Dentinal tubule penetration of AH Plus,BC Sealer and a novel tricalcium silicate sealer: a confocal laser scanning microscopy study

Objectives

The aim of this in vitro study was to assess the dentinal tubule penetration of three different sealers, AH Plus, BC Sealer and a novel tricalcium silicate sealer (NTS).

Materials and methods

Ninety-six human maxillary central incisors were divided into three experimental groups (n = 32) and were filled with gutta-percha using a single-cone technique in conjunction with one of the three sealers: AH Plus, BC Sealer or NTS. The roots in each group were cross-sectioned at 1 and 5 mm from the root apex, and the surfaces were examined under confocal laser scanning microscopy (CLSM). The sealer penetration depths were measured at their maximum depths and at four circumferential depths (12, 3, 6 and 9 o’clock) and were evaluated using ImageJ software (ImageJ, NIH).

Results

The maximum and mean penetration depths were significantly higher at 5 mm compared to 1 mm from the apex in the AH Plus (p < 0.001), BC Sealer (p < 0.001) and NTS groups (p < 0.001). No significant difference was observed between the groups at 1 mm for both parameters. The maximum and mean penetration depths were significantly lower at 5 mm for AH Plus compared with the other two groups (p = 0.012).

Conclusions

Within the study limitations, the BC Sealer and NTS demonstrated better tubule penetration results than the AH Plus sealer.

Clinical relevance

Although no study has confirmed a relationship between the penetration depth of root canal sealers and the prevention of apical periodontitis, dentinal tubule sealer penetration may improve obturation quality.

     

A comparison of galactomannan-ELISA and a newly developed galactomannan-LATEX test in the serologic diagnosis of invasive aspergillosis in patients with hematologic malignancies

We compared the sensitivity and specificity of galactomannan enzyme-linked immunosorbent assay (GM-ELISA) with that of a newly developed version of the commercially available latex agglutination test (GM-LATEX) in our patient population. Serum samples were collected from 144 healthy adult donors (controls); another 17 consecutive hematologic malignancy (HM) patients with probable or proven invasive aspergillosis (IA) were tested. Clinical, microbiological, and pathological data were obtained. The sensitivity of the GM-LATEX test was 53% per patient and 66% per sample and that of the GM-ELISA test was 41% per patient and 21% per sample. Both tests demonstrated a specificity of 99%. The GM-LATEX test demonstrated a superior sensitivity in terms of detecting galactomannan and thus may be useful in the diagnosis of IA in patients with HM.     

Study of theoretical cases of intensity-modulated beams with step-and-shoot technique]

To initiate Intensity-Modulated Radiation Therapy (IMRT) in our department, theoretical cases were used as a training, to define methods of measurements and to verify the software by comparing results of calculation and measurement on a PMMA phantom. Irradiation was performed with 6 and 25 MV X-rays from a linear accelerator. For measurements, films and ionization chambers have been chosen. The comparison between calculations and measurements shows some discrepancies at the level of junctions and also in areas of low doses especially when many segments were used. These theoretical cases provide a first step on the way towards treatments with intensity modulation.     

Failure of oral antimicrobial agents in eradicating gastrointestinal colonization with vancomycin-resistant enterococci.

Eradication of gastrointestinal colonization with vancomycin-resistant enterococci (VRE) using a combination of oral bacitracin and gentamicin was evaluated. Twenty-eight evaluable treated patients were matched with 28 control patients. After 3 months of follow-up, 5 patients (18%) in the treatment group versus 1 patient (4%) in the control group (P = .2) had negative results on stool cultures, with a similar frequency of VRE bacteremia (P = .8). The use of oral bacitracin plus gentamicin did not reduce VRE colonization or bacteremia.     

Human herpesvirus-6 DNAemia in immunosuppressed adult patients with leukemia at risk for mold infection

Little is known about human herpesvirus-6 (HHV-6) in leukemia patients. We prospectively followed 37 leukemia patients at risk for mold infection. HHV-6 DNA was detected from whole blood specimens in 11 patients (30%). History of granulocyte transfusions (p=0.05) and prior relapse of leukemia (p=0.07) were the only independent predictors of HHV-6 DNAemia.     

Treatment of MCPT8DTR mice with high‐ or low‐dose diphtheria toxin leads to differential depletion of basophils and granulocyte‐macrophage progenitors

Basophils have been recently recognized to play important roles in type 2 immune responses during allergies and parasitic infection, largely due to the development of novel tools for the in vivo study of these cells. As such, the genetically‐engineered MCPT8^DTR mouse line has been used to specifically deplete basophils following treatment with diphtheria toxin (DT). In this study, we showed that DT‐injected MCPT8^DTR mice exhibited a striking decrease of eosinophils and neutrophils in skin when subjected to a hapten fluorescein isothiocyanate (FITC)‐induced allergic contact dermatitis (ACD) experimental protocol. Unexpectedly, we found that loss of skin eosinophils and neutrophils was not due to a lack of basophil‐mediated recruitment, as DT injection caused a systemic reduction of eosinophils and neutrophils in MCPT8^DTR mice in a time‐dependent manner. Furthermore, we found that hematopoietic stem‐cell‐derived granulocyte‐macrophage progenitors (GMPs) expressed MCPT8 gene, and that these cells were depleted upon DT injection. Finally, we optimized a protocol in which a low‐dose DT achieved a better specificity for depleting basophils, but not GMPs, in MCPT8^DTR mice, and demonstrate that basophils do not play a major role in recruiting eosinophils and neutrophils to ACD skin. These data provide new and valuable information about functional studies of basophils.     

Aspergillosis caused by non-fumigatus Aspergillus species: risk factors and in vitro susceptibility compared with Aspergillus fumigatus

Invasive aspergillosis (IA) caused by inherently more antifungal-resistant non-fumigatus Aspergillus species has become an important life-threatening complication in severely immunocompromised patients with cancer. The purpose of this study was to compare the relative incidence of, risk factors for, and in vitro correlation of amphotericin B and itraconazole with the clinical outcome of IA caused by Aspergillus fumigatus with those of IA caused by non-fumigatus Aspergillus spp. in patients with cancer. A retrospective search of our tertiary care cancer center's microbiology laboratory reports from 1998-2001 revealed 40 patients with cancer and IA. A non-fumigatus Aspergillus species caused IA in 28 (70%) of those patients. A. fumigatus was the predominant cause of late-onset IA after bone marrow transplantation (p = 0.05), whereas IA due to non-fumigatus Aspergillus spp. was more common in patients with neutropenia (p = 0.01). The minimum inhibitory concentration (50/90) and minimum fungicidal concentration (50/90) for amphotericin B were higher in the non-fumigatus Aspergillus spp. group than in the A. fumigatus one. The Aspergillus species distribution in IA cases in our institution shows a predominance of the more antifungal-resistant or -tolerant non-fumigatus Aspergillus spp.