Assessment of Biomechanical Behavior of Endodontically Treated Premolar Teeth Restored with Novel Endocrown System

OBJECTIVE

Despite the increased popularity of endocrowns, there is no clear consensus considering their effectiveness to restore severely-destructed endodontically treated premolars. This study aimed to assess the biomechanical behavior of endodontically treated maxillary first premolars restored with a novel endocrown system compared to the conventional one.

MATERIALS AND METHODS

Twenty sound human maxillary first premolars were collected. After endodontic treatment, they were divided into 2 groups (n=10) according to the system used for endocrown fabrication. Group C (Control): conventional monolithic IPS e.max CAD endocrowns. Group P: novel bi-layered endocrowns (Pekkton ivory coping veneered with cemented IPS e.max CAD). All specimens were subjected to 10000 thermal cycles followed by 240000 dynamic load cycles. Surviving specimens were subjected to fracture resistance test followed by qualitative analysis using Stereomicroscopy and Scanning Electron Microscopy.

RESULTS

A significantly higher load was observed for Group P (1831.37 ± 240.69 N) than Group C (1433.47 ± 174.39 N) (p ⟨ 0.001). A statistically significant difference was observed considering the failure mode (p = 0.036), with more favorable fractures detected with Group P.

CONCLUSIONS

The tested novel endocrown system improved the biomechanical behavior of the tooth/ restoration complex in the restored endodontically treated maxillary first premolars.

CLINICAL SIGNIFICANCE

The tested novel endocrown system with a PEKK coping veneered with cemented IPS e.max CAD can be considered a promising option for restoration of severely-destructed endodontically treated premolar teeth. It can be considered as a conservative alternative option to the conventional treatment modalities.

Optimization of Brain Tumor MR Image Classification Accuracy Using Optimal Threshold, PCA and Training ANFIS with Different Repetitions

BACKGROUND

One of the leading causes of death is brain tumors. Accurate tumor classification leads to appropriate decision making and providing the most efficient treatment to the patients. This study aims to optimize brain tumor MR images classification accuracy using optimal threshold, PCA and training Adaptive Neuro Fuzzy Inference System (ANFIS) with different repetitions.

MATERIAL AND METHODS

The procedure used in this study consists of five steps: (1) T1, T2 weighted images collection, (2) tumor separation with different threshold levels, (3) feature extraction, (4) presence and absence of feature reduction applying principal component analysis (PCA) and (5) ANFIS classification with 0, 20 and 200 training repetitions.

RESULTS

ANFIS accuracy was 40%, 80% and 97% for all features and 97%, 98.5% and 100% for the 6 selected features by PCA in 0, 20 and 200 training repetitions, respectively.

CONCLUSION

The findings of the present study demonstrated that accuracy can be raised up to 100% by using an optimized threshold method, PCA and increasing training repetitions.

Ability of computed tomography to predict right heart strain on an echocardiogram in patients with acute pulmonary embolus

Patients with submassive pulmonary embolism (PE) resulting in right heart strain (RHS) have an increased risk of mortality compared to those with a preserved right ventricular function. This study aimed to investigate the predictive value of computed tomography pulmonary angiogram (CTPA) findings of right heart strain in patients with computed tomography (CT)-proven PE for the diagnosis of right heart strain by echocardiogram (ECHO). The institutional review board (IRB) approved retrospective chart review of the adult emergency department patients diagnosed with an acute PE between 2012 and 2016. A total of 128 patients diagnosed with RHS by CT who had received an ECHO during their hospitalization were included in the study. Descriptive statistics were run for the variables of interest. The majority of patients (101 patients) with reported findings of RHS on CT had similar findings on ECHO. In our cohort, a finding of enlarged right atrium (RA) on CT was 100% predictive of RHS diagnosis on ECHO, whereas having interventricular septal bowing alone on CT was the least predictive of RHS on subsequent ECHO (61%). The 2 remaining subgroups: right ventricle (RV) enlargement alone and RV enlargement with either interventricular septal bowing/hepatic vein blood reflux or both lies somewhere in between, with 80% of these patients showing strain on ECHO. We found that signs of RHS on CT are predictive of strain on an ECHO (78%) and RA enlargement in any combination was the most predictive finding of RHS on ECHO (100%). Future prospective randomized investigations are needed to confirm such findings.

Efficacy of Crocus sativus L. on reduction of cadmium-induced toxicity on spermatogenesis in adult rats

Cadmium is a toxic heavy metal element, which probably cause infertility by impairment in spermatogenesis. The present work aimed (i) to study the toxic effect of cadmium on spermatogenesis in rat, as well as (ii) the protective effect of Crocus sativus L. on cadmium-intoxicated rats. Cadmium chloride was administered intraperitoneally during 16 days at intervals of 48 h between subsequent treatments. Crocus sativus L. was pre-treated in both of control and cadmium-injected rats. Animals were sacrificed on day 17 after the first treatment. The left cauda epididymis was removed and immediately immersed into Hank's balanced salt solution for the evaluation of sperm count and viability, and left testis was fixed in 10% formalin for histological evaluation. Following contamination with cadmium, a decrease was observed in the number and viability of cauda epididymis sperm, which were increased by Crocus sativus L. pre-treatment (P < 0.05). In addition, cadmium decreased both cell proliferation and Johnsen Scores in the seminiferous tubules, which were reversed by Crocus sativus pre-treatment (P < 0.05). Furthermore, cadmium-induced decrease in the amount of free serum testosterone as well as an increase in lipid peroxidation activity in the testicular tissue was reversed by Crocus sativus L. (P < 0.05). These findings may support the concept that Crocus sativus L. can improve the cadmium toxicity on spermatogenesis.

Enteropathogenic e.coli sustains iodoacetamide-induced ulcerative colitis-like colitis in rats: modulation of IL-1β, IL-6, TNF-α, COX-2, and apoptosisi

Pathogenic or non-pathogenic bacteria from flora may play a key role in inflammatory bowel disease (IBD) pathogenesis. However, a specific infectious agent causing IBD has not been identified. This study assessed the impact of enteropathogenic E. coli (EPEC) on the modulation of IL-1beta, IL-6, TNF- alpha, COX-2, BAX and Bcl-2 expression, in sustaining inflammation of a rat colitis model. Two hundred male Sprague-Dawley rats (4 groups) were inoculated weekly or bi-weekly for 70 days, with 1 percent methylcellulose (MC), (b) 6 percent iodoacetamide (IA) in 1 percent MC, (c) 4x108 CFU of EPEC, and (d) IA+EPEC. After a month, treatment was stopped in half of the animals in each group. IL-1beta, IL-6, TNF-alpha, COX-2, BAX and Bcl-2 expression were measured in colonic mucosa scrapings. IL-1beta, IL-6, TNF-alpha, and COX-2 were significantly increased in colonic mucosa of the IA+EPEC group and to a lesser but significant level in the IA group compared to controls, or EPEC alone, both in continued and discontinued treatment groups. Additionally, the BAX/Bcl-2 ratio decreased, indicating less apoptosis in the IA+EPEC group which exhibited more necrosis. These effects increased with experiment duration. This work provides new arguments favouring the role of bacteria in IBD pathogenesis.

The safety and efficacy of desflurane

Desflurane is a new halogenated ether inhalational general anesthetic with low solubility in blood and body tissues. The aim of this study was to assess its anesthetic efficacy in elective surgical procedures, to evaluate its effect on patients' vital signs during maintenance and recovery and to detect the possible side effects (if any) on patients' liver and kidney functions. The study was carried out on thirty adult (ASA I and II) patients scheduled for different surgical procedures. All patients were premedicated with 0.1 mcg kg-1 oral midazolam and induced with 1 mcg kg-1 fentanyl followed by thiopentone sodium 4 mg kg-1 and atracurium 0.5 mg kg-1. The inspired concentration of desflurane was gradually increased until the required depth of anesthesia was reached. The results showed hemodynamic stability under desflurane. It has dose-dependent hypotensive effects with no arrhythmia. It potentiated atracurium, as the total dose needed to produce complete relaxation was 0.36 +/- 1.18 mg kg-1. There was no observable effect on both liver and kidney function given the small number of patients that were included in this study. In the post anesthetic period desflurane showed rapid recovery (3.81 +/- 4.076) and patients' recovery room stay was (17.22 +/- 1.079 min). No postoperative complications were detected.

No linkage to the 3 beta-HSD gene cluster in a kindred affected with 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase deficiency and early onset hepatic failure

We studied the segregation of the genes for 3 beta-hydroxy-C19/21-steroid dehydrogenase types I and II (3 beta-HSD I and II) in a consanguineous family affected with 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase (3 beta-OH-C27-SD) deficiency. The results show that the C27 and C19/21 steroid dehydrogenase activities are encoded by distinct genes that are not in genetic linkage. Further kindreds would assist in screening for linkage of 3 beta-OH-C27-SD to other members of the 3 beta-hydroxysteroid dehydrogenase gene family.

Role of endogenous prostaglandins in pregnancy termination by 15-methyl PGF2 alpha

Thirty pregnant women with foetal death in utero received 15-methyl PGF2 alpha to terminate their pregnancies. Two groups (15 cases each) matched for age, gravidity and age of pregnancy were studied. One group received indomethacin suppositories before and during the PG induction while the second group received the prostaglandin analogue therapy only. The group which received the prostaglandin biosynthesis inhibitor showed a longer induction-termination interval, more PG ampoules were used and the number of failed cases was higher. Thus, the Release of Endogenous prostaglandins seems to play a complementary role in the therapeutic termination of pregnancy.

Human tubal fluid collection via vagina and its quantitative variations during the menstrual cycle

The culdoscope was used for easy approach to the fallopian tube, which was delivered into the vagina, and a Foley catheter (No. 8 French) was introduced through its fimbrial end for collection of human tubal secretion. It was left from one to eight days. The technique was successful in 54 cases out of 60, but we succeeded in collecting enough fluid in 44 cases only. The volume of human tubal fluid was studied in relation to the phase of the cycle. A peak of fluid volume was found to occur at the midcycle.