Ceramic brackets and low friction : A possible synergy in patients requiring multiple MRI scanning.
OBJECTIVE
To investigate any advantages of low friction biomechanics in orthodontic patients with fixed appliances without producing metal artifacts during magnetic resonance imaging (MRI).


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.
Department of Surgery and Translational Medicine, University of Florence, Via Ponte di Mezzo 46/48, 50100, Florence, Italy.
Matteo
M
Camporesi
Departamento de Ortodontia, Faculdade de Odontologia da Universidade de São Paulo, Av. Prof. Lineu Prestes, 2227, São Paulo, CEP 05508-000, Brazil.
Mariana
M
Bulhoes Galvão
Departamento de Ortodontia, Faculdade de Odontologia da Universidade de São Paulo, Av. Prof. Lineu Prestes, 2227, São Paulo, CEP 05508-000, Brazil.
André
A
Tortamano
Departamento de Ortodontia, Faculdade de Odontologia da Universidade de São Paulo, Av. Prof. Lineu Prestes, 2227, São Paulo, CEP 05508-000, Brazil.
Gladys Cristina
GC
Dominguez
Department of Surgery and Translational Medicine, University of Florence, Via Ponte di Mezzo 46/48, 50100, Florence, Italy.
Nicolò
N
Defraia
Department of Surgery and Translational Medicine, University of Florence, Via Ponte di Mezzo 46/48, 50100, Florence, Italy.
Efisio
E
Defraia
Department of Surgery and Translational Medicine, University of Florence, Via Ponte di Mezzo 46/48, 50100, Florence, Italy. lorenzo.franchi@unifi.it.
Lorenzo
L
Franchi
D016477:Artifacts; D002516:Ceramics / Q000737:chemistry*; D003481:Cuspid / Q000033:anatomy & histology* / Q000502:physiology*; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis / Q000379:methods; D017276:Friction; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D013314:Stress, Mechanical; D014087:Tooth Movement Techniques / Q000295:instrumentation*
D003764:Dental Materials
Dental esthetics; Friction; Hybrid system; Magnetic resonance imaging; Monocrystalline ceramic bracket