Introduction: The study's purpose was to compare the maxillary All-on-four, All-on-five, and All-on-six designs in terms of stress distribution in the bone and various components of the prosthesis design.Materials and Methods: This finite element analysis study was carried out descriptively in 2024 at the Faculty of Dentistry in Isfahan. An edentulous maxillary model and three implant-based fixed prostheses were designed. Design 1 (All on four): two vertical anterior implants in the position of the lateral teeth and two posterior implants with an angle of 30 degrees in the position of the second premolars. Design 2(All on five): one vertical implant in the position of the central tooth, two vertical implants in the position of the lateral teeth, and two posterior implants with an angle of 30 degrees in the position of the second premolars. Design 3 (All on six): two vertical implants in the position of the central teeth, two vertical implants in the position of the canine teeth, and two short vertical implants in the position of the first molars. A force of 100 Newtons was applied to the left end of the superstructure, and then the maximum stress in the bone and corresponding prosthetic structures were compared.Results: The All-on-Six design caused the least stress in the bone and prosthetic structures, and the All-on-Four design caused the most stress.Conclusion: Among the designs evaluated, the All-on-six demonstrated the most favorable biomechanical performance. The All-on-four design exhibited the highest stress levels within bone and prosthetic components. While the All-on-five design presented intermediate stress levels compared to the other two models.

Objective(s): To evaluate the association of parental occupational exposures to six categories of occupational hazards including pesticides, solvents, paint and pigments, organic and non-organic dusts, and metals with the risk of Acute Lymphoblastic Leukemia (ALL) in their offspring.Methods: From 2007-2009 our hospital based case-control study was performed with 200 children diagnosed with ALL and 200 controls consisting of children suffering from endocrine or rheumatologic disorders, who were matched by age and sex. The study was performed at the Children’s Medical Center and Vali-Asr hospital, in Tehran, Iran. The parents were interviewed face to face to gather information on demographic characteristics, child’s medical history and home exposures, and parental occupational histories.Results: We found that paternal exposures to non-organic dusts {OR (95% confidence interval)=2.17 (1.11-4.26); P=0.02} and metals {OR (95% confidence interval)=2.68 (1.38-5.21); P=0.004} were related to an increased risk of ALL in their offspring.No significant relations were found for the other paternal exposure categories neither for the all maternal exposures categories with the risk of ALL in their offspring.Conclusion: Our study provides support to the association between some paternal occupational exposures and ALL risk in their offspring. Further studies are necessary to corroborate the observed associations in this study.

Background & Objective: CD34 is a prognostic factor in determining the prognosis of patients with acute myeloid leukemia. Since the relationship between expression of the marker of the CD34 cell line and many cancers has been proven today, in this study, the measurement of the expression of this marker with leukemia was investigated. Materials & Methods: The present study is a case-control study performed on 30 healthy blood samples and 30 blood samples from blood donors. Lymphocytes were isolated using Ficole method. RNA was extracted. After synthesis of cDNA, expression regions were determined using Real Time RT-PCR with an internal control of GAPDH. Results: After performing the PCR reaction with specific primers in Real Time RT PCR and analyzing the results, the expression of CD34 gene in the blood of cancer patients was increased compared to healthy subjects (F = 21. 588, P-Val = 0. 002). Conclusion: Finding new biomarkers, which are a common indicator of cancer, can help with early diagnosis and recovery during cancerous illnesses. By reviewing these biomarkers, it is possible to develop new anti-cancer drugs that can target cancerous cells and prevent growth from growing into cancerous cells.

2Aim and Background: The level of an immune response inhibitory enzyme, called indoleamine 2,3-dioxygenase (IDO), and the activity of Treg cells increase in some patients with cancer and acute leukemias such that it can lead to the inhibition of immune responses. Therefore, the very aim of the present study was to evaluate the regulatory T cells (CD4 + / FOXP3 +) and the level of the IDO expression in acute leukemias using flow cytometry and Real-Time PCR.  Materials and Methods: This study used bone marrow samples taken from  30 patients with acute lymphoid leukemia (ALL), and 20 healthy individuals. Then, the level of the IDO expression and the percentage of Treg cells were evaluated using flow cytometry and Real-Time PCR. The results revealed that the percentage of Treg in the total lymphocytes, T and Th in the ALL group was significantly higher than that of the normal groups the respectively (P <0.001). Results: In addition, the level of the IDO expression in the normal group was significantly lower than that of the ALL group (P= 0.016). Conclusion: The level of the IDO expression in the ALL groups was significantly higher than the normal group. Moreover, there was a positive and non-significant relationship between the level of the IDO expression and the percentages of Treg cells in the ALL group. Therefore, it seems necessary to conduct more studies for the behavior of this leukemia in the expression of IDO enzyme and the percentage of Treg cells and their relationship with each other.