title: The effect of osteopenia on the osteointegration of different biomaterials: histomorphometric study in rats.
abstract: The osteointegration of Hydroxyapatite (HA), Titanium (Ti-6Al-4V: Ti), Zirconia (ZrO2), Alumina (Al2O3) and 2 biological glasses (AP40 and RKKP) was comparatively investigated in normal and osteopenic rats by means of histomorphometry. Thirty-six Sprague Dawley female rats were left intact (Group C) while 36 were ovariectomized (Group OVX). Group C and OVX were further divided into 6 subgroups. After 16 weeks all animals were submitted to the femoral implant of nails made of the above-mentioned materials. Eight weeks after implantation the animals were euthanized, the femurs were harvested for histomorphometric analysis. The data showed that: (1) all the tested materials were biocompatible in vitro; (2) no significant differences existed in Affinity Index (AI) of Group C; and (3) results from paired comparison applied to the AI showed significant differences among the Groups C and OVX. The AI did not significantly change among intact groups, while it significantly decreased when some materials were implanted in OVX subgroups (AP40, ZrO2 and Ti-6Al-4V: p < 0.0005, p < 0.05 and p < 0.01). It is confirmed that bone mineral density is a strong predictor of the osteointegration of an orthopedic implant and that the use of pathological animal models is necessary to completely characterize biomaterials.
authors.affiliation: Experimental Surgery Department and Chair of Surgical Pathophysiology, University of Bologna, Research Institute Codivilla-Putti, Rizzoli Orthopedic Institute (I.O.R.), Via Di Barbiano 1/10, 40136 Bologna, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Fini
authors.forename: G
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authors.lastname: Giavaresi
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authors.initials: NN
authors.lastname: Aldini
authors.forename: P
authors.initials: P
authors.lastname: Torricelli
authors.forename: G
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authors.lastname: Morrone
authors.forename: G A
authors.initials: GA
authors.lastname: Guzzardella
authors.forename: R
authors.initials: R
authors.lastname: Giardino
authors.forename: A
authors.initials: A
authors.lastname: Krajewski
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authors.initials: A
authors.lastname: Ravaglioli
authors.forename: M M
authors.initials: MM
authors.lastname: Belmonte
authors.forename: A D
authors.initials: AD
authors.lastname: Benedittis
authors.forename: G
authors.initials: G
authors.lastname: Biagini