John Jr; Goutham Reddy; Anmol Kalha; Sunil Muddaiah; Sanju Somaiah; Balakrishna Shetty
Abstract
Background: With the emerging concept of aesthetics in orthodontics, ceramic brackets play a major role especially in the anterior region of the dental arch. However, the duration of the orthodontic treatment is one of the most important issues in treating patients with ceramic brackets.
Objectives: ...
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Background: With the emerging concept of aesthetics in orthodontics, ceramic brackets play a major role especially in the anterior region of the dental arch. However, the duration of the orthodontic treatment is one of the most important issues in treating patients with ceramic brackets.
Objectives: This study is conducted to compare space closing rate between conventional MBT and Symetri ClearTM bracket systems.
Methods: This study is comprised of 18 subjects who were equally separated into two groups. The first group was treated with conventional MBT pre-adjusted bracket and the second group with Symetri ClearTM brackets. Space closure was performed via 0.019 × 0.025 inch stainless steel wires using 9-mm nickel-titanium Sentalloy coil springs with a constant force of 150 g. The distance between the distal of the first molar buccal tube and the mesial of the canine bracket was measured by a digital caliper. The difference of the first and last values was determined to assess the sheer quantity of space closure. The value was then divided by the number of months during which the space closure was carried out to examine the ratio of space closure in mm per month. For the statistical analysis we used paired t test as well as independent t test and the P-value > 0.05 was deemed significant. Results: The MBT group showed a 0.85 mm/appointment retraction rate while the Symetri ClearTM bracket group had a 0.83 mm/appointment retraction rate. The difference in space closing between MBT and Symetri ClearTM groups was not statistically and clinically significant (P-value > 0.05).
Conclusions: As the rate of space closure was almost similar in the two types of brackets, we can use Symetri ClearTM brackets instead of MBT brackets without any concern about the duration of treatment and use the esthetic benefits of these brackets simultaneously.
Mojgan Kachoei; Faranak Eskandarinejad; Mahsa Eskandarinejad
Abstract
Aim: Friction accompanies all sliding techniques. Sliding is in the manner of tipping and uprighting with increasing angle between bracket and wire. Recently, wire coating with the different nanoparticles has been proposed to decrease the frictional forces. The present study was done to coat the stainless ...
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Aim: Friction accompanies all sliding techniques. Sliding is in the manner of tipping and uprighting with increasing angle between bracket and wire. Recently, wire coating with the different nanoparticles has been proposed to decrease the frictional forces. The present study was done to coat the stainless steel wires with the ZnO nanoparticles and determine the effect of this coating on friction reduction during different angle between the wires and brackets.
Materials and Methods: Eighty pieces of 0.016 stainless steel wires with and without zinc oxide nanoparticles were used in 80 pieces of orthodontic brackets (0.018). The coated wires analyzed by the SEM and XRD observations. Friction between the wires and orthodontic brackets at 0,5,10 degree angle were calculated using universal testing machine. Two and three group comparisons were done by means of Student t and one-way ANOVA respectively and Tukey post hoc test was used to assess the paired comparisons. Results: Frictional values were significantly increased with the increased angles between the wire and bracket. The increased friction force from 0 to 10 degree in uncoated wires were Statistically more significant than increased friction force from 0 to 10 degree in coated wires (p<0.005).Conclusion: considering the positive effects of zinc oxide nanoparticles coating in decreasing frictional forces, they might offer a novel opportunity to significantly reduce friction during sliding and consequent better anchorage control, reduced risk of root resorption.
