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Mechanical And Physical Properties Of An Mma-Based Orthodontic Base-Plate Material After Ultrasonic Treatment In Water, Wadjakorn Thummawanich, Chairat Wiwatwarrapan, Chintana Sirichompun

Chulalongkorn University Dental Journal

Background/objectives: To evaluate the mechanical and physical properties of a self-cured methyl methacrylate (MMA)-based orthodontic base-plate material after 50°C water immersion in ultrasonic bath and conventional monomer reduction methods. Materials and methods: Twenty-four rectangular and twenty-four disc shaped specimens of an MMAbased orthodontic base-plate material were prepared, and randomly divided into four groups (n=6): Group I, untreated controls; Groups II and III, immersed in room temperature water for 24 and 72 hours respectively; and Groups IV immersed in 50°C water in an ultrasonic bath (100 Watts, 40 kHz) for 10 minutes. Their flexural strength, flexural modulus, microhardness, water sorption, and …