Novel surfaces and osseointegration in implant dentistry

Survival, differentiation capability, and activity of cells are strictly related to structural features and the composition of the extracellular matrix, and its variation affects tissue homeostasis. Placement of a dental implant in bone tissue activates a sequence of molecular and cellular events that lead to the apposition of newly-formed bone directly onto the titanium surface. Due to implant's interaction with the mineralized tissue, osseointegration is affected by the surface structure of the implanted material. Surface nanotopography and microtopography can modify the shape and activity of mesenchymal stem cells leading to a higher differentiation rate of these cells into osteogenic lineage with the upregulation of osteoblastic genes. Several approaches for implant surface modification are currently under investigation or have been recently proposed to improve osseointegration. Most surface treatments are aimed at the formation of a thick layer of titanium oxide, at the alteration of surface chemical composition by incorporating bioactive molecules and drugs, and at the creation of a surface topography that is more attractive for osteoblast differentiation, adhesion, and osteogenic activity. Data on the cellular-substrate interaction, as well as in vivo studies assessing the response to these novel surfaces, are reviewed in the present study. The application of modern surfaces in dental clinical practice might increase and accelerate implant osseointegration, but could also reduce the occurrence of peri-implant bone loss and favor the re-osseointegration of an affected surface.