An evaluation of slot size in orthodontic brackets--are standards as expected?
2004; National Institutes of Health; Volume: 74; Issue: 4 Linguagem: Inglês
10.1043/0003-3219(2004)074 2.0.co;2
AutoresAlex C. Cash, Sarah Good, Richard Curtis, Fraser McDonald,
Tópico(s)Orthodontics and Dentofacial Orthopedics
ResumoThe slots of five upper left central incisor brackets from 11 commercially available bracket systems (3M Unitek, Monrovia, Calif: Twin Torque Roth, Clarity MBT, and Victory Series MBT; Dentarum, Pforzheim, Germany: Discovery Roth (0.56 mm) and Elegance Plastic Roth; Forestadent, Pforzheim, Germany: Mini Mono MBT; TP LaPorte, Indiana: Nu-Edge Roth and Mxi Advant-Edge Roth; Ormco Corp., Orange, Calif: Damon II SL Roth; Ortho Organizers, San Marcos, Calif: Elite Mini Opti-MIM Roth and Elite Mini Opti-MIM MBT) were measured in the 0.022-inch (0.5588 mm) dimension. Measurements were taken after operator calibration, and a digital readout was produced. Results indicate that all bracket slots are oversized. Three bracket systems slots (Twin Torque, Clarity, and Mini Mono) were within 5% (+/-1.08, 1.655, 1.75) of their stated dimensions with essentially parallel slot walls. The Elegance Plastic slot was parallel sided but oversized by 12% (+/-1.15). The geometry of bracket slots was also variable. The Victory Series slot was slightly divergent with the top oversized by 6% (+/-1.035). The Nu-Edge slot was divergent and slot top oversized by 14% (+/-1.32). The Mxi Advant-Edge, Damon II SL, Elite Mini Opti-MIM Roth, and MBT were all convergent, and the base of the Damon slot was oversized by 17% (+/-1.79). The Discovery bracket was convergent, and the slot base was oversized by 24% (+/-1.255), which was the largest recorded variance. This bracket also had a 7% difference between the widths of the slot top and the base. Inaccurate machining of bracket slot dimensions and the use of undersized archwires may directly and adversely affect three-dimensional tooth positioning.
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