Matteo Camporesi1, Mariana Bulhoes Galvão2, André Tortamano2, Gladys Cristina Dominguez2, Nicolò Defraia1, Efisio Defraia1, Lorenzo Franchi3. 1. Department of Surgery and Translational Medicine, University of Florence, Via Ponte di Mezzo 46/48, 50100, Florence, Italy. 2. Departamento de Ortodontia, Faculdade de Odontologia da Universidade de São Paulo, Av. Prof. Lineu Prestes, 2227, São Paulo, CEP 05508-000, Brazil. 3. Department of Surgery and Translational Medicine, University of Florence, Via Ponte di Mezzo 46/48, 50100, Florence, Italy. lorenzo.franchi@unifi.it.
Abstract
AIM: To investigate any advantages of low friction biomechanics in orthodontic patients with fixed appliances without producing metal artifacts during magnetic resonance imaging (MRI). MATERIALS AND METHODS: Frictional resistance generated by bracket-wire-ligature systems was analyzed via an experimental model that reproduced upper canine misalignment. Each sample was tested 10 consecutive times in a dry state; a total of 160 tests were carried out. We documented the frictional forces generated by a 0.012- and 0.014-inch superelastic nickel-titanium wire (SENT) with ceramic self-ligating brackets (SLB) with metal insert and ceramic monocrystalline brackets with nonconventional elastic ligatures (NCEL) in conjunction with various degrees of canine misalignment (1.5, 3.0, 4.5, and 6.0 mm). Comparisons between the frictional forces released by the two different bracket-wire-ligature systems were made by conducting 3-way analysis of variance (ANOVA) with Tukey HSD pairwise test (P < 0.005). RESULTS: We observed no clinically relevant difference between the frictional forces released by ceramic SLB and ceramic brackets in conjunction with a 0.012- and 0.014-inch SENT. Statistically significant differences were apparent with a 0.012-inch SENT at 4.5 and 6.0 mm of canine misalignment, where the SLB revealed higher frictional forces. CONCLUSIONS: Ceramic brackets with NCEL revealed frictional forces similar to those generated in conjunction with ceramic SLB, thereby helping to avoid metal artifacts in case of expected necessary MRI during orthodontic treatment with fixed appliances.
AIM: To investigate any advantages of low friction biomechanics in orthodontic patients with fixed appliances without producing metal artifacts during magnetic resonance imaging (MRI). MATERIALS AND METHODS: Frictional resistance generated by bracket-wire-ligature systems was analyzed via an experimental model that reproduced upper canine misalignment. Each sample was tested 10 consecutive times in a dry state; a total of 160 tests were carried out. We documented the frictional forces generated by a 0.012- and 0.014-inch superelastic nickel-titanium wire (SENT) with ceramic self-ligating brackets (SLB) with metal insert and ceramic monocrystalline brackets with nonconventional elastic ligatures (NCEL) in conjunction with various degrees of canine misalignment (1.5, 3.0, 4.5, and 6.0 mm). Comparisons between the frictional forces released by the two different bracket-wire-ligature systems were made by conducting 3-way analysis of variance (ANOVA) with Tukey HSD pairwise test (P < 0.005). RESULTS: We observed no clinically relevant difference between the frictional forces released by ceramic SLB and ceramic brackets in conjunction with a 0.012- and 0.014-inch SENT. Statistically significant differences were apparent with a 0.012-inch SENT at 4.5 and 6.0 mm of canine misalignment, where the SLB revealed higher frictional forces. CONCLUSIONS: Ceramic brackets with NCEL revealed frictional forces similar to those generated in conjunction with ceramic SLB, thereby helping to avoid metal artifacts in case of expected necessary MRI during orthodontic treatment with fixed appliances.
Authors: Maryam Fathimani; Garrett W Melenka; Dan L Romanyk; Roger W Toogood; Giseon Heo; Jason P Carey; Paul W Major Journal: Prog Orthod Date: 2015-06-04 Impact factor: 2.750