Search results for "ontología."
showing 10 items of 1419 documents
Coping between crises: Early Triassic–early Jurassic bivalve diversity dynamics
2011
The Triassic is bounded by two of the most severe biotic crises, but nevertheless this time was, for bivalves, both a recovery and a diversification period, and a moment to fully exploit some of their evolutionary novelties. Just how and when this was achieved is analyzed in this paper, which covers Induan to Sinemurian bivalve diversity, based on a newly compiled database. Taxonomic diversity and ecospace dynamics are examined separately. Diversity and evolutionary rates were assessed, extinction selectivity was tested using a resampling algorithm, and cohort analysis was used to study extinction patterns. During the Early Triassic most bivalve genera were survivors from the Permian and th…
Bivalves and evolutionary resilience: Old skills and new strategies to recover from the P/T and T/J extinction events
2011
Diversity dynamics among bivalves during the Triassic and Early Jurassic provides the opportunity to analyse the recovery patterns after two mass extinctions: Permian/Triassic and Triassic/Jurassic (T/J). The results presented here are based on a newly compiled worldwide genus-level database and are contrasted to the main morphological characters of the different taxonomical (orders and their constituent families and genera) and ecological groups. Many of such morphological characters are innovations appearing during the time span considered. Diversity and evolutionary rates were assessed and compared between these groups. During the Early Triassic there was a slow recovery, dominated by ep…
Social demand in ambulatory oral surgery. Experience in the Master of Oral Surgery of Madrid Complutense University (Spain)
2008
Objectives. An evaluation is made of the surgical activity in the context of the Master of Oral Surgery (Madrid Complutense University, Madrid, Spain), together with an analysis of social demand in ambulatory oral surgery. Study design. A descriptive statistical analysis (frequency and contingency tables) is made of the different parameters relating to the activity carried out in this postgraduate master during two academic years. Results. A total of 6750 interventions were carried out in 5877 patients. Females predominated over males (62% versus 38%), and 59.2% of the subjects were in the 21-40 years age range. The most common procedure was tooth extraction (91%); of these, 83.5% correspon…
Extraction and immediate placement of root analogue zirconia implants: an overview
2011
Dental implants constitute a well-established approach for replacement of lost teeth with titanium being the most favored material for implantation. However, titanium has its limitations in esthetically demanding cases and neither the form nor material of such implants has changed much over the past 40 years. Immediate implantation has been introduced to overcome the disadvantages of conventional implantation which in turn has many disadvantages owing to the incongruence of the implant to the extraction socket. Today, there is scientific evidence that zirconia dental implants osseointegrate well and offer many advantages over titanium implants. The successful use of zirconia ceramics in ort…
Foreign body granulomatous reactions to cosmetic fillers
2012
Introduction: The use of different facial cosmetic fillers has increased in recent years. The introduction of apparently inert substances in the epidermis can give rise to foreign body granulomatous reactions. Objetives: A literature review is made of the foreign body granulomatous reactions to cosmetic fillers. Material and Methods: A PubMed-Medline search was made using the following keywords: “granulomatous reactions”, “foreign body reactions”, “esthetic fillers”, “cosmetic fillers”. The search was limited to articles published in English and Spanish during the last 10 years. A total of 22 articles were reviewed. Results: A great variety of substances have been found to give rise to fore…
Depression and anxiety disorders in a sample of facial trauma: A study from Iran.
2015
Background: Various studies have shown that such patients are susceptible to psychological problems and poor quality of life. The aim of the present study was to evaluate and compare the prevalence of depression and anxiety disorders and quality of life in a group of facial trauma. Material and Methods: In the present cross-sectional study Hospital Anxiety and Depression Scale (HADS) and Oral Health Impact (OHIP-14) questionnaires were used. In this study, fifty subjects were selected from the patients with maxillofacial traumas based on the judgment of the physicians, referring to hospitals in Kerman and Rafsanjan during 2012-2013. In addition, 50 patients referring to the Dental School fo…
Osteochemonecrosis of the jaws due to bisphosphonate treatments. Update
2008
Bisphosphonates (BP),were initially used in industry and later as a drug due to their great affinity to osseous tissue, because of their powerful antiresorptive effect as a treatment in various osteopathies, such as osteoporosis, Paget disease or hypercalcemia associated with some malignant tumors, as myeloma or breast cancer. They are administered orally or intravenously, and although well tolerated, the most frequent side effects are gastrointestinal, in addition to osteonecrosis when they are administered via endovenous. The aim of this work has been to evaluate the existing publications in accredited scientific literature on biphosphonates and their action mechanism and the relationship…
Fluoride release and uptake abilities of different fissure sealants
2016
Background: The long-term capability of resin sealants and glass ionomer cements to release fluoride is associated to a reduction in pit and fissure caries. The regular use of fluoride varnishes/toothpastes can result in the absorption of fluoride into the sealant. The objective of the present study was to assess the fluoride release/uptake capacities of different fissure sealants. Material and Methods: Three different fissure sealants (Fuji Triage/GC, Fissurit FX/Voco and Grandio Seal/Voco) were examined. Ten discs of each material were prepared. Each disc was incubated with distilled water and then the solution analyzed for diluted for fluoride concentration, using a combination of fluori…
Zirconia in fixed prosthesis. A literature review
2014
Statement of problem: Evidence is limited on the efficacy of zirconia-based fixed dental prostheses. Objective: To carry out a literature review of the behavior of zirconium oxide dental restorations. Material and Methods: This literature review searched the Pubmed, Scopus, Medline and Cochrane Library databases using key search words “zirconium oxide,” “zirconia,” “non-metal restorations,” “ceramic oxides,” “veneering ceramic,” “zirconia-based fixed dental prostheses”. Both in vivo and in vitro studies into zirconia-based prosthodontic restoration behavior were included. Results: Clinical studies have revealed a high rate of fracture for porcelain-veneered zirconia-based restorations that …
Rehabilitation with implant-supported overdentures in total edentulous patients: a review
2013
Objectives: The main aim of this review article is to discuss implant-supported overdentures (ISOs) as treatment in edentulous patients. Besides, we will try to discuss among the different treatment options in such patients and to analyze their validity when ISOs are compared with other clinical modalities. At the same time, we will try to suggest clinical guidelines supported by current clinical studies. Material and methods: We performed a Medline search and review of pertinent articles on the mentioned subject from 1986 to 2011. As a searching strategy, we used the following words: implant-supported overdentures, attachment systems, Locator attachment, cantilever, fixed prosthesis. Resul…