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Item A Comparison of the Ligation Torque Expression of a Ribbonwise Bracket–Archwire Combination and a Conventional Combination: A Primary Study(Hindawi, 2022-09-28) Lin, Bin; Jiang, Feifei; Chen, Jie; Liang, Jiaxing; Mechanical and Energy Engineering, School of Engineering and TechnologyObjective: To assess the effect of the third-order mechanics of a new ribbonwise bracket-archwire combination using an orthodontic torque simulator. Material and Methods. An orthodontic torque simulator was used to measure the third-order moment of a maxillary central incisor as it changed from a neutral position to a 40° rotation in 1° increment. A new ribbonwise bracket (Xinya, China) was compared with a conventional ligation bracket (American Orthodontic, U.S.A.). The effects of different archwire sizes (i.e., 0.017″ × 0.025″ and 0.019″ × 0.025″) and materials (i.e., nickel-titanium, titanium-molybdenum alloy, and stainless steel) were analyzed. Paired sample t-tests were conducted to compare the moments between the two bracket types corresponding to each of the archwires. The effects of the stiffness of the bracket-archwire complexes were also assessed. Results: Statistically significant differences (P=0.05) between the moments from the two brackets were found. The ribbonwise bracket-archwire complex generated larger moments when the rotation angle was lower than 30°. The ribbonwise brackets produced moments that could reach a threshold of 5 Nmm more quickly as the angle was increased. The higher the stiffness of the complex, the larger the moment. Conclusion: The ribbonwise bracket-archwire complex reached the moment threshold limits earlier than the conventional complex. When the rotation angle is less than 30°, the ribbonwise bracket-archwire complex generated a greater torque moment in comparison with the conventional complex.Item Bracket, ligation, and misaligned straight wires effects on load systems during orthodontic sliding mechanics(2015-07) Hannah, Richard D.; Katona, Thomas R.Objective: The objectives of this study were to measure and compare the complete, not solely friction, load components (forces and moments) experienced by brackets as they slide along straight wires that are angled relative to the path of bracket travel. Materials and Methods: Three types of brackets (stainless steel mandibular canine and central incisor, and an all-ceramic mandibular canine) were ligated with stainless steel or elastomeric modules to 2 sizes of stainless steel wire (0.021” x 0.021” and 0.016” x 0.016”) at 0°, 1° and 2° bracket-wire misalignments. All 3 force and 3 moment components experienced by the brackets were measured as they slid along the wire. Results: Overall, all 36 permutations of the 3 brackets, 2 ligations, 2 wires and 3 alignments produced statistically different (predominantly P < .0001) load components on the bracket. Conclusions: The type of bracket, wire, ligation, and relatively small misalignments (1° and 2°) between bracket and wire affect all force and moment components applied to the bracket. Traditional friction-focused “pull through” studies miss the attendant effects on the other 5 load components.Item The effects of bracket, wire conformation and size on the load systems during orthodontic sliding mechanics(2015-07) Mika, David E.; Katona, Thomas R.Objective: The purpose of this laboratory study was to compare all 6 load components (3 force and 3 moment) acting on 2 different stainless steel brackets as they slide along 3 sizes of stainless steel archwires with 3 different conformations. Materials and Methods: Brackets were attached to a load cell and elastomeric ligated to the wires. As the load cell was pulled along a precision track, the 6 load components (forces and moments in the 3 orthogonal coordinate system) acting on the bracket were recorded. ANOVA was applied to the data. Results: Overall, there were significant differences for all effects (bracket, wire size and wire configuration), for all outcomes (the loads), except the effect of bracket on the force of friction and one of the moment components. Conclusion: The results demonstrate that the force of friction associated with sliding mechanics should not be considered in isolation, because factors that affect it also affect the other 5 load components.Item Tensile Strength, Hardness and Fluoride Release of a Newly Developed Orthodontic Bracket Adhesive(1994) Halton, Brian; Moore, B. Keith; Roberts, W. Eugene; Hohlt, William F.; Arbuckle, Gordon R.; Katona, Thomas R.Previous studies have investigated materials specifically developed for use as orthodontic cements. Composite resins have shown greater bond strength and faster setting time compared to glass ionomer cements. However, glass ionomer adhesives have significantly greater fluoride release. The purpose of this study was to evaluate the tensile bond strength, hardness and fluoride release of Photac-Bond™ (PB), a newly developed capsulated, light-cured glass ionomer resin. A composite resin, TransBond™ (TB), and a glass ionomer cement, Ketac-Cem™ (KC), were used as controls. Each was used to bond 30 orthodontic brackets to bovine tooth samples. Tensile debonding using an lnstronTM test machine was performed after all samples were thermocycled (using 5°C and 45°C water baths) and stored for 14 days (37°C, 100 percent humidity). Discs made of the adhesives were also tested for fluoride release and Knoop hardness. TB was shown to have significantly greater tensile bond strength (p<0.05) compared to PB and KC. Adhesive: Photac-Bond™ (PB); Mean-Tensile Bond Strength (MPa): 2.22; Standard Deviation: 0.51; Adhesive: Ketac-Cem™ (KC); Mean-Tensile Bond Strength (MPa): 2.08; Standard Deviation: 0.45; Adhesive: Adhesive: TransBond™ (TB): 5.56; Mean-Tensile Bond Strength (MPa): 5.56; Standard Deviation: 0.79; No significant difference in tensile bond strength was found between PB and KC. PB fluoride release was much greater than that of TB and KC. The high fluoride release rate indicates that PB is suitable for use in patients at risk of enamel decalcification. Analysis suggests that PB developed a significantly lower hardness value than the controls. These results suggest that PB should be used to bond teeth where bracket loading is expected to be low and danger of enamel decalcification is high.