E. saburreum; presença de fístula foi relacionada com o complexo laranja, Grampositivas e anaeróbios facultativos, e micro-organismos E. corrodens, P. micra, C. showae e E. saburreum. O maior volume do canal radicular foi correlacionado fortemente com anaeróbios estritos, com o complexo laranja e o micro-organismo P. micra. O PBM foi efetivo na redução de bactérias e endotoxinas do canal radicular, mas sem diferença estatística entre os três sistemas utilizados. Conclui-se que o PBM com NaOCl 2,5% é eficaz na redução de endotoxinas e na remoção de micro-organimos do canal radicular; sinais e sintomas são relacionados com micro-organismos, assim como a volumetria do canal radicular (AU)

The aims of this study are: 1) Quantify by checkerboard test the microbial load and endotoxins through LAL method (EU/ml) in primary endodontic infections; 2) To monitore levels of endotoxin (EU/ml) and microbial load before treatment, after biomechanical preparation with rotatory, reciprocating and hybrid instrumentation systems, and after use of intracanal medication; 3) To associate clinical signs and symptoms with endotoxin levels, microorganism and bacterial complexes; 4) To relate volumes of root canals through cone beam computed tomography (CBCT), with endotoxin levels, microorganisms and bacterial complexes. Thirty teeth with primary endodontic infection and periapical lesion were submitted to endodontic treatment after CBCT and evaluated the presence of clinical signs and symptoms. After coronary opening, the initial samples were collected to verify the presence of infection in root canals. Then, teeth were divided into different experimental groups according to the instrumentation system used (n=10): rotatory Mtwo (MTWO), reciprocating Reciproc (REC), and hybrid Genius (GEN). During biomechanical preparation, the canals were irrigated with 24 mL of 2.5% NaOCl. Samples were collected: after coronary opening (S1), after the instrumentation (S2) and after intracanal medication for 14 days with calcium hydroxide paste and physiological saline solution (S3). The detection of microorganisms was performed by checkerboard DNA-DNA hybridization technique. The endotoxin quantification was performed by chromogenic kinetic test of the Limulus amoebocyte lysate. The root canal volumetries were performed by Nemotec® software. All data were analyzed statistically. The results showed the detection of microorganisms and endotoxins in 100% of the S1, with the most prevalent bacteria being C. ochracea and F. nucleatum (53%). After biomechanical preparation, the most found microorganisms were F. nucleatum and L. buccalis (50%); And after intracanal medication C. gracilis (53.3%). There was no statistical difference between the groups regarding the reduction of the microbial load. In relation to endotoxins, after biomechanical preparation, the group with greatest reduction was MTWO, followed by GEN and REC; after intracanal medication, the group with greatest reduction was GEN, followed by MTWO and REC, but there was no statistical difference between them. Spontaneous pain was associated to P. nigrescens; tenderness to percussion with P. gingivalis, V. parvula, S. sputigena, P. nigrescens and E. saburreum; sinus tract was related to the orange complex, Gram-positive and facultative anaerobes, and microorganisms E. corrodens, P. micra, C. showae and E. saburreum. The root canal volume was strongly correlated with strict anaerobes, with the orange complex and the P. micra microorganism. Biomechanical preparation was effective in decreasing bacteria and endotoxin, but with no statistical difference were found between the three systems. Microorganisms are related to signs and symptoms and to root canal volume. In conclusion, biomechanical preparation with 2.5% NaOCl was effective on reducing endotoxins and decreasing microorganisms from root canals; signs and symptoms are related to microorganisms as well as root canal volumetry (AU)

Resistance profiles to antimicrobial agents in bacteria isolated from acute endodontic infections: systematic review and meta-analysis.

Infected root canal or acute apical abscess exudates can harbour several species, including Fusobacterium, Porphyromonas, Prevotella, Parvimonas, Streptococcus, Treponema, Olsenella and not-yet cultivable species. A systematic review and meta-analysis was performed to assess resistance rates to antimicrobial agents in clinical studies that isolated bacteria from acute endodontic infections. Electronic databases and the grey literature were searched up to May 2015. Clinical studies in humans evaluating the antimicrobial resistance of primary acute endodontic infection isolates were included. PRISMA guidelines were followed. A random-effect meta-analysis was employed. The outcome was described as the pooled resistance rates for each antimicrobial agent. Heterogeneity and sensitivity analyses were performed. Subgroup analyses were conducted based upon report or not of the use of antibiotics prior to sampling as an exclusion factor (subgroups A and B, respectively). Data from seven studies were extracted. Resistance rates for 15 different antimicrobial agents were evaluated (range, 3.5-40.0%). Lower resistance rates were observed for amoxicillin/clavulanic acid and amoxicillin; higher resistance rates were detected for tetracycline. Resistance rates varied according to previous use of an antimicrobial agent as demonstrated by the subgroup analyses. Heterogeneity was observed for the resistance profiles of penicillin G in subgroup A and for amoxicillin, clindamycin, metronidazole and tetracycline in subgroup B. Sensitivity analyses demonstrated that resistance rates changed for metronidazole, clindamycin, tetracycline and amoxicillin. These findings suggest that clinical isolates had low resistance to ß-lactams. Further well-designed studies are needed to clarify whether the differences in susceptibility among the antimicrobial agents may influence clinical responses to treatment.

Microbiome of Deep Dentinal Caries Lesions in Teeth with Symptomatic Irreversible Pulpitis.

This study used a next-generation sequencing approach to identify the bacterial taxa occurring in the advanced front of caries biofilms associated with pulp exposure and irreversible pulpitis. Samples were taken from the deepest layer of dentinal caries lesions associated with pulp exposure in 10 teeth diagnosed with symptomatic irreversible pulpitis. DNA was extracted and the microbiome was characterized on the basis of the V4 hypervariable region of the 16S rRNA gene by using paired-end sequencing on Illumina MiSeq device. Bacterial taxa were mapped to 14 phyla and 101 genera composed by 706 different OTUs. Three phyla accounted for approximately 98% of the sequences: Firmicutes, Actinobacteria and Proteobacteria. These phyla were also the ones with most representatives at the species level. Firmicutes was the most abundant phylum in 9/10 samples. As for genera, Lactobacillus accounted for 42.3% of the sequences, followed by Olsenella (13.7%), Pseudoramibacter (10.7%) and Streptococcus (5.5%). Half of the samples were heavily dominated by Lactobacillus, while in the other half lactobacilli were in very low abundance and the most dominant genera were Pseudoramibacter, Olsenella, Streptococcus, and Stenotrophomonas. High bacterial diversity occurred in deep dentinal caries lesions associated with symptomatic irreversible pulpitis. The microbiome could be classified according to the relative abundance of Lactobacillus. Except for Lactobacillus species, most of the highly prevalent and abundant bacterial taxa identified in this study have been commonly detected in infected root canals. The detected taxa can be regarded as candidate pathogens for irreversible pulpitis and possibly the pioneers in pulp invasion to initiate endodontic infection.

Comparison of Different Irrigants in the Removal of Endotoxins and Cultivable Microorganisms from Infected Root Canals.

This study was conducted to compare the effectiveness of different irrigants used to remove endotoxins and cultivable microorganisms during endodontic therapy. Forty root canals were contaminated and divided into groups according to the irrigant: 2% NaOCl + surfactant, 2% CHX, 2.5% NaOCl, and pyrogen-free saline solution (control). Samples were collected after root canal contamination (S1), after instrumentation (S2), and 7 days after instrumentation (S3). Microorganisms and endotoxins were recovered from 100% of the contaminated root canals (S1). At S2, 2% NaOCl + surfactant, 2% CHX, and 2.5% NaOCl were able to completely eliminate cultivable microorganisms. At S3, both 2% CHX and 2.5% NaOCl were effective in preventing C. albicans and E. coli regrowth, but E. faecalis was still detected. No microorganism species was recovered from root canals instrumented with 2% NaOCl + surfactant. At S2, a higher percentage value of endotoxin reduction was found for 2% NaOCl + surfactant (99.3%) compared to 2% CHX (98.9%) and 2.5% NaOCl (97.18%) (p < 0.05). Moreover, at S3, 2% NaOCl + surfactant (100%) was the most effective irrigant against endotoxins. All irrigants tested were effective in reducing microorganisms and endotoxins from root canals. Moreover, 2% NaOCl + surfactant was the most effective irrigant against endotoxins and regrowth of microorganisms.

Advanced Caries Microbiota in Teeth with Irreversible Pulpitis.

INTRODUCTION: Bacterial taxa in the forefront of caries biofilms are candidate pathogens for irreversible pulpitis and are possibly the first ones to invade the pulp and initiate endodontic infection. This study examined the microbiota of the most advanced layers of dentinal caries in teeth with irreversible pulpitis. METHODS: DNA extracted from samples taken from deep dentinal caries associated with pulp exposures was analyzed for the presence and relative levels of 33 oral bacterial taxa by using reverse-capture checkerboard hybridization assay. Quantification of total bacteria, streptococci, and lactobacilli was also performed by using real-time quantitative polymerase chain reaction. Associations between the target bacterial taxa and clinical signs/symptoms were also evaluated. RESULTS: The most frequently detected taxa in the checkerboard assay were Atopobium genomospecies C1 (53%), Pseudoramibacter alactolyticus (37%), Streptococcus species (33%), Streptococcus mutans (33%), Parvimonas micra (13%), Fusobacterium nucleatum (13%), and Veillonella species (13%). Streptococcus species, Dialister invisus, and P. micra were significantly associated with throbbing pain, S. mutans with pain to percussion, and Lactobacillus with continuous pain (P < .05). Quantitative polymerase chain reaction revealed a mean total bacterial load of 1 × 10(8) (range, 2.05 × 10(5) to 4.5 × 10(8)) cell equivalents per milligram (wet weight) of dentin. Streptococci and lactobacilli were very prevalent but comprised only 0.09% and 2% of the whole bacterial population, respectively. CONCLUSIONS: Several bacterial taxa were found in advanced caries lesions in teeth with exposed pulps, and some of them were significantly associated with symptoms. A role for these taxa in the etiology of irreversible pulpitis is suspected.

Antibacterial activity of Pinus elliottii against anaerobic bacteria present in primary endodontic infections.

Endodontic infections have a polymicrobial nature, but anaerobic bacteria prevail among the infectious microbes. Considering that it is easy to eliminate planktonic bacteria, biofilm-forming bacteria still challenge clinicians during the fight against endodontic diseases. The chemical constituents of the oleoresin of Pinus elliottii, a plant belonging to the family Pinaceae, stand out in the search for biologically active compounds based on natural products with potential application in the treatment of endodontic infections. Indeed, plant oleoresins are an abundant natural source of diterpenes that display significant and well-defined biological activities as well as potential antimicrobial action. In this context, this study aimed to (1) evaluate the in vitro antibacterial activity of the oleoresin, fractions, and subfractions of P. elliottii as well as the action of dehydroabietic acid against 11 anaerobic bacteria that cause endodontic infection in both their planktonic and biofilm forms and (2) assess the in vitro antibiofilm activity of dehydroabietic acid against the same group of bacteria. The broth microdilution technique helped to determine the minimum inhibitory concentration (MIC) of the oleoresin and fractions. This same technique aided determination of the MIC values of nine subfractions of Fraction 1, the most active fraction. The MIC, minimum bactericidal concentration, and antibiofilm activity of dehydroabietic acid against the tested anaerobic bacteria were also examined. The oleoresin and fractions, especially fraction PE1, afforded promising MIC values, which ranged from 0.4 to 50 µg/mL. Concerning the nine evaluated subfractions, PE1.3 and PE1.4 furnished the most noteworthy MIC values, between 6.2 and 100 µg/mL. Dehydroabietic acid displayed antibacterial activity, with MIC values lying from 6.2 to 50 µg/mL, as well as bactericidal effect for all the investigated bacteria, except for Prevotella nigrescens. Assessment of the antibiofilm activity revealed significant results--MICB50 lay between 7.8 and 62.5 µg/mL, and dehydroabietic acid prevented all the evaluated bacteria from forming a biofilm. Hence, the chemical constituents of P. elliottii are promising biomolecules to develop novel therapeutic strategies to fight against endodontic infections.

Antibiotic resistance genes in anaerobic bacteria isolated from primary dental root canal infections.

Fourty-one bacterial strains isolated from infected dental root canals and identified by 16S rRNA gene sequence were screened for the presence of 14 genes encoding resistance to beta-lactams, tetracycline and macrolides. Thirteen isolates (32%) were positive for at least one of the target antibiotic resistance genes. These strains carrying at least one antibiotic resistance gene belonged to 11 of the 26 (42%) infected root canals sampled. Two of these positive cases had two strains carrying resistance genes. Six out of 7 Fusobacterium strains harbored at least one of the target resistance genes. One Dialister invisus strain was positive for 3 resistance genes, and 4 other strains carried two of the target genes. Of the 6 antibiotic resistance genes detected in root canal strains, the most prevalent were blaTEM (17% of the strains), tetW (10%), and ermC (10%). Some as-yet-uncharacterized Fusobacterium and Prevotella isolates were positive for blaTEM, cfxA and tetM. Findings demonstrated that an unexpectedly large proportion of dental root canal isolates, including as-yet-uncharacterized strains previously regarded as uncultivated phylotypes, can carry antibiotic resistance genes.

Microflora associated with primary endodontic infections: correlations among SEM evaluation, clinical features, and radiographic findings.

The aim of the present study was to characterize, by means of SEM, primary endodontic infections and to correlate with clinical and radiographic findings. Twelve (12) human extracted teeth (19 roots) presenting primary endodontic infection were examined. SEM qualitative observations of bacterial and defense cells, their features and distribution within the root canal lumen and root dentine were recorded for association with clinical and radiographic tabled data. Although a direct correlation between biofilm composition and clinical/radiographic findings was not established, structural organization and distribution of the biofilm, as well as the characteristics of host response, could be easily related to those features. Bacterial biofilm was predominant at the apical third. Symptomatic apical periodontitis was related to presence of bacterial biofilm all thirds. Defense cells could be seen in the apical third of some samples. These cells were present in all thirds in some of the cases with open cavities. The correlations performed in this study allowed a better understanding of the picture of primary endodontic infection, host response and relevant clinical features. The combined use of scanning electron microscopy with clinical and radiographic evaluation has the potential to overcome some limits of the current knowledge related to pulpal and periapical diseases, providing important insights for improving treatment strategies.

Bacterial intensity and localization in primary molars with caries disease.

AIM: The aim was to assess the characteristics and outcomes of infections affecting the structures of carious primary molars. MATERIALS AND METHODS: Forty primary molars were used and classified according to the following clinical situation: With profound caries lesion, with bone loss at the furcation region, with perforation of the pulp chamber floor, and residual roots. The teeth were demineralized, cut, and stained with both haematoxylin-eosin and Brown and Brenn staining techniques. Assessment was performed using optical microscopy. RESULTS: Statistical analysis of the data by means of the Chi-square test suggests that there was a significant relationship (P<0.001) between the intensity and localization of infection and the level of destruction of dental structures. A significant difference was also observed in the intensity and localization of infection between the groups regarding crown, furca, and root (P<0.001). CONCLUSION: More intense and profound the infection, more severe is the dental destruction. The groups of residual roots showed the most severe bacterial infection compared to other groups.

Isolamento e identificação de enterococcus sp em infecções endodônticas primárias / Isolation and identification of enterococcus sp in primary endodontic infections

Este estudo objetivou o isolamento e caracterização bioquímica de Enterococcus sp de canais radiculares portadores de necrose pulpar de 70 pacientes. Foram isoladas 35 amostras de Enterococcus sp em 50% dos pacientes (n = 35) com a seguinte prevalência: 33 amostras Enterococcus faecalis (94,28%), 1 amostra Enterococcus faecium (2,85%) e 1 amostra Enterococcus durans (2,85%). Dos dentes com cultura positiva, 20 apresentaram sintomatologia dolorosa. Odor fétido e secreção purulenta foram observados em três dentes (8,57%). Dos 35 pacientes com cultura positiva, quatro apresentaram edema no momento da coleta e apenas um paciente apresentou fístula. A espécie E. faecalis foi majoritária, estando relacionada aos sinais e sintomas.

Lipopolysaccharide from Porphyromonas gingivalis sensitizes capsaicin-sensitive nociceptors.

Although odontogenic infections are often accompanied by pain, little is known about the potential mechanisms mediating this effect. In this study we tested the hypothesis that trigeminal nociceptive neurons are directly sensitized by lipopolysaccharide (LPS) isolated from an endodontic pathogen, Porphyromonas gingivalis. In vitro studies conducted with cultures of rat trigeminal neurons demonstrated that pretreatment with LPS produced a significant increase in the capsaicin-evoked release of calcitonin gene-related peptide (CGRP) when compared with vehicle pretreatment, thus showing sensitization of the capsaicin receptor, TRPV1, by LPS. Furthermore, confocal microscopic examination of human tooth pulp samples showed the colocalization of the LPS receptor (toll-like receptor 4, TLR4) with CGRP-containing nerve fibers. Collectively, these results suggest the direct sensitization of nociceptors by LPS at concentrations found in infected canal systems as one mechanism responsible for the pain associated with bacterial infections.

Analysis of Enterococcus faecalis in samples from Turkish patients with primary endodontic infections and failed endodontic treatment by real-time PCR SYBR green method.

OBJECTIVE: The aims of this study were to investigate the presence of Enterococcus faecalis in primary endodontic infections and failed endodontic treatments using real-time PCR and to determine the statistical importance of the presence of E. faecalis in a Turkish population with endodontic infections. MATERIAL AND METHODS: E. faecalis was investigated from 79 microbial samples collected from patients who were treated at the Endodontic Clinic of the Dental School of Atatürk University (Erzurum, Turkey). Microbial samples were taken from 43 patients (Group 1) with failed endodontic treatments and 36 patients (Group 2) with chronic apical periodontitis (primary endodontic infections). DNA was extracted from the samples by using a QIAamp DNA mini-kit and analyzed with real-time PCR SYBR Green. RESULTS: E. faecalis was detected in 41 out of 79 patients, suggesting that it exists in not less than 61% of all endodontic infections when the proportion test (z= -1.645,

Analysis of Enterococcus faecalis in samples from Turkish patients with primary endodontic infections and failed endodontic treatment by real-time PCR SYBR green method

OBJECTIVE: The aims of this study were to investigate the presence of Enterococcus faecalis in primary endodontic infections and failed endodontic treatments using real-time PCR and to determine the statistical importance of the presence of E. faecalis in a Turkish population with endodontic infections. MATERIAL AND METHODS: E. faecalis was investigated from 79 microbial samples collected from patients who were treated at the Endodontic Clinic of the Dental School of Atatürk University (Erzurum, Turkey). Microbial samples were taken from 43 patients (Group 1) with failed endodontic treatments and 36 patients (Group 2) with chronic apical periodontitis (primary endodontic infections). DNA was extracted from the samples by using a QIAamp® DNA mini-kit and analyzed with real-time PCR SYBR Green. RESULTS: E. faecalis was detected in 41 out of 79 patients, suggesting that it exists in not less than 61 percent of all endodontic infections when the proportion test (z= -1.645,

Polymerase chain reaction of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia in primary endodontic infections.

The aim of this study was to investigate the correlation between endodontic clinical signs and symptoms and the presence of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia or their association by nested polymerase chain reaction assay. Microbial samples were taken from 50 cases with necrotic pulp tissues in primary infections. DNA was extracted from the samples, which were analyzed for the presence of three endodontic pathogens by using species-specific primers. P gingivalis, T denticola, and T forsythia were detected in 46%, 38%, and 22% of the symptomatic cases, respectively. The bacterial complex composed by T forsythia, P gingivalis, and T denticola was found in 14% of the cases with spontaneous pain, tenderness to percussion, swelling, and pain on palpation. The high prevalence of P gingivalis, T denticola, and T forsythia in the samples examined suggests that these bacteria are related to the etiology of symptomatic periradicular diseases.

Assessment of the microbiota in root canals of human primary teeth by checkerboard DNA-DNA hybridization.

PURPOSE: The purpose of this study was to evaluate in vivo the prevalence of microorganisms in root canals of human primary teeth, by checkerboard DNA-DNA hybridization. METHODS: Fifty-five root canals of primary teeth with irreversible pulpitis (group 1) and 51 root canals of teeth with pulp necrosis and apical periodontitis (group 2) were selected. Microbiological samples were collected and submitted to checkerboard DNA-DNA hybridization using 34 genomic DNA probes. The results were analyzed statistically by Mann-Whitney U-test at a 5% significance level. RESULTS: The most prevalent species in group 1 were: (1) Campylobacter rectus (87%); (2) Gemella morbilorum (78%); (3) Streptococcus gordonii (71%); (4) Capnocytophaga ochracea (69%); (5) Treponema denticola (58%); and (6) Streptococcus intermedius (49%). The most prevalent species in group 2 were: (1) C. rectus (90%); (2) T. denticola (88%); (3) S. intermedius (77%); (4) G. morbilorum (73%); (5) Streptococcus oralis (67%); (6) C. ochracea (63%); (7) S. gordonii (55%); (8) Streptococcus mitis (51%); and (9) Leptotrichia buccalis (51%). Except for Peptostreptococcus micros and Actinomyces israelii, the most prevalent bacterial strains in the root canals with apical periodontitis were also those found in larger numbers (P<.05). Groups 1 and 2 differed significantly (P<.05) regarding the total number of bacterial cells detected in the root canal samples, with group 2 showing remarkably larger bacterial cell numbers. CONCLUSIONS: Root canals of primary teeth have a great bacterial diversity, characterizing a polymicrobial endodontic infection with presence of: (1) anaerobic and facultative micro organisms; (2) black-pigmented rods; and (3) streptococci. A large number of anaerobic species were detected in teeth with necrotic pulp and apical periodontitis, and a significantly smaller number of bacterial cells were found in teeth with irreversible pulpitis.