Search results for "Opera"
showing 10 items of 8665 documents
MTA apical barrier: In vitro study of the use of ultrasonic vibration
2016
Background: The apexification is the first alternative treatment on a permanent tooth when, after a tooth trauma and in the presence of immature apex trauma, pulp necrosis occurs. Many studies have demonstrated the efficacy of mineral trioxide aggregate (MTA) as apical sealing material of choice in these cases, but has a degree of filtration as all other materials. The objective of this study was to analyze the seal ability of MTA on the duct walls in immature teeth unirradicular apexes, using indirect vibration. Material and Methods: The study was conducted on 45 teeth divided into 3 groups: Group A or control group in which no vibration for placing the MTA was used, Group B and C or group…
Vertical root fracture resistance of simulated immature permanent teeth filled with MTA using different vehicles
2017
Background The aim of the study is to evaluate the resistance vertical root fracture (VRF) of mineral trioxide aggregate (MTA) filled-immature permanent roots by using three different vehicles. Material and Methods Forty-extracted human single-rooted mandibular premolars were selected and the root length was standardized to the length of 9 mm. For simulation of immature tooth apices, peeso reamers were introduced into the root canals and the prepared roots were assigned into three experimental groups according the used vehicle (distilled water-DW, prophylene glycol-PG, chlorhexidine-CHX) and control group (n=10). To simulate a periodontal membrane, the apical 7 mm of all roots was covered w…
Effect of Smear Clear and Some Other Commonly Used Irrigants on dislodgement resistance of Mineral Trioxide Aggregate to Root Dentin
2016
Background This study aimed to assess the push-out bond strength of mineral trioxide aggregate (MTA) to root canal dentin after irrigation with Smear Clear in comparison with 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) and saline as commonly used root canal irrigants. Material and Methods The coronal and mid-root areas of maxillary anterior teeth were horizontally sectioned into one-millimeter thick slices. The root canal lumen of dentinal slices was dilated using a diamond bur with 1.3 mm diameter. After the application of MTA, the samples were incubated in 100% humidity for 10 minutes and were then randomly divided into four groups (n=20) and immersed in Smear Clear, 2.5% NaO…
Relationship between internal root resorption and dens in dente
2020
Background The aim is to report the treatment and follow-up of three lateral incisors with internal root resorption and dens in dente as a possible cause for their development, managed by root canal treatment and apical obturation with MTA or gutta-percha. Case description This case report presents three clinical cases in which dens invaginatus type 2 is shown as a potential cause for the development of internal root resorption. Two cases were filled with a MTA apical plug technique and one with gutta-percha, and all were follow-up through time. Practical implications The incidence of the association of internal root resorption with dens invaginatus may be underestimated and should be studi…
Autologous dental pulp mesenchymal stem cells for inferior third molar post-extraction socket healing : a split-mouth randomised clinical trial
2018
Background Since the discovery of adult mesenchymal stem cells extensive research has been conducted to determine their mechanisms of differentiation and effectiveness in cell therapy and regenerative medicine. Material and Methods To assess the efficacy of autologous dental pulp mesenchymal stem cells delivered in a collagen matrix for post-extraction socket healing, a single-centre, double-blind, randomised, split-mouth, controlled clinical trial was performed. Both impacted mandibular third molars were extracted from 32 patients. Dental pulp was collected and dissociated; the resulting cell suspension, obtained by centrifugation, was incorporated into a resorbable collagen matrix and imp…
Danger zone analysis using cone beam computed tomography after apical enlargement with K3 and K3XF in a manikin model
2015
Background The objective of the study was to evaluate and compare how apical enlargement with K3 and K3XF nickel-titanium (NiTi) rotary instruments reduces the root thickness in the danger zone and affects canal transportation and centering ability in mandibular molar mesial canals in a manikin extracted tooth model. Material and Methods Seventy-two mesial root canals of first mandibular molars were instrumented. Initial and post-instrumentation Cone Beam Computed Tomography scans were performed after root canal preparation up to size 25, 30, 35 and 40 files. Canal transportation, canal centering and remaining root dentin thickness toward the danger zone were calculated in sections 1, 2 and…
Cheek-splitting technique for marginal mandibulectomy: A novel approach
2019
When performing marginal mandibulectomy, ensuring complete tumor removal and preventing postoperative iatrogenic mandibular fracture are essential. Pathological fracture can result due to stress concentration at the site requiring acute angle resection. To perform marginal mandibulectomy without making acute angles in patients with a lesion in the molar or more posterior region, a submandibular or transbuccal approach is necessary. Compared to the submandibular approach, the transbuccal approach is considered useful as it reduces operative time and prevents injury to the facial and mental nerves. Additionally, this approach does not leave a scar in the surgical field, which is beneficial in…
Transformation of Amorphous Polyphosphate Nanoparticles into Coacervate Complexes: An Approach for the Encapsulation of Mesenchymal Stem Cells.
2018
Inorganic polyphosphate [polyP] has proven to be a promising physiological biopolymer for potential use in regenerative medicine because of its morphogenetic activity and function as an extracellular energy-donating system. Amorphous Ca2+ -polyP nanoparticles [Ca-polyP-NPs] are characterized by a high zeta potential with -34 mV (at pH 7.4). This should contribute to the stability of suspensions of the spherical nanoparticles (radius 94 nm), but make them less biocompatible. The zeta potential decreases to near zero after exposure of the Ca-polyP-NPs to protein/peptide-containing serum or medium plus serum. Electron microscopy analysis reveals that the particles rapidly change into a coacerv…
Management of hepatitis C virus infection in patients with chronic kidney disease: position statement of the joint committee of Italian association f…
2018
Abstract Hepatitis C virus (HCV) infection is now considered a systemic disease due to the occurrence of extra-hepatic manifestations. Among these, the renal involvement is frequent. HCV infection, in fact, is strongly associated with proteinuria and chronic kidney disease (CKD) and negatively affects the prognosis of renal patients. In the last few years, availability of more specific and effective drugs against HCV has dramatically changed the clinical course of this disease. These drugs may provide further advantages in the CKD population as a whole by reducing progression of renal disease, mortality rate and by increasing the survival of graft in renal transplant recipients. The strict …
Evidence of the Red-Queen Hypothesis from Accelerated Rates of Evolution of Genes Involved in Biotic Interactions in Pneumocystis.
2018
Pneumocystis species are ascomycete fungi adapted to live inside the lungs of mammals. These ascomycetes show extensive stenoxenism, meaning that each species of Pneumocystis infects a single species of host. Here, we study the effect exerted by natural selection on gene evolution in the genomes of three Pneumocystis species. We show that genes involved in host interaction evolve under positive selection. In the first place, we found strong evidence of episodic diversifying selection in Major surface glycoproteins (Msg). These proteins are located on the surface of Pneumocystis and are used for host attachment and probably for immune system evasion. Consistent with their function as antigen…