title: Biomechanical evaluation of osseous implants having different surface topographies in rats.
abstract: Biomechanical and biological factors can co-dependently influence the establishment of implant-tissue integration; thus, concurrent evaluation of these factors should provide a better understanding of osseointegration. This study aimed to establish and validate an in vivo rat model frequently used in molecular/cellular biology for implant biomechanical studies. We tested the hypotheses that the implant push-in test assesses the degree of osseointegration by the breakpoint load at the implant-tissue interface and that it sensitively differentiates between the effects of different implant surface topographies. The implant push-in test, which produces a consistent load-displacement measurement, was used to test miniature cylindrical titanium implants placed at the distal edge of the adult rat femur. The push-in test values obtained at each post-implantation healing point (weeks 0, 2, 4, and 8) significantly increased in a time-dependent manner. The implant surface after the push-in test was associated with remnant tissues containing host-derived elements, such as calcium, phosphate, and sulfate. In this model, acid-etched implants (average roughness, 0.159 microm) showed significantly greater push-in test values than did turned implants (average roughness, 0.063 microm) throughout the experimental period (p < 0.0001). These results support the validity of the push-in test in rats, which may be used as a rapid and sensitive biomechanical assay system for implant osseointegration research.
authors.affiliation: The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA 90095-1668, USA.
authors.forename: T
authors.initials: T
authors.lastname: Ogawa
authors.forename: S
authors.initials: S
authors.lastname: Ozawa
authors.forename: J H
authors.initials: JH
authors.lastname: Shih
authors.forename: K H
authors.initials: KH
authors.lastname: Ryu
authors.forename: C
authors.initials: C
authors.lastname: Sukotjo
authors.forename: J M
authors.initials: JM
authors.lastname: Yang
authors.forename: I
authors.initials: I
authors.lastname: Nishimura
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001696:Biomechanical Phenomena; D003758:Dental Implantation, Endosseous; D004577:Electron Probe Microanalysis; D005269:Femur; D020007:Implants, Experimental; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D016348:Osseointegration; D051381:Rats; D017207:Rats, Sprague-Dawley; D018709:Statistics, Nonparametric; D013499:Surface Properties; D014025:Titanium
chemical_list: D014025:Titanium