Current Issue : April - June Volume : 2013 Issue Number : 2 Articles : 5 Articles
Dental implants made from binary titanium-zirconium (TiZr) alloys have shown\r\npromise as a high strength, yet biocompatible alternative to pure titanium, particularly for\r\napplications requiring small diameter implants. The aim of this review is to summarize\r\nexisting literature reporting on the use of binary TiZr alloys for endosseous dental implant\r\napplications as tested in vitro, in animals and clinically. And furthermore to show that TiZr\r\nis ââ?¬Å?at least as good asââ?¬Â pure titanium in terms of biocompatibility and osseointergration.\r\nFrom the twelve papers that met the inclusion criteria, the current literature confirms that\r\nTiZr alloys produce small diameter implants with a strength up to 40% higher than\r\nconventional, cold-worked, grade IV titanium implants, and with a corrosion resistance and\r\nbiocompatibility that is at least as good as pure titanium. The surface structure of TiZr is\r\ncompatible with established surface treatments proven to aid in the osseointegration of\r\ntitanium implants. Furthermore, binary TiZr alloys have been shown to achieve good\r\nosseointegration and high success rates both in animal and in clinical studies....
Implantable medical devices are increasingly important in the practice of modern medicine. However, patients with severely\r\npoor bone quality and quantity require highest implant osseointegration for the long-term success. A number of newly-developed\r\nadvanced surface modifications of medical implants have recently been introduced to the medical implant system. Understanding the\r\nmechanisms by which osteogenic cells respond to such materials is therefore of major importance in developing the most effective\r\nmaterials to promote functional osseointegration. Diverse studies using materials with a wide range of new surface modification\r\ntechniques have demonstrated the pivotal role of surface treatments in cell adhesion, proliferation and lineage specific differentiation.\r\nThese events underlie the tissue responses required for bone healing following implant placement, with the interaction between adsorbed\r\nproteins on the implant surface and surrounding cells eliciting body responses to the treated implant surface. This review illustrates\r\ntissue responses to the implant material following implant placement and highlights cellular responses to new advanced implant surface\r\nmodifications. Such information is of utmost importance to further develop several new advanced surface modifications to be used in\r\nthe new era medical implantable devices....
Aims: To compare if there is an improvement in visual functions with age-related cataracts between patients\r\nreceiving customized selected aspherical intraocular lens (IOL) implants and patients randomly assigned lenses.\r\nMethods: Ninety-four patients (94 eyes) with age-related cataracts were placed in experimental group or a\r\ngroup receiving randomly assigned (RA) lenses. All patients were undergone Pentacam corneal spherical aberration\r\nmeasurement before surgery; The targeted range for residual total spherical aberration after surgery was set to 0-0.3\r\n�µm in experimental group. Patients with a corneal spherical aberration = 0.3 �µm were implanted with a zero-spherical\r\naberration advanced optics (AO) aspherical intraocular lens and patients with an aberration 0.3 �µm received a Tecnis\r\nZA9003 aspherical lens. RA patients were randomly implanted with an AO lens or a Tecnis ZA9003 lens. Three months\r\nafter surgery total spherical aberration, photopic/mesopic contrast sensitivities, photopic/mesopic with glare contrast\r\nsensitivities, and LogMAR vision were measured.\r\nResults: Statistical analysis on LogMAR vision showed no significant difference between two groups (P = 0.308).\r\nThe post-surgical total spherical aberration was 0.120 �± 0.097 �µm and 0.158 �± 0.152 �µm in the experimental and RA\r\ngroups, respectively (P = 0.08). The mesopic contrast sensitivities at spatial frequencies of 6, 12 and 18 c/d in the\r\nexperimental group were significantly higher than of the RA group (P = 0.00; P = 0.04; P = 0.01). The mesopic with\r\nglare contrast sensitivity in the RA group at a spatial frequency of 18 c/d was also significantly higher vs. the RA group\r\n(P = 0.02).\r\nConclusion: Pre-surgical corneal spherical aberration measurement in cataract patients followed by customized\r\nselection of aspherical intraocular lens implants improved mesopic contrast sensitivities and mesopic with glare contrast\r\nsensitivities at high spatial frequencies, and thus is a superior strategy compared to the random selection of aspherical\r\nintraocular lens implants....
Purpose. The immunological mechanisms of peri-implant crestal bone loss have, hitherto, not been elucidated. We hypothesized\r\nthat bacterial products from the microgap cause upregulation of cytokines in otherwise healthy peri-implant cells, which results in\r\nosteoclast formation and, ultimately, in bone resorption. Materials and Methods. We used RT-PCR and ELISA to assay mediators\r\nof osteoclastogenesis in rat and human macrophages (r-and hMO); bone marrow derived stromal cells (r-and hBMCs); and\r\nhuman gingival fibroblasts (hGF)ââ?¬â?with or without stimulation by LPS. TRAP positive multinucleate cells were assessed for\r\ntheir resorptive ability. Results. We show that IL-1a, IL-1Ã?Ÿ, and IL-6 were expressed by all examined cell types, and TNF-a was\r\nupregulated in hGF. Secretion of IL-1a and IL-1Ã?Ÿ proteins was stimulated in hMO by LPS, and IL-6 protein secretion was highly\r\nstimulated in hBMCs and hGF. Both LPS and RANKL stimulated macrophages to form osteoclast-like TRAP positive cells, which\r\nresorbed calcium phosphate substrates. Conclusion. Taken together, the results of our study support the hypothesis that bacterial\r\nendotoxins upregulate enhanced mediators of osteoclastogenesis in resident cells found in the healthy peri-implant compartment\r\nand that the local synergistic action of cytokines secreted by such cells results in the genesis of resorptively active osteoclasts...
Implant therapy has become a reliable and predictable treatment alternative for the replacement of missing teeth with conventional\r\nremovable and fixed partial dentures. Recently though, in the pursuit for improved esthetics, the literature has dedicated a\r\nconsiderable amount of its research on the successful maintenance and regeneration of the surrounding gingiva and bone, which\r\nare lost following extraction of a tooth. Thoroughly analyzing the anatomic situation and well-planned treatment has become a\r\nrequirement, because incorrectly planned and positioned implants may jeopardize long-term esthetic and functional prognosis.\r\nIn addition, many types of biocompatible materials, autogenous hard and soft tissue grafts, and different surgical techniques have\r\nbeen developed, and their viability has been investigated. As a result, implant specialists have gained a greater understanding\r\nof the dynamics and anatomical and biological concepts of the periodontium and peri-implant tissues both at the surgical and\r\nprosthetic phases of treatment, which contributes to better soft and hard tissue management (SHTM). This may further contribute\r\nto achieving a superior final result which is obtained by having a harmonious soft tissue profile, a correctly placed and contoured\r\nfinal restoration, and the reestablishment of masticatory function and phonetics....
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