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.

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.

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.

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.

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.

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.

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.

[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.

[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.

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.

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.

[Thermoelastic analysis of nickel-titanium endodontic files]. / Analisi termoelastica di lime endodontiche in nichel-titanio.

BACKGROUND: Technological progress in the endodontic field has allowed the creation of innovative nickel-titanium endodontic instruments, made with a superelastic alloy with a reduced modulus of elasticity. The elastic properties of the NiTi alloy can undergo significant variations in connection with mechanical movements and cyclic fatigue induced on the instruments caused by their repeated usage, especially in canals which are anatomically difficult to shape. The state of tension of the instrument determines a deformation of the geometry of the files and, therefore, a modification in their properties. Similarly to mechanical stress, thermal treatments can influence the properties of the alloy. The aim of the study is to subject the NiTi alloy to repeated thermomechanical cycles, examining the influence of the mechanical and thermal stress on the temperature at the beginning and end of the martensite transformation, on the increase of recovery of deformation during the cooling phase and on the change in the internal structure of the material. METHODS: The instruments (30 ProFile Maillefer) were subdivided into 5 groups: Group I, composed of 6 new ProFiles submitted to 14 sterilization cycles in an autoclave for 30 minutes each; Group II, formed by 6 unused ProFiles subjected to one sterilization cycle in an autoclave; Group III made up of 6 new ProFiles used as controls; Group IV made up of 6 ProFiles submitted to clinical use on endodontic simulators in plexiglas for a total time of 240 seconds; Group V consisting of 6 ProFiles used on endodontic simulators for a total time of 480 seconds. All the above mentioned samples were tested using a thermomechanic dynamic analyzer (DMTA) produced by Rheometric Scientific. RESULTS: The files from Group III (control) show an elastic deformation curve typical of nickel-titanium instruments. The samples from Groups IV and V subjected to sequential use on endodontic simulators evidenced modifications in their elastic behaviour compared to the control instruments. The operative use caused modifications in the original properties of the alloy, with a reduction in elasticity proportional to the number of uses. The instruments that underwent 14 cycles of sterilization in the autoclave (I group) present dynamic analysis curves which are different compared to the new unsterilized ProFiles. After 14 cycles there is a modification in the response of the instruments to thermodynamic stress. CONCLUSIONS: Both the samples undergoing repeated mechanical stress on Plexiglas endodontic simulators and those sterilized in the autoclave at thermodynamic analysis show significant modification in modulus of elasti- city. The different taper does not influence the experimental results, there not being any significant differences found in the elastic behaviour between ProFiles.

[Von Recklinghausen osteitis fibrosa cystica. A clinical case]. / Osteite fibroso cistica di Von Recklinghausen. Caso clinico.

In Recklinghausen's disease the skeleton lesions are often the first signal of the pathology. The main clinical manifestations are represented by bony lesions which appear as multicystic lesions with loss of the hard lamina and skull malformation and asymmetry. In this disease there is a relevant osteoclastic activity which prevails over the osteoblastic one associated to the fibrous substitution of the marrow, sometimes producing micro or macro cysts. The typical alteration consists of an increase along the endosteal and trabecular surfaces in the number of osteoclasts which can be found in small reabsorption gaps. This is the cause of a cortical and trabecular reduction which can appear as interrupted. Histologic lesions consist in the replacement of bone tissue with fibrous and osteoid tissue. These bony lesions are not characteristic of the disease but to be distinguished from other pathologies such as for example Paget's disease and other forms of fibrous dysplasia (Gardner's syndrome, Leontiasis ossea). A case personally observed is described: a women, 29 years old, suffering from Recklinghausen's disease with face and skull asymmetry, condyles and glenoid cavity deformation, abnormal face reduction. Observing the planigraphy on the right side of the temporomandibular articulation, flattened glenoid cavity and condyles with irregular outlines can be noticed, aplastic coronoid cuts, altered jaw. The patient was submitted to surgery for dental extraction followed by a biopsy which showed some regressive alterations on cellular level of the bony structure.

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.

[Comparison of different finishing methods for composites and compomers. Profilometric analysis]. / Differenti metodiche di rifinitura di compositi e compomeri. Analisi al profilometro.

BACKGROUND: Reconstructions with aesthetical materials neither finished nor polished can be extremely irregular and wrinkled. For this reason they represent an ideal basis for the growing of pigmentation which come from food remainings and the nestle of bacteria on the plaque. The finishing of aesthetical materials is a fundamental step in conservative dentistry. The finishing session regarding the aesthetical restorations should be considered and planned at the moment of their insertion in the prepared hollows. The finishing should not be considered an option, but the conclusion of all the conservative treatment. Purpose of the search is to examine and assess, through a technical equipment measuring the superficial wrinkledness of the materials, the action of 4 systems of finishing and polishing on two aesthetical materials widely used in the daily practice by dental surgeons: a compomer (Compoglass, Vivadent) and a composite (Spectrum, Dentsply). METHODS: For each of these two materials some little slabs model have been prepared, choosing the universal colour in the colorimetric scale. The two types of filling materials have been compared with 4 systems of finishing and polishing: Sof-Lex Pop-on (3M), Enhance system (Dentsply), Hawe Micro Disc (Howe Neos), Heawe Gommini Polisher (Heawe Neos). The total working time did not overcome 1 minute. The little slabs have been obtained, pressing the resin between two slides used in microscopy. In the hope to guarantee in the different samples, a uniform thickness, we have used a technical device. On each covering slide we have put a weight of 0.5 kg for 5 minutes. The thickness of the little slabs obtained was 2 mm. Thus, pressed between the two slides, the aesthetical material has been photopolymerized according to the time suggested by Manufacturing Industries. The sizes concerning the wrinkledness of samples subjected to different treatments have been carried out using a pointed profilometer with high sensitivity. (Tencor-P10). This instrument used in the National Laboratory of Catania, called INFN, is able to graphitize the wrinkledness of a surface "survbeying" it with a diamond ultramicrometric point. RESULTS: All tested systems gradually produce the upper layers of the materials less suitable to resist the assault of plaque bacteria as time passed. The 3M coarse and medium grain Disks are very abrasive and for this reason the surface of the materials is ill-shaped. Those disks with fine and extra fine grain, smooth the tracks left by previous disks. As they have been always used according to their decreasing granulometry, the disks are used only for removing small composite pieces in excess and to improve micromorphology of the restauration. The "Gommini" are less abrasive than Disks. In a few minutes and often with only one step they produce a much regular and polished fillings surface. CONCLUSIONS: The "Gommini" have a preference when the last photopolymerization has left a regular layer, with a very good micromorphology. Actually, "Gommini" do not remove much material, but they continue to smooth the outline of the reconstruction. Disks are not classified as being of first quality in the finishing of composites and compomers.

[Evaluation of two root canal preparation and obturation methods: the Mc Spadden method and the use of ProFile-Thermafil]. / Valutazione delle preparazioni e otturazioni canalari realizzate secondo Mc Spadden e con i ProFile-Thermafil.

BACKGROUND: In endodontic field different instruments and techniques have been suggested for the preparation and filling or radicular bent canals. The purpose of this study is to compare two different cleaning and canal filling methods: preparation and filling technique, according to Mc Spadden's method, instrument technique and the closing of the canal system according to ProFile-Thermafil method. METHODS: In this study ten molars divided into two groups of five elements each were used. The five molars of the first group were prepared according to the "crown-down" technique with nickel-titanium instruments by NT Engine Files Quantec 2000 series. The 18 canals found out in the five molars have been filled with Pac Mac and gutta-percha preheated. The five molars of the second group have 17 radicular canals which, firstly, have been cleaned with ProFile .04 and .06 taper fitted to a manipulator at 220 revolutions per minute and then filled by Thermafil n. 30 with plastic carrier. All ten molars were X-rayed first, during and after the treatment. All teeth were soaked into polymerised resin, dissected into three different points and observed through Optical Microscope. RESULTS: Both cleaning techniques succeed in being efficient in bent canals. The instruments made by Mc Spadden highlight a greater preservation of canal dentine than the ProFile. In samples of the first group there is an excellent adaptation of multiphase gutta-percha to the canal walls and a correct relationship between the filling material and the apical foramen. In filling with Thermafil the adaptation of gutta-percha inside the radicular canal shows outstanding differences in relation to sections taken into account. Actually, while in portion of the crown the filling can be considered satisfactory towards the canal walls, in apical sections there is a decrease in the quantity of gutta-percha step by step, while a contact of plastic carrier with dentine walls is highlighted. CONCLUSIONS: Wheter in the shaping or in the canal filling phase, the two methods are efficient and conservative towards dental structure at the same time. These methods, have an outstanding reduction in dental weakening and in times of the endodontic treatment performance.