Lithium Disilicate Ceramic Endocrown Biomechanical Response According to Different Pulp Chamber Extension Angles and Filling Materials

The purpose of this study is to evaluate the effect of pulp chamber extension angles and filling material mechanical properties on the biomechanical response of a ceramic endocrown. A 3D model of maxillary molar that underwent endodontically treatment was exported to computer aided design software to conduct finite element analysis (FEA). The endocrown model was modified considering different pulp chamber extension angles (right angle; 6°, 12° and 18° of axial divergence). The solids were imported into the computer aided engineering software in Standard for the Exchange of Product Data (STEP) format. Nine different filling materials were simulated to seal the orifice of the root canal system under each endocrown restoration (resin composite, bulk-fill resin composite, alkasite, flowable resin composite, glass ionomer cement, autocured resin-reinforced glass ionomer cement, resin cement, bulk-fill flowable resin composite, zinc oxide cement), totaling 36 models. An axial load (300 N) was applied at the occlusal surface. Results were determined by colorimetric graphs of von-Misses stress (VMS) and Maximum Principal Stress (MPS) on tooth, cement layer, and endocrown restorations. VMS distribution showed a similar pattern between the models, with more stress at the load region for the right-angled endocrowns. The MPS showed that the endocrown intaglio surface and cement layer showed different mechanical responses with different filing materials and pulp chamber angles. The stress peaks plotted in the dispersion plot showed that the filling material stiffness is proportional to the stress magnitude in the endocrown, cement layer and tooth adhesive surface. In addition, the higher the pulp chamber preparation angle, the higher the stress peak in the restoration and tooth, and the lower the stress in the cement layer. Therefore, 6° and 12° pulp chamber angles showed more promising balance between the stresses of the adhesive interface structures. Under the conditions of this study, rigid filling materials were avoided to seal the orifice of root canal system when an endocrown restoration was planned as rehabilitation. In addition, the pulp chamber axial walls were prepared between 6° and 12° of divergence to balance the stress magnitude in the adhesive interface for this treatment modality.     

Liver cirrhosis mortality in Mexico. I. Relevant epidemiological characteristics]

Previous studies have emphasized the impact of alcoholism on public health, especially on the incidence of liver cirrhosis, which ranks among one of the main causes of death in Mexico. Accordingly, the epidemiologic features of liver cirrhosis mortality (LCM) are examined, highlighting its historical trends, its geographical distribution and other risk factors like age and sex. The data show a consistently high LCM rate over time, male rates moving slightly up and female rates down. Proportional mortality has been increasing. The significant risk increment with age has determined LCM to be the leading cause of death for both sexes in the 30-64 years age group. A particularly interesting finding relates to the continuous excess of LCM seen in Mexico City and four surrounding states; on the contrary, in the northern states, LCM is considerably low. This difference is valid for women too. Comparing all states, a gradient of LCM rates from high to low mortality areas is observed. The social and health implications of LCM regional distribution demand the conduction of epidemiological studies to identify possible explanatory variables related to the pattern of alcohol consumption or other risk factors. Nonetheless, these data alone justify the implementation of an effective action plan in the high-risk areas to deal with this health problem, inherently associated with individual and social behaviors.     

Pristanic Acid Provokes Lipid,Protein, and DNA Oxidative Damage and Reduces the Antioxidant Defenses in Cerebellum of Young Rats

Zellweger syndrome (ZS) and some peroxisomal diseases are severe inherited disorders mainly characterized by neurological symptoms and cerebellum abnormalities, whose pathogenesis is poorly understood. Biochemically, these diseases are mainly characterized by accumulation of pristanic acid (Prist) and other fatty acids in the brain and other tissues. In this work, we evaluated the in vitro influence of Prist on redox homeostasis by measuring lipid, protein, and DNA damage, as well as the antioxidant defenses and the activities of aconitase and α-ketoglutarate dehydrogenase in cerebellum of 30-day-old rats. The effect of Prist on DNA damage was also evaluated in blood of these animals. Some parameters were also evaluated in cerebellum from neonatal rats and in cerebellum neuronal cultures. Prist significantly increased malondialdehyde (MDA) levels and carbonyl formation and reduced sulfhydryl content and glutathione (GSH) concentrations in cerebellum of young rats. It also caused DNA strand damage in cerebellum and induced a high micronuclei frequency in blood. On the other hand, this fatty acid significantly reduced α-ketoglutarate dehydrogenase and aconitase activities in rat cerebellum. We also verified that Prist-induced increase of MDA levels was totally prevented by melatonin and attenuated by α-tocopherol but not by the nitric oxide synthase inhibitor N^ω-nitro-l-arginine methyl ester, indicating the involvement of reactive oxygen species in this effect. Cerebellum from neonate rats also showed marked alterations of redox homeostasis, including an increase of MDA levels and a decrease of sulfhydryl content and GSH concentrations elicited by Prist. Finally, Prist provoked an increase of dichlorofluorescein (DCFH) oxidation in cerebellum-cultivated neurons. Our present data indicate that Prist compromises redox homeostasis in rat cerebellum and blood and inhibits critical enzymes of the citric acid cycle that are susceptible to free radical attack. The present findings may contribute to clarify the pathogenesis of the cerebellar alterations observed in patients affected by ZS and some peroxisomal disorders in which Prist is accumulated.     

The effects of exergames on anxiety levels: A systematic review and meta-analysis

There are currently many different approaches to performing exergames and there is still no consensus as to whether exergames are able to reduce anxiety levels, as well as whether exergames provide greater reductions on anxiety levels when added to traditional forms of clinical interventions. Therefore, the aim of the present systematic review and meta-analysis was to access data from studies that evaluated the effects of exergames on anxiety levels in humans. PubMed, Scopus and Cochrane databases were searched up to 22 February 2019. Inclusion criteria were acute and chronic (short-term and long-term interventions) studies which evaluated the effects of exergames in anxiety levels as primary or secondary aim. Of the 1342 studies found, 17 and 10 were included in qualitative analyses and meta-analyses, respectively. The within-group analysis found that exergames (standardized mean difference [SMD]: −0.57 [95% Confidence interval (CI): −0.86 to −0.28], P < .001) and usual care (SMD: −0.21 [95% CI: −0.34 to −0.08], P = .002) resulted in significant improvements on anxiety levels. However, the between-group meta-analysis on the effects of control interventions vs exergames (SMD: 0.02 [95% CI: −0.55 to 0.60], P = .939) found no significant difference between groups in anxiety levels reductions. There was also no significant difference (SMD: −0.04 [95% CI: −0.32 to 0.25], P = .805) between usual care vs exergames plus usual care interventions in anxiety levels reductions. Although exergames demonstrated within-group improvements in anxiety levels across different clinical populations, it was not greater than the effects from non-exercise interventions. Also, given the paucity of studies, small sample sizes, different research designs, and different population investigated, the existing evidence is insufficient to support the advantages of usual care supplemented by exergame intervention over usual care standalone in anxiety levels reduction.     

Ultrasound salivary gland involvement in Sjogren’s syndrome vs. other connective tissue diseases: is it autoantibody and gland dependent?

Clinical Rheumatology - This study aims to investigate ultrasound (US) findings on salivary glands (SG) in patients with Sjögren syndrome (SS) vs. other connective tissue diseases (CTDs) and...     

10-Year Follow-up of Calcifying Odontogenic Cyst in the Periapical Region of Vital Maxillary Central Incisor

Introduction

Radiographic images may lead to misinterpretations of lesions of endodontic and nonendodontic origin. This report describes a case of a 10-year follow-up of a calcifying odontogenic cyst (COC) in the periapical region of a vital maxillary central incisor in a 9-year-old boy.

Methods

The patient revealed a history of a swelling in the periapical area of tooth #9. The patient denied any dental trauma or history of pain. Clinical examination revealed no mobility, but there was discrete discomfort when horizontal pressure was applied. Pulp vitality was present in all maxillary anterior teeth. Radiographs revealed an oval radiolucent lesion in the periapical region of maxillary central incisor. The therapeutic option was enucleation of the periapical lesion and histologic examination of the specimen. Microscopic findings suggested the diagnosis of a COC.

Results

At a follow-up visit 10 years after surgery, panoramic and periapical radiographs showed new bone formation; the patient did not have any pain, and pulp vitality was maintained in all teeth in this area.

Conclusions

A COC should be part of the differential diagnosis of other jaw lesions, such as apical periodontitis. The definitive diagnosis of a COC can only be made after microscopic evaluation of the specimen. The follow-up is a helpful reference because it confirms the survival of pulp tissue and no recurrence of the COC.     

Prevalence of oral anticoagulation in atrial fibrillation

OBJECTIVES:

Atrial fibrillation is the most common sustained arrhythmia and is associated with poor outcomes, including stroke. The ability of anticoagulation therapy to reduce the risk of stroke has been well established; however, the prevalence of anticoagulation therapy use in the Public Health System is unknown. The aim of this study is to evaluate both the prevalence of anticoagulation therapy among patients with atrial fibrillation and the indications for the treatment.

METHODS:

In this cross-sectional study, we included consecutive patients who had atrial fibrillation documented by an electrocardiogram performed between September 2011 and March 2012 at a university hospital of the Public Health System. The variables analyzed included the risk of a thromboembolic event and/or bleeding, the use of antiplatelet or anticoagulation therapy, the location where the electrocardiogram report was initially reviewed and the specialty of the physician who initially reviewed it.

RESULTS:

We included 162 patients (mean age 68.9 years, 56% men). Hypertension (90.1%), heart failure (53.4%) and stroke (38.9%) were the most prevalent diseases found. Only 50.6% of the patients knew that they had atrial fibrillation. Regarding the use of therapy, only 37.6% of patients classified as high risk according to the CHADS2 scores and 35.5% according to the CHA2DS2VASc used oral anticoagulation. A presumptive diagnosis of heart failure and the fact that the electrocardiogram was evaluated by a cardiologist were the only independent predictors of the use of anticoagulants.

CONCLUSIONS:

Our study found a low prevalence of oral anticoagulation therapy among patients with atrial fibrillation and an indication for stroke prophylaxis for the use of this therapy, including among those with high CHADS2 and CHA2DS2VASc scores.