Evaluation of kinetic friction in monocrystalline ceramic, polycrystalline ceramic and composite brackets in dry and wet field

Author: 
Dr. R. Rajab Ali, Dr. A. Nandakumar, Dr. Pradeep Babu Kommai and Dr. Roshan Eliyas

Introduction: Friction and sliding mechanics results in a reduced delivery of force in the orthodontics appliance system. As the demand for esthetic brackets is on the rise, kinetic friction of these brackets needs to be taken into consideration. The resistance to orthodontic movement within the appliance system has been challenge since the inception of orthodontics.
Aim& objectives: The purpose of the study was to evaluate the kinetic frictional resistance generated by esthetic brackets (Monocrystalline ceramic brackets, polycrystalline ceramic brackets and composite brackets) using a 0.019”x0.025” SS straight length wire in a 0.022” slot in a simulated sliding movement.
Methodology: This study was performed with 3 different types of brackets of MBT discipline. Group 1: Monocrystalline ceramic (Illusion, JJ orthodontics),Group 2: Polycrystalline ceramic (Clear, JJ orthodontics) and, Group 3: Composite brackets (Oro, JJ orthodontics). Samples size of each group n=48.  Four mandibular central incisor brackets with 00 tip and -60 torque was used, in 0.022” X 0.030” slot Pre adjusted edgewise appliance. Brackets were bonded to an acrylic sheet. The brackets and wire units were submitted to frictional test with Instron machine (No-3382). This test was done in both dry and wet condition. Artificial saliva was used to stimulate oral condition. The lower cross head was design to hold the acrylic fixture, and upper cross head was holding the wire. Each sample was pulled at the speed of 2mm per minute. Student T test and Two-way ANOVA were applied and results tabulated.
Results: In both dry and wet condition composite brackets expressed a statically significant higher frictional value with respect to monocrystalline and polycrystalline brackets. Polycrystalline ceramic brackets showed least frictional resistance. Monocrystalline ceramic brackets showed intermittent frictional value.
Conclusion: The polycrystalline ceramic brackets showed least friction among the 3 groups followed by monocrystalline ceramic and composite Brackets.

 

Page: 
4169-4173
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DOI: 
http://dx.doi.org/10.24327/23956429.ijcmpr201905648
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