Susceptibilities of enterococcus faecalis biofilms to some antimicrobial medications

Enterococcus faecalis has bEnterococcus faecalis has been suggested to be an important etiological agent in endodontic failures. The purpose of this study was to evaluate the effectiveness of chlorhexidine- or antibiotics-based medications in eliminating E. faecalis biofilms. One-day and three-day biofilms of E. faecalis were induced on cellulose nitrate membrane filters. Each biofilm-containing membrane was thoroughly covered with 1 ml of the test medications and incubated for 1 day at 37°C. Treated biofilms were then aseptically transferred to vials containing a neutralizing agent in saline solution and vortexed. Suspensions were 10-fold diluted, seeded onto Mitis salivarius agar plates, and the colony-forming units counted after 48 h of incubation. There were significant differences between the formulations tested. The association of clindamycin with metronidazole significantly reduced the number of cells in 1-day biofilms. However of all medications tested, only 2% chlorhexidine-containing medications were able to thoroughly eliminate most of both 1-day and 3-day E. faecalis biofilms

Successful regenerative endodontic treatment in a tooth with incomplete root apex and posttreatment apical periodontitis : a case report

This case report describes the procedure and outcome of regenerative endodontic treatment (RET) in a tooth with incomplete root apex and posttreatment apical periodontitis. A 44-year-old patient was referred to the endodontist because of a periapical les

Antimicrobial activity and flow rate of newer and established root canal sealers

Endodontic sealers that possess both optimum flow ability and antimicrobial properties may theoretically assist in the elimination of microorganisms located in confined areas of the root canal system. The antimicrobial effects and the flow rate of the following sealers were investigated and compared: Kerr Pulp Canal Sealer EWT, Grossman's Sealer, ThermaSeal, Sealer 26, AH Plus, and Sealer Plus. The agar diffusion test was used to assess the antimicrobial activity of the sealers. In the flow assay, the sealers were placed between two glass slabs and a weight of 500 g was placed on the top of the glass. The diameters of the formed discs were recorded. All root canal sealers tested showed some antimicrobial activity against most of the microorganisms. There were no significant differences between the materials tested (p > 0.05). All root canal sealers also flowed under the conditions of this study. Statistical analysis of the results revealed that AH Plus and Kerr Pulp Canal Sealer EWT had flow values significantly superior to the other sealers tested (p > 0.05). Taken together, these findings suggest that these sealers have the potential to help in the microbial control in the root canal system

Efficacy of instrumentation techniques and irrigation regimens in reducing the bacterial population within root canals

The purpose of this study was to compare the in vitro intracanal bacterial reduction produced by using two instrumentation techniques and different irrigation methods. Root canals inoculated with Enterococcus faecalis were prepared by using the following techniques and irrigants: alternated rotary motions (ARM) technique, hand nickel-titanium files and 2.5% sodium hypochlorite (NaOCl) as irrigant; ARM technique and combined irrigation with 2.5% NaOCl and citric acid; ARM technique and combined irrigation with 2.5% NaOCl and 2% chlorhexidine gluconate; and Greater Taper rotary files, using 2.5% NaOCl as irrigant. Controls were instrumented by using the ARM technique and irrigated with sterile saline. Canals were sampled before and after preparation. After serial dilution, samples were plated onto Mitis-Salivarius agar, and the colony forming units that were grown were counted. All test techniques and solutions significantly reduced the number of bacterial cells within the root canal (p 0.05). Nonetheless, all of them were significantly more effective than the control group (p < 0.05). These findings support the importance of using antimicrobial irrigants during the chemomechanical preparation, regardless of the solutions or instrumentation techniques used

Department of Pathogenic Fungi, Division of Fungal Resources and Development

<p>Average relative abundance of bacterial phyla composition in root apex samples from teeth with post-treatment apical periodontitis.</p

DEVICE FOR IN VITRO WEAR ANALYSIS OF BIOMATERIALS IN THE HINGED PROSTHESIS CONFIGURATION

We have developed a device that, coupled to the tribometer, allows movement simulation of the hinged type knee prosthesis. Two tests were performed using the samples designed and one test without the device using a pin-on-flat configuration. For the first and the third tests, the metallic samples were used as machined while for the second one they were electrolytically polished. The test parameters were running length of 0.663 rad and compression load of 22.35 N. The Hertzian contact stress of 15.93 MPa obtained between the samples designed is close to that for the real prosthesis. The measured volumetric wear revealed the influence of roughness of the counterpart surface on the wear behavior. The device has allowed its coupling to the tribometer without any interference on its functioning thus making a contribution to the scientific investigations related to wear behavior of a couple of different biomaterials

Antibacterial Activity of Root-end Filling Materials

Svrha istraživanja bila je ocijeniti i usporediti antibakterijsku učinkovitost pet retrogradnih punila korijenskih kanala. Materijal i metode: Metodom difuzije u agru ocijenjena je zona inhibicije bakterijskog rasta na podlozi pet retrogradnih punila korijenskih kanala: Pro Root MTA, cementa Portland, Super-EBA, IRM-a, Sealera 26 te amalgama. Za ciljane mikroorganizme bilo je odabrano pet anaeroba (Porphyromonas gingivalis, Parvimonas micra, Fusobacterium nucleatum, Propionibacterium acnes i Eubacterium saburreum) te dva fakultativna (Actinomyces viscosus i Enterococcus faecalis). Rezultati: Sealer 26 postigao je najveću inhibiciju rasta. Punila IRM i Super-EBA spriječila su rast samo Porphyromonas gingivalis, ali učinak je bio znatno slabiji u usporedbi s djelovanjem Sealera 26. Kao neučinkovita antibakterijska sredstva pokazali su se MTA, cement Portland i amalgam. Zaključak: Rezultati istraživanja potvrdili su da Sealer 26 ima najjače antibakterijsko djelovanje u usporedbi s ostalim često upotrebljavanim apikalnim punilima korijenskih kanala.Purpose: The present study was undertaken to evaluate and compare the antibacterial effectiveness of five root-end filling materials. Material and methods: The agar diffusion method was employed to evaluate the inhibition zone provided by the following root-end filling materials: Pro Root MTA, Portland cement, Super-EBA, IRM, Sealer 26, and silver amalgam. The target microorganisms included five anaerobic bacterial species (Porphyromonas gingivalis, Parvimonas micra, Fusobacterium nucleatum, Propionibacterium acnes and Eubacterium saburreum) and two facultative bacterial species (Actinomyces viscosus and Enterococcus faecalis). Results: Sealer 26 demonstrated the largest inhibitory effects on all species tested. IRM and Super-EBA were inhibitory only to P. gingivalis, but this effect was far less pronounced as compared to Sealer 26. MTA, Portland cement, and amalgam proved ineffective against all species tested. Conclusion: These findings revealed that Sealer 26 has more pronounced antibacterial effects when compared to other commonly used root-end filling materials

Antibacterial Activity of Root-end Filling Materials

Svrha istraživanja bila je ocijeniti i usporediti antibakterijsku učinkovitost pet retrogradnih punila korijenskih kanala. Materijal i metode: Metodom difuzije u agru ocijenjena je zona inhibicije bakterijskog rasta na podlozi pet retrogradnih punila korijenskih kanala: Pro Root MTA, cementa Portland, Super-EBA, IRM-a, Sealera 26 te amalgama. Za ciljane mikroorganizme bilo je odabrano pet anaeroba (Porphyromonas gingivalis, Parvimonas micra, Fusobacterium nucleatum, Propionibacterium acnes i Eubacterium saburreum) te dva fakultativna (Actinomyces viscosus i Enterococcus faecalis). Rezultati: Sealer 26 postigao je najveću inhibiciju rasta. Punila IRM i Super-EBA spriječila su rast samo Porphyromonas gingivalis, ali učinak je bio znatno slabiji u usporedbi s djelovanjem Sealera 26. Kao neučinkovita antibakterijska sredstva pokazali su se MTA, cement Portland i amalgam. Zaključak: Rezultati istraživanja potvrdili su da Sealer 26 ima najjače antibakterijsko djelovanje u usporedbi s ostalim često upotrebljavanim apikalnim punilima korijenskih kanala.Purpose: The present study was undertaken to evaluate and compare the antibacterial effectiveness of five root-end filling materials. Material and methods: The agar diffusion method was employed to evaluate the inhibition zone provided by the following root-end filling materials: Pro Root MTA, Portland cement, Super-EBA, IRM, Sealer 26, and silver amalgam. The target microorganisms included five anaerobic bacterial species (Porphyromonas gingivalis, Parvimonas micra, Fusobacterium nucleatum, Propionibacterium acnes and Eubacterium saburreum) and two facultative bacterial species (Actinomyces viscosus and Enterococcus faecalis). Results: Sealer 26 demonstrated the largest inhibitory effects on all species tested. IRM and Super-EBA were inhibitory only to P. gingivalis, but this effect was far less pronounced as compared to Sealer 26. MTA, Portland cement, and amalgam proved ineffective against all species tested. Conclusion: These findings revealed that Sealer 26 has more pronounced antibacterial effects when compared to other commonly used root-end filling materials

The Influence of Depression on the Psychometric Properties of the Maslach Burnout Inventory–Human Services Survey: A Cross-Sectional Study With Nursing Assistants

Background: The Maslach Burnout Inventory-Human Services Survey (MBI-HSS) is the most commonly used instrument to assess burnout. Although various factors have been reported to influence its validity, the influence of major depressive disorder (MDD) has not been previously considered. We developed this study to investigate the influence of MDD on the psychometric properties of the MBI-HSS in nursing assistants.Results: From a sample of 521 nursing assistants, we found in those with MDD (n = 138, 24.56%) a degree of data misfit into the model, revealed by non-acceptable values for the root mean square error of approximation (RMSEA; 0.073; p = 0.004) and for the comparative fit index (CFI; 0.912), while in the non-MDD group these indices were acceptable and good, respectively, for RMSEA (0.048; p = 0.639) and for CFI (0.951). Also, we found higher coefficients of correlation among MBI-HSS factors and less items loading properly in their respective factors in the MDD subset, when compared to the non-MDD subset. For the total sample, while original 3-factor solution was an acceptable model, the bifactor model fitted data better.Conclusions: MDD may impair the construct validity of MBI-HSS subscales, by increasing measurement error and decreasing model fitness. Therefore, researchers and health professionals should be aware of potential changes in the psychometric properties of the MBI-HSS when applied in subjects with depression

Comparing the Bacterial Diversity of Acute and Chronic Dental Root Canal Infections

This study performed barcoded multiplex pyrosequencing with a 454 FLX instrument to compare the microbiota of dental root canal infections associated with acute (symptomatic) or chronic (asymptomatic) apical periodontitis. Analysis of samples from 9 acute abscesses and 8 chronic infections yielded partial 16S rRNA gene sequences that were taxonomically classified into 916 bacterial species-level operational taxonomic units (OTUs) (at 3% divergence) belonging to 67 genera and 13 phyla. The most abundant phyla in acute infections were Firmicutes (52%), Fusobacteria (17%) and Bacteroidetes (13%), while in chronic infections the dominant were Firmicutes (59%), Bacteroidetes (14%) and Actinobacteria (10%). Members of Fusobacteria were much more prevalent in acute (89%) than in chronic cases (50%). The most abundant/prevalent genera in acute infections were Fusobacterium and Parvimonas. Twenty genera were exclusively detected in acute infections and 18 in chronic infections. Only 18% (n = 165) of the OTUs at 3% divergence were shared by acute and chronic infections. Diversity and richness estimators revealed that acute infections were significantly more diverse than chronic infections. Although a high interindividual variation in bacterial communities was observed, many samples tended to group together according to the type of infection (acute or chronic). This study is one of the most comprehensive in-deep comparisons of the microbiota associated with acute and chronic dental root canal infections and highlights the role of diverse polymicrobial communities as the unit of pathogenicity in acute infections. The overall diversity of endodontic infections as revealed by the pyrosequencing technique was much higher than previously reported for endodontic infections