title: Biomaterials for orthopedics: a roughness analysis by atomic force microscopy.
abstract: We conducted an AFM analysis of roughness on 7 materials widely used in bone reconstruction. Roughness was evaluated by measuring Root Mean Square (RMS) values and RMS/average height (AH) ratio, in different dimensional ranges, varying from 100 microns square to a few hundreds of nanometers. The results showed that Titanium presented a lower roughness than the other materials analyzed, frequently reaching statistical significance. On the contrary, bioactive materials, such as hydroxyapatite (HA) and bioactive glasses, demonstrated an overall higher roughness. In particular, this study focuses attention on AP40 and especially RKKP, which proved to have a significant higher roughness at low dimensional ranges. This determines a large increase in surface area, which is strongly connected with osteoblast adhesion and growth and to protein absorption. Therefore, the biointegration properties of bioactive glasses can also be given as answer in terms of surface structures in which chemical composition can influence directly the biological system (e.g. with chemical exchanges and development of specific surface electrical charge) and indirectly, via the properties induced on tribological behavior that expresses itself during the smoothing of the surfaces. We also test two new bioactive glasses, RBP1 and RBP2, with a chemical composition similar to AP40, but with some significant small additions and substitutions of components, in order to make preliminary considerations on their potential role in orthopedics.
authors.affiliation: Nanoworld Institute--CIRNNOB and Biophysics Division, University of Genova, Corso Europa 30, 16132 Genova, Italy.
authors.forename: Ugo
authors.initials: U
authors.lastname: Covani
authors.forename: Luca
authors.initials: L
authors.lastname: Giacomelli
authors.forename: Adriano
authors.initials: A
authors.lastname: Krajewski
authors.forename: Antonio
authors.initials: A
authors.lastname: Ravaglioli
authors.forename: Lorenza
authors.initials: L
authors.lastname: Spotorno
authors.forename: Patrizia
authors.initials: P
authors.lastname: Loria
authors.forename: Saradindu
authors.initials: S
authors.lastname: Das
authors.forename: Claudio
authors.initials: C
authors.lastname: Nicolini
mesh_terms: D001672:Biocompatible Materials / Q000627:therapeutic use*; D001861:Bone Regeneration; D018786:Bone Substitutes / Q000737:chemistry*; D002516:Ceramics; D017886:Durapatite; D006801:Humans; D018625:Microscopy, Atomic Force / Q000379:methods*; D009985:Orthopedics / Q000379:methods*; D013499:Surface Properties; D014025:Titanium
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; C031323:bio-vitroceramic AP40; D017886:Durapatite; D014025:Titanium