Search PubMed⌕ Search

PubMed · 2168765

Surface physics methods and in vitro bone-biomaterial interface control.

Abstract

After a brief review of the main characteristics of some spectroscopic and microscopic methods for surface and interface analysis, preliminary and prospective studies of biocompatible materials (hydroxyapatite, alumina) for implant coating purposes are presented. The results show that the use of complementary techniques allows information on the physical and chemical properties of the coatings both on a microscopic and on an atomic scale to be obtained.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

D Muster, P Humbert, A Mosser. 1990. Surface physics methods and in vitro bone-biomaterial interface control.. https://pubmed.ncbi.nlm.nih.gov/2168765/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Lifetime of alumina- and zirconia ceramics used for crown and bridge restorations.

The lifetime of a ceramic is dependent on the presence of incidental cracks and their gradual propagation under the conditions of the oral cavity. The objective of this study was to examine the long-term strength of glass-infiltrated alumina- and various zirconia ceramics currently used in CAD/CAM systems to manufacture crown and bridge frameworks. Fracture mechanics were applied to determine characteristic strength (sigma(omicron)), Weibull modulus (m), fracture toughness (K(Ic)), and the subcritical crack growth parameters n and B. Based on these parameters, lifetime diagrams were generated which allowed the evaluation of the long-term behavior. The results showed that in a moist environment, the glass-infiltrated alumina- and some zirconia ceramics have a high susceptibility to subcritical crack growth. Zirconia ceramics with an alumina oxide content of 0.25 wt %, however, exhibited the highest initial and most favorable long-term strength, and should therefore be suitable for crown and bridge restorations.

Aluminum Oxide↗

Role of core support material in veneer failure of brittle layer structures.

A study is made of veneer failure by cracking in all-ceramic crown-like layer structures. Model trilayers consisting of a 1 mm thick external glass layer (veneer) joined to a 0.5 mm thick inner stiff and hard ceramic support layer (core) by epoxy bonding or by fusion are fabricated for testing. The resulting bilayers are then glued to a thick compliant polycarbonate slab to simulate a dentin base. The specimens are subjected to cyclic contact (occlusal) loading with spherical indenters in an aqueous environment. Video cameras are used to record the fracture evolution in the transparent glass layer in situ during testing. The dominant failure mode is cone cracking in the glass veneer by traditional outer (Hertzian) cone cracks at higher contact loads and by inner (hydraulically pumped) cone cracks at lower loads. Failure is deemed to occur when one of these cracks reaches the veneer/core interface. The advantages and disadvantages of the alumina and zirconia core materials are discussed in terms of mechanical properties-strength and toughness, as well as stiffness. Consideration is also given to the roles of interface strength and residual thermal expansion mismatch stresses in relation to the different joining methods.

Aluminum Oxide↗

Role of indenter material and size in veneer failure of brittle layer structures.

The roles of indenter material and size in the failure of brittle veneer layers in all-ceramic crown-like structures are studied. Glass veneer layers 1 mm thick bonded to alumina layers 0.5 mm thick on polycarbonate bases (representative of porcelain/ceramic-core/dentin) are subject to cyclic contact loading with spherical indenters in water (representative of occlusal biting environment). Two indenter materials-glass and tungsten carbide-and three indenter radii-1.6, 5.0, and 12.5 mm-are investigated in the tests. A video camera is used to follow the near-contact initiation and subsequent downward propagation of cone cracks through the veneer layer to the core interface, at which point the specimen is considered to have failed. Both indenter material and indenter radius have some effect on the critical loads to initiate cracks within the local Hertzian contact field, but the influence of modulus is weaker. The critical loads to take the veneer to failure are relatively insensitive to either of these indenter variables, since the bulk of the cone crack propagation takes place in the contact far field. Clinical implications of the results are considered, including the issue of single-cycle overload versus low-load cyclic fatigue and changes in fracture mode with loading conditions.

Aluminum Oxide↗