Aesthetic colour performance of plastic and ceramic brackets — an in vitro study

AbstractObjective: To evaluate the aesthetic colour performance (colour blending) of plastic and ceramic brackets by determining the colour changes of shade guide tabs before and after bracket placement.Design: In vitro, laboratory study.Materials and methods: Four plastic and four ceramic brackets were investigated (n = 5). Brackets were placed on the labial surface of the A1 and A4 tabs of a Vitapan classic shade guide. The colours of the areas corresponding to the central and inferior areas of the brackets were measured before and after bracket placement according to the CIELAB colour scale with a spectroradiometer. Changes in colour (ΔE*ab) and colour coordinates (ΔL*, Δa*, Δb* and ΔC*ab) of the tabs after bracket placement were calculated.Results: Colour changes in the central and inferior areas were in the ranges of 5·6–11·1 and 4·3–12·3 ΔE*ab units, respectively. Changes in colour and colour coordinates were influenced by shade tab colour and bracket brand (P<0·05). Compared to A1 tab, ΔE*ab, Δa*, ...