Geometry of Implants Surfaces
Recent studies showed the importance of surface geometry in promoting bone formation also in extraskeletal sites. The implant topographic surface modification may optimize the interactions with host tissue during healing phase, in order to obtain the best tissue response in a shorter time.
The surface geometry constituted by a sequence of concavities that go continuing in an underlying porous network seems to be able to directly stimulate the cells to give complete expression of the osteogenic phenotype.
The osteoblasts together with growth factors and specific cytokines, that is, molecular signals that govern cellular activity, tend to preferentially concentrate into concavities.
This is the natural process taking place during the bone remodelling phase, a genetically regulated and coded phenomenon, which has been characterizing the life of all organisms with skeleton for millions of years. During bone remodelling, osteoclasts resorb bone, thus creating cavities that are immediately populated by vessels and osteoblasts able to form new bone. Cavities represent indeed a real “universal motive” of bone tissuE.”
The DLMF (Direct Laser Metal Forming) technique, a new Rapid Prototyping (RP) application, allows the manufacture of implants with controlled porosity, pore size, shape and interconnections.Using DLMF, it is now possible to fabricate dental implants with different shape and texture, by the laser fusion of titanium microparticles.
As proved by Anoticel Susej Method, DLMF allows the manufacturing of implants with graded isoelasticity values, which are similar to those of the surrounding bone, from the inner core to the outer surface. This new functionally graded material has the potential to transfer the loading stress more naturally.
Van Eeden SP, Ripamonti U. Bone differentiation in porous hydroxyapatite in baboons is regulated by the geometry of the substratum: implications for reconstructive craniofacial surgery. Plast Reconstr Surg 1996; 93:959–966.
Ripamonti U, Crooks J, Kirkbride AN. Sintered porus hydroxyapatites with intrinsic osteoinductive activity: geometric induction of bone formation. South African Journal of Sciences 1999; 95:335-343.
Mangano C, Ripamonti U, Mangano F. Bioingegneria applicata all’implantologia osteointegrata: realtà clinica o ricerca pura? Implantologia Orale 2006; 4:7-1
Ripamonti U, Ma S, Reddi AH. The critical role of geometry of porous hydroxyapatite delivery system in induction of bone by osteogenin, a bone morphogenetic protein. Matrix 1992; 12:202-212.
Ripamonti U. Osteoinduction in porous hydroxyapatite implanted in heterotopic sites of different animal models. Biomaterials 1996; 17:31-35.
Bartolucci E, Mangano C. Il successo in implantologia. Masson Ed. 2004
Mangano C, Ripamonti U, Mangano F. Superfici biomimetiche e osteointegrazione: studio su primati non umani. Oral Surgery 2005; 2:9-17
Dental Implants Cost website – http://costofdentalimplant.com/