This study examined and compared surface of human dentine after acidic etching with hydrogen peroxide, phosphoric acid liquid and gel. Surface demineralization of dentin is necessary for a strong bond of adhesive at dental surface. Split human teeth were used. After application of mentioned substances at dentin level measures of the contact angle and surface morphology were employed. Surface morphology was analyzed with the help of scanning electron microscopy and atomic force microscopy. Liquid phosphoric acid yielded highest demineralization showing better hydrophobicity than the rest, thus having more contact surface. Surface roughness are less evident and formed surface micropores of 4 �m remained open after wash and air dry providing better adhesive canalicular penetration and subsequent bond.

This paper presents the effect of the sandblasting and sintering processes on the surface properties of some commercial yttria stabilized zirconia (Y-TZP) for monolithic dental restorations in dentistry. The surface properties of dental zirconia can be improved further through various surface treatment methods, like surface abrasion, roughening, chemical treatment, tribochemical coating, or selective infiltration etching. But all these treatments are made on the sintered samples, not on the pre-sintered discs as are delivered by the dental suppliers. The hypothesis of this paper was that the mechanical effect on the surface of pre-sintered disc of Y-TZP assured by airborne-particle abrasion with alumina will be maintained after the sintering process. Additionally, we will follow the presence of alumina particles on the Y-TZP surface after airborne-particle abrasion process. Surface modifications of the experimental samples was performed by sandblasting for 15 s with Al2O3 particles (average particle size 83 mm) at pressure of 2 bars, using a SAB-Caloris equipment. Morphological and surface changes in the sandblasted, respectively sandblasted and sintered samples of Y-TZP are examined by using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. It is found that the surface modifications made on the pre-sintered Y-TZP disc remain after sintering process, which not affects these mechanical modifications of the surface. Also, it was detected the presence of alumina particles on the Y-TZP samples after airborne-particle abrasion process and for this reason we recommend the use of zirconia particle for airborne-abrasion process.