A physico-chemical study on amphiphilic cyclodextrin/liposomes nanoassemblies with drug carrier potential.

In this paper, two medusa-like ACyDs, modified at the primary rim bearing four (ACyD4) and eight carbons (ACyD8) acyl chain length, and one bouquet-like CyD, modified at primary side with thiohexyl and at secondary one with oligoethylene moiety (SC6OH), were investigated for their ability to assemble in nanostructures or to form hybrid dipalmitoylphosphatidylcholine (DPPC)/ACyDs systems. The lipophilicity of these molecules and the different preparation methods used in this study (thin layer evaporation and nanoprecipitation method) significantly affect the aggregation behaviour in aqueous medium. Except for the shortest medusa-like ACyD4, the other ACyDs formed stable nanoaggregates for at least 45 days. The effect of ACyDs on the thermotropic behaviour of DPPC liposomes was also studied by differential scanning calorimetry analysis, thus elucidating their interaction with liposomes to afford hybrid liposome/ACyDs systems. The medusa-like ACyD4 cannot be used to realize nanosystems because it quickly aggregates or it induces a complete destabilization of the liposomes. At the highest concentration investigated (0.01 molar fraction), both ACyD8 and SC6OH interacted with DPPC liposomes, forming ACyD/DPPC or SC6OH/DPPC hybrid vesicular carriers.

Revisiting the role of sucrose in PLGA-PEG nanocarrier for potential intranasal delivery.

The efficient design of nanocarriers is a major challenge and must be correlated with the route of administration. Intranasal route is studied for local, systemic or cerebral treatments. In order to develop nanocarriers with suitable properties for intranasal delivery, to achieve brain and to market the product, it is extremely important the simplification of the formulation in terms of raw materials. Surfactants and cryoprotectants are often added to improve structuration and/or storage of polymeric nanoparticles. PLGA-PEG nanocarriers were prepared by nanoprecipitation method evaluating the critical role of sucrose as surfactant-like and cryoprotectant, with the aim to obtain a simpler formulation compared to those proposed in other papers. Photon correlation spectroscopy and Turbiscan analysis show that sucrose is a useful excipient during the preparation process and it effectively cryoprotects nanoparticles. Among the investigated nanocarriers with different degree of PEG, PEGylated PLGA (5%) confers weak interaction between nanoparticles and mucin as demonstrated by thermal analysis and mucin particle method. Furthermore, in vitro biological studies on HT29, as epithelium cell line, does not show cytotoxicity effect for this nanocarrier at all texted concentrations. The selected nanosystem was also studied to load docetaxel, as model drug, and characterized by a technological point of view.

Quadrupole transition strength in the (74)Ni nucleus and core polarization effects in the neutron-rich Ni isotopes.

The reduced transition probability B(E2;0(+)→2(+)) has been measured for the neutron-rich nucleus (74)Ni in an intermediate energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory at Michigan State University. The obtained B(E2;0(+)→2(+))=642(-226)(+216) e(2) fm(4) value defines a trend which is unexpectedly small if referred to (70)Ni and to a previous indirect determination of the transition strength in (74)Ni. This indicates a reduced polarization of the Z=28 core by the valence neutrons. Calculations in the pfgd model space reproduce well the experimental result indicating that the B(E2) strength predominantly corresponds to neutron excitations. The ratio of the neutron and proton multipole matrix elements supports such an interpretation.

Nonsudden limits of heavy-ion induced knockout reactions.

We report on the single neutron and proton removal reactions from unstable nuclei with large asymmetry ΔS = S(n)-S(p) at incident energies below 80 MeV/nucleon. Strong nonsudden effects are observed in the case of deeply-bound-nucleon removal. The corresponding parallel momentum distributions exhibit an abrupt cutoff at high momentum that corresponds to an energy threshold occurring when the incident energy per particle is of comparable magnitude to the nucleon separation energy. A large low-momentum tail is related to both dissipative processes and the dynamics of the nucleon removal process. New limits for the applicability of the sudden and eikonal approximations in nucleon knockout are given.

Towards an Eco-Friendly Coffee Rust Control: Compilation of Natural Alternatives from a Nutritional and Antifungal Perspective.

Hemileia vastatrix (HV) is the pathogen responsible for the coffee leaf rust (CLR) disease that has spread globally. CLR causes losses of up to a billion dollars annually and affects all types of crops regardless of their production regime (organic or inorganic). Additionally, smallholders produce approximately 80% of coffee in developing countries. The condition causes losses of up to a billion dollars annually. It affects all types of crops regardless of their production regime (organic or inorganic). Approximately 80% of coffee is produced by smallholders in developing countries. Until the 90s, shaded-production systems and native varieties were encouraged; however, the rapid spread of CLR has forced farmers to migrate towards inorganic schemes, mainly due to a lack of knowledge about natural alternatives to pesticides that can be implemented to control HV. Therefore, the purpose of this article is to compile the currently existing options, emphasizing two key factors that guarantee efficient rust control: selective fungicidal activity against HV and the nutrition of coffee crops. Thus, by comprehending how these natural compounds (such as plant, bacteria, fungi, animals, or algae metabolites) impact coffee rust proliferation. Furthermore, since a various range of biochar effects contributes to the control of foliar fungal pathogens through modification of root exudates, soil properties, and nutrient availability, which influence the growth of antagonist microorganisms, we present a review of the pathogen-suppressive effects of biochar, and new control strategies suitable for organic schemes can be developed.

Improvement of the fatigue resistance of NiTi endodontic files by surface and bulk modifications.

AIM: To assess the failure mechanism of rotary NiTi instruments by chemical, structural and morphological analyses to provide a rational explanation of the effects of surface and bulk treatments on their resistance to fatigue fracture. METHODOLOGY: Thermal treatment (350-500 °C) was performed on electropolished (EP) and non-electropolished (Non-EP) NiTi endodontic instruments. Bulk and surface chemical composition and crystallographic structures were determined by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) to evaluate the effects of thermal treatment and electropolishing on the NiTi alloy. Fatigue tests of all instruments were performed. Surface morphology before and after the tests, and fractured section were analysed using scanning electron microscopy to determine crack extensions. Results were analysed statistically using analysis of variance (anova) and post hoc Student-Newman-Keuls test. RESULTS: Before thermal treatment, significant differences (P < 0.05) in fatigue resistance between EP and Non-EP instruments (the number of revolutions to failure, N(f) , was 385 and 160, respectively) were attributed to differences in the surface morphology of the instruments. SEM analysis of the fracture surfaces indicated that flexural fatigue fractures occurred in two steps: first by a slow growth of initial cracks and then rapid rupture of the remaining material. Thermal treatment did not affect the surface morphology but resulted in significant changes in the instrument bulk with the appearance of an R-phase and an improved fatigue resistance; indeed after treatment at 500 °C, N(f) increased up to 829 and 474 for EP and Non-EP instruments, respectively. CONCLUSIONS: Both thermal treatment and electropolishing improved the resistance of NiTi rotary instruments against fatigue fracture.

Topographic lymph node staging system shows prognostic superiority compared to the 8th edition of AJCC TNM in gastric cancer. A western monocentric experience.

INTRODUCTION: The current Tumor Node Metastasis staging system (TNM) for gastric cancer classifies the extent of lymph node metastasis based upon the number of lymph nodes involved. Choi et al. have recently proposed a new anatomical classification based upon the regionality of the involved nodes. This new classification seems to have a better predictive prognostic value than the traditional one. We investigated the prognostic role of the new anatomical based classification, reviewing our institutional gastric cancer database. METHODS: We performed a retrospective chart review of 329 patients who underwent gastrectomy at our Institution from 2003 to 2017. We excluded from data analysis any patient with distant metastases at the time of first diagnosis and or surgery, pathology other than adenocarcinoma, lymphadenectomy less than D2, impossibility to identify location of lymph nodes (LNs) on pathological report and neoadjuvant chemotherapy. The extent of D2 lymphadenectomy was defined according to Japanese Gastric Cancer Association criteria. LN metastasis were reclassified into three topographic groups (lesser, greater curvature, and extraperigastric nodes) and staged according to Choi. The new N stage was combined with the current pT according to the 8th edition of TNM and a new hybrid TNM stage was established. All patients were followed up until June 2019. The prognostic performance of the new stage and of the current anatomical numeric based system (TNM) was analyzed and assessed by the C-index, AIC and likelihood ratio χ2 value. RESULTS: In predicting both Overall Survival (OS) and Disease free Survival (DFS) the new N stage and the new TNM staging system had the highest C-index and likelihood ratio χ2 value and the lowest Akaike Information Criterion (AIC), showing a better accuracy and displaying a better prognostic performance. CONCLUSIONS: Our study is the first from the Western world to compare the new hybrid classification, based on the anatomical location of metastatic nodes, to the 8th of American Joint Committee on Cancer (AJCC) TNM staging system. Our findings on a small, monocentric sample suggest that hybrid topographic lymph node staging system is more accurate than TNM.

Dual-drugs delivery in solid lipid nanoparticles for the treatment of Candida albicans mycosis.

Nowadays, a combinatorial drug delivery system that simultaneously transports two or more drugs to the targeted site in a human body, also recognized as a dual-drugs delivery system, represents a promising strategy to overcome drug resistance. Solid lipid nanoparticles loaded with clotrimazole (CLZ) and alphalipolic acid (ALA), considered as an effective agent in the reduction of reactive oxygen species, can enhance anti-infective immunity being proposed as a non-toxic and mainly non-allergic dual-drugs delivery system. In this study, uncoated and cationic CLZ-ALA-loaded SLN were prepared and compared. Suspensions with a narrow size distribution of particles of mean size below 150 nm were obtained, having slight negative or highly positive zeta potential values, due to the presence of the cationic lipid, which also increased nanoparticles stability, as confirmed by Turbiscan® results. Calorimetric studies confirmed the rationale of separately delivering the two drugs in a dual-delivery system. Furthermore, they confirmed the formation of SLN, without significant variation in presence of the cationic lipid. In vitro release studies showed a prolonged drug release without the occurrence of any burst effect. In vitro studies performed on 25 strains of Candida albicans showed the antimicrobial drug activity was not altered when it was loaded into lipid nanoparticles. The study has proved the successfully encapsulation of CLZ and ALA in solid lipid nanoparticles that may represent a promising strategy to combine ALA protective effect in the treatment with CLZ.

Nose to brain delivery in rats: Effect of surface charge of rhodamine B labeled nanocarriers on brain subregion localization.

Nose to brain delivery and nanotechnology are the combination of innovative strategies for molecules to reach the brain and to bypass blood brain barriers. In this work we investigated the fate of two rhodamine B labeled polymeric nanoparticles (Z-ave <250nm) of opposite surface charge in different areas of the brain after intranasal administration in rats. A preliminary screening was carried out to select the suitable positive (chitosan/poly-l-lactide-co-glycolide) nanocarrier through photon correlation spectroscopy and turbiscan. Physico-chemical and technological characterizations of poly-l-lactide-co-glycolide (negative) and chitosan/poly-l-lactide-co-glycolide (positive) fluorescent labeled nanoparticles were performed. The animals were allocated to three groups receiving negative and positive polymeric nanoparticles via single intranasal administration or no treatment. The localization of both nanocarriers in different brain areas was detected using fluorescent microscopy. Our data revealed that both nanocarriers reach the brain and are able to persist in the brain up to 48h after intranasal administration. Surface charge influenced the involved pathways in their translocation from the nasal cavity to the central nervous system. The positive charge of nanoparticles slows down brain reaching and the trigeminal pathway is involved, while the olfactory pathway may be responsible for the transport of negatively charged nanoparticles, and systemic pathways are not excluded.

[Domestic injuries in childhood. Results of a survey carried out in a Sicilian area]. / Incidenti domestici nell'infanzia. Risultati di un'indagine condotta nell'area etnea.

A retrospective investigation was performed with an anonymous questionnaire administered to the mothers of 2208 children aged between 3 and 11 years, randomly selected from the residents of three target areas: a country town, a residential and a popular quarter of a chief town (Catania, Sicily). Of the 2208 mothers in the three areas, 1151 completed the questionnaire with an overall response rate of 52.12%. In the last 6 months a large number of children (17.29%) suffered at least one accident at home. Predominating injuries were falls (71.86%) followed by cutting or stab-wounds (13.57%). The more frequent lesions were contusions (42.13%), wounds (29.95%) and fractures (14.22%). Almost the half of children victims of injuries required hospital care (44.72%). The majority of domestic accidents occurred in the bathroom (17.10%), in the kitchen (15.10%) and in the bedroom (10.55%). Fractures and wounds were more frequent among children aged 6-11 and 3-5 years, respectively. The highest frequency of domestic accidents among children of all ages living in the popular quarter (20.89%) and in the country town (19.18%) compared with those living in the residential quarter (11.67%) (chi2= 12,768, P<0.01) could be related to their lower socio-economic condition.

Signatures of the Giant Pairing Vibration in the 14C and 15C atomic nuclei.

Giant resonances are collective excitation modes for many-body systems of fermions governed by a mean field, such as the atomic nuclei. The microscopic origin of such modes is the coherence among elementary particle-hole excitations, where a particle is promoted from an occupied state below the Fermi level (hole) to an empty one above the Fermi level (particle). The same coherence is also predicted for the particle-particle and the hole-hole excitations, because of the basic quantum symmetry between particles and holes. In nuclear physics, the giant modes have been widely reported for the particle-hole sector but, despite several attempts, there is no precedent in the particle-particle and hole-hole ones, thus making questionable the aforementioned symmetry assumption. Here we provide experimental indications of the Giant Pairing Vibration, which is the leading particle-particle giant mode. An immediate implication of it is the validation of the particle-hole symmetry.

Wear of nickel-titanium endodontic instruments evaluated by scanning electron microscopy: effect of ion implantation.

The present work analyzes possible increases in resistance to wear of nickel-titanium endodontic instruments that have undergone a process of ionic implantation. ProFile .04 taper #25 instruments were subjected to ionic implantation with bands of nitrogen ions of 250 KeV, currents in the order of 10 microA/cm2, and doses of 2 x 10(17) ions/ cm2. The instruments were used to make preparations in acrylic endodontic training blocks. Scanning electron microscopic investigations showed that after 60 s of work inside the endodontic training blocks nonionic implanted control instruments showed small modifications in their blades, and their tips showed the first signs of wear. After 240 s the control instruments showed consistent signs of wear and frequent changes to their surfaces. After 240 s of use the ionic-implanted instruments did not present any significant changes in the micromorphology of their surfaces. The implanted instruments did not manifest the typical signs of wear and did not show the surface changes that quickly affect the working life of untreated endodontic instruments manufactured from nickel-titanium.

Defects in GT rotary instruments after use: an SEM study.

Used rotary nickel-titanium instruments require frequent replacement. This laboratory study evaluated defects of GT Rotary instruments before and after usage. The instruments were fixed into custom-made holders and photographed in an SEM at x 260 to x 12,000 magnification at preset points. Instrument sizes 20 with 1.0, 0.8, and 0.6 taper and instrument sizes 35 with 1.2 taper were used in 12 canals. The used instruments were cleaned and then reexamined in an SEM as before. The presence of 11 types of conditions was scored from the pre- and postusage photographs. No instruments fracturing or plastic deformation was observed during the test. The presence of debris, pitting, and scraping changed significantly. Imperfections were found on used GT Rotary instruments and the presence of defects (pitting, scraping, and blunt-cutting edges) increased in all of the instruments. The behavior of GT Rotary instruments with usage seems to be different, compared with that found in other instruments.

Effect of sterilization on the cutting efficiency of rotary nickel-titanium endodontic files.

OBJECTIVE: Nickel-titanium instruments that offer greater flexibility than instruments made of other metallic materials have been developed. This study evaluated the behavior in vitro of nickel-titanium rotary instruments under repeated sterilization cycles. STUDY DESIGN: To investigate changes in cutting ability and superficial alterations, 36 ProFile instruments, 18 with a taper of .04 and 18 with a taper of .06, were exposed to different sterilization cycles. Samples were divided into 3 groups of 12 files each. The 12 group A samples were exposed to 14 cycles of sterilization for 30 minutes; the 12 group B samples were exposed to 7 cycles of sterilization for 30 minutes; the 12 group C samples were not sterilized and served as a control group. Chemical compositions of the near surface layers of samples of each group were determined by means of Auger spectroscopy. RESULTS: The instruments that underwent the greatest number of sterilizations (group A) showed in-depth distributions of chemical composition that were different from those seen in the control group; this was the result of greater amounts of titanium oxide on the surfaces of the sterilized instruments. The files of group A showed a decrease in cutting efficiency in comparison with those of the control group. CONCLUSIONS: On the basis of this research on nickel-titanium files, we determined that repeated sterilizations under autoclave alter the superficial structure of such instruments.

The effect of surface treatments of nickel-titanium files on wear and cutting efficiency.

OBJECTIVES: This study was designed to verify whether nitridation treatment of the cutting surfaces resulted in surface or subsurface changes that produced an increase in the resistance to wear in nickel titanium (NiTi) endodontic files. STUDY DESIGN: Some experimental samples were exposed to ionic implantation by using 150 keV of nitrogen ions and doses of 1 x 10(17) ions per cm(2). Other samples were exposed to thermal nitridation processes performed for 480 minutes at 500 degrees C temperature. Control samples were not exposed to any process. The chemical composition of the surface layers of each sample was determined by means of x-ray photoelectron spectroscopy. The cutting efficiency was tested on an endotraining bloc. RESULTS: The experimental instruments showed in-depth distributions of chemical composition that were different from those seen in the control group; thermal-nitridated instruments demonstrated a surface ratio of nickel to titanium of 0.5. Implanted samples had a higher N/Ti ratio (1.2); this ratio may be due to the presence of a layer of titanium nitride. Samples in the experimental groups showed an increase in cutting ability as compared with the controls. CONCLUSIONS: Thermal nitridation and nitrogen-ionic implantation treatment of nickel-titanium files produced a higher wear resistance and an increased cutting capacity.

[Pancreatic pseudocysts. Clinical contribution]. / Le pseudocisti del pancreas. Contributo clinico.

Aim of this study was to compare, taking into consideration data from the literature, the various diagnostic examinations and therapeutic modalities nowadays available to manage patients affected by pancreatic pseudocysts. Personal experience regarding three patients with post-necrotic pancreatic pseudocysts is reported; these patients complained of epigastric pain with nausea and tenderness in the upper abdominal quadrants. Diagnosis was made by CT. In one case a progressive decrease of the pseudocyst was observed; the second patient was treated by a pseudocyst-jejunostomy; the last patient initially underwent a trans-gastric percutaneous drainage for infection of the pseudocyst and afterwards an open pseudocyst-gastrostomy. All patients were cured, even if the second patient during the postoperative course developed a pleuric effusion, which was treated by thoracentesis. Pancreatic pseudocysts in 20% of cases resolve spontaneously, as observed in one of our patients. In other cases, a surgical operation is needed, now feasible through an endoscopic, percutaneous, laparotomic or laparoscopic approach. The endoscopic and percutaneous approach are indicated only in selected cases, so that the "gold standard" treatment is still the laparotomic one, especially by a pseudocyst-jejunostomy, which also in our experience has given the best result. Very promising also, according to the latest data from the literature, seems the laparoscopic approach, by which a wide communication between the stomach and the pseudocyst is obtained.

[Changes in the biological and immunologic parameters in the oral cavity of the aged. Review]. / Modificazioni dei parametri biologici ed immunologici nel cavo orale dell'anziano. Review.

Senescence is the effect of the immune system incapacity to see "self" and "non-self"; timo-involution induced down-regulation of immunoregulatory -T and B-lymphocytes. Immunosenescence mutations in oral cavity are examined. Even the oral ecosystem presents disorders in quality and quantity of the bacterial plaque and a different immune response. Age senescence is particularly evident in the masticatory apparatus, in fact the dental tissues have remarkable morpho-structural physiological changes; the epithelial, connective and osseous tissues of the periodontium have structural age changes related to the collagen synthesis and physical properties, with an increase of the stroma and a decrease of cell population. The osseous tissue presents cellular atrophy, sclerosis, osteoporosis and is undergoing a continuous structural remodelling; the oral mucous membranes show a thinning of epithelium and an increase of the stroma related to the parenchyma. Specific individual changes could be appraised in the involution of stomatognathic apparatus, more than an indefinite reduction of the performances.

[The role of cell adhesion molecules in the formation of periapical granulomas]. / Ruolo delle molecole di adesione cellulare nella formazione dei granulomi periapicali.

Cell adhesion molecules (CAMs) are cell surface proteins involved in the binding of cells, usually leukocytes, to each other, to endothelial cells, or to extracellular matrix. Specific signals produced in response to wounding and infection control the expression and activation of certain of these adhesion molecules. The interactions and responses then initiated by binding of these CAMs to their receptors/ligands play important roles in the mediation of the inflammatory and immune reactions that consult one line of the body's defense against these insults. Most of the CAMs characterized so far fall into three general families of proteins: the immunoglobulin (Ig) superfamily, the integrin family, or the selectine family. Recent studies have indicated that selectins (E,L,P) are implicated in cell trafficking, an important aspect of inflammation-related process. Regulation of white blood cell trafficking from the blood vascular compartment to regions of pathogenic exposure is one of the most important functions of the immune system. The distinct phases of leukocyte migration include: rolling, activation, firm adhesion, transendothelial migration and subendothelial migration. The selectins have been implicated in the first step of this cascade. An inflammatory response is first evoked in the pulpal tissue in an attempt to neutralize the injurious agent and to dispose of damaged tissue and cells. The pulpal vessels dilate and blood flow to the tooth increases. At the same time, permeability of the vessels increases allowing leakage of fluid and leukocytes into the tissue.

[Cell communication in the development of the oral cavity]. / La comunicazione cellulare nello sviluppo della cavità orale.

The cadherins are a family of a calcium-dependent cell adhesion molecules that are regulated both spatially and temporally during development. Epithelial cadherin (E-cadherin) is present in the epithelial cells in both the embryo and yolk sac during organogenesis. In many studies, the presence of E-cadherin was analyzed during normal and disturbed craniofacial development with respect to palate and tooth formation. E-cadherin was present in epithelia of both ectodermal and endodermal origin. The expression level of E-cadherin increased with age and differentiation. The expression pattern of E-cadherin implies that this molecule has a role during normal development of the epithelia of the cranio-facial complex. Morphogenesis and cell differentiation in the developing tooth are controlled by a series of reciprocal interactions between the epithelial and mesenchymal tissues. The exact molecular mechanisms operating in these interactions are unknown at present, but both structural components of the extracellular matrix (ECM) and diffusible growth factors have been suggested to be involved. In this review article we summarize our findings on the distribution patterns of three ECM molecules and two cell surface receptors during tooth morphogenesis through bud, cap, and bell stages of development. The examined molecules include fibronectina and tenascin, which all represent components of the mesenchymal ECM, the cell surface proteoglycan, syndecan, which functions as a receptor for interstitial matrix. Based on the observed changes in distribution patterns and on experimental evidence, roles are suggested for these molecules in epithelial-mesenchymal interactions during tooth development. C-Cam is a cell surface glycoprotein that is involved in cell adhesion and may play a role in histogenesis and organogenesis. It is a member of the carcinoembryonic antigen (CEA) gene family, which is a subfamily of the immunoglobulin gene superfamily. The presence of C-CAM in all proliferating craniofacial epithelia indicates that this molecule may play an important role in development.

[SEM (Scanning Electron Microscopy) study of the deterioration of ProFile .04 and .06]. / Studio al SEM sul deterioramento dei proFile .04 e .06.

BACKGROUND: The ProFile are endodontic instruments made by a special nickel-titanium alloy. They have to work on constant rotation at a speed of 350 revolutions per minute. The purpose of the study is to assess, through SEM research, a possible deterioration of different ProFile conicity. METHODS: Sixteen dental elements pulled out for period dental reasons have been used as samples to assess the progressive deterioration of .04 and .06 ProFile conicity. Eight molars and eight premolars with a total of 36 radicular canals were examined. The types of ProFile tested were 8: they were respectively 4 with .04 conicity and 4 with .06 conicity. Before being used, all instruments are previously studied through SEM. The tested ProFile with .04 conicity had a diameter of 15, 25, 30 and 45. Those with .06 conicity had a diameter of 20, 25, 30 and 35. Each tested ProFile was introduced inside a radicular canal and was turned for 180 seconds with a constant rotation of 200 revolutions per minute. After this first step, the alterations produced by the instrument could be observed through SEM. Afterwards, the same ProFile has worked again inside another radicular canal with the same time and the same number of turns, before being observed again through SEM. We have continued using this method up to the break of the instrument. RESULTS: The instruments with .04 conicity and smaller diameter are subject to a faster deterioration, more visible at the point. After a working time of 180 seconds all the instruments have their distinct morphological alterations: after other 180 seconds it is possible to often observer an alteration to the pitch of the instrument. The breaking times are related to the diameter and conicity of ProFile tested. CONCLUSIONS: Endodontic nickel-titanium instruments, even if they represent a progress in the field of canal preparation, undergo some alterations in their shape if they are put under inevitable mechanical stress. The damages can be: break at the top of the instrument and loss of cutting abilities at the turns level.