Browsing by Author "Isikbay, Serkis C."

Now showing 1 - 5 of 5
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    An analytical approach to 3D orthodontic load systems
    (The Angle Orthodontist, 2014-09) Katona, Thomas R.; Isikbay, Serkis C.; Chen, Jie; Department of Orthodontics and Oral Facial Genetics, IU School of Dentistry
    OBJECTIVE: To present and demonstrate a pseudo three-dimensional (3D) analytical approach for the characterization of orthodontic load (force and moment) systems. MATERIALS AND METHODS: Previously measured 3D load systems were evaluated and compared using the traditional two-dimensional (2D) plane approach and the newly proposed vector method. RESULTS: Although both methods demonstrated that the loop designs were not ideal for translatory space closure, they did so for entirely different and conflicting reasons. CONCLUSIONS: The traditional 2D approach to the analysis of 3D load systems is flawed, but the established 2D orthodontic concepts can be substantially preserved and adapted to 3D with the use of a modified coordinate system that is aligned with the desired tooth translation.
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    Clinical Outcomes of 0.018-Inch and 0.022-Inch Bracket Slot Using the ABO Objective Grading System
    (E.H Angle Education and Research Foundation, 2010-05-01) Detterline, David A.; Isikbay, Serkis C.; Brizendine, Edward J.; Kula, Katherine S.; Orthodontics and Oral Facial Genetics, School of Dentistry
    Objective: To determine if there is a significant difference in the clinical outcomes of cases treated with 0.018-inch brackets vs 0.022-inch brackets according to the American Board of Orthodontics (ABO) Objective Grading System (OGS). Materials and Methods: Treatment time and the ABO-OGS standards in alignment/rotations, marginal ridges, buccolingual inclination, overjet, occlusal relationships, occlusal contacts, interproximal contacts, and root angulations were used to compare clinical outcomes between a series of 828 consecutively completed orthodontic cases (2005–2008) treated in a university graduate orthodontic clinic with 0.018-inch- and 0.022-inch-slot brackets. Results: A two-sample t-test showed a significantly shorter treatment time and lower ABO-OGS score in four categories (alignment/rotations, marginal ridges, overjet, and root angulations), as well as lower total ABO-OGS total score, with the 0.018-inch brackets. The ANCOVA—adjusting for covariants of discrepancy index, age, gender, and treatment time—showed that the 0.018-inch brackets scored significantly lower than the 0.022-inch brackets in both the alignment/rotations category and total ABO-OGS score. Conclusions: There were statistically, but not clinically, significant differences in treatment times and in total ABO-OGS scores in favor of 0.018-inch brackets as compared with the 0.022-inch brackets in a university graduate orthodontic clinic (2005–2008).
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    The effects of application time of a self-etching primer and debonding methods on bracket bond strength
    (Allen Press, 2012) Parrish, Brandon C.; Katona, Thomas R.; Isikbay, Serkis C.; Stewart, Kelton T.; Kula, Katherine S.; Orthodontics and Oral Facial Genetics, School of Dentistry
    Objective: To test the manufacturer's recommendation for the application rubbing time of a self-etching primer (Transbond Plus, 3M Unitek) and to compare the resulting bond strength of a resin composite (Transbond XT, 3M Unitek) in the traditional laboratory tension on all four wings with a simulation of the clinical single-wing lift-off debonding instrument (LODI; 3M Unitek). Materials and methods: Flattened stainless-steel maxillary incisor orthodontic brackets (Victory Series, 3M Unitek) were bonded to 108 flattened bovine incisors. The enamel was rubbed with the self-etching primer for 0, 5 (the manufacturer's recommendation), and 10 seconds during a 10-second application. Traditional four-wing and LODI simulated debonding forces and the adhesive remnant index (ARI) were recorded. Results: One-way analysis of variance testing among rubbing times and debonding methods indicated a significant difference in strength with 0 and 5 seconds of rubbing and between traditional and LODI simulated tension. The bond strengths were higher in the ARI = 1 subset compared to the ARI = 3-5 subsets. Conclusions: The manufacturer's recommendation for primer rubbing time produced the highest bond strength. Less force is required for debonding when tension is applied to one wing (LODI simulation) vs on all four wings.
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    Quantification of three-dimensional orthodontic force systems of T-loop archwires
    (E.H Angle Education and Research Foundation, 2010-07-01) Chen, Jie; Isikbay, Serkis C.; Brizendine, Edward J.; Orthodontics and Oral Facial Genetics, School of Dentistry
    Objective: To demonstrate the three-dimensional (3D) orthodontic force systems of three commercial closing T-loop archwires using a new method and to quantify the force systems of the T-loop archwires. Materials and Methods: An orthodontic force tester (OFT) and a custom-made dentoform were developed to measure force systems. The system simulated the clinical environment for an orthodontic patient requiring space closure, which included measurement of three force components along, and three moment components about, three clinically defined axes on two target teeth. The archwires were attached to the dentoform and were activated following a standard clinical procedure. The resulting force system was measured using the OFT. Results: The force systems of the T-loops on the teeth were 3D. Activation in one direction resulted in force and moment components in other directions (side effects). The six force and moment components as well as the moment-to-force ratios in the clinically defined coordinate system were quantified. Conclusions: The commercial archwires do not provide force systems for pure translation. Quantification of the force system is critical for the selection and design of optimal orthodontic appliances.
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    Using an Orthodontic Force Tester to Simulate Clinical Environment for Space Closure and Measuring the Applied Three-Dimensional Load System
    (2007) Isikbay, Serkis C.; Chen, Jie; Katona, Thomas R.; Hohlt, William H.; Baldwin, James J.; Shanks, James C.
    Applied orthodontic load systems (forces and moments) cause teeth to move from their existing position in the dental arch. The types of tooth movement can be classified as tipping, rotation and translation in three-dimension. If the desired tooth movement is pure translation, a force should be applied directly at the center of resistance. Since the center of resistance of teeth cannot be identified or accessed easily and reliably, and orthodontic brackets are applied most practically on the buccal surfaces of the tooth crowns, applying a force at the center of resistance is not realistic. Therefore, the applied force should be accompanied by a moment to moderate tipping. The control of the movement relies on the ability to quantify and manipulate the orthodontic load system, specifically the moment-to-force ratio (M:F). The inability to control the orthodontic load system can result in undesirable tooth movement as well as a decrease in the efficiency of overall treatment. The importance of the three-dimensional (3-D) load system is well established although it has never been satisfactorily measured. The purpose of this study was to measure forces and moments generated by a commercially available T-loop closing loop archwire in three axes simultaneously at two different locations utilizing the orthodontic force tester (OFT) and a custom-made dentoform that simulates a typical space closure clinical case. The parameters in the design of a closing archwire that influence the 3-D orthodontic load system were tested to analyze the effects of these variations. The five parameters that were investigated include activation, loop location, gable direction, gable angle, and gable type. The overall null hypothesis was that the variations in the design of a closing archwire would not influence the 3-D orthodontic load system (p>0.05). A full factorial analysis of variance (ANOVA) model was used to model the absolute value of the forces (Fx, Fy, Fz ) and moments (Mx, My, Mz) in each plane separately. Additionally the ratios of the moment in the x-plane (Mx) to the force in the y-plane (Fy) and of the moment in the y-plane (My) to the force in the x-plane (Fx) were calculated for each experimental run. Separate ANOVA models were run for each sensor type (lateral incisor and canine). In lieu of multiple pair-wise comparisons, Tukey's minimum significant difference was estimated assuming a significance level of alpha = 0.05. Along with estimates of the means and standard deviations of the forces and moments, appropriate 95% confidence intervals were estimated for each mean. Statistical significant interactions were found for the variations that were tested, therefore the Null Hypothesis was rejected. The various directions of Fy and its overall low magnitude at the lateral incisor bracket challenged the accepted notion that the lateral incisor moved distally during space closure. A resultant force may indeed be in the direction toward the center of the arch rather than the center of the space. It was noted that the intrusive/extrusive, the buccal/lingual root moments forces and the mesial/distal root moments were influenced more by the Second Order Gable Bends than the First Order Gable Bends. It could be concluded that 10,10 First Order Gable Bends and 10,10 or 20,0 Second Order Gable Bends should be used for most clinical space closure needs at anterior or middle T-loop spring positions with 1 mm or 2 mm activations. Future studies investigating self-ligating brackets, different closing loop designs, modifications, and materials are necessary to understand the 3D orthodontic force system further and design the ideal system that would allow clinical space closure as desired.