Movement kinematics and cyclic fatigue of NiTi rotary instruments: a systematic review.

The aim of this review was to provide a detailed analysis of the literature concerning the correlation between different movement kinematics and the cyclic fatigue resistance of NiTi rotary endodontic instruments. From June 2014 to August 2015, four independent reviewers comprehensively and systematically searched the Medline (PubMed), EMBASE, Web of Science, Scopus and Google Scholar databases for works published since January 2005, using the following search terms: endodontics; nickel-titanium rotary files; continuous rotation; reciprocating motion; cyclic fatigue. In addition to the electronic searches, manual searches were performed to include articles listed in the reference sections of high-impact published articles that were not indexed in the databases. Laboratory studies in English language were considered for this review. The electronic and manual searches resulted in identification of 75 articles. Based on the inclusion criteria, 32 articles were selected for analysis of full-text copies. Specific analysis was then made of 20 articles that described the effects of reciprocating and continuous movements on cyclic fatigue of the instruments. A wide range of testing conditions and methodologies have been used to compare the cyclic fatigue resistance of rotary endodontic instruments. Most studies report that reciprocating motion improves the fatigue resistance of endodontic instruments, compared to continuous rotation, independent of other variables such as the speed of rotation, the angle or radius of curvature of simulated canals, geometry and taper, or the surface characteristics of the NiTi instruments.

Electrochemical-induced dissolution of nickel-titanium endodontic instruments with different designs.

AIM: To compare the active dissolution process of K3, ProTaper and Mtwo NiTi endodontic rotary instruments in chloride and fluoride containing solutions. METHODS: Anodic polarization of K3 size 20, 0.06 taper, ProTaper size F1 and MTwo size 20, 0.06 taper instruments was performed, and anova (P < 0.05) was used to compare the weight loss, the time of dissolution and the electrical charge generated by the groups of instruments. Fragments of the instruments were polarized in simulated root canals to evaluate the dissolution process. After the tests, a size 10 K-file was used to verify whether the fragment could be bypassed. Radiographic analysis of the simulated canals was used before and after the tests to verify fragment dissolution. RESULTS: A progressive consumption of the instruments was observed. K3 and ProTaper instruments had significantly greater weight loss than Mtwo instruments after 30 min of polarization. K3 instruments had the highest values of total electrical charge, and MTwo instruments the lowest (P < 0.05). After 60 min, the anodic polarization of instrument fragments in simulated root canals resulted in their partial dissolution. CONCLUSION: The anodic polarization of K3, ProTaper and MTwo instruments resulted in their progressive consumption with increasing polarization time. Sixty minutes anodic polarization of the various NiTi instrument fragments in simulated root canals resulted in their partial dissolution.

Electrochemical induced dissolution of fragments of nickel-titanium endodontic files and their removal from simulated root canals.

AIM: To improve the dissolution process of NiTi endodontic rotary files aiming at fragment removal and the recovery of the original path of the root canal during a clinically acceptable period of time. METHODOLOGY: Anodic polarization curves and redox curves were obtained to determine the conditions necessary for the dissolution of endodontic files. Anodic polarization of K3 files was performed, and analysis of variance (P < 0.05) was used to compare different test times in relation to weight loss, length loss and electrical charge generated in each solution. The polarization of fragments in simulated root canals was undertaken to evaluate the dissolution process. After the tests, a size 10 K-file was used to verify the possibility to bypass the fragment. The total electrical charge of each test was obtained from the corresponding graph area. Radiographic analysis of the simulated canals was used before and after the tests to verify fragment dissolution. RESULTS: The weight loss values, the length loss values and the total values of electrical charge in each period of time were significantly higher (P < 0.05) in the tests using the selected solution compared with the solution previously proposed. A progressive consumption of the K3 file tip was observed up to 30 min. The anodic polarization of file fragments in simulated root canals for 60 min resulted in their partial dissolution and enabled the recovery of the original canal pathway with size 10 K-files. CONCLUSIONS: Increasing fluoride concentration resulted in greater active dissolution of NiTi files. The dissolution of fractured files in simulated root canals enabled the recovery of its original path during a clinically acceptable period of time.

Targeting IL-23 by employing a p40 peptide-based vaccine ameliorates murine allergic skin and airway inflammation.

BACKGROUND: Studies have found that the IL-23/Th17 pathway plays an important role in the pathogenesis of atopic dermatitis (AD) and severe and steroid-resistant asthma. Targeting IL-23/Th17 pathway with monoclonal antibodies (mAb) has been successful in the reduction of skin and airway inflammation in animal models. However, the mAb has a short half-life, requiring repeated administrations. For the long-term suppression of IL-23/Th17 pathway, we have previously developed an IL-23p40 peptide-based virus-like particle vaccine, which induces long-lasting autoantibodies to IL-23. OBJECTIVE: We sought to evaluate the effects of this IL-23p40 peptide-based vaccine on the down-regulation of allergic skin and airway inflammation in mice. METHODS: Mice were subcutaneously injected three times with the IL-23p40 vaccine, or the vaccine carrier protein or saline as controls. Two weeks later, mice were epicutaneously sensitized with ovalbumin four times at a 2-week interval. One week after the final sensitization, mice were nasally administrated with ovalbumin daily for 3 days. One day later, bronchoalveolar lavage fluids (BALF), sera, lung and skin tissues were obtained and analysed. RESULTS: Mice immunized with the vaccine produced high levels of IgG antibodies to IL-23, p40 and IL-12 that in vitro inhibited IL-23-dependent IL-17 production. The numbers of total cells, neutrophils, and eosinophils in BALF were significantly reduced in the vaccine group, compared with controls. The levels of IL-13, IL-5, IL-23 and, IL-17 in BALF and levels of serum ovalbumin-specific IgE, IgG1, and total IgE were also significantly decreased. Histological analysis showed less inflammation of the lung and skin tissues in the vaccine group, compared with controls. CONCLUSION AND CLINICAL RELEVANCE: Administration of an IL-23p40 peptide-based vaccine down-regulates allergic skin and airway inflammation, suggesting that this strategy may be a potential therapeutic approach in the treatment of AD and asthma.

Identification of major antigenic proteins of bovine herpesvirus 1 and their correlation with virus neutralizing activity.

The polypeptides of an Australian isolate of bovine herpesvirus 1 were analysed by polyacrylamide gel electrophoresis, and Western blotting was used to identify those polypeptides which reacted most strongly with sera from infected animals. Approximately 20 polypeptides ranging in molecular weight from 11,000 to 240,000 daltons (11-240K) were identified by 35S-methionine labelling of virus and approximately half of these classed as glycoproteins using 14C-mannose and 3H-glucosamine incorporation into infected cells. Convalescent sera from cattle all reacted strongly with glycoprotein bands at 85 and 70K, with most sera also recognizing another band at 140-150K. The intensity of bands on the Western blot analyses was found to correlate well with neutralization titres of individual serum samples, indicating the involvement of these proteins in virus neutralization. The importance of the 70K glycoprotein was supported by the finding that, of 12 monoclonal antibodies studied, those 3 with the strongest neutralizing activity, were those which recognized a band at 70K in Western blot experiments.

Acute myelofibrosis with associated intracerebral haemorrhage.

The case of a 42-year-old woman with clinical and histopathological features suggesting acute myelofibrosis is reported. The patient succumbed to massive intracerebral haemorrhage.