Abstract:

Aim of the study: The purpose of current study was to evaluate and compare the effect of different connector designs on the 

compressive strength of posterior inlay-retained fixed dental prostheses made from two different ceramic systems.

Materials and Methods: Twenty-eight inlay retained fixed partial denture (IRFPDs) were used to replace missing lower right first 

molar. According to the IRFPDs material (lithium disilicate ceramic and Zirconia), the specimens were divided into two main groups A 

and B (n=14). These groups were further subdivided into 2 sub-groups 1&2 (n=7) according to the connector designs used (round and 

sharp). The IRFPDs were manufactured using the hot press and CAD-CAM techniques respectively. All specimens were cemented using 

self-adhesive resin cement. Each specimen was placed on the test device, and compressive force was applied till the failure occurred. All 

the results obtained were statistically analyzed by two way ANOVA test and student t test (level of significance p < 0.05). 

Results: Revealed that the highest mean value of compressive strength was for round connector with zirconia IRFPDs. While the lowest 

value was for sharp connector with lithium disilicate IRFPDs.

Conclusions: Within the limitations of this in-Vitro study the following conclusion could be obtained; zirconia demonstrated high 

compressive strength than lithium disilicate. Despite the lithium disilicate possessed the lowest compressive strength values for both 

types of connector design. However these values were greater than the average occlusal force recorded in several studies.

Keywords: IRFPDs, Connector design, Fixed prosthesis, CAD/CAM, Zircoina, Lithium disilicate, Compressive strength.

 Interleukin-10 (IL-10) is an anti-inflammatory cytokine that has been shown to play a role in inflammatory and autoimmune disorders as well as in neuropathic pain conditions.

The objective of the present study was to assess the levels of IL-10 in rat’s dorsal root ganglion (DRG) and the sciatic nerve following four different forms of sciatic nerve injury. The models used to induce the injury included two models of partial nerve injury: partial sciatic ligation (PSL) and chronic constriction injury (CCI), a model of complete sciatic transection (CST) and a model of perineural inflammation with minimal nerve damage (neuritis). Withdrawal responses for mechanical stimulus and withdrawal latency for thermal stimulation were used to measure mechanical and thermal hyperalgesia, respectively, and duration of the nociceptive withdrawal reflex to mechanical stimulus was used to measure mechanical hyperalgesia.

The affected and contra-lateral nerves and the affected side DRG IL-10 levels were assessed by the means of enzyme-linked immunosorbent assay (ELISA), 3 and 8 days following the procedure and were compared to naïve rats’ IL-10 levels.

The rats exposed to CCI and neuritis developed significant mechanical and thermal hyperalgesia as well as mechanical hyperalgesia 3 and 8 days following the surgical procedure. Rats exposed to CST did not respond to mechanical stimulation and developed thermal hypoalgesia 3 and 8 days after the surgery.

The DRG IL-10 levels were significantly reduced 3 and 8 days following CCI and PSL, significantly increased 3 and 8 days following CST, and remained unchanged following neuritis.

The sciatic nerve IL-10 levels reduced significantly in both injured and contra-lateral nerves 3 and 8 days following CCI and PSL, elevated significantly in the injured but not in the contra-lateral nerve 3 and 8 days following CST and remained unchanged following neuritis. The results of this study suggest that IL-10’s role in the neuropathic pain etiology may be specific to nerve injury type.

Complete nerve transection increases while partial nerve injury reduces IL-10 levels in the involved nerve, and DRG. Perineural inflammation with minimal nerve damage has no effect on IL-10 levels.

ABSTRACT Introduction: Salivary gland tumors (SGTs) may represent a considerable diagnostic challenge, primarily because of the complexity of the classification and the rarity of several entities. Since proliferative activity is a reliable method to assess tumor biology. There has been continuous research to find such biological markers. Ki-67 is a widely accepted proliferation marker, with its expression tightly associated with the cell cycle. It is implicated in many of human cancers as a prognostic factor. MCM-3, member of minichromosome maintenance proteins family, is upregulated in proliferating cells. MCM-3 overexpression in almost all human cancers implicates that it might facilitate the tumorigenesis by playing a role in the malignant transformation of cells. Objectives: to evaluate the MCM-3 protein expression in benign and malignant salivary gland tumors and compare the obtained results with the expression of Ki-67 proliferation antigen. Materials and methods: Immunohistochemical analysis of 20 cases of SGTs with 2 sections from each specimen (20 sections for antiKi67antibody and 20 sections for antiMCM3antibody) and 5 control cases. Immunohistochemical staining was performed using a Labeled StreptAvidin Biotin method (LSAB). Results: Normal salivary gland tissue showed negative immunoreactivity for both Ki-67 and MCM-3 in epithelial and myoepithelial cells. All the examined cases showed positive expression for both proliferative markers in benign and malignant SGTs, with different intensities. Conclusions: The proliferative markers Ki-67 and MCM-3 proteins are overexpressed in malignant salivary gland tumors, than benign ones. Both Ki-67 and MCM-3 may be reliably applied as diagnostic markers to distinguish benign from malignant salivary gland tumors. Keywords: Salivary gland tumor, Immunohistochemistry, MCM-3, KI-67.

Circulating microvesicles (cMVs) are the extracellular MVs released from the cells in the blood and on the vascular wall. Our previous study demonstrates that cMVs of diabetic mouse are detrimental to endothelial progenitor cells (EPCs), which are known to be very important for maintaining normal endothelial function and structure. In this study, we compared the levels of circulating EPCs and EPC-derived MVs (EPC-MVs) in diabetic and healthy subjects. Also, the migration ability, apoptosis rate and reactive oxygen species (ROS) production of EPCs cultured from diabetic and healthy subjects were determined. More importantly, we evaluated whether cMVs from healthy subjects (ch-MVs) improves the function of EPCs from diabetic patients (d-EPCs), and whether cMVs from diabetic patients (cd-MVs) impairs the function of EPCs from healthy subjects (h-EPCs). The d-EPCs or h-EPCs were incubated with ch-MVs or cd-MVs for 24 hours. The migration ability of EPCs was analyzed by an assay kit. The apoptotic rate and ROS production were analyzed by labeling with propidium iodide (PI) and dihydroethidium (DHE) respectively, followed with flow cytometeric analysis. Our data showed that (1) there was a decrease in EPCs iv and an elevation in EPC-MVs in diabetic patients when compared to healthy subjects; (2) The migration ability of d-EPCs were decreased, and the apoptosis rate and ROS production were increased in d-EPCs; (3) ch-MVs improve the function of d-EPC through improving its migration ability and decreasing the apoptosis and ROS production; (4) cd-MVs increase h-EPC apoptosis, and increase ROS production. We conclude that cMVs modulate EPC function and this role of cMVs is reversed in diabetes with the mechanism linked to ROS production.