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Biomedical subjects

D R Radford

Publications and source records attributed to D R Radford.

At least 19 recordsLinked to original sources
PubMed1999

The criteria used by editors of scientific dental journals in the assessment of manuscripts submitted for publication.

OBJECTIVE: To examine the factors that influence editors of scientific dental journals in deciding whether or not to publish submitted manuscripts and to determine if there is a consistent pattern for their decisions. DESIGN: The study was by a postal questionnaire. SETTING: The questionnaires were sent to editors of 50 major English language scientific dental journals in September 1996. MATERIALS AND METHODS: Respondents were asked to rank a number of frequently stated criteria for success in the production of papers. The editors were asked to suggest other factors which 'influenced their decision to accept or reject a manuscript'. Additionally they were asked to suggest factors that 'gave them most heartache', 'would make their life easier' and 'would expedite publication'. Information was sought on editorial policy regarding the use of referees. RESULTS: Forty two editors responded (84%). 6 replies were from journals regarded as 'generalist', and excluded from the final analysis. Factors which most frequently led to rejection included 'poor construction of the paper' (cited by 49% of respondents) and 'poor research design' (37%). Factors which editors valued highly were 'scientific novelty and timeliness of the topic' (29%). Factors that caused most problems were 'poor use of English and careless preparation of the manuscript' (46%). 'Attention to guide lines to authors' was cited by 68% of editors as a means of expediting publication. CONCLUSIONS: The application of these results can help authors to prepare manuscripts that are more attractive to editors of dental journals. Editors valued papers that were appropriate to the stated aims of their journal and regarded the significance and validity of the research work as the most important aspects of manuscripts submitted for publication.

Dental Research↗
PubMed1999

Are graduates as good as they used to be?

A theme runs through discussions on dental undergraduate education, that 'they are not as good as they used to be'. Based largely on anecdotal evidence, we question whether this is true. Dentistry is changing. Today's graduates are different, but not worse. Graduates must qualify with basic competencies--agreed between all those responsible for their education. We maintain that vocational trainers are teachers, just as we are, and as such they have similar responsibilities. Close liaison between training practices and dental schools is essential.

Clinical Competence↗
PubMed1999

Preliminary study of the impact of loss of part of the face and its prosthetic restoration.

STATEMENT OF PROBLEM: Loss of a part of the face or having a congenitally missing ear, nose, or eye is likely to have both a social and a psychologic impact on those affected. The nature and extent of this impact has not been explored previously. The provision of facial prostheses is an increasingly viable and beneficial treatment option, but the psychologic and social adjustment to the prosthesis has not been described. PURPOSE: This study performed a preliminary investigation of patients' responses to loss of part of the face, and their perceptions of the prosthetic restoration of their missing facial part. METHODS: Nine individuals who had experienced prosthetic replacement of an ear, nose, or eye were interviewed. Interviews were semistructured, each respondent was interviewed individually and the interviewer followed a predetermined interview schedule. Themes emerging in the interviews were identified. RESULTS: The main themes relating to the loss of the facial part were the importance of the story of the loss, coping through bargaining, and the impact of the loss on relationships. The important themes identified in regard to the prosthesis were issues in the maintenance of the prosthesis and the reactions of other people to the prosthesis. CONCLUSION: Loss of part of the face requires great adjustment. The reactions of other people were marked. Provision of a facial prosthesis can assist in the process of adjustment.

Adaptation, Psychological↗
PubMed1999

Flexural properties and surface finishing of acetal resin denture clasps.

PURPOSE: This study examined flexural properties of acetal resin to determine the appropriate design for an acetal resin removable partial denture clasp. The effectiveness of various acetal resin polishing procedures was also evaluated using scanning electron microscopy. MATERIALS AND METHODS: Loads of up to 1,500 g were applied to cylindrical acetal resin specimen lengths of 5, 10, and 15 mm, and the degree of deflection of the specimen tip was measured. Specimens were 2 mm and 1.5 mm in diameter with a round cross-section (R2 and R1.5, respectively), as well as 2 mm in diameter and half-round in cross-section. Half-round specimens were loaded with their flat surface vertical and then horizontal (HRV and HRH, respectively). Contour plots showing load and deflection for varying lengths of resin were developed for each cross-sectional type based on specimen length, and the stiffness was calculated. Additional acetal resin specimens underwent polishing techniques including tungsten carbide burs, aluminium oxide stones, abrasive impregnated rubber points, and "Polish-D." Polished specimens were examined with scanning electron microscopy to compare surface roughness. RESULTS: For the 5-mm-length specimens, the median stiffness values decreased in the following order: R2 > HRV > HRH > R1.5. The median stiffness values for the 10-mm and 15-mm lengths followed a similar trend. At each length, the R2 specimen was generally at least twice as stiff as other designs. Regarding polishing, the smoothest surface was seen on the specimen that was polished with the rubber point followed by "Polish-D." CONCLUSIONS: To have stiffness similar to a cast cobalt-chromium clasp 15 mm long and 1 mm in diameter, a suitable acetal resin clasp must be shorter (approximately 5 mm) with greater cross-sectional diameter (approximately 1.4 mm). To obtain a smooth surface, the acetal resin clasp should be polished with a rubber point followed by a material such as "Polish-D."

Chromium Alloys↗
PubMed1999

Denture plaque and adherence of Candida albicans to denture-base materials in vivo and in vitro.

The aim of this paper is to review our understanding of the mechanisms and clinical significance of adhesion of C. albicans to denture-base materials in relation to denture plaque and denture-related stomatitis. Earlier reports in the literature of a 65% prevalence level of denture-related stomatitis seem to be exaggerated. More recent studies indicate that denture-related stomatitis is considerably less common, particularly in normal healthy subjects. The etiology of the condition is discussed in this review, and although much of the literature supports the view that the condition is strongly associated with C. albicans, this is not always so. In some subjects, the cause appears to be related to a non-specific plaque. This review also considers the role of denture plaque in the pathogenesis of denture-related stomatitis, the sequential development of denture plaque, and its colonization by Candida organisms. Designing controlled in vivo studies is difficult, and as a consequence, many investigators have had to resort to in vitro studies. The majority of these studies have attempted to investigate the hydrophobicity of C. albicans, relating the surface free-energy of denture-base materials, particularly acrylic resin, to that of the organism. Surprisingly little work has been directed at surface roughness and how it affects retention of organisms. Further, no attention has been paid to the properties and character of the surface, other than average surface roughness, as it affects adhesion. A comparison of results from in vitro studies on the effect on adhesion of pre-coating the surfaces of denture-base materials with saliva has produced equivocal conclusions. This is largely due to little standardization of experimental protocols between studies, particularly in the collection and handling of the saliva used. In conclusion, the review strongly supports the suggestion that adherence of C. albicans to denture-base materials in vitro is related to the hydrophobicity of the organism. The clinical significance of the observation and the mechanisms for the development and maturation of denture plaque are yet to be understood. There is a clear need for further investigation of other factors that may moderate the adhesion of organisms and subsequent colonization of denture-base materials.

Acrylic Resins↗
PubMed1998

Adherence of Candida albicans to denture-base materials with different surface finishes.

OBJECTIVES: To assess the in vitro adherence of Candida albicans to heat-cured hard and soft denture-base materials with varying surface roughness, and to observe the effect of a mixed salivary pellicle on candidal adhesion to these surfaces. METHODS: In vitro adhesion assays on heat-cured acrylic resin (Trevalon), Molloplast B and Novus using the type strain of C. albicans (NCPF 3153A). Surfaces for the assays were prepared using clinically appropriate rotary instruments. Unstimulated, pooled and clarified whole saliva was used to assess its effect on adhesion. RESULTS: Significantly greater adhesion of C. albicans to rough rather than smooth surfaces was found (P < 0.001), as well as increased adhesion to the machined soft lining materials compared with acrylic. Pre-coating denture-base materials with saliva reduced candidal adhesion on all materials. CONCLUSIONS: Rough surfaces on denture-base materials promote the adhesion of C. albicans in vitro. However, saliva reduces adhesion of C. albicans and thus diminishes the effect of surface roughness and free surface energy differences between materials.

Acrylic Resins↗
PubMed1997

The effects of surface machining on heat cured acrylic resin and two soft denture base materials: a scanning electron microscope and confocal microscope evaluation.

STATEMENT OF PROBLEM: Rough surfaces promote the adhesion and colonization of denture plaque, therefore it is important to know the character of the surface left by rotary instruments on denture base materials. As a single microscopic technique can introduce artifact, complementary microscope techniques need to be used. PURPOSE: This study investigated the surface characteristics of the machined surfaces of heat-cured acrylic resin, Molloplast B and Novus. MATERIAL AND METHODS: Scanning electron microscopy and confocal microscopy were used to investigate surfaces that had been prepared with appropriate clinical rotary instruments. Thirty samples of each material were prepared with steel and tungsten carbide burs, Molloplast stones, and Arbor bands. An analysis of variance, with the Scheffe multiple comparison of means test, was used to compare average surface roughness of the individual surfaces. RESULTS: The tungsten carbide bur produced a smoother nongrooved surface than the steel bur on acrylic resin. The roughest surfaces were produced on the soft lining materials by the Arbor band and Molloplast stone. CONCLUSIONS: The confocal microscope is a valuable complementary instrument to scanning electron microscopy and provides surface roughness data by using a noncontact method. Each type of rotary instrument produces its own characteristic surface on denture base materials.

Acrylic Resins↗
PubMed1997

Scanning electron microscopy of the development of structured aerial mycelia and satellite colonies of phenotypically switched Candida albicans.

Candida albicans is an asexual diploid fungus that can express high frequency phenotypic switching. Switched variants can develop structured aerial mycelia (SAM) and cultures that have been grown for a protracted period exhibit satellite colonies. This study investigated the development of both SAM and satellite colonies by means of a freeze-drying technique and scanning electron microscopy. The results show that SAM may develop due to hyphae developing in the colony at the base of the structures. The development of satellite colonies is a result of cells that have grown deep into the agar re-emerging on to the agar/air surface and producing a new colony. Although both SAM and satellite colonies are often seen together on mature colonies, their cause and development are different.

Candida albicans↗
PubMed1994

A distance learning programme: 'managing health services'.

Management education is important in general dental practice, community and hospital dentistry. Such education can be acquired via open learning. The distance learning programme, the Managing Health Services Course, offered by The Open Business School of the Open University is recognised by the Institute of Health Services Management and the Committee of Regional Advisers in General Medical Practice for England. The course material, contemporary teaching methods, the level of commitment and the eventual rewards are discussed in this article.

Administrative Personnel↗
PubMed1994

A scanning electronmicroscopy investigation of the structure of colonies of different morphologies produced by phenotypic switching of Candida albicans.

Variant colony formation by Candida albicans has been described and the phenomenon of phenotypic switching has been studied extensively. Whereas the microstructure of non-variant colonies has been investigated by scanning electronmicroscopy (SEM), the relationship between switched variant colonies and microstructure has not been described. The object of this study was to investigate and compared by SEM the microstructure of the normal colony type and five common variant colony types of C. albicans and to determine whether a pattern of dimorphic growth could account for the characteristic colony morphologies. A general relationship between colony type and structure was observed; smooth colonies consisted entirely of blastospores whereas regular, irregular-wrinkled and semi-rough colonies consisted of different proportion of true hyphae and blastospores. Regular extreme-jagged shaped colonies consisted of an almost pure culture of pseudohyphae, and colonies producing aerial hyphae were composed of pseudo- and true hyphae, as well as blastospores. These results show a clear relationship between colony morphology and development of particular cell types.

Candida albicans↗
PubMed1993

A SEM study of denture plaque and oral mucosa of denture-related stomatitis.

The aim of this study was to compare the morphology of denture plaque and adjacent palatal mucosa in five subjects with denture-related stomatitis and a control group of five healthy subjects. Scanning electron microscope examination of copper plate replicas, which preliminary studies established were superior to epoxy resin replicas, showed that there were no consistent differences between the morphology of denture plaque and adjacent mucosa in the denture-related stomatitis group and control group. In each, the surface of the denture plaque was composed predominantly of coccoid- and rod-shaped bacteria with only some yeast cells. The mucosa was largely devoid of microorganisms and individual epithelial cells were shedding from its surface.

Bacteria↗
PubMed1993

Copper plate replica SEM of developing dental plaque in monkeys (Macaca fascicularis).

The aim of the study was to examine the development of dental plaque in macaque monkeys (Macaca fascicularis). Copper plate replicas were constructed from impressions of the labial surface of one of the upper central incisor teeth after tooth cleaning and when plaque had accumulated for 12, 24 and 48 h in each of five animals. Scanning electron microscope examination of the replicas showed that bacteria were present on the tooth surface as scattered individual cells, which after 24 h had formed a continuous layer. Both coccoid and filamentous bacteria were visible in 48-hour-old plaque. Such a rapid accumulation of potentially periodontopathic dental plaque emphasizes the importance of regular and meticulous oral hygiene.

Animals↗
PubMed1991

A two part hinged partial denture design for lower Kennedy Class 4 cases.

It is often difficult to provide patients who have lost lower anterior teeth with a retentive and aesthetic restoration, particularly if the molar and premolar teeth are lingually tilted. A two part hinged denture fully engaging all lingual undercuts for retention provides a useful extension to recognised partial denture design practice.

Denture Design↗