• The korean journal of orthodontics
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• v.54 no.1
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• pp.16-25
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• 2024

Objective: To compare the effectiveness of laser-engineered copper-nickel titanium (SmartArch) and superelastic nickel-titanium (SENT) archwires in aligning teeth and inducing root resorption and pain experienced by patients. Methods: Two-arm parallel groups with a 1:1 allocation ratio were used. The participants were patients aged 11.5 years and older with 5-9 mm of mandibular anterior crowding who were indicated for non-extraction treatment. The primary outcome was alignment effectiveness, assessed using Little's irregularity index (LII) over 16 weeks with a single wire (0.016-inch) in the SmartArch group and 2 wires (0.014- and 0.018-inch) in the SENT group (8 weeks each). Secondary outcomes included root resorption evaluated by pre- and post-intervention periapical radiographs and pain levels recorded by the participants during the first week. Results: A total of 40 participants were randomly allocated into 2 groups; 33 completed the study and were analyzed (16 in the SmartArch group and 17 in the SENT group, aged 16.97 ± 4.05 years). The total LII decrease for the SmartArch and SENT groups was 5.63 mm and 5.29 mm, respectively, which was neither statistically nor clinically significant. Root resorption was not significantly different between the groups. The difference in pain levels was not statistically significant for the first 5 days following wire placement; however, there was a significant difference favoring the SENT group in the final 2 days. Conclusions: SmartArch and SENT archwires were similarly effective during the alignment phase of orthodontic treatment. Root resorption should be observed throughout the treatment with either wire. SmartArch wires demonstrated higher pain perception than SENT wires.

• The korean journal of orthodontics
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• v.35 no.5 s.112
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• pp.381-387
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• 2005

The aim of this study was to compare the clinical performance of 4 types of orthodontic wires, indicated for initial tooth alignment: stainless steel, multistranded steel, superelastic and thermoactivated nickel-titanium. A prospective randomized clinical trial was conducted on a sample of 45 patients, at the Dental School of the State University of Rio do Janeiro, Brazil. Fixed appliances were fitted and study casts were obtained from each patient. Randomly, the wires were allocated as follows: 26 dental arches for superelastic NiTi wires, 22 for stainless steel, 22 for multistranded and 20 for thermoactivated archwires. After 8 weeks, the archwires were removed and impressions for study casts were taken again. Using a 3D digitization technique of defined anatomical points on the study cast crowns, a Dental Irregularity Index (DII) was created for each study cast. The difference between DII before and after the archwire insertion expressed the aligning effect of the wires. ANOVA tests were employed to evaluate the anatomical point approximation (positive DII) and separation (negative DII), for each area of the dental arches: upper and lower whole arch and anterior arch. Results showed no significant difference between the different archwires.

• The korean journal of orthodontics
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• v.23 no.2 s.41
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• pp.217-227
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• 1993

Preadjusted appliance, following the original concept of the Andrews Straight-Wire appliance, became increasingly common in the 1980s. In six phases of treatment, anchorage control, leveling and aligning, overbite control, overjet reduction, space closure, and finishing are very effective with using the preadjusted appliances. Space closure is the phase of treatment in which the difference between standard edgewise and preadjusted mechanics is most noticeable. Orthodontists have been able to reduce the use of closing loops and, because of the level slot lineup, enjoy the advantages of sliding mechanics. In 1990, Dr. John C. Bennett and Richard P. McLaughlin introduced the new space closure system, namely, elastic 'tiebacks'. They found an $.019'\times.025'$ working archwire most effective in an .022'-slot system. Hooks of .024' stainless steel or .028' brass wire are soldered to the upper and lower archwires. The force required for space closure is delivered by elastic 'tiebacks'. An elastic modulo stretched by 2-3mm(to twice its normal length) usually delivers 0.5-1.5mm of space closure per month. Group movement and sliding mechanics are combined for gentle, controlled space closure, so that about 0.5mm of incisor retraction and 0.5mm of mesial molar movement can be seen each month. The tiebacks are replaced every four to six weeks. By using the elastic 'tiebacks', the next two cases were treated during space closure. Even though we found some clinical problems of this mechanics, long treatment time, hard to control of vertical dimension and anchorage, the application method of this system is so simple that orthodontists can manage many patients during short chair time. But we must apply this mechanics after perfect understanding of the biomechanics in tooth movement.