Evaluation and Comparison of Moment-to-Force Ratio of a New “PRP Loop” with that of Opus Loop and L Loop- A Finite Element Method Study
ZC11-ZC15
Correspondence
Smita Kumari,
Student (Postgraduate), Department of Orthodontics and Dentofacial Orthopaedics, Sharad Pawar Dental College, Wardha, Maharashtra, India.
E-mail: smita3345@gmail.com
Introduction: Extraction space closure is one of the most challenging procedures in the field of orthodontics which requires a robust understanding of biomechanics. There are two commonly used methods of space closure, one involves friction, also called sliding mechanics, and the other is frictionless. The advantages of frictionless mechanics are that there is no force loss due to friction and low anchorage taxing. The preferred method for the retraction of teeth is loop mechanics, which ensures controlled tooth movement.
Aim: To evaluate and compare the Moment-to-Force (M/F) ratio of PRP loop with that of the Opus loop and L loop using the Finite Element Method (FEM).
Materials and Methods: An in-vitro study was conducted by using FEM analysis at DMIHER University with technical assistance from the Department of Mechanical Engineering VNIT Nagpur. Computer models of the loop designs were prepared on Analysis of Systems (ANSYS) version 10 (V10) software. Opus loop, L loop and PRP loop were modeled as SOLID 64 beam elements. Different pre-activation bends were given to the models in α and β nodes of the loop. Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS) version 27.0 software to compare the means of all three loops.
Results: A total of 36 FEM models were studied. PRP loop showed a greater M/F ratio than the Opus and L loop with 15ºα and 25ºβ pre-activation bends in both 0.017×0.025 and 0.019×0.025-inch Titanium Molybdenum Alloy (TMA) wire, i.e., 9.09 and 9.12, respectively. On comparison of the M/F ratio of PRP loop, Opus loop and L loop prepared with 0.017×0.025 and 0.019×0.025 TMA wire, at 15ºα and 25ºβ pre-activation bend in 0.019×0.025 TMA, PRP loop showed the highest M/F ratio of 9.12 as compared to 0.017×0.025 TMA wire.
Conclusion: The study concluded that the PRP loop is an efficient retraction loop with an ideal moment force ratio for translatory movement of tooth. PRP loops had a higher M/F ratio than the Opus loop and L loop, indicating that PRP can be used for translatory movement of teeth in wires of different materials. Therefore, for the proper utilisation of PRP loop, it must be prepared with either 0.017×0.025 inch TMA or 0.019×0.025 inch TMA wire.