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Biomedical subjects

J G Steele

Publications and source records attributed to J G Steele.

At least 37 records · Page 2Linked to original sources
PubMed2002

Crowns and other extra-coronal restorations: aesthetic control.

A pleasing dental appearance is the subjective appreciation of the shade, shape and arrangement of the teeth and their relationship to the gingiva, lips and facial features. Achieving such a pleasing appearance in our patients is not always easy but is critical, not least because our work is effectively on display and this has implications for patients' perceptions of our practice. To be successful, thorough assessment, careful planning and precise clinical execution is required. Every bit as important though, is good communication, both with the dental laboratory and particularly with the patient. In few areas of dentistry can effective communication be as critical as it is here.

Attitude to Health↗
PubMed2002

Crowns and other extra-coronal restorations: occlusal considerations and articulator selection.

For many dentists, occlusion carries an air of mystique. It even seems sometimes that a perverse pleasure is derived in making the whole subject more complicated than it really is. As a clinician, you need to be able to decide what you expect from your proposed restoration, and to identify situations where you may need to alter the existing occlusal scheme. At a fundamental level, you also need to provide the laboratory with appropriate clinical records to ensure that when you fit them, adjustments to the expensively prepared restorations are minimal. This requires a sound understanding of the basics.

Centric Relation↗
PubMed2002

Crowns and extra-coronal restorations: considerations when planning treatment.

Considerations when planning treatment is the third in the series of crowns and other extra-coronal restorations. Articles or chapters on treatment planning in restorative dentistry can make pretty dry reading, often built around a list of factors that might influence your decision-making. In truth though, planning and placing crowns or other extra-coronal restorations cannot be distilled into a series of lists. The decision-making involved requires experience, subtle understanding and a flexible approach, none of which come easily.

Adolescent↗
PubMed2002

Crowns and extra-coronal restorations: materials selection.

Materials selection is the second in the series on crowns and other extra-coronal restorations. Some of us are less than inspired by dental materials science. Nevertheless, many of the things that concern us clinically with crowns and their alternatives are based on material properties. We worry about the strength of the restoration, how well it fits and its aesthetics. We also worry about wear, occlusal control and biocompatibility. Not least of our concerns are dental laboratory charges, which inevitably have to be passed on to the patient.

Biocompatible Materials↗
PubMed2002

Changing patterns and the need for quality.

This series of articles is aimed at anybody who places crowns and other extra-coronal restorations (ie veneers and shims) on individual teeth. We hope that everyone from experienced practitioners to undergraduate students may find something of value. Whoever reads them, we would ask to do so with an open mind. We have tried not to be dogmatic, and the techniques and materials described are not the only ones available, but are the ones which accord with the principles we describe.

Crowns↗
PubMed2001

The impact of oral health on people in the UK in 1998.

Knowledge of the extent of dental disease gives a clinical indication of the experience of dental problems but it does not necessarily reflect the problems that people experience as a result of their dentition. It is becoming increasingly appreciated that the way a disease affects people's lives is just as important as epidemiological measures of its prevalence or incidence. The 1998 Adult Dental Health survey is the first of the decennial series of UK adult dental health surveys to use and report a measure of the self-perceived impact on people of the dental and periodontal diseases and other oral conditions. Over half (51%) of dentate adults said they had been affected in some way by their oral health, and in 8% of cases the impact was sufficient to have reduced their quality of life.

Adult↗
PubMed2001

Dental restorations in adults in the UK in 1998 and implications for the future.

People in their late fifties in the UK today can expect to live another 20 years and most want to maintain a functional and aesthetically acceptable dentition. However, 50% of the teeth of dentate adults aged 45 years and over are filled and crowned. The challenges for the dental profession in addressing these aspirations are discussed.

Adolescent↗
PubMed2001

Stimulation of epithelial tissue migration by certain porous topographies is independent of fluid flux.

A surface with columnar pores 0.1 or 0.4 microm in diameter is shown to have a novel effect on the migration of corneal epithelial tissue sheets; migration is stimulated in a nondirectional manner with respect to migration over a planar, nonporous surface (Dalton, Evans, McFarland, and Steele, J Biomed Mater Res 1999;45:384-394; Steele, Johnson, McLean, Beumer, and Griesser, J Biomed Mater Res 2000;50:475-482). By blind-ending the pores, we show that this increase in tissue migration is not dependent on fluid flux through the pores and so appears to occur as a result of surface topography. From transmission electron micrographs, the migrating tissue appears to form either close contacts or focal adhesions at the edge of some pore channels; we speculate that this may provide a fulcrum for the enhanced migration. Scanning electron micrographs suggest that within tissue that migrates over the surfaces that contain blind-ended pores, the cells are more extensively spread than those in tissue migrating on a planar surface. The migration of disaggregated epithelial cells is enhanced on surfaces that contain 0.1- or 0.4-microm-diameter pores (compared with a planar surface), and this is similarly independent of fluid flux.

Animals↗
PubMed2001

Modulation of epithelial tissue and cell migration by microgrooves.

We used a polystyrene substratum to study the response of migrating epithelium to 1- or 5-microm depth microgrooves with groove/ridge widths of 1, 2, 5, or 10 microm. The migration of a tissue sheet was enhanced along the microgrooves, while migration across the microgrooves was inhibited. Changing the depth of the microgrooves had a greater effect on migration than alteration of the groove/ridge width. The migration of epithelial cells from a confluent monolayer culture followed a similar pattern to that of intact epithelial tissue. Cellular extensions generally followed the microgroove direction by tracking along the top of the ridges or following the ridge walls, as revealed by scanning electron microscopy. Actin filaments within the basal cell layer of the tissue were aligned with the microgrooves, unlike filaments in the superficial layers that did not appear to be affected by the presence of underlying microgrooves. The basal cell layer of the tissue conformed to the contours of the microgroove following migration. However, the ultrastructure of the tissue above the ridges resembled that of tissue on a flat surface. We concluded that surface microgrooves have the potential to direct the migration of immediately adjacent epithelial tissue, the effect of which is to guide epithelial tissue on the surface of implanted biomaterials.

Actin Cytoskeleton↗
PubMed2001

Migration mechanisms: corneal epithelial tissue and dissociated cells.

The migratory mechanism of intact bovine corneal epithelial tissue and individual corneal epithelial cells over synthetic surfaces in vitro were compared. In migrating tissue, adhesion between component cells was demonstrated by immunostaining for desmoplakin and identification of desmosomes by electron microscopy. The apparent intermeshing of microtubules within the tissue and interdigitation of cytoplasmic membranes showed the close association of cells. Portions of the advancing edge of the tissue contained actin filaments that were orientated parallel to the leading tissue front. These filaments appeared to span adjacent cells suggesting that migration partially involved the contraction of the actin cable, similar to the 'purse-string' mechanism originally identified in the closure of fetal skin wounds. Intact actin filaments and microtubules were necessary to maintain optimum migration rates for tissue and cells. However, tissue morphology was not dependent on microtubule integrity. During the migration of individual epithelial cells, no staining for desmoplakin was observed and there were clear divisions between the microtubules of adjacent cells. Actin filaments tended to be arranged parallel to the direction of cell movement.Therefore, migration of epithelial tissue sheets over synthetic surfaces occurs by mechanisms that differ from the migration of individual epithelial cells. Model systems based on the migration of intact tissue would give a more realistic assessment of the suitability of a material for biomaterial applications than the use of separate epithelial cells.

Actin Cytoskeleton↗
PubMed2001

Prevalence of impacts of dental and oral disorders and their effects on eating among older people; a national survey in Great Britain.

OBJECTIVE: The objective was to assess the prevalence, in a British population aged 65 years and older, of oral health related impacts and the effects they had on the quality of daily life and in particular on eating. METHODS: 753 free living and 202 institutionalised subjects aged 65 years and over, participating in the oral health survey of the British National Diet and Nutrition Survey (NDNS), had a dental examination and interview. Data on the impact of dental and oral disorders on the activities of daily living based upon the modified Oral Impacts on Daily Performance (OIDP) indicator were collected. RESULTS: 17% of the free living edentate participants reported that their mouth affected their pattern of daily living on a regular basis. Oral impacts levels were lowest in dentate subjects with the greatest number of teeth. For the dentate, the most common oral impacts were on eating and speaking. Impacts relating to emotional stability, sleeping, relaxing, carrying out physical activity and social contact were very infrequent, but were severe when they did occur. Among those with an impact on eating, 25% said it was severe and 42% had the impact nearly every day or in a spell of 3 or more months. Oral impacts were more prevalent among the institution sample, particularly the dentate. The impacts were associated with the inability or difficulty to eat a range of 16 common foods. CONCLUSION: This survey has shown that the oral status of older people fairly frequently affects the quality of life of older people, and in particular, the ability to eat several common types of foods.

Aged↗
PubMed2001

Clinical and behavioural risk indicators for root caries in older people.

OBJECTIVE: To investigate the clinical and behavioural factors indicating root caries risk among older people. DESIGN: Cross-sectional clinical and interview data from the National Diet and Nutrition Survey (aged 65 years and over) in Great Britain. Logistic regression models of the prevalence of root caries and linear regression models of the extent of root caries were constructed to quantify the role of a range of clinical and behavioural risk indicators, including sugars intake. SETTING: A national sample of older British adults, free-living and institutionalised. PARTICIPANTS: 462 dentate adults aged 65 years or over. RESULTS: Nine or more intakes of sugars per day more than doubled the odds of root caries being present (OR 2.2-2.4). Other clinical and behavioural factors affecting root caries included wearing a partial denture in the presence of heavy plaque deposits (OR 2.1-2.6) and infrequent tooth brushing (OR 2.8-4.1). Linear regression models showed that, amongst those that had root caries, sucking sweets in the presence of a dry mouth, poor hygiene, partial dentures and living in an institution contributed to the extent of root caries, as measured by the RCI(d). CONCLUSIONS: Of the factors open to possible clinical or behavioural intervention, frequent sugars intake, poor hygiene and partial dentures were all associated with large increases in risk.

Aged↗
PubMed2001

The relationship among dental status, nutrient intake, and nutritional status in older people.

Dental health status may influence nutrition. The objective of this part of the National Diet and Nutrition Survey was to assess if there is a relationship between dental status in people 65 years and older and intake of certain nutrients and any link between dental status and blood-derived values of key nutrients. Random national samples of independently living subjects and those living in institutions had dental examinations, interviews, four-day food diaries, and blood and urine analyzed. In the sample living independently, intakes of most nutrients were lower in edentate than dentate subjects. Intake of non-starch polysaccharides, protein, calcium, non-heme iron, niacin, and vitamin C was significantly lower in edentate subjects. People with 21 or more teeth consumed more of most nutrients, particularly of non-starch polysaccharide. This relationship in intake was not apparent in the hematological analysis. Plasma ascorbate and plasma retinol were the only analytes significantly associated with dental status.

Aged↗
PubMed2001

The influence of stromal contraction in a wound model system on corneal epithelial stratification.

PURPOSE: The healing process of some corneal wounds involves closure by stromal contraction and the renewal of the stratified epithelium. In wound gape injury such stromal contraction occurs with epithelial stratification. In previous in vitro studies of noncontracted and contracted corneal fibroblast-seeded collagen gels (FSCGs) it was shown that initiation of wound contraction by the myofibroblast phenotype (present within the wounded stroma) was dependent on vitronectin and/or fibronectin. This study considers one aspect of the epithelial-stromal interaction that occurs during wounding. The stratification of corneal epithelial cells on noncontracted and contracted corneal FSCGs was compared. METHODS: Dissociated bovine corneal epithelial cells were seeded on noncontracted and contracted corneal FSCGs, and these assemblies were cultured for 7 days. The epithelium that formed was evaluated using laser confocal microscopy and immunohistochemical markers directed against cytokeratin 3, desmoplakin I and II, integrin alpha-6 subunit, laminin, and collagen VII. The characteristics of the epithelium were compared with stromal carriers comprised of dissociated bovine corneal epithelial cells seeded on intact stroma and basement membrane (stromal carrier biopsies). RESULTS: The stratified epithelium that developed on contracted corneal fibroblast-seeded collagen gels was similar to that formed on stromal carriers, whereas nonstratified epithelium formed on noncontracted FSCGs. CONCLUSIONS: These studies showed that the contracted state of fibroblast-seeded gels enhanced the development of well-organized, stratified corneal epithelium.

Animals↗
PubMed2001

Geriatric oral health issues in the United Kingdom.

The current status of geriatric oral health in the United Kingdom is influenced by an historical pattern of care prevalent during the early years of the National Health Service in 1948, when inexpensive oral health care became available to all. At that time, tooth extraction was perceived as an acceptable, and among some people a preferred, approach to oral care. This has left a legacy of edentulism among senior citizens, which affects both oral and general health, in addition to an attitude that places oral health as a low priority. This legacy is now beginning to unwind as cohorts of adults, who have benefited from low-cost dental care for the majority of their lives, are entering their senior years. Many of these young-old retain their natural teeth and have more positive attitudes towards oral health. This paper discusses the impact of this history as well the effect of income on access to care, the influence of the ageing process on adequate oral hygiene and the availability of dentists trained to treat both dentate and edentulous geriatric patients. A brief outlook for the future is also provided.

Adult↗
PubMed2000

Total tooth loss in the United Kingdom in 1998 and implications for the future.

The 1998 Adult Dental Health Survey, published this year, showed that the number of people without teeth should fall over the next three decades, to only 4% of the UK population. Patterns of tooth loss and retention are also changing. This article, the first of a series on the interpretation of the Adult Dental Health Survey, discusses the implications of these trends for dentistry.

Adolescent↗
PubMed2000

Peptoid-containing collagen mimetics with cell binding activity.

Collagen mimetic peptides containing the peptoid residue Nleu (Goodman Bhumralkar, Jefferson, Kwak, Locardi. Biopolymers 1998;47:127-142) were tested for interactions with epithelial cells and fibroblasts. Molecules containing the sequence Gly-Pro-Nleu with a minimum of nine repeats showed cell binding activity. The activity of these molecules appeared to be conformationally sensitive, with the triple-helical form being preferred. When immobilized on a surface, the (Gly-Pro-Nleu)(10)-Gly-Pro-NH(2) sequence stimulated the attachment and growth of corneal epithelial cells and fibroblasts and the migration of epithelial tissue. The peptide sequence KDGEA inhibited cell attachment to the (Gly-Pro-Nleu)(10)-Gly-Pro-NH(2) sequence, suggesting that cell binding to this collagen mimetic involves the alpha2beta1 heterodimer integrin receptor. Interestingly, peptides containing the sequence (GlyNleu-Pro-)(10)-NH(2) did not have cell binding activity. The discovery that triple-helical peptides containing the Gly-Pro-Nleu sequences interact with cells opens up new opportunities in the design of collagen mimetic biomaterials.

Amino Acid Sequence↗