Comparison of surface-treated and untreated orthodontic bands: evaluation of shear force and surface roughness

In an attempt to increase retention of orthodontic bands, orthodontic companies market bands with surfaces prepared to increase roughness. A comparison of six groups of bands, including two with untreated surfaces, revealed a wide range of variation in shear forces. Three classes of retention may be differentiated on the basis of non-statistically significantly different mean shear forces in each category: high (Unitek, treated), moderate (Unitek, untreated; A Co., treated; GAC, treated), and low (A Co., untreated; Dentaurum, treated). Surface roughness, as evaluated through atomic force microscopy, correlated moderately with shear force (r = 0.61; p < 0.05). This method is examined and compared with the qualitative profiles of the orthodontic band surfaces provided by optical micrography.