title: Bone response to modified titanium surface implants in nonhuman primates (Papio ursinus) and humans: histological evaluation.
abstract: The aim of this study is a comparative histological and histomorphometrical evaluation of the effect on early bone formation of 2 different implant surfaces: a machined and a new acid-etched implant surface (Leader, Milano, Italy). Ten screw-type microimplants were placed in 5 patients. Each patient received 2 microimplants (2 mm in diameter and 5 mm in length): 1 with a machined surface (control) and 1 with an acid-etched surface (test). The microimplants were retrieved after 60 days of healing with a 4-mm trephine bur and processed for histology. Moreover, 24 regular size implants--12 with a machined surface (control) and 12 with an acid-etched surface (test)--were placed in 2 adult nonhuman primates 3 months after the extraction of premolars and molars. Each animal received 3 machined implants (control) in the right hemimandible and 3 acid-etched implants (test) in the left hemimandible. The same animals received 3 control implants and 3 test implants in the rectus abdominis muscle. After 1 month, the implants were retrieved from the mandible and the rectus abdominis muscle and processed for histology. Histomorphometric evaluation demonstrated a higher bone-to-implant contact in the test implants compared with the controls in both primates (25.55% vs 15.8%) and humans (62% vs 45%). Moreover, in nonhuman primates after 1 month of healing, it was possible to observe a poor osseointegration in the control specimens, while newly formed bone in direct contact with test implants was evident. The rectus abdominis muscle specimens showed that the acid-etched surfaces can stimulate the formation and attachment of new connective and vascular tissues more than machined surfaces can. Implant surface geometry can speed up bone formation by the development of a special microenvironment that promotes angiogenesis. Long-term studies are needed to further test this new acid-etched implant surface.
authors.affiliation: Dental School, University of Varese, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Mangano
authors.forename: Vittoria
authors.initials: V
authors.lastname: Perrotti
authors.forename: Giovanna
authors.initials: G
authors.lastname: Iezzi
authors.forename: Antonio
authors.initials: A
authors.lastname: Scarano
authors.forename: Francesco
authors.initials: F
authors.lastname: Mangano
authors.forename: Adriano
authors.initials: A
authors.lastname: Piattelli
mesh_terms: D000134:Acid Etching, Dental; D000368:Aged; D000818:Animals; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D003775:Dental Polishing; D017267:Dental Prosthesis Design; D005260:Female; D006801:Humans; D020007:Implants, Experimental; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D048549:Papio ursinus; D013499:Surface Properties; D014025:Titanium
chemical_list: D015921:Dental Implants; D014025:Titanium