Search results for "Cone"
showing 10 items of 772 documents
Postoperative Komplikationen nach Silikonölinstillation
1997
Die Verwendung von Silikonol beinhaltet verschiedene Komplikationen, die den Erfolg des vitreoretinalen Eingriffes oftmals reduzieren. In einer retrospektiven Studie analysierten wir den Krankheitsverlauf von insgesamt 511 Augen (503 Patienten) mit komplizierter NH-Amotio verschiedener Genese, bei denen eine Pars-plana-Vitrektomie mit Silikonoltamponade durchgefuhrt worden war, um Komplikationen nach Silikonoltamponade festzustellen. Bei den untersuchten Augen handelte es sich um 267 komplizierte PVR-Amotiones, 126 diabetische Traktionsamotiones, 74 Amotiones nach perforierender Bulbusverletzung, 27 Amotiones mit Riesenris und 17 Augen mit verschiedenen anderen Netzhauterkrankungen wie Endo…
Reproducible optical fiber tips for photon scanning tunneling microscopy with very small (>5°) cone angle
1998
Sharp optical fiber tips for photon scanning tunneling microscopes (PSTMs) have been fabricated by employing a new alternative technique for etching multimode optical fibers. The tip diameter is less than 30 mm, while the cone full-angle can be as sharp as 3/spl deg/. To the knowledge of the authors, such tips are the sharpest reported up to now. Measurements, with 19 tips, of the evanescent wave decay distance produced by frustrated reflection of light on a same sample, show good reproducibility. Furthermore, the PSTM images, taken with the new tips, are very sharp and fit with images of the same sample obtained with an atomic force microscope (AFM).
Comparison of the Ultraviolet Light Filtering across Different Intraocular Lenses.
2018
SIGNIFICANCE We have analyzed the ultraviolet transmittance of some commercial intraocular lenses (IOLs). The results show differences of wavelength cutoff among them. PURPOSE The purpose of this study was to measure and compare the ultraviolet light transmittance of different IOLs made out of acrylic hydrophobic, hydrophilic, and hydrophilic with hydrophobic surface materials from different manufacturers. METHODS The spectral transmission curves of eight monofocal IOLs with the same dioptric power of +20.0 diopters were measured using a PerkinElmer Lambda 35 ultraviolet/visible spectrometer. Two IOLs of each type were tested three times. The ultraviolet cutoff wavelength at 10% transmissio…
Establishment of a commercial organic hopyard in a Mediterranean environment: Production attributes and their relationship with soil texture
2023
The cultivated hops are recently moving towards new growing areas in Southern Europe, boosted by the increasing number of craft breweries and by the higher vulnerability to climate change observed, for this crop, in the traditional growing regions. Despite this clear market and geographic trend, there is a lack of knowledge about pedoclimatic needs and agronomic performances of hops grown in the Mediterranean environment. Particularly, the agronomic potential of a new hopyard during its establishment period is poorly studied even in traditional growing zones. Moreover, a restricted number of plants were usually sampled to gather the few data available, thus leading to a probable overestimat…
Controls of mud mound formation: The Early Devonian Kess-Kess carbonates of the Hamar Laghdad, Antiatlas, Morocco
1992
The origin and development of Early Devonian (late Pragian to late Zlichovian; predominantly uppermost Zlichovian as indicated by conodont faunas) mud mounds of the Hamar Laghdad area in the eastern Antiatlas, Morocco, are controlled by extrinsic and intrinsic factors. Extrinsic factors include the existence of a paleohigh (Lochkovian volcaniclastics), unidirectional currents and repeated storm events as well as sea level fluctuations. Intrinsic, biologically induced factors are the preferred growth of organisms on the top and the flanks of the mounds because of more favourable ecological conditions, and a rapid synsedimentary lithification of the steep mound flanks by interskeletal cementa…
Comparative analysis of impacted upper canines: Panoramic radiograph Vs Cone Beam Computed Tomography.
2016
Background The use of CBCT exam in the study of IMC is not new. However, it's still not known in what specific aspects CBCT exam shows a better result than then conventional exams. The aim of this study was to compare and conclude in what way the opinion regarding upper canine impaction differed when observing a panoramic image compared to the observation of a set of CBCT reconstructions. Material and Methods Twenty patients (10 males and 10 females) with a total of 28 impacted maxillary canines were identified from the database of the Department of Dentistry, Faculty of Medicine, University of Coimbra. For each canine, two different images were available: a panoramic image and a set of CBC…
Dental measurements and Bolton index reliability and accuracy obtained from 2D digital, 3D segmented CBCT, and 3d intraoral laser scanner
2017
Background To compare the reliability and accuracy of direct and indirect dental measurements derived from two types of 3D virtual models: generated by intraoral laser scanning (ILS) and segmented cone beam computed tomography (CBCT), comparing these with a 2D digital model. Material and methods One hundred patients were selected. All patients' records included initial plaster models, an intraoral scan and a CBCT. Patients´ dental arches were scanned with the iTero® intraoral scanner while the CBCTs were segmented to create three-dimensional models. To obtain 2D digital models, plaster models were scanned using a conventional 2D scanner. When digital models had been obtained using these thr…
Influence of Three-dimensional Imaging on Implant Treatment Planning: Implant Diameter and Length
2018
Aim To investigate the influence of the radiographic modalities panoramic radiography (PR) and cone beam computed tomography (CBCT) on selection of implant length and diameter. Materials and methods Potential implant sites (59 sites, 40 patients) with available PRs and CBCTs were selected from the databases of two University dental schools. Six experienced clinicians were asked to select the appropriate implant length and diameter based on PR and CBCT. Results were compared with the actual surgical procedure and intra- /interrater agreement was calculated using Cohen's kappa. Results On average, greater implant length was more often planned based on PR (24.2 vs 8.8% with CBCT), while wider …
Comparison of diagnostic accuracy between periapical and panoramic radiographs and cone beam computed tomography in measuring the periapical area of …
2019
Background The aim of the study was compare the sensitivity and measurements obtained from teeth with apical lesions scheduled for periapical surgery using three different diagnostic methods: periapical radiography (Gendex Expert DC), panoramic radiography (Planmeca® Promax 3D Classic) and cone beam computed tomography (CBCT) (Planmeca® Promax 3D Classic). Material and methods This cross-sectional study involved 35 patients (45 teeth) scheduled for periapical surgery in which periapical radiographs, panoramic radiographs and CBCT scans had been obtained. The images were used to analyze the maximum vertical and horizontal dimension and the resulting areas of the periapical lesions based on t…
Radiological implications of crestal and subcrestal implant placement in posterior areas. A cone-beam computed tomography study
2020
Background Subcrestal implant placement has been suggested as a method that could contribute to maintain the periimplant soft and hard tissues in comparison with crestal placement. The objective of this study was to investigate the relationship between implant placement at different depths in the alveolar bone and (a) the thickness of the buccal bone plate (BBP); and (b) crestal cortical bone thickness, based on the use of cone-beam computed tomography (CBCT). Material and Methods A cross-sectional study was performed, analyzing CBCT scans from the database of the Oral Surgery Unit of the University of Valencia. Individuals with single missing teeth in posterior sectors were included. Two t…