Search results for "cements"
showing 10 items of 136 documents
Toward a Comprehensive Dam Monitoring: On-Site and Remote-Retrieved Forcing Factors and Resulting Displacements (GNSS and PS–InSAR)
2021
Many factors can influence the displacements of a dam, including water level variability and environmental temperatures, in addition to the dam composition. In this work, optical-based classification, thermal diachronic analysis, and a quasi-PS (Persistent Scatter) Interferometric SAR technique have been applied to determine both forcing factors and resulting displacements of the crest of the Castello dam (South Italy) over a one-year time period. The dataset includes Sentinel-1A images acquired in Interferometric Wide swath mode using the Terrain Observation with Progressive Scans SAR (TOPSAR); Landsat 8 Thermal Infrared Sensor (TIRS) thermal images, and Global Navigation Satellite System …
COMMENT TO LEHRMANN ET AL. NEW SECTIONS AND OBSERVATIONS FROM THE NANPANJIANG BASIN, SOUTH CHINA
2016
In the study of Earth-surface environmental processes during the events associated with the Permian–Triassic boundary, a key issue is the nature of the latest Permian pre-extinction surface in shallow marine limestones in numerous sites, principally within the Tethyan realm. Sediments below this surface pre-date the extinction event, so that the limestones comprising these latest Permian facies contain diverse fossil remains of organisms that lived just before the extinction. At all reported sites, this surface is disconformably overlain by post-extinction sediments, which contain microbialites in many places, particularly in Tethys. The nature of the youngest pre-extinction surface remains…
Hybrid layers of etch-and-rinse versus self-etching adhesive systems.
2010
Objective: To evaluate the effectiveness in the formation of resin tags, adhesive lateral branches and hybrid layers of five adhesive systems, when bonding to dentine. Material and Methods: Flat dentin surfaces from 25 molars were bonded with several adhesive systems according to the manufacturers? instructions. Composite build-ups were constructed incrementally with Tetric Ceram. The Specimens were sectioned parallel to the long axis. One section was treated with phosphoric acid and sodium hypochlorite in order to reveal the hybrid layer formation. The other section was stored in 30% hydrochloric acid to detect resin tags and adhesive lateral branch formation. Results: The two etch-and-rin…
Current dental adhesives systems. A narrative review.
2012
Adhesive dentistry is based on the development of materials which establish an effective bond with the tooth tissues. In this context, adhesive systems have attracted considerable research interest in recent years. Successful adhesive bonding depends on the chemistry of the adhesive, on appropriate clinical handling of the material as well as on the knowledge of the morphological changes caused on dental tissue by different bonding procedures. This paper outlines the status of contemporary adhesive systems, with particular emphasis on chemical characteristics and mode of interaction of the adhesives with enamel and dentinal tissues. Dental adhesives are used for several clinical application…
Autologous Iliac Bone Graft Compared with Biphasic Hydroxyapatite and Calcium Sulfate Cement for the Treatment of Bone Defects in Tibial Plateau Frac…
2019
Background Bone-graft substitutes are commonly used for the augmentation of traumatic bone defects in tibial plateau fractures. However, their clinical performance compared with that of autologous bone-grafting, the gold standard in bone defect reconstruction, still remains under debate. This study investigates the differences in quality of life, pain, and radiographic outcomes in the treatment of tibial plateau fracture-associated bone defects with either autologous bone grafts or a bioresorbable hydroxyapatite and calcium sulfate cement (CERAMENT BONE VOID FILLER [CBVF]; BONESUPPORT). Methods In this study, 135 patients with acute depression and split-depression fractures of the proximal …
Two-year clinical performance of a packable posterior composite with and without a flowable composite liner
2003
The aim of the study was to evaluate the clinical performance of a packable fine hybrid dental composite (Prodigy Condensable) and the influence of the additional application of a flowable resin composite (Revolution, SDS Kerr) layer on marginal integrity after 2 years in stress-bearing posterior cavities according to the Ryge criteria. In 50 patients (40.5+/-17.5 years of age), 116 class II fillings (metal matrix system, glass ionomer-cement-base in 36%, rubberdam isolation in 70%) were placed, with at least two restorations per patient. The adhesive Optibond Solo Plus was used for all the restorations. In one of the two fillings in each patient, an additional layer of the flowable composi…
Effect of self-etching primer/adhesive and conventional bonding on the shear bond strength in metallic and ceramic brackets
2011
Introduction: Bracket debonding from the tooth surface is a common problem in fixed orthodontics. The aims of the present study were to assess the bond strength and failure sites in two ways of bonding technique, with metallic and ceramic brackets. Material and Methods: One hundred premolars were assigned to 4 groups of 25 each: Group A, metallic brackets/ conventional procedure; Group B, metallic brackets/Transbond XT; Group C, ceramic brackets/conventional procedure; and Group D, ceramic brackets/Transbond XT. Transbond XT composite paste was used for bracket bonding and cured by conventional light-cure device. Specimens were subjected to thermocycling. One week after bonding shearing for…
How can droplet formation occur in endodontically treated teeth during bonding procedures?
2008
PURPOSE: The aim of this in vivo study was to clarify how blistering formation occurs along intraradicular dentin bonded interfaces. MATERIALS AND METHODS: Patients were selected and post space was prepared in vivo in endodontically treated teeth. Post space was etched, dried with ethanol, and bonded with one of the following adhesive systems: All Bond 2, XP-Bond, Clearfil SE Bond, Xeno III. The four adhesives were considered as representative of each bonding system class. An additional group was prepared with phosphoric acid treatment + application of Pre-Bond unfilled resin of All Bond 2, without the use of the primer agent. Etching was avoided for self-etching materials. Replicas of the …
Biomaterials in periapical regeneration after microsurgical endodontics: A narrative review
2021
Background: The objective of this narrative review was to analyze the available scientific evidence regarding the application of biomaterials in endodontic microsurgery and its influence in post-surgical tissue repair. Material and Methods: The review question was Do biomaterials used in endodontic microsurgery influence post-surgical tissue repair and regeneration? Systematic MEDLINE/PubMed review was used to evaluate and present the results. Results: The search yielded 131 references, 82 of which were selected for full text review after reading the abstracts. After a manual search in the references of the articles selected, 52 references were eliminated. Finally, 30 articles were selected…
Crystallized nano-sized alpha-tricalcium phosphate from amorphous calcium phosphate: microstructure, cementation and cell response
2015
New insight on the conversion of amorphous calcium phosphate (ACP) to nano-sized alpha tricalcium phosphate (α-TCP) provides a faster pathway to calcium phosphate bone cements. In this work, synthesized ACP powders were treated with either water or ethanol, dried, crystallized between 700 and 800 °C, and then cooled at different cooling rates. Particle size was measured in a scanning electron microscope, but crystallite size calculated by Rietveld analysis. Phase composition and bonding in the crystallized powder was assessed by x-ray diffraction and Fourier-transform infrared spectroscopy. Results showed that 50 nm sized α-TCP formed after crystallization of lyophilized powders. Water trea…