Ahmed Zaher

Influence of selective immunosuppressive drugs on the healing of exposed dogs' dental pulp capped with mineral trioxide aggregate.

INTRODUCTION Immunosuppressive drugs are used in clinical medicine for a variety of disorders, but their effects on the reparative capacity of the dental pulp are unknown. This study evaluated the influence of selected immunosuppressive drugs on pulpal tissue healing after direct pulp capping of mechanically exposed dogs teeth with mineral trioxide aggregate (MTA). METHODS Ten healthy male dogs were assigned into 5 experimental groups: a control group in which no drug was received and 4 experimental groups in which the immunosuppressive drugs prednisone, mycophenolate mofetil, sirolimus, and cyclosporine A were administered 45 days before the operative procedures and until the dogs were killed. Class V cavities were prepared on the buccal surfaces of 12 teeth in each dog. In each cavity, the pulp was exposed and capped with MTA. The pulpal tissue responses to capping material were assessed 65 days postoperatively. RESULTS Compared with the control group, variable responses was recorded in the groups treated with mycophenolate mofetil, sirolimus, and cyclosporine A, which were characterized by moderate to severe inflammatory reactions, tissue necrosis, and total absence of hard tissue bridging. Pulpal tissue responses in the group treated with prednisone were characterized by inflammatory cell infiltration, limited tissue necrosis, as well as partial to complete hard tissue bridging. CONCLUSIONS From these findings, it seemed evident that acceptable repair of the dentin-pulp complex, eg, wound healing with hard tissue formation after capping with MTA, is unlikely with mycophenolate mofetil, sirolimus, or cyclosporine A immunosuppressive drug therapy.

Juvenile nasopharyngeal angiofibroma with intracranial extension: Analysis of 23 Egyptian patients

The purpose of this study was to present our experience with definitive surgical management of patients with Juvenile nasopharyngeal angiofibroma with intracranial extension. The study included 23 male adolescents with histologically proven juvenile nasopharyngeal angiofibroma. The mean age was 14.7 years (12-20 years). CT, MRI+/-angiographies were for taken for the patients. Preoperative embolization was done with gel foam before the operation. Two surgical procedures were used; anterior subcranial transfacial transmaxillary approach (21 patients), while craniofacial resection was used in two patients. Middle cranial fossa was affected in 22 patients while anterior cranial fossa was affected in only one patient. Complete resection of the tumor was achieved in 19 patients with residual or recurrence in four patients. Complications of the surgical approaches were reported in 14 patients. The subcranial transfacial transmaxillary approach avoids the complications of craniotomy and provides adequate access for excision of Juvenile nasopharyngeal angiofibroma with intracranial extradural extension.

Vasculitis of Dental Pulp Associated with Cryoglobulinemia in Hepatitis C Virus Patients: Case Report

INTRODUCTION This report presents a case of impacted lower third molar extracted for surgical reasons in patient with uncontrolled hepatitis C. After decalcification, dental pulp vasculature and its tissue quality were investigated. METHODS Serial sections of 4-μm thickness along the midline buccolingually for the demineralized specimen were obtained, mounted on a glass slide, stained with hematoxylin-eosin, covered, and viewed under the light microscope. RESULTS The histologic investigation of the pulp tissue revealed thickening, stenosis, and occlusion of the vessel wall, ectopic calcification of the pulp tissue in close association with pulpal blood vessels, interrupted and vacuolated odontoblastic layer in the coronal pulp chamber, with an inflammatory cell infiltrate throughout the pulpal tissue. CONCLUSIONS Cryoglobulinemia associated with uncontrolled hepatitis C virus infection in patients endangers the dental pulp vasculature and alters its normal tissue architecture.

Altered coronal tissue of the human dental pulp in chronic hepatitis C virus infected patients.

INTRODUCTION Hepatitis C virus (HCV) infection is characterized by a high rate of chronicity and concerns 170 million individuals worldwide. Extrahepatic manifestations are frequently observed in patients with chronic viral hepatitis. Although extrahepatic manifestations do exist with all hepatitis viruses, they are more commonly associated with chronic HCV infection. This study aimed to evaluate qualitatively and quantitatively the effect of chronic HCV infection on the coronal tissue of the human dental pulp. METHODS Thirty sound impacted teeth were obtained from healthy individuals as healthy controls. The patient group included another 30 sound impacted teeth obtained from chronic HCV-infected patients. The coronal pulp tissues were carefully removed, fixed, and processed to be stained with hematoxylin-eosin, alcian blue (2.5)/periodic acid-Schiff, van Gieson, and fibronectin. RESULTS The tissue sections of chronic HCV patients revealed disorganized pulp tissue, chronic inflammatory cell infiltrate, thickening, stenosis and occlusion of large-sized blood vessel arteriole, and collapsed venule and lymphatic system. The acidic, neutral, and mixed mucins were increased, whereas the amount of collagen was decreased, accompanied with marked decrease in the distribution and quantity of fibronectin glycoprotein. Application of Kruskal-Wallis test showed that there were statistically significant changes between the 2 groups (P ≤ .05). CONCLUSIONS The coronal tissue of the dental pulp, like any other body tissues, is affected by chronic HCV infection, with an inappropriate cellularity, vasculature, and extracellular matrix proteins. The clinician should be alerted to these histologic changes and their subsequent implications.

Efficacy of Human Platelet Rich Fibrin Exudate vs Fetal Bovine Serum on Proliferation and Differentiation of Dental Pulp Stem Cells

Background and Objectives The imperative role of dental pulp stem cells (DPSCs) in regenerative therapy demands an in-vitro expansion which must deal with the safety and ethical problems associated with fetal bovine serum (FBS). The primary aim of this study was to compare the effects of human platelet rich fibrin (hPRF) exudate Vs FBS on proliferation and osteodifferentiation of human dental pulp stem cells (hDPSCs). The secondary one was to determine the optimum concentration of hPRF exudate inducing hDPSCs proliferation and osteodifferentiation. Methods The direct method was used to prepare hPRF exudate. hDPSCs were isolated from impacted mandibular third molars of twelve donors by the outgrowth method. For cell viability and proliferation rate testing, 96 well plates were used and the assay was done in duplicate and the trial repeated four times under the same conditions. Six wells were used to contain 10% FBS, serum free media, 1%, 5%, 10% and 20% concentrations of hPRF exudates, respectively. The proliferation assay was carried out by MTS tetrazolium cell proliferation assay kit and Elisa reader. The study design for osteodifferentiation protocol was exactly as the proliferation one and instead the assay was carried out by alizarin red with Elisa reader. Results Compared to 10% FBS, 10% hPRF exudate was the optimum concentration for hDPSCs proliferation, while 1% hPRF exudate was the optimum concentration for osteodifferentiation of hDPSCs. Conclusions Avoiding the risk of zoonosis which may be occurred with FBS, it is recommended to use 10% hPRF exudate for proliferation and 1% for osteodifferentiation.

The Effect of Different Routes of Injection of Bone Marrow Mesenchymal Stem Cells on Parotid Glands of Rats Receiving Cisplatin: A Comparative Study

Background and Objectives Cisplatin is a powerful antitumor chemotherapeutic agent that is widely used in the treatment of many cancers but it has many side effects on many organs including salivary glands. Bone marrow is considered to be a rich environment that comprises many types of stem cells of which BMSCs (Bone marrow mesenchymal stem cells) are the most studied with potentiality to differentiate into many cell types. This study was conducted to evaluate the effect of different routes of injection of BMSCs on parotid glands of rats receiving cisplatin. Methods and Results Sprague-Dawley rats were divided into 3 groups: a negative control group receiving phosphate buffered saline, a positive control group receiving cisplatin, and an experimental group where rats received cisplatin and then received iron oxide-labeled BMSCs by either intravenous or intraparotid routes or both. Animals were sacrificed at periods of 3,6,10 and 15 days after cisplatin injection, then histological, ultrastructural and immunohistochemical studies were done. The experimental stem cell treated group showed better histological features and increased PCNA proliferation index when compared to the control. The systemic and combination groups showed better results than the local group. Iron oxide-labeled cells were detected with Prussian blue stain. Conclusions This study proved that BMSCs can improve cisplatin induced cytotoxicity in parotid glands. Systemic administration showed to have a better effect than local intraparotid administration and comparable effect to combined administration.