Surface and biological evaluation of hydroxyapatite-based coatings on titanium deposited by different techniques.

Hydroxyapatite coatings have been deposited on titanium cp by plasma spray, sol-gel, and sputtering techniques for dental implant applications. The latter two techniques are of current interest, as they allow coatings of micrometer dimensions to be deposited. Coating morphology, composition, and structure have been investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). All coatings were homogeneous and exhibited a rough morphology suitable for implant applications. The sputtered (after annealing), plasma spray, and sol-gel coatings all showed diffraction peaks corresponding to hydroxyapatite. The surface contaminants were observed to be different for the different coating types. The sputtered coatings were found to have a composition most similar to hydroxyapatite; the sol-gel deposits also showed a high concentration of hydroxyl ions. A discrepancy in the Ca/P ratio was observed for the plasma spray coatings, and a small concentration of carbonate ions was found in the sputter-deposited coatings. The in vitro cell-culture studies using MG63 osteoblast-like cells demonstrated the ability of cells to proliferate on the materials tested. The sol-gel coating promotes higher cell growth, greater alkaline phosphatase activity, and greater osteocalcin production compared to the sputtered and plasma-sprayed coatings.

[The utilization of Medline for the solution of real clinical problems. A prospective study in Italy]. / Utilizzo di Medline per la soluzione di problemi clinici reali. Uno studio prospettico in Italia.

AIM: Measure of usefulness of Medline searches requested for clinical problems. METHODS: open prospective uncontrolled study lasted for 3 months. Collection of online or CD-ROM Medline searches operated by clinicians or librarians at 5 biomedical libraries. User interviews about use and usefulness of Medline, recorded with a closed-answer self-administered questionnaire, adapted from a U.S. National Library of Medicine product. RESULTS: Of the 6 participating libraries, one was excluded from analysis from data collection inadequacies. Among 668 searches, 55 (8.2%) were produced for real patients. Physicians judgement about clinical usefulness of their searches (available for 46 cases) indicate a significant importance for diagnostic evaluation (23%) and therapy administration (46%). After applying search results into clinical practice, clinicians think that positive outcomes are achieved in the doctor-patient-family relationship area (19%), a better use of health care system facilities is obtained (26%) and, less consistently, positive effects are perceived on longevity (5%), abnormality correction (10%), symptomatic relief (7%) and functional recovery (6%). CONCLUSION: Physicians judge that Medline searches actually can contribute to diagnosis and treatment of real patients, with significant benefits on the process of care, on doctor-patient relationship and on patient's health.