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Background: Dental technician expose to large amounts of crystalline silica that increase their risk of developing silicosis. Neopterin are produced upon stimulation with the cytokine interferon-γ. Neopterin is produced by activated monocytes, macrophages, and dendritic cells upon stimulation by interferon gamma produced by Tlymphocytes. Neopterin production provides prognostic information in patients with autoimmune diseases. Objective: Assessment of serum neopterin, inflammatory cytokines, enzyme activities and trace elements in smokers and non smokers dental technicians and to compare them with the corresponding levels in a control group. Subjects and Methods: Serum was examined in 45 dental technician, 15 subjects as a control group and 30 subjects exposed to silica. The surveyed dental technician were divided into three groups: 1 st group (control group), 2 nd group (smokers dental technician) and 3 rd group (non smokers dental technician). Serum neopterin, some trace elements, LDH, ALP, ACP, TNF-α, and IL-8 were determined. Result: Higher levels of neopterin were established in smokers dental technician exposed to crystalline silica (16.48 ng/ml) by comparison with non smokers dental technicians (9.85 ng/ml) and the control group (4.24 ng/ml). Significant increase in the levels of silica, calcium, copper, enzymatic activities, TNF-α, IL8 and a significant decrease in Zn levels in serum of smokers subject compared with both non smokers and control subjects. Conclusion: Research on biomarkers for silicosis is still at its nascent stage. The concentration of serum neopterin could be used as a biomarker in the diagnostic criteria for silicosis moreover it is suitable for introduction into the routine clinical laboratory practice.

INTRODUCTION: The use of short implants has been introduced as an alternative treatment for posterior regions, however, it leads to serious prosthetic complications. Using CAD/CAM, materials like zirconia and Bio-HPP can be used to fabricate implant supported restorations. OBJECTIVES: This study aimed to evaluate and compare the strains developed around short and standard implant length using two different crown materials. MATERIALS AND METHODS: Polyurethane blocks (n=20) were used as alternative materials for human cancellous bone. Blocks were divided into two groups, group A received ten standard length implants 12 mm, and group B received ten short implants 7 mm. Each group was equally subdivided into two subgroups, according to crown material (BioHPP and zirconia). Universal testing machine was used to apply a load of 100 N axially and obliquely at 45° on the restorations. Microstrains were measured using strain meter. RESULTS: The difference in microstrain values between BioHPP and zirconia was statistically insignificant for both group A and group B. Comparing between group A and group B having the same restorative materials, it was found that, the difference was statistically significant for zirconia in axial loading only. A significant difference was observed between oblique and axial loads in standard implant length for both BioHPP and zirconia restorations, and for zirconia in short implants as well (p value=0.043), while the difference was insignificant for BioHPP in short implants. CONCLUSIONS: Short implants are comparable treatment modality to standard implant lengths for single tooth restoration. Oblique forces produce more stresses than vertical forces. According to the average of loads, there is no significant difference between BioHPP and zirconia for both short and standard implant length. However, it is advisable not to use zirconia restorations with short implants.