Criteria for the evaluation of dental implant success are proposed These criteria are applied in an assessment of the long-term efficacy of currently used dental implants including the subperiosteal implant, the vitreous carbon implant, the blade-vent implant, the single-crystal sapphire implant, the Tubingen implant, the TCP-implant, the TPS-screw, the ITI hollow-cylinder implant, the IMZ dental implant, the Core-Vent titanium alloy implant, the transosteal mandibular staple bone plate, and the Branemark osseointegrated titanium implant An attempt has been made to standardize the basis for comments on each type of implant

https://coimplante.odo.br/Biblioteca/Trabalhos%20classicos/A%20review%20and%20proposed%20a%20criteria%20of%20success%20-%20Albrektson%20et%20al.pdf

The long-term efficacy of currently used dental implants: a review and proposed criteria of success.

Osteoinduction is the process by which osteogenesis is induced. It is a phenomenon regularly seen in any type of bone healing process. Osteoinduction implies the recruitment of immature cells and the stimulation of these cells to develop into preosteoblasts. In a bone healing situation such as a fracture, the majority of bone healing is dependent on osteoinduction. Osteoconduction means that bone grows on a surface. This phenomenon is regularly seen in the case of bone implants. Implant materials of low biocompatibility such as copper, silver and bone cement shows little or no osteoconduction. Osseointegration is the stable anchorage of an implant achieved by direct bone-to-implant contact. In craniofacial implantology, this mode of anchorage is the only one for which high success rates have been reported. Osseointegration is possible in other parts of the body, but its importance for the anchorage of major arthroplasties is under debate. Ingrowth of bone in a porous-coated prosthesis may or may not represent osseointegration.

/pdf/osteoinduction-osteoconduction-and-osseointegration-1aufckjsjh.pdf

Osteoinduction, osteoconduction and osseointegration.

The literature on university entrepreneurship is rapidly expanding, in both the United States and Europe. Since the literature is also fairly fragmented, however, we submit that it is time to take stock of the current knowledge to provide directions for future research and guideposts for policy makers. To accomplish this, we present an unusually comprehensive and detailed literature analysis of the stream of research on university entrepreneurship, now encompassing 173 articles published in a variety of academic journals. Four major research streams emerge in this area of study: (i) entrepreneurial research university, (ii) productivity of technology transfer offices, (iii) new firm creation, and (iv) environmental context including networks of innovation. We inductively derive a framework describing the dynamic process of university entrepreneurship based on a synthesis of the literature. We submit that this framework is useful in guiding future research on this important, yet complex and under-researched topic.

/pdf/university-entrepreneurship-a-taxonomy-of-the-literature-4b9y2nciv4.pdf

University entrepreneurship: a taxonomy of the literature

This paper reviews the theory and applications of photoacoustic (also called optoacoustic) methods belonging to the more general area of photothermal measurement techniques. The theory covers excitation of gaseous or condensed samples with modulated continuous light beams or pulsed light beams. The applications of photoacoustic methods include spectroscopy, monitoring deexcitation processes, probing physical properties of materials, and generating mechanical motions. Several other related photothermal methods, as well as particle-acoustics and wave-acoustics methods are also described. This review complements an earlier and narrower review [Rev. Mod. Phys. 53, 517 (1981)] that is mainly concerned with sensitive detection by pulsed photoacoustic spectroscopy in condensed matter.

Applications of photoacoustic sensing techniques

Carbon (C) is a crucial material for many branches of modern technology. A growing number of demanding applications in electronics and telecommunications rely on the unique properties of C allotropes. The need for microwave absorbers and radar-absorbing materials is ever growing in military applications (reduction of radar signature of aircraft, ships, tanks, and targets) as well as in civilian applications (reduction of electromagnetic interference among components and circuits, reduction of the back-radiation of microstrip radiators). Whatever the application for which the absorber is intended, weight reduction and optimization of the operating bandwidth are two important issues. A composite absorber that uses carbonaceous particles in combination with a polymer matrix offers a large flexibility for design and properties control, as the composite can be tuned and optimized via changes in both the carbonaceous inclusions (C black, C nanotube, C fiber, graphene) and the embedding matrix (rubber, thermoplastic). This paper offers a perspective on the experimental efforts toward the development of microwave absorbers composed of carbonaceous inclusions in a polymer matrix. The absorption properties of such composites can be tailored through changes in geometry, composition, morphology, and volume fraction of the filler particles. Polymercomposites filled with carbonaceous particles provide a versatile system to probe physical properties at the nanoscale of fundamental interest and of relevance to a wide range of potential applications that span radar absorption, electromagnetic protection from natural phenomena (lightning), shielding for particle accelerators in nuclear physics, nuclear electromagnetic pulse protection, electromagnetic compatibility for electronic devices, high-intensity radiated field protection, anechoic chambers, and human exposure mitigation. Carbonaceous particles are also relevant to future applications that require environmentally benign and mechanically flexible materials.

A review and analysis of microwave absorption in polymer composites filled with carbonaceous particles

The interface zone between titanium implants and bone is considered at the macroscopic, microscopic, and molecular levels. A high rate of successful dental implants of pure titanium is associated with a very close apposition of the bone to the titanium surface, called osseointegration. At the macroscopic level, osseointegration allows efficient stress transfer from the implant to the bone without abrasion or progressive movement that can take place if a fibrous layer intervenes. At the microscopic level, surface roughness and porosity provide interlocking of the implant and bone tissue which grows into direct contact with titanium. Sections studied in the electron microscope show that calcified tissue can be identified within 50 A of the implant surface. The interface zone includes a tightly adherent titanium oxide layer on the surface of the implant which may be similar to a ceramic material in relation to tissue response. The five year success rate of 90% in 2895 implants in clinical trials since 1965 is associated with the favorable behavior of bone tissue at the interface zone with pure titanium.

The interface zone of inorganic implants in vivo: Titanium implants in bone.

The dielectric behaviour of various carbon black polymer composites has been characterized by the critical frequency ωc denoting the crossover from the dc plateau of the conductivity to its frequency dependent ac behaviour. The critical frequency can be related to the dc conductivity using a power law, ωc∝σdcz, with the exponent z. Presently accepted models predict z to be greater than one when varying the filler content. However, in accordance with published experimental results this work shows that z is rather close to one indicating a nearly constant static permittivity. Furthermore, the above power law makes it possible to describe all investigated compounds using a single master curve ranging over ten decades of dc conductivity. These findings are explained by a qualitative percolation model based on electron tunnelling. Increasing the dc conductivity along the percolation curve does not require the establishment of more physical links between carbon black aggregates. Rather, new conduction paths of nearly the same lengths but with higher tunnelling probability due to smaller gaps satisfy the percolation theory. This scenario allows the number of capacitive gaps to be nearly constant making z near one.

https://iopscience.iop.org/article/10.1088/0022-3727/34/17/319/pdf

Douglas H. McQueen

Papers

The interface zone of inorganic implants in vivo: Titanium implants in bone.

Electron transport and ac electrical properties of carbon black polymer composites

Comparison of two infrared spectroscopic methods for cheese analysis.

Spin-off companies from Chalmers University of Technology

Fractal agglomerates and electrical conductivity in carbon black polymer composites