Defining surfaces : Implant topography – a review (Preprint)

Abstract

BACKGROUND . A variety of claims are made regarding the effects of surface topography on implant osseointegration. The development of implant surfaces topography has been empirical, requiring numerous in vitro and in vivo tests. Most of these tests were not standardized, using different surfaces, cell populations or animal models. The exact role of surface chemistry and topography on the early events of the osseointegration of dental implants remain poorly understood. OBJECTIVE This review considers the major claims made concerning the effects of titanium implant surface topography on osseointegration. The osseointegration rate of titanium dental implants is related to their composition and surface roughness. The different methods used for increasing surface roughness or applying osteoconductive coatings to titanium dental implants are reviewed. Important findings of consensus are highlighted, and existing controversies are revealed. METHODS This review considers many of the research publications listed in MEDLINE and presented in biomedical research publications and textbooks. Surface treatments, such as titanium plasma-spraying, grit-blasting acid-etching,alkaline etching, anodization,polymer demixing ,sol gel conversion and their corresponding surface morphologies and properties are described. RESULTS Many in vitro evaluations are not predictive of or correlated with in vivo outcomes. In some culture models, increased surface topography positively affects pro-osteogenic cellular activities. Many studies reveal increase in bone-to-implant contact,with increased surface topography modifications on implant surfaces. CONCLUSIONS Increased implant surface topography improves the bone-to-implant contact and the mechanical properties of the enhanced interface.

The Sun as a probe of Fundamental Physics and Cosmology

“…As a nuclear physics community, if you remember the 30's and 40's, the Sun has played a key role in the progress and development of nuclear physics, namely, by contributing to the understanding of the basic nuclear processes that lead to the discovery of the nuclear chain reactions (PP chains, CNO cycle and 3α reactions) by H. Bethe, C. F. von Weizsäcker and F. Hoyle among others. Therefore, it is no surprise, that in particular the Sun, and in general the other stars, can play an important role to explore the validity of new fundamental laws of physics, such as testing new theories of gravity proposed as alternative to General Gravity [1], to discuss the precision of new measurements of fundamental constants [2], to study the properties of neutrino flavour oscillations [3,4], and, as discussed in this talk, as a tool to determine the properties of dark matter (DM)) [5][6][7].…”