Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Front Mater ; 82021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34113623

RESUMO

The interfaces that biological tissues form with biomaterials are invariably defective and frequently the location where failure initiates. Characterizing the phenomena that lead to failure is confounded by several factors including heterogeneous material/tissue interfaces. To seamlessly analyze across these diverse structures presents a wealth of analytical challenges. This study aims to develop a molecular-level understanding of a peptide-functionalized adhesive/collagen hybrid biomaterial using Raman spectroscopy combined with chemometrics approach. An engineered hydroxyapatite-binding peptide (HABP) was copolymerized in dentin adhesive and dentin was demineralized to provide collagen matrices that were partially infiltrated with the peptide-functionalized adhesive. Partial infiltration led to pockets of exposed collagen-a condition that simulates defects in adhesive/dentin interfaces. The spectroscopic results indicate that co-polymerizable HABP tethered to the adhesive promoted remineralization of the defects. The spatial distribution of collagen, adhesive, and mineral as well as crystallinity of the mineral across this heterogeneous material/tissue interface was determined using micro-Raman spectroscopy combined with chemometrics approach. The success of this combined approach in the characterization of material/tissue interfaces stems from its ability to extract quality parameters that are related to the essential and relevant portions of the spectral data, after filtering out noise and non-relevant information. This ability is critical when it is not possible to separate components for analysis such as investigations focused on, in situ chemical characterization of interfaces. Extracting essential information from complex bio/material interfaces using data driven approaches will improve our understanding of heterogeneous material/tissue interfaces. This understanding will allow us to identify key parameters within the interfacial micro-environment that should be harnessed to develop durable biomaterials.

2.
J Dent Educ ; 85(10): 1674-1682, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33942890

RESUMO

PURPOSE: Student engagement is typically measured by class attendance and questionnaires. Learning management systems (LMS) provide additional sources of objective data that can evaluate student performance. This study compared dental students' self-report of course video viewing with LMS data. METHODS: Dental students in a 2018 flipped pediatric dentistry course were given a questionnaire after course completion that captured self-reported course video viewing. Student data and time spent on videos were extracted from the LMS and matched to the questionnaire. McNemar's test evaluated differences between self-reported and matching LMS data. RESULTS: Of the 109 enrolled students, 99 (91%) completed the questionnaire. Most students self-reported that they watched more than half of the videos (71%), re-watched at least once (89%), and watched at times other than 8 a.m.-5 p.m. (80%). Of the 104 students with data from the LMS, 40% of students watched more than half of the videos, 49% re-watched at least one video, and 60% watched between 8 a.m.-5 p.m. LMS data showed 14 (13%) students did not watch any videos. Significant differences were found between self-reported video viewing and matched LMS video data in (1) percentage of videos watched, (2) number of times videos were re-watched, and (3) most frequent time for watching the videos (p < 0.001 for all). CONCLUSION: Technology is a tool that helps instructors more accurately track students' study habits compared to observation or self-report. When evaluating time spent watching videos via an LMS, students tend to overestimate the amount of viewing time.


Assuntos
Avaliação Educacional , Aprendizagem , Criança , Humanos , Autorrelato , Software , Estudantes , Gravação em Vídeo
3.
J Dent Educ ; 81(12): 1430-1435, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29196330

RESUMO

In recognition of the importance for dental education programs to take a student-centered approach in which students are encouraged to take responsibility for their learning, a pediatric dentistry course redesign aimed at promoting greater active and self-directed learning was implemented at one U.S. dental school. The aim of this study was to examine the association between the students' self-reported study habits and active learning practices necessary for meaningful learning in the flipped/blended classroom. A convenience sample of two classes of second-year dental students in spring 2014 (SP14, n=106) and spring 2015 (SP15, n=106) was invited to participate in the study. Of the SP14 students, 84 participated, for a response rate of 79%; of the SP15 students, 94 participated, for a response rate of 87%. Students' self-reported responses to questions about study strategies with the prerecorded lecture materials and assigned reading materials were examined. Non-parametric analyses resulted in a cohort effect, so data are reported by class. In the SP15 class, 72% reported watching all/more than half of the prerecorded lectures versus 62% of the SP14 class, with a majority watching more than one lecture per week. In the SP15 cohort, 68% used active learning strategies when watching the lectures versus 58.3% of the SP14 cohort. The time of day preferred by the majority of both cohorts for interacting with course materials was 7-11 pm. Both SP14 and SP15 students reported being unlikely to read assigned materials prior to coming to class. Overall, the course redesign appeared to engage students in self-directed active learning. However, the degree to which active learning practices were taking place to achieve meaningful learning was questionable given students' self-reported study strategies. More work is needed to examine strategies for promoting study practices that will lead to meaningful learning.


Assuntos
Educação em Odontologia/métodos , Estudantes de Odontologia/psicologia , Avaliação Educacional , Hábitos , Humanos , Aprendizagem , Odontopediatria/educação , Ensino
4.
J Dent Educ ; 80(11): 1319-1327, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27803204

RESUMO

The aim of this study was to explore student and course director experiences with the redesign of a traditional lecture-based course into a flipped classroom for teaching didactic content in pediatric dentistry to second-year dental students. The study assessed student satisfaction, extent of student engagement, overall course grades, and course director satisfaction. The students enrolled in a flipped classroom pediatric dentistry course (spring semester 2014; SP14) were asked to complete pre- and post-course questionnaires to assess their perceptions of active learning, knowledge acquisition, and course satisfaction. The process was repeated with the class enrolled in the same course the following year (SP15). Responses for SP14 and SP15 resulted in an overall response rate of 95% on the pre questionnaire and 84% on the post questionnaire. The results showed that the greatest perceived advantage of the flipped classroom design was the availability and access to online content and course materials. Students reported enhanced learning due to heightened engagement in discussion. The results also showed that students' overall course grades improved and that the course director was satisfied with the experience, particularly after year two. Many calls have been made for educational strategies that encourage critical thinking instead of passive learning environments. This study provides one example of a course redesign and demonstrates the need for both faculty and student development to ensure success when a flipped classroom methodology is introduced.


Assuntos
Educação em Odontologia/métodos , Odontopediatria/educação , Estudantes de Odontologia , Satisfação Pessoal , Faculdades de Odontologia , Autorrelato
5.
Clin Cosmet Investig Dent ; 5: 33-42, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23750102

RESUMO

Restoring posterior teeth with resin-based composite materials continues to gain popularity among clinicians, and the demand for such aesthetic restorations is increasing. Indeed, the most common aesthetic alternative to dental amalgam is resin composite. Moderate to large posterior composite restorations, however, have higher failure rates, more recurrent caries, and increased frequency of replacement. Investigators across the globe are researching new materials and techniques that will improve the clinical performance, handling characteristics, and mechanical and physical properties of composite resin restorative materials. Despite such attention, large to moderate posterior composite restorations continue to have a clinical lifetime that is approximately one-half that of the dental amalgam. While there are numerous recommendations regarding preparation design, restoration placement, and polymerization technique, current research indicates that restoration longevity depends on several variables that may be difficult for the dentist to control. These variables include the patient's caries risk, tooth position, patient habits, number of restored surfaces, the quality of the tooth-restoration bond, and the ability of the restorative material to produce a sealed tooth-restoration interface. Although clinicians tend to focus on tooth form when evaluating the success and failure of posterior composite restorations, the emphasis must remain on advancing our understanding of the clinical variables that impact the formation of a durable seal at the restoration-tooth interface. This paper presents an update of existing technology and underscores the mechanisms that negatively impact the durability of posterior composite restorations in permanent teeth.

6.
Braz Dent Sci ; 15(1): 4-18, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24855586

RESUMO

Composite restorations have higher failure rates, more recurrent caries and increased frequency of replacement as compared to dental amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and failure. The gingival margin of composite restora tions is particularly vulnerable to decay and at this margin, the adhesive and its seal to dentin provides the primary barrier between the prepared tooth and the environment. The intent of this article is to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface.

7.
Braz. dent. sci ; 15(1): 4-18, 2012. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: lil-728072

RESUMO

Composite restorations have higher failure rates, more recurrent caries and increased frequency of replacement as compared to dental amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and failure. The gingival margin of composite restora tions is particularly vulnerable to decay and at this margin, the adhesive and its seal to dentin provides the primary barrier between the prepared tooth and the environment. The intent of this article is to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface.


Restaurações em resina composta apresentam elevada taxa de falhas, recorrência de cárie e maior necessidade de troca quando comparadas às restaurações em amálgama. A penetração de enzimas bacterianas, fluidos orais e da própria bactéria nas fendas existentes entre o dente e o compósito, enfraquecem a restauração e levam à recorrência de cárie e falhas. A margem gengival das restaurações em resina composta é particularmente vulnerável à cárie e, nesta margem, o adesivo e o selamento dentinário funcionam como a primeira bareira entre o dente preparado e o ambiente oral. O objetivo deste artigo de revisão é examinar os fatores físico-químicos que afetam a integridade e a durabilidade da interface de adesão adesivo/dentina e explorar como esses fatores agem sinergicamente para minar a restauração de resina composta. A revisão irá examinar as diversas possibilidades para solucionar esses problemas, bem como explorar como alterações na química dos materiais poderiam solucionar o impacto negativo do estresse físico-químico na interface adesiva com a dentina.


Assuntos
Materiais Dentários
8.
Ann Biomed Eng ; 38(6): 1989-2003, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20195761

RESUMO

Results from clinical studies suggest that more than half of the 166 million dental restorations that were placed in the United States in 2005 were replacements for failed restorations. This emphasis on replacement therapy is expected to grow as dentists use composite as opposed to dental amalgam to restore moderate to large posterior lesions. Composite restorations have higher failure rates, more recurrent caries, and increased frequency of replacement as compared to amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and premature failure. Under in vivo conditions the bond formed at the adhesive/dentin interface can be the first defense against these noxious, damaging substances. The intent of this article is to review structural aspects of the clinical substrate that impact bond formation at the adhesive/dentin interface; to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface.


Assuntos
Resinas Compostas/química , Cimentos Dentários/química , Dentina/química , Adesividade , Animais , Humanos , Teste de Materiais , Propriedades de Superfície , Resistência à Tração
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...