Abstract
Major drawbacks of ceramic brackets are their fragility and low resistance to pressure that is due to natural physical characteristics of ceramic material. The resistance is related to bracket shape and material used.
Aim: The present study aims to assess resistance of selected commercially available ceramic brackets to tosional force from archwires, i.e. third order archwires activations. Material and method: 12 different brands of commercially available ceramic brackets ( 5 of each brand ) were subject to stress test.
Archwire torsion was elicited by a universal testing machine Instron 5882. Results: Brackets made of monocrystalline aluminium oxide are significantly more resistant than those made of polycrystalline aluminium oxide; true - twin brackets are more resistant than semitwin brackets.
The highest values were measured for brackets Radiance (maximum moment of force 10980 cNmm), the lowest for TruKlear brackets (minimum moment of force 4392 cNmm). Conclusion: Ceramic brackets tested are fully resistant to clinically recommended tooth torquing force and satisfy clinical requirements