Comparative evaluation of the penetration depth into dentinal tubules of three endodontic irrigants

This study aimed to examine the penetration depth into dentinal tubules of some chelating agents. The 17% EDTA and two preparations containing surfactants (Smear Clear, Bioakt Endo) were tested. Surface tension and liquid viscosity were measured using a Dynamic Contact Angle Analyzer and a Haake rotational rheometer. To measure the penetration depth inside dentinal tubules, thirty maxillary central incisors were selected from a pool of extracted human permanent teeth and allocated to three experimental groups (10 samples each), as well as were mechanically shaped and cleansed with 5.25% NaOCl, followed by each of the chelators being labeled with 0.1 wt % Rhodamine B according to final irrigation protocol established. The samples were embedded in an epoxy resin, after which 200 μm thick transverse sections were obtained at 2, 5, and 8 mm from the apex with a saw microtome. The specimens were then observed using a confocal laser microscope (CLSM) and the penetration of the labeled solution was measured in every third of each sample. Statistical analysis was performed using ANOVA or Kruskal–Wallis tests according to the distribution of data, evaluated with the Shapiro–Wilk normality test. Viscosity and surface tension tests have shown that BioAKT Endo has the lowest values compared to EDTA and Smear Clear. The medium penetration depth did not significantly differ among the three irrigants, while it increased considerably from the apical to the coronal level in all groups. Additionally, the maximum penetration depth increased significantly from the apical to coronal level, while among groups, BioAKT Endo showed the highest values at the apical and middle level compared to the other irrigants. No significant differences were observed among the three groups in medium and maximum penetration depths when the entire root was considered. New irrigants containing surfactants show reduced surface tension and, in one case (BioAKT Endo), viscosity. The lowering of the surface tension allows for better penetration of liquids into dentinal tubules than EDTA alone, thus improving the cleaning of the root canal system

Sicurezza dell’acqua negli edifici. Traduzione italiana.

Una delle sfide maggiori in ambito sanitario è la gestione dell’acqua negli edifici, spesso trascurata. In molti paesi e regioni, la gestione dell’acqua negli edifici non rientra nelle responsabilità dell’azienda acquedottistica. Per gli edifici generalmente non vengono applicati i cosiddetti Piani di Sicurezza per l’Acqua per la gestione dell’acqua pubblica. Questo testo, traduzione italiana del volume Water Safety in Buildings, fa parte della serie dei documenti di supporto che forniscono indicazioni sull’attuazione delle Linee guida per la qualità dell’acqua potabile dell’Organizzazione Mondiale della Sanità. Può essere un utile supporto per il controllo e il miglioramento della qualità e della sicurezza dell’acqua negli edifici

Application of Tribology Concept in Dental Composites Field: A Scoping Review

Tribology is the discipline concerning the application of friction, lubrication, and wear concepts of interacting surfaces in relative motion. A growing interest has developed in tribology application in medical biomaterials, such as resin composites used in restorative dentistry. Yet, the keywords “tribology” and “biotribology” are little applied in the pertinent publications. The aim of this scoping review was to offer an overview of tribology application in dental composites research and to identify knowledge gaps and address future research. A literature search was conducted on Pubmed and Scopus databases and the studies investigating the tribological behavior of resin composites were included for qualitative synthesis. The majority of studies on dental tribology were published in the research areas of mechanical engineering/nanotechnology and differed in several methodological aspects. The preponderant engineering approach and the lack of standardized testing make the laboratory findings poorly informative for clinicians. Future research should focus on the tribological behavior of dental materials composites by means of an integrated approach, i.e., engineering and clinical, for improving development and advancement in this field of research

Influence of NiTi wire diameter on cyclic and torsional fatigue resistance of different heat-treated endodontic instruments

We compared the mechanical properties of 2Shape mini TS2 (Micro-Mega, Besançon, France) obtained from 1.0 diameter nickel-titanium (NiTi) wires and 2Shape TS2 from 1.2 diameter nickel-titanium (NiTi) wires differently thermally treated at room and body temperature. We used 120 NiTi TS2 1.0 and TS2 1.2 files made from controlled memory (CM) wire and T-wire (n = 10). Cyclic fatigue resistance was tested by recording the number of cycles to fracture (NCF) at room and body temperatures using a customized testing device. Maximum torque and angle of rotation at failure were recorded, according to ISO 3630-1. Data were analyzed by a two-way ANOVA (p < 0.05). The CM-wire files had significantly higher NCFs at both temperatures, independent of wire dimensions. Testing at body temperature negatively affected cyclic fatigue of all files. The 1.0-mm diameter T-wire instruments showed higher NCF than the 1.2-mm diameter, whereas no significant differences emerged between the two CM wires at either temperature. The maximum torque was not significantly different across files. The TS2 CM-wire files showed significantly higher angular rotation to fracture than T-wire files. The TS2 CM-wire prototypes showed higher cyclic fatigue resistance than T-wire prototypes, regardless of wire size, exhibiting suitable torsional properties. Torsional behavior appears to not be affected by NiTi wire size

Modification induced by laser irradiation on physical features of plastics materials filled with nanoparticles

The Thermal Laser Welding (TLW) process involves localized heating at the interface of two pieces of plastic that will be joined. Polymeric materials of Ultra High Molecular Weight Polyethylene (UHMWPE), both pure and containing nanostructures at different concentrations (titanium and silver nanoparticles), were prepared as thin foils in order to produce an interface between a substrate transparent to the infrared laser wavelength and an highly absorbent substrate, in order to be welded by the laser irradiation. The used diode laser operates at 970 nm wavelength, in continuum, with a maximum energy of 100 mJ, for times of the order of 1 -60 s, with a spot of 300 μm of diameter. The properties of the polymers and of nanocomposite sheets, before and after the laser welding process, were measured in terms of optical characteristics, wetting ability, surface roughness and surface morphology

Specie esotiche invasive di rilevanza unionale in Italia: aggiornamenti e integrazioni

La Commissione Europea (CE) ha inserito ad oggi 36 taxa esotici vegetali nella lista delle specie esotiche invasive di rilevanza unionale ai sensi del Regolamento (UE) n. 1143/2014 del Parlamento Europeo e del Consiglio, recante disposizioni volte a prevenire e gestire l’introduzione e la diffusione delle specie esotiche invasive. La lista delle specie di rilevanza unionale viene periodicamente aggiornata e include quelle specie che rappresentano una grave minaccia per la biodiversità, ma anche per la salute dei cittadini e le attività economiche nei territori dell’Unione Europea e che necessitano di una gestione concertata a livello comunitario. La CE vigila sullo stato di ogni taxon grazie anche a periodiche rendicontazioni da parte dei paesi dell'Unione. In vista di tali report, tra il 2020 e il 2021 è stata definita e integrata la distribuzione di queste specie in Italia

A Liquid contact angles on biocompatible surfaces

Measurements of liquid contact angles on biocompatible surfaces have been performed at the Physics Department of Messina University. Biological solutions, polymers, ceramics and metals have been studied. Surface treatments by using different laser irradiations, depending on the laser intensity and wavelength, permit to change drastically the wet-ability of many materials and to enhance their biocompatibility and functionality. Results of our investigations put in evidence the best materials to increase or to reduce the wetability of the biological liquids. Results will be presented and discussed in detail with special regard to their applications in biological environment where the materials can be embedded