Marginal adaptation and fracture resistance of feldspathic and polymer-infiltrated ceramic network CAD/CAM endocrowns for maxillary premolars

OBJECTIVE

The aim of this study was to evaluate the marginal adaptation and fracture resistance of feldspathic and Polymer-Infiltrated Ceramic Network (PICN) CAD/CAM endocrowns for maxillary premolars.

MATERIALS AND METHODS

Twenty extracted human permanent maxillary premolars were randomly divided into two groups (n = 10); Group CEREC (GC), which was produced by feldspathic ceramic and the Group Enamic (GE), which was produced by PICN. All teeth were endodontically treated and decoronated horizontally at 2 mm above the cemento-enamel junction. Endocrown preparations were done with 4 mm depth into the pulp chamber. Endocrowns were manufactured using CAD/CAM from ceramic blocks. Following adhesive cementation, all specimens were subjected to thermocycling. Marginal adaptation evaluated under SEM at 200 × magnification. Each specimen was fixed in a universal testing machine and a compressive load was applied at 45° to long axis of the teeth until failure. Failure load was recorded and failure modes were evaluated. Statistical analyses were performed with SPSS 19.0 software and data were compared using Mann-Whitney U test.

RESULTS

There were no significant differences in the marginal adaptation between two groups (P > 0.05). GE presented significantly higher fracture resistance when compared to GC (P < 0.05). Failure pattern was similar and characterized by the tooth-ceramic fracture on the force-applied side.

CONCLUSIONS

CAD/CAM fabricated feldspathic ceramic and PICN endocrowns provide sufficient marginal adaptation, but the PICN endocrowns shows higher fracture resistance than the feldspathic ceramic endocrowns.

Endometrial Flushing Tumor Necrosis Factor Alpha and Interleukin 2 Levels in Women with Polycystic Ovary Syndrome, Leiomyoma and Endometrioma: Comparison with Healthy Controls

Introduction An important open question in the literature is whether endometrial receptivity marker levels are different in infertility related diseases than healthy women. The aim of the study is to compare the levels of interleukin two (IL-2) and tumor necrosis factor alpha (TNF-α) during the implantation window in the endometrial flushing fluid of polycystic ovary syndrome (PCOS), endometrioma, leiomyoma patients with healthy controls. Material and Methods In this case control study, after obtaining endometrial flushing fluids at mid-luteal phase of ovulatory women with PCOS (n = 20), endometrioma (n = 19), leiomyoma (n = 20) and healthy controls (n = 20), IL-2 and TNF-α levels were measured using ELISA kits in BioTek ELISA devices. Results Mean TNF-α levels (ng/mL) were similar for the PCOS (305.6, p = 0.220) and the leiomyoma group (246.3, p = 0.502) compared to healthy patients (261.1). However, the levels were higher in the endometrioma group (338.2, p = 0,004) than the control group (261.1) in a statistically significant way. Mean IL-2 levels (ng/mL) were significantly lower in the PCOS (290.9, p = 0.0005), the leiomyoma (282.9, p = 0.0002) and the endometrioma patients (229.5, p = 0.0009) than the control group (416.0). Conclusion Relative to the control group, endometrial flushing fluid TNF-α levels were significantly higher in endometrioma patients and IL-2 levels were significantly lower in PCOS, leiomyoma and endometrioma patients. In benign gynecological diseases, endometrial markers related to infertility seem to show differences in endometrial flushing fluid. Future studies might identify the reference values for these markers, and endometrial markers can be used to diagnose gynecologic disorders causing infertility.

The Protective Effects of Epigallocatechin Gallate Against Distant Organ Damage After Severe Skin Burns--Experimental Study Using a Rat Model of Thermal Trauma

BACKGROUND

Epigallocatechin gallate (EGCG), a green tea polyphenol, has potent antioxidant properties.

OBJECTIVES

The purpose of the present study was to examine the possible preventative effects of EGCG against internal organ injury due to large-surface skin burns in a rat model.

MATERIAL AND METHODS

The study design involved three groups of rats: a sham group and two groups with 25-30% full-thickness burns: (a) the sham group without burns or treatment (n=18); (b) the control burn group (burns+sterile saline, n=18); and (c) the burn treatment group (burns+treatment with EGCG, n=18). EGCG was administered intraperitoneally immediately after the thermal injury, and daily in 100 μmol/kg doses. Kidney and lung tissue samples were taken to determine the levels of malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), and glutathione peroxidase (GPX) after the first, third and seventh post-burn days.

RESULTS

In the EGCG-treated burn group, SOD and GPX activity were significantly higher than in the burn control group. Additionally, MDA and TNF-α levels were significantly lower in the EGCG-treated burn group.

CONCLUSIONS

Based on this study, it might be anticipated that EGCG treatment may be beneficial in burn injury cases.

Clinical biochemistry laboratory rejection rates due to various types of preanalytical errors

INTRODUCTION

Preanalytical errors, along the process from the beginning of test requests to the admissions of the specimens to the laboratory, cause the rejection of samples. The aim of this study was to better explain the reasons of rejected samples, regarding to their rates in certain test groups in our laboratory.

MATERIALS AND METHODS

This preliminary study was designed on the rejected samples in one-year period, based on the rates and types of inappropriateness. Test requests and blood samples of clinical chemistry, immunoassay, hematology, glycated hemoglobin, coagulation and erythrocyte sedimentation rate test units were evaluated. Types of inappropriateness were evaluated as follows: improperly labelled samples, hemolysed, clotted specimen, insufficient volume of specimen and total request errors.

RESULTS

A total of 5,183,582 test requests from 1,035,743 blood collection tubes were considered. The total rejection rate was 0.65 %. The rejection rate of coagulation group was significantly higher (2.28%) than the other test groups (P < 0.001) including insufficient volume of specimen error rate as 1.38%. Rejection rates of hemolysis, clotted specimen and insufficient volume of sample error were found to be 8%, 24% and 34%, respectively. Total request errors, particularly, for unintelligible requests were 32% of the total for inpatients.

CONCLUSIONS

The errors were especially attributable to unintelligible requests of inappropriate test requests, improperly labelled samples for inpatients and blood drawing errors especially due to insufficient volume of specimens in a coagulation test group. Further studies should be performed after corrective and preventive actions to detect a possible decrease in rejecting samples.

Effect of epigallocatechin gallate on ischemia-reperfusion injury: an experimental study in a rat epigastric island flap

Epigallocatechin gallate (EGCG), a polyphenol derived from green tea, is known to have potent antioxidant and anti-inflammatory properties. The aim of this study was to investigate the protective effects of EGCG against ischemia reperfusion injury in the epigastric artery island flap model in rats. The experiment was designed with two groups (control n=40, experiment n=40) of rats with epigastric artery island flaps. Each main group was randomly divided into five sub-groups to apply ischemia at different time intervals (0, 3, 6, 9 and 12 hours). Thirty minutes prior to reperfusion, 100 μmol/kg of EGCG was injected intraperitoneally, and this injection was repeated after 12 hours and continued as a daily injection. Similarly, 2 ml of sterile saline was administered to the rats in the control groups. Superoxide dismutase, glutathione peroxidase, malondialdehyde and tumor necrosis factor alpha levels, together with neutrophil counts, were measured in the tissues taken from the distal portions of the flaps 24 hours after reperfusion. Additionally, flap necrosis was examined on the seventh day after reperfusion. Superoxide dismutase levels were significantly lower in all control groups, and Malondialdehyde and Tumor Necrosis Factor Alpha levels were significantly higher in all control groups. Glutathione peroxidase levels were found to be significantly lower in the control groups after 0, 3, 9 and 12 hours of ischemia. There was no statistically significant difference between the groups undergoing 0, 3, 9 or 12 hours of ischemia with regard to the neutrophil count. Partial flap necrosis occurred in the 9-hour ischemia groups, and significantly lower rates of necrosis were observed in the experimental groups compared to the control groups. The findings of our study showed that EGCG has a protective effect against ischemia-reperfusion injury in skin flaps in the epigastric island flap model.