An Investigation about the Influence of Bleaching on Shear Bond Strength of Orthodontic Brackets and on Enamel Colour
Figure 2
2(a)–2(c) Spectrophotometrically evaluated tooth colour. The difference in colour is expressed by the parameter for lightness (L*), red-green (a*), and yellow-blue (b*). The three test series displayed as box-whisker plots represent the difference between bleached and unbleached (left), debonded and bleached (middle), and plus debonded and unbleached (right). 2(d) Shear bond strength of ceramic brackets bonded to enamel after a 20% phosphoric acid etching for 20 s. Results are displayed for Group II (left) and Group I (right) in MPa.
