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| Scientific References |
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| Removal torque values of titanium implants in the
maxilla of miniature pics. Univerity of Berna Switzerland |
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Buser D, Nydegger T, Hirt
HP, Cochran DL, Nolte LP.
Int J Oral Maxillofac Implants. 1998 Sep-Oct;13(5):611-9.
Department of Oral Surgery, School of Dental Medicine, University
of Berne, Switzerland |
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| The purpose of this study was to compare side-by-side
two different titanium screw-type implants in the maxillae of miniature
pigs. The test implants had a machined and acid-etched surface (Osseotite)
whereas the control implants were sandblasted and acid-etched (SLA).
After 4, 8, and 12 weeks of healing, removal torque testing was performed
to evaluate the shear strength of the bone-implant interface for both
implant types. The results demonstrated significant differences between
both implant types (P < .01). Osseotite implants revealed mean
removal torque values (RTV) of 62.5 Ncm at 4 weeks, 87.6 Ncm at 8
weeks, and 95.7 Ncm at 12 weeks of healing. In contrast, the SLA implants
demonstrated mean RTV of 109.6 Ncm, 196.7 Ncm, and 186.8 Ncm at corresponding
healing periods. The mean RTV for SLA implants was 75% to 125% higher
than for Osseotite implants up to 3 months of healing. |
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Interface shear strength of titanium implants with
sandblasted and acid etched surface
A biomechanical study in the maxilla of miniature pics |
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Buser D, Nydegger T, Oxland
T, Cochran DL, Schenk RK, Hirt HP, Snetivy D, Nolte LP.
J Biomed Mater Res. 1999 May;45(2):75-83.
Department of Oral Surgery, School of Dental Medicine, University
of Berne, Freiburgstrasse 7, CH-3010 Berne, Switzerland |
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| The purpose of the present study was to evaluate
the interface shear strength of unloaded titanium implants with a
sandblasted and acid-etched (SLA) surface in the maxilla of miniature
pigs. The two best documented surfaces in implant dentistry, the machined
and the titanium plasma-sprayed (TPS) surfaces served as controls.
After 4, 8, and 12 weeks of healing, removal torque testing was performed
to evaluate the interface shear strength of each implant type. The
results revealed statistically significant differences between the
machined and the two rough titanium surfaces (p <.00001). The machined
surface demonstrated mean removal torque values (RTV) between 0.13
and 0.26 Nm, whereas the RTV of the two rough surfaces ranged between
1.14 and 1.56 Nm. At 4 weeks of healing, the SLA implants yielded
a higher mean RTV than the TPS implants (1.39 vs. 1. 14 Nm) without
reaching statistical significance. At 8 and 12 weeks of healing, the
two rough surfaces showed similar mean RTVs. The implant position
also had a significant influence on removal torques for each implant
type primarily owing to differences in density in the periimplant
bone structure. It can be concluded that the interface shear strength
of titanium implants is significantly influenced by their surface
characteristics, since the machined titanium surface demonstrated
significantly lower RTV in the maxilla of miniature pigs compared
with the TPS and SLA surfaces. |
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| The effects of surface topography of micromachined
titanium substrata on cell behavior in vitro and in vivo |
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Brunette DM, Chehroudi
B.
J. Biomech Eng. 1999 Feb;121(1):49-57.
Department of Oral Biological and Medical Sciences, Faculty of Dentistry,
University of British Columbia, Vancouver, Canada. |
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| Surface properties, including topography and chemistry,
are of prime importance in establishing the response of tissues to
biomaterials. Microfabrication techniques have enabled the production
of precisely controlled surface topographies that have been used as
substrata for cells in culture and on devices implanted in vivo. This
article reviews aspects of cell behavior involved in tissue response
to implants with an emphasis on the effects of topography. Microfabricated
grooved surfaces produce orientation and directed locomotion of epithelial
cells in vitro and can inhibit epithelial downgrowth on implants.
The effects depend on the groove dimensions and they are modified
by epithelial cell-cell interactions. Fibroblasts similarly exhibit
contact guidance on grooved surfaces, but fibroblast shape in vitro
differs markedly from that found in vivo. Surface topography is important
in establishing tissue organization adjacent to implants, with smooth
surfaces generally being associated with fibrous tissue encapsulation.
Grooved topographies appear to have promise in reducing encapsulation
in the short term, but additional studies employing three-dimensional
reconstruction and diverse topographies are needed to understand better
the process of connective-tissue organization adjacent to implants.
Microfabricated surfaces can increase the frequency of mineralized
bone-like tissue nodules adjacent to subcutaneously implanted surfaces
in rats. Orientation of these nodules with grooves occurs both in
culture and on implants. Detailed comparisons of cell behavior on
micromachined substrata in vitro and in vivo are difficult because
of the number and complexity of factors, such as population density
and micromotion, that can differ between these conditions. |
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| SCIENTIFIC ABSTRACTS |
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| Compiled by Dr. Juan José Gersberg |
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