A Clinical Trial on the Failure Rates of Metallic and Ceramic Orthodontic Brackets

"Orthophosphoric acid 37% acid (Gerhò Etchant gel 37%, Gerhò spa, Terlano, Italy) will be applied for 30 s for the etching of the vestibular surfaces of teeth. The, after rinsing and drying, a thin layer of Transbond XT Light Cure Adhesive Primer (3M Unitek, Monrovia, CA, USA) will be applied and then cured for 10 s with a LED unit. At last, Transbond XT Light Cure Adhesive Paste (3M Unitek) will be applied on the base of stainless steel brackets (Queen Series Low Profile Brackets MBT 0.022, Aestetika, Terni, TR, Italy); brackets will be applied on the vestibular surfaces of teeth with a light pressure and the extra paste will be removed. Curing will be performed with the LED unit at 2 mm distant from the enamel-bracket interface for 40 s, 10 s per each surface (mesial, distal, gingival and occlusal). The following sequence of archwires will be adopted for the first six months: 0.012-in Niti, 0.014-in Niti, 0.016-in NiTi, 0.018 SS, 0.020 SS, 0.017X0.025-in NiTi, 0.019X0.025-in SS."

"Orthophosphoric acid 37% acid (Gerhò Etchant gel 37%, Gerhò spa, Terlano, Italy) will be applied for 30 s for the etching of the vestibular surfaces of teeth. The, after rinsing and drying, a thin layer of Transbond XT Light Cure Adhesive Primer (3M Unitek, Monrovia, CA, USA) will be applied and then cured for 10 s with a LED unit. At last, Transbond XT Light Cure Adhesive Paste (3M Unitek) will be applied on the base of ceramic brackets; brackets (Super Clear Series Brackets MBT 0.022, Aestetika, Terni, TR, Italy) will be applied on the vestibular surfaces of teeth with a light pressure and the extra paste is removed. Curing will be performed with the LED unit at 2 mm distant from the enamel-bracket interface for 40 s, 10 s per each surface (mesial, distal, gingival and occlusal). Then, the following sequence of archwires will be adopted for the first six months: 0.012-in Niti, 0.014-in Niti, 0.016-in NiTi, 0.018 SS, 0.020 SS, 0.017X0.025-in NiTi, 0.019X0.025-in SS"