The roughness of deciduous dentin surface and shear bond strength of glass ionomers in the treatment with four minimally invasive techniques

The concept of minimally invasive technique in dentistry emphasizes conservative strategies in the management of caries, which results in less destruction of healthy tooth structure. The use of different techniques seems to interfere in the roughness of dentin and the mechanisms of adhesion with the restorative material. This study characterized the roughness of deciduous dentin surface treated with four minimally invasive techniques using profilometry, atomic force microscopy (AFM) and scanning electron microscopy (SEM); moreover, shear bond strength of Vitremer (TM) glass ionomer was determined. Samples were divided into four groups: G1_CB carbide bur, G2_PB polymer bur, G3_C Carisolv (TM), and G4_AA air abrasive. No differences were found between groups before and after treatment in the roughness. Samples treated with a carbide bur presented a smear layer; smart bur surface exhibited the remains of the material; G3_C Carisolv (TM) showed a rough surface, and air abrasive presented particle traces. Concerning the shear bond strength of Vitremer (TM) glass ionomer were not found differences after treatment (p > 0.05). It is concluded that roughness showed characteristic patterns derived from the technique used and the shear bond strength is not significantly affected after using any minimally invasive method.