Seyed Hosein Moslemzade; Mojgan Kachoei; Aydin Sohrabi; Ali Rafighi; S. Bahmani
Abstract
Background and aim: The frequency of exposure of dental personnel to infection and of patient to cross contaminated instruments has prompted concern about adequate sterilization of dental instruments. Aim of the present study was to evaluate the changes in the frictional properties of Ni-Ti orthodontic ...
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Background and aim: The frequency of exposure of dental personnel to infection and of patient to cross contaminated instruments has prompted concern about adequate sterilization of dental instruments. Aim of the present study was to evaluate the changes in the frictional properties of Ni-Ti orthodontic wires after sterilization with chemical agents.
Materials and methods: In the present study the friction between Ni-Ti wires measuring 16 mm in diameter and 18-slot stainless steel brackets were measured and compared in two groups as follows: 1) without sterilization (as received); 2) after chemical sterilization. Each group consisted of 30 specimens and friction was measured in a Universal testing machine.Results: Comparison of unsterilized samples with the group sterilized with chemical agents showed a significant difference (P=0.000) in shear stress.Conclusion: Based on the results of the present study, this sterilization techniques result in an increase in the friction of Ni-Ti orthodontic wires.
Ali Rafighi; Aydin Sohrabi; Saeid Foroughi Moghaddam; Seyed Hossein Moslemzadeh; Reza Nemati; Leila Roshangar
Abstract
Background and aim: The aim of this study was to find out influence of the orthodontic devices on the oral epithelial cells.Materials and methods: Cells of lower lip oral mucosa from 32 orthodontic patients were collected by exfoliative cytology in three times: Day 0 (just before appliance placement), ...
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Background and aim: The aim of this study was to find out influence of the orthodontic devices on the oral epithelial cells.Materials and methods: Cells of lower lip oral mucosa from 32 orthodontic patients were collected by exfoliative cytology in three times: Day 0 (just before appliance placement), and 14 and 60 days after appliance insertion. Nuclear (NA) and cytoplasmic (CA) areas, NA/CA ratio, cell morphology, and cellularity of smears were analyzed by using cytologic and cytomorphometric methods.Results: The NA of the cells adjacent to orthodontic devices diminished after appliance placement, and reached to its lower level in day 60 (p = 0.000). Investigated epithelial cells showed insignificant changes in CA. Type II inflammatory smears, according to Papanicolau, increased insignificantly after the treatment initiation. Superficial epithelial cells, were predominant cell type in day 14 and 60 (p= 0.002)..Conclusion: Orthodontic appliances cause reduction in NA and induce epithelial hyperkeratosis in lower lip mucosa.
