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Biomedical subjects

A Hannigan

Publications and source records attributed to A Hannigan.

12 recordsLinked to original sources
PubMed2006

Dental school admissions in Ireland: can current selection criteria predict success?

INTRODUCTION: Entry into university education in Ireland, including dental school, is based solely on academic performance in the Leaving Certificate Examination, held at the end of formal school education. The aim of this investigation was to examine the suitability of this process for the selection of dental students in Ireland. MATERIALS AND METHODS: Information for all dental students who entered the dental degree programme immediately following completion of the Leaving Certificate Examination at the National University of Ireland, Cork, during the years 1997-1999 was retrieved. Information was collected relating to gender, the number of times the student had attempted the Leaving Certificate Examination, their performance in this examination, the total number of marks awarded to each student at the end of the First and Final Dental Examinations, and their performance in individual modules. RESULTS: Whilst there was a significant relationship between performance in the Leaving Certificate Examination and the First Dental Examination (correlation coefficient = 0.22, P < 0.05), this relationship could only explain 12% of the variation within the performance of students in this examination. There was no relationship between performance in the Leaving Certificate and the Final Dental Examination (correlation coefficient = 0.09, P > 0.05). There was a significant correlation between performance in the Leaving Certificate Examination and performance in seven of the 55 programme modules, all of which were pre-clinical modules, and of which five were related to basic sciences. CONCLUSIONS: Based on the limitations of this study, the current selection process for dental students in Ireland seems to be of limited value.

Clinical Competence↗
PubMed2004

Chewing side preferences in children.

The dentition of 57 children aged 6-8 years old was examined clinically and radiographically. Subjects were divided into groups according to state of the dentition: caries free, no pathology and no pain; caries, no pathology and no pain; caries, pathology and no pain; caries, pathology and pain. The existence of a preferred chewing side (PCS) was determined using a visual spot-checking method. Subjects were instructed to chew gum on their posterior teeth. After 15 s the position of the chewing gum was recorded as right or left. This procedure was carried out seven times consecutively. Subjects had an 'observed preferred chewing side' (OPCS) when they chewed 5/7, 6/7 or 7/7 times on the same side. To determine if children were aware of their chewing side preference each subject's stated PCS was then recorded as left, right or none. 'Coincidence' between stated and OPCSs was said to occur if the stated PCS corresponded to the OPCS. Seventy-seven per cent of children had a PCS. The majority (70%) of caries free children also had a PCS (P < 0.05). The percentage with an OPCS varied from 70% of the caries free group to 92% of the group with caries, pathology and pain. However, there was no statistically significant association between state of the dentition and the presence of a PCS. Coincidence occurred in 56% of children. There was a statistically significant association between state of the dentition and coincidence (P=0.02). Children in pain were most likely to show coincidence (kappa=0.81).

Awareness↗
PubMed2004

Using survival methodologies in demonstrating caries efficacy.

Exploiting recent advances in statistical methods, particularly for correlated intra-subject data, could increase the efficiency of caries clinical trials. Methods of analysis using the tooth surface as the unit should be investigated. Whole-mouth measures such as the DMFS increment ignore the variation in the number of surfaces at risk between subjects and within a subject over time. The use of "survival time" for each surface as the outcome measure--i.e., the time from the start of the trial to when a surface is recorded as decayed or filled--is proposed. Data from caries clinical trials could be described as clustered survival data, where clustering of tooth surfaces exists such that survival times within the same cluster or subject are correlated. Advances in the analysis of clustered survival data, such as the use of marginal models with robust variance estimators, have recently been exploited in the analysis of caries clinical trials. The analysis produced results similar to those achieved by conventional DMFS-based analysis. The results using survival analysis are easily interpreted-for example, the median survival time of tooth surfaces in female subjects using a toothpaste with a higher level of fluoride (1500 ppm F) is 1.07 times the median survival time of surfaces in female subjects using toothpaste with less fluoride (1000 ppm F). Further research is required to investigate if survival analysis is a more sensitive method of analysis, i.e., whether causative factors can be identified with fewer subjects than with the conventional method of analysis.

Cariostatic Agents↗
PubMed2004

Soluble cell adhesion molecules in gingival crevicular fluid in periodontal health and disease.

BACKGROUND: Cell adhesion molecules (CAMs) are cell surface proteins involved in the binding of cells to each other, to endothelial cells, or to the extracellular matrix. The soluble forms of CAMs (sCAMs) are thought to be produced by proteolytic cleavage from the cell surface and are shed into the gingival crevicular fluid (GCF). The aim of this study was to investigate whether sCAMs, sICAM-1, sVCAM-1, and sE-Selectin were present in GCF in both periodontal health and disease and to examine their relationship with periodontal inflammation. METHODS: GCF was collected from a clinically healthy, a gingivitis, and a periodontitis site in 29 subjects with chronic periodontitis and from a single clinically healthy site in 22 subjects without chronic periodontitis. The volume of GCF was measured and each sample was analyzed for sCAMs by enzyme-linked immunosorbent assay (ELISA). The effect of treatment (oral hygiene instruction, scaling and root planing) on the levels of sCAMs in each site of the diseased group was also investigated. RESULTS: Statistically significant differences (P < 0.05) were found between the levels of sVCAM-1 in periodontal health and disease. These results indicate that changes in the levels of sCAMs may be a sensitive indicator to differentiate healthy sites from those with periodontitis. Statistically significant changes in the levels of sICAM-1 were recorded after treatment (P < 0.05). CONCLUSIONS: Further studies are required to establish if these potential biomarkers will enable the identification of those sites most at risk for disease progression and also evaluate the response to treatment, thereby playing a preventive role in the pathogenesis of periodontal disease.

Adult↗
PubMed2003

Randomized clinical trial and economic analysis of four-layer compression bandaging for venous ulcers.

BACKGROUND: The aim of this study was to compare the cost-effectiveness of four-layer compression bandaging for venous leg ulcers with that of other available treatments. METHODS: In this pragmatic trial, 200 patients with a venous leg ulcer were randomized either to four-layer bandaging (intervention group; n = 100) or to continue their usual system of care (control group; n = 100). The follow-up for each patient was 12 weeks. Analysis was by intention to treat; the main outcome measures were time to healing and cost to the health board per leg healed. RESULTS: Baseline characteristics were well matched in the two groups. The Kaplan-Meier estimate of the healing rate at 3 months was 54 per cent with four-layer bandaging and 34 per cent in the control group. Throughout the 3 months, four-layer bandaging healed leg ulcers significantly earlier (P = 0.006). There was a significant reduction in the median cost per leg healed with four-layer bandaging (euro 210 versus euro 234; P = 0.040). CONCLUSION: Four-layer bandaging is currently the most effective method of treating venous leg ulcers in a community setting.

Aged↗
PubMed2001

A re-analysis of a caries clinical trial by survival analysis.

The decline in caries prevalence, the increases in the level of fluoride exposure, and the lack of placebo control subjects have complicated caries clinical trials in recent times. There has been a substantial increase in the numbers of subjects required for the detection of statistically significant differences between dental products, and hence, the cost of these trials has grown enormously. This study uses a new statistical approach to the analysis of the data from these trials with the ultimate aim of providing a more sensitive method of analysis. The new approach uses survival analysis, where the outcome measure is the survival time of an individual tooth surface. It exploits recent developments in the analysis of clustered survival data where survival times within the same cluster or subject are correlated. To illustrate, the new method of analysis was used for the North Wales, UK, caries clinical trial. It is concluded that survival analysis uses most of the data available in a caries clinical trial, an outcome measure that is easily understood and may lead to a more sensitive method of analysis.

Analysis of Variance↗
PubMed2001

Surface hardness of light-activated resin composites cured by two different visible-light sources: an in vitro study.

OBJECTIVE: Microhardness values of upper and lower surfaces of disk specimens of 3 commercially available resin composites were compared and cured using both the traditional halogen source and a plasma arc lamp. METHOD AND MATERIALS: Twenty samples of each of the resin composites were cured in nylon washers. Ten samples of each composite were cured using the appropriate halogen lamp protocol, and 10 samples of each were cured using the plasma lamp protocol. Surface microhardness measurements were carried out using a calibrated Vickers indenter on both top and bottom surfaces after 7 days of storage in air at 20 degrees C. Statistical analysis of the data was carried out using a commercial statistical package. The data for top and bottom surfaces were analyzed separately using a repeated measures analysis of variance (ANOVA). RESULTS: Lamp, composite, and the interaction between lamp and composite were significant in determining the results for both top and bottom surfaces of the disk-shaped specimens. The plasma lamp yielded lower hardness values for all surfaces compared with the halogen source, but the size of the difference depended on the composite. CONCLUSION: Caution must be exercised in the plasma irradiation of resin composites as a curing method due to the possibility of reduced surface microhardness values that may reflect a reduced percent conversion of monomer to polymer.

Analysis of Variance↗
PubMed2000

Reasons for choosing dentistry as a career--a survey of dental students attending a dental school in Ireland during 1998-99.

The motivations for choosing dentistry as a career in the Republic of Ireland are not clearly defined. To better understand why students choose this occupation, 150 undergraduate dental students of all grades at a University Dental School were surveyed during the academic year 1998-99. Candidates were asked to score the influence of certain factors on their decision to choose dentistry as a career, and were given the opportunity to add commentary. The overall response rate was 80.6%. About 2/3 indicated dentistry was their 1st career choice, with medicine being the primary alternative. Reasons for choosing dentistry included perceived ease of employment, being self-employed, working regular hours, followed by an opportunity of good income, and the opportunity to help people. Having relatives or friends in the profession and lifelong ambition were the least important factors for this sample. Extrinsic factors relating to employment conditions had a strong positive correlation (p<0.0001) with each other, while lifelong ambition had a strong negative correlation (p=0.004) with significant financial reward. No significant differences were found in most responses when analysed by gender or year in school. It is concluded that this sample of students is attracted to dentistry primarily due to a positive perception of working conditions, followed by the altruistic motivations of helping people and improving their appearance.

Career Choice↗
PubMed2000

Tenure in supportive housing for homeless persons with severe mental illness.

OBJECTIVE: The study examined the long-term effectiveness of approaches to housing homeless persons with serious mental illness. METHODS: A total of 2,937 persons placed in high-, moderate, -and low-intensity housing were followed for up to five years. Intensity reflected on the amount of structure and degree of clients' independence. The outcome variable was tenure in housing. Cox stepwise regression was used to calculate risk ratios of becoming discontinuously housed. RESULTS: Thirty percent of the sample were initially placed in high-intensity settings, 18 percent in moderate-intensity settings, and 52 percent in low-intensity settings. Those in high-intensity settings tended to be younger, to be referred from hospitals, and to have a history or diagnosis of substance abuse. Individuals in moderate-intensity settings were more likely to be female and were least likely to have substance abuse problems. Individuals in low-intensity settings were more likely to be referred by municipal shelters and to have lived in municipal shelters for four or more months. After one, two, and five years, 75 percent, 64 percent, and 50 percent, respectively, of the sample were continuously housed. Older age was associated with longer tenure, and having a history of substance abuse was associated with shorter tenure. Individuals referred from a state psychiatric center had a greater risk of shorter tenure than other types of referrals. CONCLUSIONS: Results show that homeless persons with serious mental illness can remain in stable housing for periods of up to five years, supporting the premise that long-term residential stability can be enhanced by providing access to safe and affordable supportive housing.

Adult↗
PubMed1999

A survey of the computer literacy of undergraduate dental students at a University Dental School in Ireland during the academic year 1997-98.

As dental practice management becomes more computer-based, the efficient functioning of the dentist will become dependent on adequate computer literacy. A survey has been carried out into the computer literacy of a cohort of 140 undergraduate dental students at a University Dental School in Ireland (years 1-5), in the academic year 1997-98. Aspects investigated by anonymous questionnaire were: (1) keyboard skills; (2) computer skills; (3) access to computer facilities; (4) software competencies and (5) use of medical library computer facilities. The students are relatively unfamiliar with basic computer hardware and software: 51.1% considered their expertise with computers as "poor"; 34.3% had taken a formal typewriting or computer keyboarding course; 7.9% had taken a formal computer course at university level and 67.2% were without access to computer facilities at their term-time residences. A majority of students had never used either word-processing, spreadsheet, or graphics programs. Programs relating to "informatics" were more popular, such as literature searching, accessing the Internet and the use of e-mail which represent the major use of the computers in the medical library. The lack of experience with computers may be addressed by including suitable computing courses at the secondary level (age 13-18 years) and/or tertiary level (FE/HE) education programmes. Such training may promote greater use of generic softwares, particularly in the library, with a more electronic-based approach to data handling.

Chi-Square Distribution↗
PubMedDate not supplied

A caries susceptibility classification of tooth surfaces by survival time.

Individual tooth surfaces have vastly different susceptibilities to caries and this susceptibility also varies over time. The aim of this study was to develop a method of grouping tooth surfaces into a caries susceptibility classification based on their survival experience. The data used in the study were from a 3-year caries clinical trial. The definition of survival time was taken to be the time from the start of the trial to when a surface is recorded as decayed or filled. Cluster analysis was used to divide the tooth surfaces into groups in such a way that surfaces in the same group have similar survival time distributions. The 13 groups identified were ordered from 1 to 13 starting with the group with the shortest survival time, i.e. the occlusal surfaces of the four first molars. Approximately 80% of symmetrical pairs of tooth surfaces were in the same group. The groups obtained using cluster analysis were compared to groups defined using dental/anatomical criteria. It is concluded that the cluster analysis method developed for grouping the tooth surfaces cn provide a useful descriptive measure of caries susceptibility which can be applied to data from any longitudinal study of caries.

Child↗