<strong>Introduction:</strong> The aim of this study was to determine whether there was a significant difference in shear bond strength between metal and ceramic brackets when exposed to acidic dietary com...<strong>Introduction:</strong> The aim of this study was to determine whether there was a significant difference in shear bond strength between metal and ceramic brackets when exposed to acidic dietary components (beverages) and to observe the chromogenic potential of each <em>in vitro</em>. <strong>Methods:</strong> Metal and clear orthodontic brackets were placed on extracted maxillary second premolars and exposed to select beverages three times daily for four weeks. Shade was taken using a colorimeter device at seven intervals and the shear bond strength of each bracket was recorded. <strong>Results:</strong> There was a variable change in tooth shade with respect to the various beverages in which they were submerged. Coffee and Dr. Pepper had the most pronounced change, whereas Red Bull and water produced little to none, respectively. Compared to controls, brackets submerged in coffee had the greatest reduction in shear bond strength, followed by Dr. Pepper, then Red Bull. Overall, clear brackets showed higher shear bond strength than metal brackets. <strong>Conclusion: </strong>Acidic dietary components have a negative effect on the shear bond strength of orthodontic brackets, and more pigmented beverages have a higher chromogenic staining potential.展开更多
Background and purpose: Periodontitis is the inflammation of the supporting tissues of teeth. In this disease, overproduction of free radicals by polymorphonuclears (PMNs) will result in the imbalance between saliva’...Background and purpose: Periodontitis is the inflammation of the supporting tissues of teeth. In this disease, overproduction of free radicals by polymorphonuclears (PMNs) will result in the imbalance between saliva’s oxidants and antioxidants. Therefore, due to insufficient levels of anti-oxidants, free radicals can start chain reactions that eventually will lead to destruction of periodontal tissues. The purpose of this research is to compare the amount of whole saliva’s antioxidant capacity in people with major periodontitis with that of healthy people. Methods and materials: In this case-control study, the amount of antioxidants capacity and saliva antioxidants were measured in 43 cases with periodontitis, as well as in 43 healthy people (controls);and the measurements were compared between the two groups. The amount of antioxidants capacity and their saliva antioxidants capacity was measured by FRAP (ferric reducing ability of plasma) and with the help of a Spectrophotometer. Findings: Average and Standard deviation of saliva’s antioxidants was 184.25 ± 63.209 in subject group and 399.419 ± 90.298 micro moles in control group. Using the T-TEST revealed that the difference in capacity of whole saliva’s antioxidants in two groups is significant. Conclusion: whole saliva’s antioxidants capacity is less among patients with periodontitis compared to control group.展开更多
从Louis Boucheron为印度土邦君主巴提亚拉(Maharajah of Patiala)的珍藏宝玉石打造的东方珠宝,到瑞士巴塞尔举办的世界顶级珠宝展上那场名为"紫气东来"的东方首饰秀,再到各种东方元素在珠宝设计中大量的运用……这一切,足以...从Louis Boucheron为印度土邦君主巴提亚拉(Maharajah of Patiala)的珍藏宝玉石打造的东方珠宝,到瑞士巴塞尔举办的世界顶级珠宝展上那场名为"紫气东来"的东方首饰秀,再到各种东方元素在珠宝设计中大量的运用……这一切,足以看出,珠宝界的天枰,早已向东方倾斜。展开更多
文摘<strong>Introduction:</strong> The aim of this study was to determine whether there was a significant difference in shear bond strength between metal and ceramic brackets when exposed to acidic dietary components (beverages) and to observe the chromogenic potential of each <em>in vitro</em>. <strong>Methods:</strong> Metal and clear orthodontic brackets were placed on extracted maxillary second premolars and exposed to select beverages three times daily for four weeks. Shade was taken using a colorimeter device at seven intervals and the shear bond strength of each bracket was recorded. <strong>Results:</strong> There was a variable change in tooth shade with respect to the various beverages in which they were submerged. Coffee and Dr. Pepper had the most pronounced change, whereas Red Bull and water produced little to none, respectively. Compared to controls, brackets submerged in coffee had the greatest reduction in shear bond strength, followed by Dr. Pepper, then Red Bull. Overall, clear brackets showed higher shear bond strength than metal brackets. <strong>Conclusion: </strong>Acidic dietary components have a negative effect on the shear bond strength of orthodontic brackets, and more pigmented beverages have a higher chromogenic staining potential.
文摘Background and purpose: Periodontitis is the inflammation of the supporting tissues of teeth. In this disease, overproduction of free radicals by polymorphonuclears (PMNs) will result in the imbalance between saliva’s oxidants and antioxidants. Therefore, due to insufficient levels of anti-oxidants, free radicals can start chain reactions that eventually will lead to destruction of periodontal tissues. The purpose of this research is to compare the amount of whole saliva’s antioxidant capacity in people with major periodontitis with that of healthy people. Methods and materials: In this case-control study, the amount of antioxidants capacity and saliva antioxidants were measured in 43 cases with periodontitis, as well as in 43 healthy people (controls);and the measurements were compared between the two groups. The amount of antioxidants capacity and their saliva antioxidants capacity was measured by FRAP (ferric reducing ability of plasma) and with the help of a Spectrophotometer. Findings: Average and Standard deviation of saliva’s antioxidants was 184.25 ± 63.209 in subject group and 399.419 ± 90.298 micro moles in control group. Using the T-TEST revealed that the difference in capacity of whole saliva’s antioxidants in two groups is significant. Conclusion: whole saliva’s antioxidants capacity is less among patients with periodontitis compared to control group.
