Comparative Evaluation of Friction Resistance of Titanium, Stainless Steel, Ceramic and Ceramic with Metal Insert Brackets with Varying Dimensions of Stainless Steel Wire: An In vitro Multi-center Study.
BACKGROUND
The orthodontist seeks an archwire-bracket combination that has both good biocompatibility and low friction. Hence, the aim of this multicenter in vitro study was to evaluate and compare the frictional resistance generated between titanium (Ti), stainless steel (SS), ceramic and ceramic with metal insert (CMI) brackets with SS wires of varying dimensions in a specially designed apparatus.


METHODS
The material used in this study were Ti, SS, Ceramic and CMI with 0.018″ slot manufactured with zero degree tip and -7° torque premolar brackets (3M, Unitek) and SS wires of varying dimensions (0.016″ round, 0.016 × 0.016″ square, 0.016 × 0.022″ rectangular and 0.017 × 0.025″ rectangular) used. The frictional resistance was measured using Instron Universal testing machine (Model no. 4301). The specimen population in each center composed each of 160 brackets and wires. Differences among the all bracket/wire combinations were tested using (one-way) ANOVA, followed by the student Newman Keuls multiple comparisons of means ranking (at P < 0.05) for the determination of differences among the groups.


RESULTS
Ti bracket in combination with 0.017 × 0.025″ SS rectangular wire produced significant force levels for an optimum orthodontic movement with least frictional resistance.


CONCLUSIONS
Ti brackets have least resistance and rectangular wires produced significant force. These can be used to avoid hazards of Nickel. SS brackets revealed higher static frictional force values as the wire dimension increased and showed lower static friction than Ti brackets for all wires except the thicker wire. Our study recommends the preclusion of brackets with rough surface texture (Ti brackets) with SS ligature wire for ligating bracket and archwire are better to reduce friction.
Professor and Head, Department of Orthodontics and Dentofacial Orthopedics, Saraswati Dhanwantari Dental College and Hospital, Parbhani, Maharashtra, India.
B Sunil
BS
Kumar
Professor and Head, Department of Orthodontics and Dentofacial Orthopedics, HKES SN Institute of Dental Sciences and Research, Gulbarga, Karnataka, India.
Suresh
S
Miryala
Professor and Head, Department of Orthodontics and Dentofacial Orthopedics, SB Patil Dental College and Hospital, Naubad, Bidar, Karnataka, India.
K Kiran
KK
Kumar
Reader, Department of Orthodontics and Dentofacial Orthopedics, SB Patil Dental College and Hospital, Naubad, Bidar, Karnataka, India.
K
K
Shameem
Professor and Head, Department of Orthodontics and Dentofacial Orthopedics, Rajiv Gandhi Institute of Medical Sciences, Adilabad, Andhra Pradesh, India.
Ravindra Reddy
RR
Regalla
Archwire; ceramic brackets; ceramic with metal insert brackets; friction resistance; instron machine; stainless steel brackets; titanium brackets