Aim: to assess surface roughness and coating retention of epoxy coated wires after clinical use and to compare them to conventional nickel titanium archwires.
Materials and methods: Wires were retrieved from 26 patients attending the Outpatient Clinic of Orthodontic Department Faculty of Dentistry, Ain Shams University. Patients enrolled in group A (n=13) received conventional superelastic nickel titanium archwires with wire sequence 0.014 niti, 0.016 niti, 0.016 X 0.022 niti, while patients enrolled in group B (n=13) received coated nickel titanium archwires (Ortho Technology) with the same wire sequence. Wires were divided into 4 main groups; two groups containing wires as received from the manufacturer and the other two groups were wires retrieved from patients after alignment. Each group was further divided into 3 subgroups according to wire size. Surface roughness of retrieved and as received coated and conventional nickel titanium wires was assessed using AFM. SEM was used to assess the micro morphological characteristics of coated archwires before and after use in the oral cavity.
Results: In as received: surface roughness in group A was significantly higher than in group B regarding 0.014 NiTi, 0.016 NiTi, and 0.016X0.022 NiTi. In retrieved: surface roughness in group A was significantly lower than in group B regarding 0.014 NiTi, 0.016 NiTi, and 0.016X0.022 NiTi.
Conclusions: Surface roughness of coated nickel titanium archwires is initially less that of conventional archwires, with clinical use surface roughness increased in both groups with significant higher increase regarding coated archwires. Coated retrieved archwires showed areas of coating loss.