Prostate cancer is the second highest cause of cancer mortality after lung tumours. In USA it affects about 2.8 million men and the incidence increases with age in many countries. Therefore, early diagnosis is a very important step for patient clinical evaluation and for a selective and efficient therapy. The study of miRNAs' functions and molecular mechanisms has brought new knowledge in biological processes of cancer. In prostate cancer there is a deregulation of several miRNAs that may function as tumour suppressors or oncogenes. The aim of this review is to analyze the progress made to our understanding of the role of miRNA dysregulation in prostate cancer tumourigenesis.
Objective: To compare the surface roughness of different orthodontic archwires. Materials and Methods: Four nickel-titanium wires (SentalloyH, SentalloyH High Aesthetic, Titanium Memory ThermaTi LiteH, and Titanium Memory EstheticH), three b-titanium wires (TMAH, Colored TMAH, and Beta TitaniumH), and one stainless-steel wire (Stainless SteelH) were considered for this study. Three samples for each wire were analyzed by atomic force microscopy (AFM). Three-dimensional images were processed using Gwiddion software, and the roughness average (Ra), the root mean square (Rms), and the maximum height (Mh) values of the scanned surface profile were recorded. Statistical analysis was performed by one-way analysis of variance (ANOVA) followed by Tukey's post hoc test (P , .05). Results: The Ra, Rms, and Mh values were expressed as the mean 6 standard deviation. Among as-received archwires, the Stainless Steel (Ra 5 36.6 6 5.8; Rms 5 48 6 7.7; Mh 5 328.1 6 64) archwire was less rough than the others (ANOVA, P , .05). The Sentalloy High Aesthetic was the roughest (Ra 5 133.5 6 10.8; Rms 5 165.8 6 9.8; Mh 5 949.6 6 192.1) of the archwires. Conclusions: The surface quality of the wires investigated differed significantly. Ion implantation effectively reduced the roughness of TMA. Moreover, TeflonH-coated Titanium Memory Esthetic was less rough than was ion-implanted Sentalloy High Aesthetic. (Angle Orthod. 2012;82:922-928.)
Ametrano G, D'Antò V, Di Caprio MP, Simeone M, Rengo S, Spagnuolo G. Effects of sodium hypochlorite and ethylenediaminetetraacetic acid on rotary nickeltitanium instruments evaluated using atomic force microscopy. International Endodontic Journal, 44, 203-209, 2011.Aim To use atomic force microscopy (AFM) to evaluate the effects of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) on the surface characteristics of ProTaper rotary nickel-titanium instruments. Methodology A total of twenty ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) instruments (S1, S2, F1, F2) were divided into five groups: no immersion, immersion in 5.25% NaOCl for 5 or 10 min and immersion in 17% EDTA for 5 or 10 min. Twenty surface areas along 3-mm sections at the tip of the files (perfect squares of 1 · 1 lm) were analysed by AFM operating in contact mode under ambient conditions. Three-dimensional images (400 · 400 lines) were processed using Gwyddion software, and the roughness average (Ra) and the root mean square value (RMS) of the scanned surface profiles were recorded. Data were analysed by means of anova and paired samples t-test. Results Three-dimensional AFM images of the surface of ProTaper instruments, including new and those immersed in NaOCl and EDTA solutions, revealed topographic irregularities at the nanometric scale. RMS and Ra values of instruments treated with NaOCl and EDTA solutions were statistically higher than that of the new ones (P < 0.05). Conclusions Atomic force microscopy threedimensional images and roughness values indicated that short-term contact between NaOCl and EDTA endodontic irrigants and ProTaper instruments caused alterations in the surface of instruments.
Objective: To evaluate the effects of intraoral aging on surface properties of esthetic and conventional nickel-titanium (NiTi) archwires. Materials and Methods: Five NiTi wires were considered for this study (Sentalloy, Sentalloy High Aesthetic, Superelastic Titanium Memory Wire, Esthetic Superelastic Titanium Memory Wire, and EverWhite). For each type of wire, four samples were analyzed as received and after 1 month of clinical use by an atomic force microscope (AFM) and a scanning electronic microscope (SEM). To evaluate sliding resistance, two stainless steel plates with three metallic or three monocrystalline brackets, bonded in passive configuration, were manufactured; four as-received and retrieved samples for every wire were pulled five times at 5 mm/min for 1 minute by means of an Instron 5566, recording the greatest friction value (N). Data were analyzed by one-way analysis of variance and by Student's t-test. Results: After clinical use, surface roughness increased considerably. The SEM images showed homogeneity for the as-received control wires; however, after clinical use esthetic wires exhibited a heterogeneous surface with craters and bumps. The lowest levels of friction were observed with the as-received Superelastic Titanium Memory Wire on metallic brackets. When tested on ceramic brackets, all the wires exhibited an increase in friction (t-test; P , .05). Furthermore, all the wires, except Sentalloy, showed a statistically significant increase in friction between the as-received and retrieved groups (t-test; P , .05). Conclusion: Clinical use of the orthodontic wires increases their surface roughness and the level of friction. (Angle Orthod. 2014;84:665-672.)
146ORIGINAL ARTICLE sibility to combine the best properties of both polymeric and inorganic materials. Briefly, the sol-gel chemistry involves the hydrolysis and polycondensation of metal alkoxides M(OR) x , where M = Si, Sn, Zr, Ti, Al, Mo, V, W, Ce, and so forth (17,23,24). The main advantage of the sol-gel technique is that the sintering process of organicinorganic hybrid biomaterials can be performed at low temperature (e.g., room temperature) (25, 26).Organic-inorganic hybrid materials can be divided into different classes based on the nature of the interface (17,27). Class I consists of organic and inorganic compounds that are embedded, and the cohesion of the whole structure is due to weak bonds (hydrogen, van der Walls, or ionic bonds). In class II, the organic and inorganic phases are linked through strong chemical bonds (covalent or ionic-covalent bonds).A wide range of polymers as the organic phase has been introduced into inorganic networks to obtain hy- ABSTRACT Purpose: The importance of polymer-based composite materials to make multifunctional substrates for tissue engineering and the strategies to improve their performances have been stressed in the literature. Bioactive features of sol-gel synthesized poly(ε-caprolactone)/TiO 2 or poly(ε-caprolactone)/ZrO 2 organic-inorganic hybrid materials are widely documented. Accordingly, the aim of this preliminary research was to develop advanced composite substrates consisting of a poly(ε-caprolactone) matrix reinforced with sol-gel synthesized PCL/TiO 2 or PCL/ZrO 2 hybrid fillers.Methods: Micro-computed tomography and atomic force microscopy analyses allowed to study surface topography and roughness. On the other hand, mechanical and biological performances were evaluated by small punch tests and Alamar Blue TM assay, respectively. Results: Micro-computed tomography and atomic force microscopy analyses highlighted the effect of the preparation technique. Results from small punch tests and Alamar Blue TM assay evidenced that PCL reinforced with Ti2 (PCL=12, TiO 2 =88 wt%) and Zr2 (PCL=12, ZrO 2 =88 wt%) hybrid fillers provided better mechanical and biological performances. Conclusions: PCL reinforced with Ti2 (PCL=12, TiO 2 =88 wt%) and Zr2 (PCL=12, ZrO 2 =88 wt%) hybrid fillers could be considered as advanced composite substrates for hard tissue engineering.
The microCT analysis provided interesting information on voids distribution and on the ratio between post shape and cement thickness. These results might address the clinician in the reconstruction of teeth with fiber posts.
Objective:Aim of the study was to determined by microcomputed tomography (µCT) the horizontal distance between the main (MB1) and the second mesiobuccal canal (MB2) orifices, the vertical distance between the MB1 and MB2 orifices planes, and the distance between the anatomic apex and major apical foramen (AF). Furthermore, we characterized the entire internal and external anatomy of the MB, distalbuccal (DB) and palatal (P) maxillary first molars roots.Materials and Methods: Twenty-two intact extracted first maxillary molars were scanned by X-ray computed transaxial µCT and then 2D and 3D images were processed and analyzed.Results:The results showed that 77.27% of the mesiobuccal (MB) roots presented a second MB canal, and 29.41% of the MB2 were independent from the MB1 canals. In 15 teeth, there were three root canal orifices on the chamber floor, and 10 of these teeth presented MB2 canals. The mean vertical distance between the MB1 and MB2 planes was 1.68 ± 0.83 mm. Seven teeth had four orifices. The mean horizontal interorificial distance between the MB1 and MB2 orifices was 1.21 ± 0.5 mm. Accessory canals were observed in 33.33% of the roots, loops in 6.06%, while isthmuses were found in 15 of the 22 MB roots. Of the total roots, 74.24% presented one foramen, while all of the roots showed a major apical foramen that was not coincident with the anatomic apex. Conclusions:Our µCT analysis provided interesting features on the horizontal and vertical distance between the MB1 and MB2 orifices and on the distance of AF and anatomic apex.Clinical Relevance:These results have an important clinical value because might support the endodontist in the recruitment, negotiation and obturation of maxillary first molar canal system.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.