Biomedical subjects

D A Stewardson

Publications and source records attributed to D A Stewardson.

8 recordsLinked to original sources

PubMed2004

Thermal changes and cure depths associated with a high intensity light activation unit.

OBJECTIVES: The objectives of this study were to evaluate the thermal emission and curing characteristics of a high intensity halogen light (Astralis 10-Ivoclar Vivadent, Schaan. Leichtenstein) alone and on curing a conventional and a fast-curing micro-hybrid composite. METHODS: A bead thermistor was placed in the base of a standard model cavity. The cavity was irradiated using the light unit whilst empty, and when filled with either composite. Temperature rises were recorded using the light in four different output modes. Further samples were prepared to assess depth of cure via a digital penetrometer, light transmission using a computer-based radiometer, and microhardness with a Wallace hardness tester. RESULTS: Mean peak temperature rises recorded during polymerisation of the composites ranged from 6.9 degrees C for the product InTen-S cured with the Adhesive programme (Adh) to 11.0 degrees C for the product Tetric Ceram HB cured with the High Power (HI P) programme. A significantly greater depth of cure was obtained for InTen-S in line with the greater light transmission obtained for this material. DISCUSSION: The very high thermal emission characteristics reported in a recently published investigation for this light unit were not confirmed. CONCLUSIONS: As the extent of thermal trauma that can be tolerated by the dental pulp is unknown consideration should be given to the choice of light activation unit and curing programme when polymerising light activated resin based restorations in deep cavities close to the pulp.

Bisphenol A-Glycidyl Methacrylate↗

PubMed2004

The incidence of occupational exposures among students in four UK dental schools.

OBJECTIVES: To evaluate: the incidence of occupational exposures (OE) to patient body fluids among a sub-group of dental students; the rate of reporting of incidents; and the association of various factors. DESIGN: Multicentre retrospective analysis. SETTING: Four UK dental schools in 2000. SUBJECTS: Dental students from 4 UK schools completed a confidential questionnaire at the end of the clinical years of their undergraduate course. RESULTS: The response rates ranged from 71-100%, showing that 12-40% of students among the schools had experienced one or more OE incidents since starting their course. No statistically significant association was found between OE incidence and age, sex, dominant hand or time of day; most OE occurred with handling of local anaesthetic syringes. 61-78% of incidents were penetrative in nature, and 28-53% of students had not reported their last OE. OE incidence was associated with school, year of course, presence of patient and presence of an assistant. There were substantial differences in the numbers of students experiencing OE among the schools. CONCLUSIONS: Within the limitations of the survey and variations within the clinical activity of schools, it may be seen that improvements are needed in some schools to reduce cross-infection risks, and increase reporting of incidents. Suggestions are offered which may increase the safety of dental treatment.

Anesthetics, Local↗

PubMed2003

Organizing a practice-based research group.

There is an urgent need for more dental research to come from the 'real-life' setting of general practice in order to complement the information arising from laboratory testing and institution-based clinical trials. This paper outlines some of the problems and opportunities encountered in undertaking research in practice, and describes the experiences of one such practice-based research group.

Clinical Trials as Topic↗

PubMed2002

Occupational exposures occurring in students in a UK dental school.

BACKGROUND: Students whilst training may encounter a number of incidents where infection from patient body fluids may occur, especially as their manual skills are underdeveloped and their clinical experience is limited. PURPOSE OF STUDY: (a) To assess the nature of the occupational exposures occurring to students in a UK dental school, (b) to assess the rate of reporting of incidents, and (c) to evaluate the association of various factors with these exposures. Students in the third, fourth and final years of the 5-year undergraduate dental course at the University of Birmingham were asked to complete a questionnaire that inquired into personal details, number and nature of incidents, their reporting and follow-up. A 100% response rate was achieved. RESULTS: Across the years, there was no significant correlation (p > 0.01) between sex, dominant hand, use of protective glasses or time of day. Slightly more exposures occurred in males, right-handed students, and in the afternoon. A significant decrease in exposures (p < 0.01) occurred within final year, and when an assistant was employed. Significantly more incidents occurred while a patient was being treated than during operational clean-up procedures. A substantial number of dental students had experienced one or more occupational exposures during training. Of these, percutaneous injuries predominated. Junior students appear to be more likely to experience exposures, and in these students, needlestick injuries are the most common source. CONCLUSIONS: To reduce the incidence of these exposures, more instruction and training may be required in the earlier clinical years and more chairside assistance. Improvements are required in the monitoring of post-screening for seroconversion after HBV immunization, and in the reporting of test results in the event of an exposure incident. Under-reporting of incidents is common and ways to encourage and facilitate reporting should be sought.

Adolescent↗

PubMed2002

Patients' attitudes to rubber dam.

AIM: The aims of this study were to record patients' views of their experience of RD use in an objective manner, and to evaluate the influence of some personal and clinical factors on patients' opinion. METHODOLOGY: A questionnaire was designed which was then distributed to patients receiving dental treatment under RD by (a) final-year dental students at Birmingham Dental School, and (b) general dental practitioners. Patients completed the confidential questionnaire anonymously after treatment, outside the treatment room. After 100 correctly completed forms were collected from group (a) and 106 from group (b), data were entered into a database and subsequently analyzed using SPSS. Analyses were confined to simple cross-tabulations of the patients' responses and potential associated factors, with chi-square analysis and appropriate follow-up comparisons wherever necessary. RESULTS: In both groups, the majority of patients said they would prefer RD to be used at their next appointment, and most had a positive opinion of the experience. No statistically significant association between age, sex, procedure, application time or duration of use and preference for rubber dam was found. Prolonged RD use showed some association with a negative opinion of the experience of RD. Compared with the dentists, students took longer to apply rubber dam and it was in place for longer. Fewer student patients preferred RD next time, and were less positive about its use than the dentists' patients. CONCLUSIONS: Further evidence is presented that (i) Patients generally are not averse to RD. (ii) Placement of rubber dam does not take long. (iii) Operator experience improves patient compliance.

Adolescent↗

PubMed2001

Non-metal post systems.

For many years metals, whether cast or prefabricated, have been exclusively used to construct posts as foundations for indirect restorations. Developments in composite and ceramic materials have resulted in the introduction of metal-free post systems as alternatives. This article provides an overview of the systems currently available, gives guidance on their use, and discusses some of the principles underlying the clinical performance of posts.

Carbon↗

PubMedDate not supplied

Endodontic standards in general dental practice--a survey in Birmingham, Part I.

A postal questionnaire was used to evaluate endodontic treatment performed in the general dental services in Birmingham, assessing whether practice type--private or National Health Service (UK), or year of graduation, influences compliance with established guidelines. For the aspects of treatment investigated, many dentists were not following guidelines. More private practitioners adhered to the guidelines. Practitioner age was not related to compliance with guidelines, although there were differences in the procedures and materials employed among the different age groups. Within the survey's limits, it was concluded that endodontic performance varies from established guidelines.

Age Factors↗

PubMedDate not supplied

Endodontic standards in general dental practice--a survey in Birmingham, UK, Part 2.

A postal questionnaire was used to ascertain the views of practitioners on postgraduate education, and on the way they performed endodontic treatment. Attendance at postgraduate courses was low and was influenced by the style and content of courses as well as financial considerations. Hands-on courses were the preferred mode of delivery for postgraduate education. Most practitioners wished to change the way they carried out their endodontic treatment, and the majority felt this could only occur with an increase in fees.

Education, Dental, Graduate↗