Study of UV-curable composite resin of transfer tray for orthodontics

Abstract

Objectives: the aim of this study was to investigate the properties of UV-curable composite resin of transfer tray for indirect bonding system of the lingual brackets. Methods: the conversion of double-bond in the different concentration of UV-initiator was monitored by real time infrared (RTIR). The three-point flexure strength was measured by a universal testing machine. The storage modulus, loss modulus, and loss factor (tan delta) of the resin were measured by a Dynamic Mechanical Analyzer. The cytotoxicity of composite resin was evaluated by the agar covering test. Results: the double bond conversion exceeded 70% at [benzophenone] = 0.7 wt.%, [Ethyl 4-dimethylaminobenzoate] = 0.7 wt.% and [2-Hydroxy-2-methyl-1-phenyl propanon] = 1 wt.%. The mean value of flexural strength came to 122 MPa. The value of storage modulus was 1.04 × 10⁹ MPa at 23°C. The glass transition temperature was 142°C. The toxicity grade was zero at 2 h and one at 24 h. Conclusions: in the preliminary evaluations, we indicated that the UV-curable composite resin of transfer tray could satisfy the clinical requirements.

Keywords

composite resin / indirect bonding / transfer tray / UV-curable