Exploring fiberglass post numbers for enhanced fatigue resistance in molars without coronary remnants.

This study aimed to assess the fatigue resistance of molars lacking a coronary remnant, using zero, one, two, or three fiberglass posts. Forty caries/crack-free human molars with coronal portions removed at the pulp chamber floor were randomly allocated into four groups (n=10). Following endodontic treatment, posts (Whitepost DC/DC.

Fatigue behavior, failure mode, and stress distribution of occlusal veneers: influence of the prosthetic preparation cusp inclinations and the type of restorative material.

Objective: To evaluate the effects of cusp inclination of the prosthetic preparation's occlusal surface and type of restorative material on the fatigue behavior, failure mode, and stress distribution of occlusal veneers.

Materials And Methods: Glass fiber-reinforced epoxy resin prosthetic preparations for occlusal veneers with three different occlusal surface cusp inclination degrees (0°, 15°, and 30°) were produced and assigned into six testing groups (n = 11) according to the cusp inclination (0°, 15°, or 30°) and type of restorative material (lithium disilicate-LD or resin composite-RC). Despite different substrate preparation cusp inclination degrees, the restorations were designed maintaining 30° inclination between the cusps at the occlusal surface and a thickness of 0.

How does the occlusal contact region influence the mechanical fatigue performance and fracture region of monolithic lithium disilicate ceramic crowns?

Objective: To characterize the effect of the occlusal contact region on the mechanical fatigue performance and on the fracture region of monolithic lithium disilicate ceramic crowns.

Materials And Methods: Monolithic lithium disilicate ceramic crowns were machined in a CAD/CAM system and adhesively luted onto glass-fiber reinforced epoxy resin preparations with resin cement. The crowns were divided into three groups (n = 16) according to load application region (cusp tip: restricted to cusp tips; cusp plane: restricted to cuspal inclined plane; or mixed: associating tip cusp and cuspal inclined plane).

Endocrown restorations in premolars: influence of remaining axial walls of tooth structure and restorative materials on fatigue resistance.

Objectives: To evaluate the effect of the remaining tooth structure and different CAD/CAM materials on the fatigue performance and failure mode of endodontically treated premolars restored with endocrowns.

Materials And Methods: Ninety maxillary premolars were endodontically treated and assigned into 6 groups (n = 15) according to the number of remaining axial walls (four, three, and two) and restorative materials (ultra-translucent zirconia 5Y-PSZ [KATANA UTML] and lithium disilicate [IPS e.max-CAD]).

Ceramic surface conditioning, resin cement viscosity, and aging relationships affect the load-bearing capacity under fatigue of bonded glass-ceramics.

This study aimed to evaluate the influence of ceramic surface treatments, resin cement viscosities, and storage regimens on the fatigue performance of bonded glass-ceramics (lithium disilicate, LD; feldspathic, FEL). Ceramic discs (Ø = 10 mm; thickness = 1.5 mm) were allocated into eight groups per ceramic (n = 15), considering three factors: "ceramic surface treatment" in two levels - 5% hydrofluoric acid etching and silane-based coupling agent application (HF), or self-etching ceramic primer (E&P); "resin cement viscosity" in two levels - in high or low viscosity; and "storage regimen" in two levels - baseline, 24 h to 5 days; or aging, 180 days + 25,000 thermal cycles.

Weak adhesion between ceramic and resin cement impairs the load-bearing capacity under fatigue of lithium disilicate glass-ceramic crowns.

Objective: To evaluate the fatigue behavior of lithium disilicate crowns with a simplified anatomy against progressive cement/ceramic debonding scenarios.

Materials And Methods: Lithium disilicate crowns were fabricated via CAD/CAM and luted onto a dentin analogue material using resin cement following the manufacturer's instructions. Then, the different crown regions were isolated with paraffin oil for the absence of chemical adhesion according to four experimental groups (n = 15): Shoulder; Shoulder + Axial; Fully isolated; and Control (no insulation/fully bonded).

Adhesive application after ceramic surface treatment is detrimental to load-bearing capacity under fatigue of a lithium disilicate glass-ceramic.

Objective: To evaluate whether an adhesive application after surface treatment on a lithium disilicate ceramic (LD) has an influence on its load-bearing capacity under fatigue.

Methods: LD discs (Ø= 10 mm; thickness= 1 mm) were allocated into 8 groups (n= 15), considering 3 factors: "ceramic surface treatment" - HF: hydrofluoric acid + universal primer application; or MEP: single-component ceramic primer; "adhesive application" - with or without; and "aging protocol" - baseline: 24 h to 7 days; or aging: 180 days of storage + 25,000 thermal cycles. The LD discs were adhesively bonded to glass fiber-reinforced epoxy resin discs (Ø= 10 mm; thickness= 2 mm) and stored according to the condition and each group.

Effects of material and piston diameter on the fatigue behavior, failure mode, and stress distribution of feldspathic ceramic simplified restorations.

This study evaluated the influence of the piston material (glass fiber-reinforced epoxy resin or stainless steel) and the piston tip diameter (6 or 40 mm) on the fatigue mechanical behavior, failure mode, and stress distribution of feldspathic ceramic simplified restorations. Pistons were machined in glass fiber-reinforced epoxy resin (ER) and in stainless steel (SS), with active tips simulating the curvature radius of 6- or 40-mm diameter spheres. A total of sixty (N= 60) feldspathic ceramic discs (Ø= 10 mm; thickness= 1.

Cyclic fatigue tests on non-anatomic specimens of dental ceramic materials: A scoping review.

The aim of the present scoping review was to identify and discuss the methods, testing parameters, and characteristics used to induce cyclic fatigue on non-anatomic dental ceramic specimens. In vitro studies written in English which evaluated commercially-available non-anatomic dental ceramic specimens subjected to mechanical cyclic fatigue were selected. The search was performed in the PubMed, Scopus and Web of Science databases.

Accelerated loading frequency does not influence the fatigue behavior of polymer infiltrated ceramic network or lithium disilicate glass-ceramic restorations.

This study aimed to evaluate the influence of loading frequency on the fatigue mechanical behavior of adhesively cemented polymer-infiltrated ceramic-network (PICN) and lithium disilicate (LD) simplified monolithic restorations. Thirty (30) disc-shaped specimens (Ø = 10 mm; thickness = 1.0 mm) of each ceramic material (PICN - Enamic, Vita Zahnfabrik or LD - IPS e.

Mediastinum Teratoma Rupture: A Rare Manifestation.

Unlabelled: We present the case of a 22-year-old man who presented with cough, haemoptysis and fever of 3 days' duration. A teratoma had been diagnosed 2 years previously. Physical examination was unremarkable but laboratory tests showed anaemia, neutrophilic leucocytosis and an increase in C-reactive protein.

Estimation of Tumor Size Evolution Using Particle Filters.

Cancer is characterized by the uncontrolled growth of cells with the ability of invading local organs and/or tissues and of spreading to other sites. Several kinds of mathematical models have been proposed in the literature, involving different levels of refinement, for the evolution of tumors and their interactions with chemotherapy drugs. In this article, we present the solution of a state estimation problem for tumor size evolution.

[Pulmonary Artery Sarcoma - diagnostic and treatment difficulties].

Primary Pulmonary Artery Sarcoma is a rare entity, which shares some clinical features with Thromboembolic Pulmonary Disease (TEPD), complicating differential diagnosis. The authors report a Clinical Case of a Primary Pulmonary Artery Sarcoma in a 59 years old man, admitted with a history of dyspnoea on exertion, chest pain and general symptoms. Chest X-ray, Computed Tomography Scan, Angiographies and Magnetic Resonance Imaging suggested TEPD.

[Malignant localized fibrous tumor of the pleura].

The authors report a case of a localized fibrous tumour of the pleura with huge proportions of 26 x 14 x 12 cm and 1.25 Kgr of weight, in a 56 year old female patient. The tumour occupied practically the inferior 2/3 of the right pulmonary field and had an unusual insertion in the diaphragmatic parietal pleura.

[Annuloaortic ectasia: report of a case].

The authors describe a case of a patient with annuloaortic ectasia (AAE) and severe aortic regurgitation. The diagnostic was made by angiography. He was submitted to a Bentall's procedure; replacement of the ascending aorta by a conduit and of aortic valve by a mechanical prosthesis with reimplantation of coronary arteries into the conduit.

[Infective endocarditis of pulmonary valve. Considerations apropos of a case associated with interventricular communication and aortic insufficiency ].

We report the case of a 23 year old patient in whom heart disease was detected in childhood. He began to have suddenly fever and symptoms of right side heart failure. There were signs of aortic regurgitation, a systodiastolic murmur in the left parasternal region and a diastolic murmur in the left 4th intercostal space.

[Isolated hypoplasia of the right ventricle--apropos of a case].

Objective: To report one case of a rare heart disease (Isolated Hypoplasia of the Right Ventricle) and discuss the methodology used to propose surgery with goal. Good follow up results.

Design: To report a case.