**2.5 Resorbable blasting media**

The previously described method of SLA surface modification of miniscrews consisted of sandblasting with alumina (Al2O3) particles. These particles do not resorb *in vivo* and therefore, are non-resorbable blasting media. However, sandblasting of implant surfaces with resorbable blasting media (RBM) such as hydroxyapatite or calcium phosphate particles has also been reported recently [48]. In an *in vitro* comparative evaluation of the physical characteristics of machined, acid-etched, RBM treated and hybrid (machined + acid-etched) orthodontic mini-implants, Kim et al. reported
