Search results for "PULP"

Chemical characterization and ultrastructure study of pulp fibers

2020

Abstract Understanding the ultrastructure and chemical characterization of pulp fibers is highly important in utilizing wood as a raw material in a wide scope of applications, such as forest biomass-based biorefineries and low-cost renewable materials. The observation of the ultrastructure is not possible without advanced microscopy and spectroscopy techniques. Therefore, this study focuses on exploring the ultrastructure of pulp fibers with helium ion microscopy (HIM) and scanning electron microscopy (SEM). For the analysis of chemical characterization in the pulp fibers, Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) were pe…

Microhardness of different resin cement shades inside the root canal

2012

Objectives: To compare microhardness along the root canal post space of two resin cements in different shades and a dual-cure resin core material. Study Design: Root canals of 21 bovine incisors were prepared for post space. Translucent posts (X•Post, Dentsply DeTrey) were luted using one the following resin luting agent: Calibra (Dentsply DeTrey) in Translucent, Medium and Opaque shades, RelyX Unicem (3M ESPE) in Translucent, A2 and A3 shades and the dual-cure resin core material Core•X flow. All materials were applied according to manufacturers’ instructions and were all photopolymerized (Bluephase LED unit, Ivoclar Vivadent, 40s). After 24 hours, roots were transversally cut into 9 slice…

Valorisation of urban green areas for producing renewable energy and biochar as growing substrate of Sicilian aromatic and nutraceutical species in a…

2020

This work is aimed at evaluating the possible building up of a gasifier for the energy valorisation of residual biomass deriving from urban areas and their surroundings. The area and the volumes of supply and economic convenience have been determined by implementing a GIS-based geographic method to the localisation and quantification of non-uniform elements of plant biomass. The pyrolysis and gasification processes of the lignocellulosic biomass obtained from pruning and maintenance operations of the urban and ornamental green include the production of a residual amount of biochar. The biochar can be used in agriculture as a soil improver and a substrate alternative to peat in the sustainab…

Influence of pulp bleaching and compatibilizer selection on performance of pulp fiber reinforced PLA biocomposites

2019

From Wood and Hemp Biomass Wastes to Sustainable Nanocellulose Foams

2021

Abstract Transition to the circular economy requires the implementation of recycling and reuse routes for waste products. This research addresses one of the leading emerging areas, i.e., the development of sustainable materials and natural waste processing, namely wood and hemp byproducts. The cellulosic nanomaterials derived from these under-utilized waste residues and byproducts also serve as promising natural precursors for advanced applications, e.g., biomedical, pollution filtering, and thermal insulation. The wood and hemp fibrils were prepared by microfluidic processing of 0.2 – 1.0 wt% cellulose water suspensions. After freeze-drying, the resulting foam materials were characterized …

Roentgenographic in vitro investigation of frequency and location of curvatures in human maxillary premolars.

2006

The aim of this study was to determine the location of the root canal curvature and measure the distance from the CEJ to the first curvature using in vitro methods. Extracted maxillary premolars (n = 358) were fixed and digitally radiographed using the parallel technique. Excluded from further analysis were teeth with root caries, artificial crowns, extensive fillings, or endodontic treatments. The results were descriptively analyzed and the cumulative frequencies were calculated. The median values of the distance between CEJ and first curvature were for the first right premolars 8.4 mm (buccal) and 8.5 mm (palatal), for the first left premolars 9.1 mm (buccal) and 8.9 mm (palatal). The med…

Considerations on factors affecting biochar densification behavior based on a multiparameter model

2021

The optimization of upscaled biochar pelleting is limited by lack of knowledge regarding the effects of process parameters. A multiparameter model, coupled to a single pellet press unit, was for the first time applied to biochar production to predict the upscaled biochar pelleting process behavior. The model permits to estimate in a time and cost-effective way how the die friction forces, quantified through the pellet exiting pressure, are affected by the key process parameters. It was observed that to achieve acceptably low exiting pressures (in the order of 100 MPa), it was critical to produce biochar at high temperatures (e.g. 600 °C). Addition of water as a binder is also beneficial, wh…

On the use of EMI for the assessment of dental implant stability

2014

The achievement and the maintenance of dental implant stability are prerequisites for the long-term success of the osseointegration process. Since implant stability occurs at different stages, it is clinically required to monitor an implant over time, i.e. between the surgery and the placement of the artificial tooth. In this framework, non-invasive tests able to assess the degree of osseointegration are necessary. In this paper, the electromechanical impedance (EMI) method is proposed to monitor the stability of dental implants. A 3D finite element model of a piezoceramic transducer (PZT) bonded to a dental implant placed into the bone was created, considering the presence of a bone- impla…

A case of unusual anatomy: a maxillary lateral incisor with three canals.

1999

Case report A case of an unusual maxillary lateral incisor with three root canals is presented. The patient presented with localized swelling and a sinus tract. Because of its abnormal anatomical configuration, the tooth presented diagnostic and procedural difficulties. Conventional root canal treatment was performed successfully.

Endodontic management of type II dens invaginatus with open apex and large periradicular lesion using the XP-endo Finisher : a case report

2018

Dens invaginatus (DI) represents an endodontic challenge because of its complex root canal morphology. This case report presents the clinical management of a 22-year-old woman with type II DI in right maxillary lateral incisor with a painful swelling. Pulp testing revealed no response with the tooth. Type II DI with open apex and large periradicular lesion was seen on radiograph. The treatment was planned by using cone-beam computed tomography (CBCT) imaging. Canal treatment was completed in two appointments with the aid of a dental operating microscope. In the first appointment, the internal anatomy was modified using an ultrasonic tip, and chemo-mechanical preparation was performed using …