Search results for "20(60)"
showing 10 items of 368 documents
Digital protocol for creating a virtual gingiva adjacent to teeth with subgingival dental preparations.
2019
Abstract Purpose This article describes a digital technique used to record gingival emergence profiles modeled for the prosthetic restoration of teeth prepared using biologically oriented preparation technique (BOPT). Materials and methods The description of the technique of intraoral recording, manipulation of digital files, and chairside protocol of prosthetic restorations is developed in the present manuscript on two anterior teeth treated with vertical and subgingival dental preparations for restoration with ceramic crowns. The manipulation of the digital files registered with an intraoral scanner with software that allows its alignment (best-fit) and the performance boolean of operatio…
Assessment of the stresses produced on the bone implant/tissue interface to the different insertion angulations of the implant - a three-dimensional …
2020
Background The present study aimed to assess the stresses produced on the surface of the bone tissue around dental implants with three different insertion angulations subjected to axial and oblique loading. Material and methods The study was created according to the recommendations of the Checklist for Reporting In-vitro Studies (CRIS). The Straumann™ bone level RC (4.1 x 10 mm) implant, Cone Morse connection (CM), RC Straumann Variobase™ with abutment (3.5 mm) was placed in the region of element 16, with the platform positioned at the height of the bone crest. Three assessment models were produced: model M1 or control - implant perpendicular to the bone crest; model M2 - implant angulated …
Micro-computed tomographic evaluation of dentinal defects after root canal preparation with hyflex edm and vortex blue rotary systems
2018
Background To evaluate the incidence of dentinal microcracks formation after root canal shaping procedures with HyFlex EDM and Vortex Blue rotary systems comparing with that of hand instrumentation using micro-computed tomography. Material and methods Mandibular first molar teeth (n=60) having 50 to 200mesial root curvature were scanned using high resolution micro-CT imaging before root canal preparation to identify the presence of dentinal defects. Post-instrumentation cross-sectional images were taken and increased number and type of root defects were assessed and recorded. The data was statistically analysed by using chi-square test and McNemar's test at a significance level of 5%. Resul…
Extra short 4mm implants used to rehabilitation of atrophic posterior mandible. A serial case reports
2020
Rehabilitation of patients through implants in areas with severe bone resorption in the posterior mandible is a challenge in implant dentistry. In this context, extra short implants configure a treatment option for this type of patient, as they can avoid increased financial cost, treatment time and patient morbidity. The present study evaluated the marginal bone stability in individualized extra-short implants for masticatory function in the posterior mandible. Using digitized periapical radiographs of 13 extra-short implants performed on 7 patients. The mesial and distal regions of each implant were selected, from the bone crest to the region parallel to the apex, and the bone stability of…
Comparison of Shaping Ability of 10 Rotary and Reciprocating Systems: an In Vitro Study with AutoCAD
2017
Cilj: Usporediti reznu površinu, očuvanje anatomije korijenskog kanala i neinstrumentiranu površinu nakon instrumentacije sustavima F360®, F6SkyTaper®, HyflexEDM®, iRace®, Neoniti®, O.Shape®, P.Next®, Reciproc®, Revo-S® i WaveOneGold® s veličinom instrumenta 25. Materijali i metode: Tristo zubi s jednim ravnim korijenom i okruglim ili eliptičnim presjekom korijenskog kanala podijeljeno je u 10 skupina (1-F360®, 2-F6SkyTaper®, 3-HyflexEDM®, 4-iRace®, 5-Neoniti®, 6-O Shape®, 7-P.Next®, 8-Reciproc®, 9-Revo-S® i 10-WaveOneGold®) i poprečno prerezano na trećine ultrafinim reznim diskovima. Uzorci su fotografirani pod stereomikroskopom i provedena je predinstrumentacijska analiza prije ponovnog s…
Management of a crown-root fracture : a novel technique with interdisciplinary approach
2018
Anterior teeth with subgingival fractures require a complex treatment plan that addresses biologic, functional and aesthetic factors. This case report describes the management of a crown-root fractured maxillary left central incisor. An interdisciplinary approach was used to restore the tooth due to the complex nature of the treatment. Orthodontic extrusion was performed to move the fracture line above the alveolar bone and periodontal surgery to recontour the altered gingival margin. Finally, the incisor was restored performing a root canal retreatment with a fiber post and a full ceramic crown. The treatment resulted in secured periodontal health and good aesthetics. Key words:Crown-root …
Canal shaping with a reciprocating system is easy to learn.
2018
To assess progressive learning of root canal shaping in order to define the number of simulated canals in resin blocks needed to reach a level of learning beyond which no further improvement in performance is observed.A total of 216 simulated canals in resin blocks were instrumented by 18 operators without experience in Endodontics and by 18 Endodontists. The R25 file of the Reciproc system (VDW, Munich, Germany) was used to prepare the canals. The blocks were photographed before and after instrumentation. An analysis was made of the variations in the dimensions of the canals at 6 locations and of the instrumentation time. A Student's t-test was used to analyse the data (P 0.05).The group …
Blind source separation based interference suppression schemes for OFDM and DS-CDMA
2015
In statistical wireless signal processing, extraction of unobserved signals from observed mixtures can be achieved using Blind Source Separation (BSS) algorithms. Orthogonal Frequency Division Multiplexing (OFDM) and Direct Sequence-Code Division Multiple Access (DS-CDMA) can be pronounced as the well established predominant air interface communication techniques. Consequences of an effort taken and counteractive solutions to diminish the undesirable influences encountered within the wireless air interface of those techniques with aid of BSS schemes are disclosed. Filter coefficients for the receiver are ascertained with the support of a set of energy functions and the iterative fixed point…
Exploring the Virchow-Robin spaces function: A unified theory of brain diseases.
2016
Background: Cerebrospinal fluid (CSF) transport across the central nervous system (CNS) is no longer believed to be on the conventional lines. The Virchow-Robin space (VRS) that facilitates CSF transport from the basal cisterns into the brain interstitial fluid (ISF) has gained interest in a whole new array of studies. Moreover, new line of evidence suggests that VRS may be involved in different pathological mechanisms of brain diseases. Methods: Here, we review emerging studies proving the feasible role of VRS in sleep, Alzheimer's disease, chronic traumatic encephalopathy, and traumatic brain injury (TBI). Results: In this study, we have outlined the possible role of VRS in different path…
Pectin biopolymer mechanics and microstructure associated with polysaccharide phase transitions.
2019
Polysaccharide polymers like pectin can demonstrate striking and reversible changes in their physical properties depending upon relatively small changes in water content. Recent interest in using pectin polysaccharides as mesothelial sealants suggests that water content, rather than nonphysiologic changes in temperature, may be a practical approach to optimize the physical properties of the pectin biopolymers. Here, we used humidified environments to manipulate the water content of dispersed solution of pectins with a high degree of methyl esterification (high-methoxyl pectin; HMP). The gel phase transition was identified by a nonlinear increase in compression resistance at a water content …