Differential efficacy of endodontic obturation procedures: an ex vivo study.

By means of a double-chamber model, different root canal filling materials and procedures were compared. Briefly, the root canals of single-rooted human teeth, extracted for periodontal reasons, were instrumented and obturated by gutta-percha/Pulp Canal Sealer EWT (PCS) or by Resilon, in association with different sealers (Real Seal, RelyX Unicem or Meta). Obturation was achieved by traditional continuous wave of condensation technique (TCWCT), a modified version of it (MCWCT), or single cone technique (SCT). The obturated roots, inserted in a double-chamber model, were sterilized by gamma irradiation. Next, Enterococcus faecalis was added to the upper chamber and the specimens were incubated at 37 °C for up to 120 days; the development of turbidity in the lower chambers' broths indicated bacterial leakage through the obturated root canals. The kinetics of leakage were analyzed in different groups by means of Kaplan-Meier statistics and compared by log-rank test. The results showed that root canals obturated with either gutta-percha/PCS using the MCWCT, Resilon/Real Seal SCT or Resilon/RelyX Unicem using the TCWCT displayed significantly better performance than the remaining groups (p < 0.01). Histological evaluation, performed to investigate microbial localization inside specimens, confirmed that this parameter varied according to the obturation procedures and materials employed. This ex vivo study indicates that gutta-percha/PCS, if used with the MCWCT, is as effective as Resilon when coupled to Real Seal with the SCT or, interestingly, to RelyX Unicem with the TCWCT. These data suggest that further improvement of the currently employed root canal filling procedures is achievable, depending on both the filling materials and the technique employed, thus encouraging clinical studies in this direction.

Influence of hyaluronic acid on bacterial and fungal species, including clinically relevant opportunistic pathogens.

Hyaluronic acid (HA) has several clinical applications (aesthetic surgery, dermatology, orthopaedics and ophtalmology). Following recent evidence, suggesting antimicrobial and antiviral properties for HA, we investigated its effects on 15 ATCC strains, representative of clinically relevant bacterial and fungal species. The in vitro system employed allowed to assess optical density of broth cultures as a measure of microbial load in a time-dependent manner. The results showed that different microbial species and, sometimes, different strains belonging to the same species, are differently affected by HA. In particular, staphylococci, enterococci, Streptococcus mutans, two Escherichia coli strains, Pseudomonas aeruginosa, Candida glabrata and C. parapsilosis displayed a HA dose-dependent growth inhibition; no HA effects were detected in E. coli ATCC 13768 and C. albicans; S. sanguinis was favoured by the highest HA dose. Therefore, the influence of HA on bacteria and fungi warrants further studies aimed at better establishing its relevance in clinical applications.

The protein "mycoarray": a novel serological assay for the laboratory diagnosis of primitive endemic mycoses.

A protein microarray containing fungal antigens (the "mycoarray") has been set up to provide rapid and appropriate serodiagnosis of primitive endemic mycoses, an important cause of morbidity and mortality in an increasingly high number of patients. The mycoarray consists of three antigen extracts (histoplasmin, coccidioidin and Coccidioides "TP") and antibody dilution curves were spotted on microarray slides. The arrays were processed with coccidioidomycosis and histoplasmosis patients� sera or with control sera and the occurring immunocomplexes were detected by indirect immunofluorescence. In agreement with clinical and microbiological diagnosis, the results distinguished between histoplasmosis and coccidioidomycosis patients. In addition, the assay could clearly discriminate between IgM and IgG antibody reactivity. No reactivity was ever observed in the arrays processed with negative control sera. Therefore, this pilot study demonstrates that the "mycoarray" is sensitive and specific enough to discriminate between healthy individuals and patients with histoplasmosis or coccidioidomycosis. Because of miniaturization and multiparametricity, the new assay cuts costs and processing time. Thus, once clinically validated and implemented as a large-scale array, the "mycoarray" will be ready to be applied to the daily clinical practice.

The mycoarray as an aid for the diagnosis of an imported case of histoplasmosis in an Italian traveler returning from Brazil.

We describe an imported case of histoplasmosis, whose serological profile was established by means of a protein-based microarray platform, the recently described mycoarray. Because of its peculiarities, such a novel tool greatly facilitates the rapid and multiparametric assessment of patients' serological status and lends itself to be employed as an aid in the diagnosis of primary mycoses, especially in nonendemic countries.