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Biomedical subjects

F J T Burke

Publications and source records attributed to F J T Burke.

At least 19 recordsLinked to original sources
PubMed2006

Cuspal movement and microleakage in premolar teeth restored with resin-based filling materials cured using a 'soft-start' polymerisation protocol.

OBJECTIVES: To investigate the effect of polymerisation shrinkage strain of four posterior filling materials on cuspal movement, degree of conversion (DC) and cervical gingival microleakage of mesio-occlusal-distal (MOD) restorations placed incrementally in maxillary premolar teeth using a 'soft-start' polymerisation protocol. METHODS: Forty sound extracted upper premolar teeth were subjected to standardised preparation of a large MOD cavity before restoration. A 'soft-start' polymerisation curing regimen was used and each posterior filling material was placed in eight increments with the appropriate bonding system. A twin channel deflection measuring gauge allowed a measurement of individual cusp deflections at each stage of polymerisation. Restored teeth were thermocycled before immersion in a 0.2% basic fuchsin dye for 24h. After sagittal sectioning of the restored teeth in a mesio-distal plane, the sectioned restorations were examined to assess cervical microleakage. The DC was also assessed using a diffuse-reflectance accessory on a Fourier transform infra-red spectrophotometer. RESULTS: A significant increase in cuspal movement recorded for Z100 (20.06+/-4.71) compared with Filtek Z250 (16.52+/-3.26), P60 (14.23+/-3.71) and Admira (11.11+/-2.47). No significant reduction in cuspal movement was identified when compared with a previous study [6] where a full-intensity standard polymerisation protocol was employed. No significant differences were also identified between the materials when the cervical gingival microleakage scores or DC were examined for the 'soft-start' compared with the standard polymerisation protocol. CONCLUSIONS: Although material type remained a significant factor, the use of a 'soft-start' polymerization compared with a standard curing regime did not offer any significant reduction in associated cuspal movement, DC or gingival microleakage at the cervical dentine cavosurface margin of the cavities restored with the resin-based filling materials.

Bicuspid↗
PubMed2006

Investigation of polymerisation shrinkage strain, associated cuspal movement and microleakage of MOD cavities restored incrementally with resin-based composite using an LED light curing unit.

OBJECTIVES: To investigate the polymerisation shrinkage strain, associated cuspal movement, degree of conversion (DC) and cervical gingival microleakage of mesio-occlusal-distal (MOD) cavities restored with four resin-based composite (RBC) filling materials placed incrementally using a light emitting diode (LED) light curing unit (LCU). METHODS: Standardised extensive MOD cavity preparations on extracted teeth were performed on 40 sound upper premolar teeth. Restoration of the teeth involved the placement of RBCs in eight increments with the appropriate bonding system before irradiation using an LED LCU. Buccal and palatal cusp deflections at each stage of polymerisation were recorded using a twin channel deflection measuring gauge. Following restoration, the teeth were thermocycled, immersed in a 0.2% basic fuchsin dye for 24 h, sagittally sectioned and examined for cervical microleakage. The DC was determined using a Fourier transform infra-red (FT-IR) spectrometer. RESULTS: No significantly difference (P=0.677) in cuspal movement was recorded for Z100 (13.1+/-3.2 microm) compared with Filtek Z250 (8.4+/-3.5 microm), P60 (7.3+/-3.8 microm) and Admira (6.7+/-2.7 microm). The LED LCU deflections were compared with a halogen LCU used in a conventional (Fleming GJP, Hall D, Shorthall ACC, Burke FJT. Cuspal movement and microleakage in premolar teeth restored with posterior filling materials of varying reported volumetric shrinkage values. Journal of Dentistry, 2005;33:139-146) and soft-start mode (Fleming GJP, Cara RR, Palin WM, Burke FJT. Cuspal movement and microleakage in premolar teeth restored with posterior filling materials cured using 'soft-start' polymerization. Dental Materials, 2006, , in press) and a significant reduction in cuspal movement was identified for curing type and material type (P<0.001 and P=0.002, respectively). No significant differences were noted between the four RBC materials investigated when the DC or microleakage scores were examined for the LED LCU. SIGNIFICANCE: It would appear that irradiation of RBCs using the LED LCU offered a significant reduction in associated cuspal movement in large MOD cavities. However, the microleakage scores following polymerisation were significantly increased with dye penetration into the pulp chamber from the axial wall evident in teeth restored with the LED LCU.

Bicuspid↗
PubMed2006

Lost data.

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Dental Health Surveys↗
PubMed2006

Assessing the quality of radiographic processing in general dental practice.

OBJECTIVES: To determine if a commercial device (Vischeck) for monitoring film processing quality was a practical option in general dental practice, and to assess processing quality among a group of GDPs in the West Midlands with this device. DESIGN: Clinical evaluation. SETTING: General dental practice, UK, 2004. METHOD: Ten GDP volunteers from a practice based research group processed Vischeck strips (a) when chemicals were changed, (b) one week later, and (c) immediately before the next change of chemicals. These were compared with strips processed under ideal conditions. Additionally, a series of duplicate radiographs were produced and processed together with Vischeck strips in progressively more dilute developer solutions to compare the change in radiograph quality assessed clinically with that derived from the Vischeck. RESULTS: The Vischeck strips suggested that at the time chosen for change of processing chemicals, eight dentists had been processing films well beyond the point indicated for replacement. Solutions were changed after a wide range of time periods and number of films processed. The calibration of the Vischeck strip correlated closely to a clinical assessment of acceptable film quality. CONCLUSIONS: Vischeck strips are a useful aid to monitoring processing quality in automatic developers in general dental practice. Most of this group of GDPs were using chemicals beyond the point at which diagnostic yield would be affected.

General Practice, Dental↗
PubMed2006

Effectiveness of a self-adhesive resin luting system on fracture resistance of teeth restored with dentin-bonded crowns.

Laboratory studies have demonstrated satisfactory fracture resistance of all-ceramic crowns placed using a conventional resin-composite luting material and a dentine bonding system. This study investigated the fracture resistance of teeth restored with dentine-bonded ceramic crowns luted with a self-etching luting material. Standardized preparations were carried out on two groups of ten sound, unrestored, maxillary premolar teeth. Ceramic crowns were constructed, their internal surfaces etched and placed using two luting system combinations. Compressive fracture resistance was determined for each group using a Universal Testing Machine. Mean compressive fracture resistance of 890 (222) N and 760 (271) N were recorded for the RelyX Unicem Aplicap and Mirage groups, respectively. There was no significant difference in the mean compressive fracture resistance of the restored teeth in both groups (P<0.05). The failure modes were different for each cements with more severe (Mode V)failures associated with the Mirage group compared with the consistent Mode II failures associated with RelyX Unicem Aplicap. We conclude that the fracture resistance of dentine-bonded crowns luted with a self-adhesive resin-based luting material was no different from that of a conventional resin-based luting system. The fracture resistance of dentine-bonded ceramic crowns may be clinically satisfactory when a self-adhesive resin-based luting material is utilised.

Analysis of Variance↗
PubMed2005

Evaluating restorative materials and procedures in dental practice.

A wide variety of research methods are appropriate to general dental practice, including clinical trials of materials, assessment of materials and techniques, treatment trends, and assessment of behavior and attitudes, of dentists as well as patients. This paper will describe the use of practice-based networks to evaluate the effectiveness of materials and techniques in dental practice. Several practice-based research groups are presently in operation in the UK and the USA, generally carrying out evaluations of the handling of materials, but with increasing emphasis on the clinical evaluation of restorations. Use of the Dental Practice Board (of England and Wales) database has proved to be a fruitful source of data on the long-term outcome of restorations. Dental practice can provide the large pool of patients available for research. To utilize this pool of patients, dental practitioners and their support staff require training in collecting data.

Data Collection↗
PubMed2005

Outcome of direct restorations placed within the general dental services in England and Wales (Part 3): variation by dentist factors.

AIM: It is the aim of this paper to investigate the survival of direct-placement restorations provided within the General Dental Services in England and Wales, in relation to the dentist factors which may affect this. METHODS: For this work, survival of a restoration was considered to be the time between the date of completion of the course of treatment in which it was placed and the date of acceptance of the course of treatment when the next tooth-specific treatment was carried out on the same tooth. A modified version of Kaplan-Meier statistical methodology was used to plot survival curves for restorations placed by different subgroups of dentists. RESULTS: The age and experience of the dentist who placed the original restoration were found to be related to restoration survival, with older dentists having shorter intervals from placement of restorations to re-intervention (P<0.001). Country of qualification seems not to be relevant within Europe in terms of restoration survival, but dentists who qualified outside Europe achieve different restoration survival times for the restorations that they place. Dentist's gender has no relationship with time from restoration to re-intervention. CONCLUSIONS: Dentist factors such as age, country of qualification, and employment status, but not the gender of the dentist, have been found to influence the survival of directly placed restorations.

Adult↗
PubMed2005

Outcome of direct restorations placed within the general dental services in England and Wales (Part 2): variation by patients' characteristics.

AIM: It is the purpose of this paper to investigate the outcome of direct-placement restorations provided within the General Dental Services in England and Wales, and to identify the patient factors which may affect this using a database derived from patient treatment data at the Dental Practice Board. METHODS: For this work, survival of a restoration was considered to be the time between the date of completion of the course of treatment in which it was placed and the date of acceptance of the course of treatment when the next tooth-specific treatment was carried out on the same tooth. A modified version of Kaplan-Meier statistical methodology was used to plot survival curves for restorations in different subgroups of patients within the population of patients for whom data were available. RESULTS: The results indicated that patients' gender was of little significance in the long-term survival of restorations, but patient age had a significant effect, with the restorations of older patients surviving less well than those of younger patients (P<0.001). The charge-paying status of the patient had a statistically significant but small effect (P<0.001), with survival for charge-payers being slightly higher throughout the observation period. There was a strong relationship between attendance frequency and survival time, with restorations of more frequent attenders performing less well than those of less frequent attenders (P<0.001). CONCLUSIONS: Patient factors such as age, charge-paying status, interval between courses of treatment, continuity of care by one dentist, and annual gross fees incurred, have all been found to influence the survival of directly placed restorations.

Adolescent↗
PubMed2005

Outcome of direct restorations placed within the general dental services in England and Wales (Part 1): variation by type of restoration and re-intervention.

AIM: It is the aim of this paper to consider the dental factors associated with the need for re-intervention on a restoration, such as the tooth position, size of cavity, and restoration material. METHODS: Patients whose data were included in this study were those whose birthdays were included within a set of randomly selected dates, one of which was chosen in each possible year of birth. The restoration records consisted of all those records containing directly placed restorations which related to courses of treatment of patients 18 years or older with last date on the claim form after 31st December 1990, and with date of acceptance after September 1990 and before January 2002. For each tooth treated with a direct restoration the subsequent history of intervention on that tooth was consulted, and the next date of intervention, if any could be found in the extended data set, was obtained. Thus a data set was created of direct restorations with their dates of placement and their dates, if any, of re-intervention. RESULTS: Data for over 80,000 different adult patients were analyzed, of whom 46% were male and 54% female. A total of 503,965 tooth restoration occasions were obtained from the data over a period of eleven years. Single surface amalgam restorations were found to have the longest survival --58% at 10 years, and glass ionomer the shortest 38% at 10 years. Factors which were found to reduce restoration outcome included involvement of the incisal angle in composite restorations--this resulted in a reduction in median survival of around two years--and the placement of pins in a restoration. The presence of a root filling was also found to reduce the survival of restorations in the crown of the root filled tooth. CONCLUSIONS: Small amalgam restorations have longer survival times before re-intervention than large amalgam restorations such as MOD. Composite and glass ionomer restorations perform less well than amalgam restorations. Pin placement and root filling reduce the survival time of restorations.

Acrylic Resins↗
PubMed2005

Outcome of direct restorations placed within the general dental services in England and Wales (Part 4): influence of time and place.

AIM: It is aim of this paper to investigate the outcome of direct-placement restorations provided within the General Dental Services in England and Wales, in relation to the factors related to time and place of restoration placement. METHODS: A modified version of Kaplan-Meier statistical methodology was used to plot survival curves for restorations placed at different times and places, within the population of patients for whom data were available. RESULTS: The results indicated that overall, restoration survival time to re-intervention has declined over the last decade, but that most of the decline can be accounted for by the change in the relative numbers of amalgam and other direct restorations. Restoration survival to re-intervention is independent of whether the water is fluoridated in the area of the dentist's surgery address. Variation with region is not great, but restorations placed in Wales survived to re-intervention significantly longer than those in England (P<0.0001). CONCLUSIONS: Overall, there was some evidence of a reduction in survival times with time. Restorations placed in Wales survived longer to re-intervention than restorations placed in England. Restoration survival was not dependent on whether the dentist who placed the restoration practised in an area in which the water was fluoridated. Performance of amalgam restorations was not found to have altered significantly with time, but performance of composite and glass ionomer deteriorated with time.

Acrylic Resins↗
PubMed2005

Analysis of an administrative database of half a million restorations over 11 years.

AIM: This paper describes the analytical approach used to extract empirical distributions of the interval from the date of placement of a direct restoration to the date when the next intervention took place on the same tooth, that is, an estimate of restoration survival. METHODS: Data, based on the complete attendance and treatment history, over the eleven years from 1991 to 2001, of a statistically representative sample of 82,537 General Dental Services' patients in England and Wales, all of whom received at least one directly placed restoration during the observation period, have been analysed. The patients on the database received a total of 719,009 courses of treatment, and there were 503,965 occasions when a tooth was directly restored. The method of analysis involved, first, the estimation of the probability that the patient will eventually return, given an interval without attending, by analysing the observed patterns of re-attendance. This estimated probability of re-attendance was then used to modify the standard Kaplan-Meier procedure to produce realistic estimates of the hazard of re-intervention. RESULTS: The results demonstrate that the newly developed methodology has produced robust estimates of the distribution of survival intervals to next intervention on the same tooth. Regarding attendance patterns, re-attendance probability varies with length of interval since last attendance. There is also a strong association with patient age. The older the patient, the more likely it is that a gap in attendance is indicative that the patient will never return. The detailed cumulative survival curve over eleven years has been plotted and forty-seven per cent of restorations, overall, survived without re-intervention for at least ten years. The entire analysis was then successfully replicated on a second, independently selected, sample of attendance and treatment records, confirming the ten-year survival estimate. CONCLUSIONS: This newly developed methodology has produced robust estimates of the distribution of survival intervals to next intervention on the same tooth. Patient re-attendance probability varies with length of interval since last attendance and with patient age. The ten-year overall survival rate to next intervention on the same tooth for direct restorations placed within the GDS in England and Wales is circa 47%.

Adolescent↗
PubMed2005

UK dentists' attitudes and behaviour towards Atraumatic Restorative Treatment for primary teeth.

BACKGROUND: Atraumatic Restorative Treatment (ART) was introduced a decade ago as a minimal intervention treatment for caries in unindustrialised countries, but UK general dental practitioners (GDPs) may also be using this technique. OBJECTIVE: This study aimed to determine the materials and techniques used by a group of UK GDPs to treat caries in primary teeth. METHOD: A questionnaire, designed to determine GDPs' use of materials and techniques in the restoration of caries in primary teeth, was distributed to 600 GDPs in Scotland and England, with an explanatory letter and reply-paid envelope. The questionnaire included colour illustrations of two carious cavities in primary molar teeth and a request that respondents draw the cavity outline that they would use on the illustrations. The cavity outlines were assessed independently by two examiners. All other data were collated and analysed. RESULTS: 390 usable replies were received, a response rate of 65%. Of the respondents, 99% treated child patients and 42% of respondents were aware of ART. For treatment of a small Class II cavity, 37% drew a cavity outline without extension beyond removal of caries and a majority suggested use of an adhesive material (51% glass ionomer, 13% compomer). For cavity preparation, 47% of respondents used a drill, 10% an excavator and 41% used both. For treatment of a large occluso-lingual cavity, again most used an adhesive technique (44% glass ionomer, 12% compomer) for its restoration, while 50% used a drill, 7% an excavator and 42% used both for cavity preparation. CONCLUSION: Most respondents used adhesive materials for restoration of caries in primary molars, but, despite 42% of respondents stating that they were aware of the treatment, "true" ART was adopted by fewer than 10% of respondents.

Attitude of Health Personnel↗
PubMed2005

Two-year evaluation of restorations of a packable composite placed in UK general dental practices.

OBJECTIVE: The aim of this study was to assess the clinical performance at two years of 100 Solitaire 2 restorations placed in five United Kingdom dental practices by members of a practice-based research group. METHOD AND MATERIALS: Restorations were assessed after two years by a trained evaluator and the dental practitioner who had placed the material, for anatomic form, marginal adaptation, surface roughness, gingival condition and the presence or absence of secondary caries. In addition, the patients completed a questionnaire requesting details of the comfort and performance of the Solitaire 2 restoration(s). RESULTS: A total of 88 (58 Class II and 30 Class I) restorations of Solitaire 2 placed in 49 patients (mean age 43 years) were assessed. Twelve restorations could not be evaluated because of patient unavailability for the dates of the examinations. Two Class II restorations (2%) had failed by the time of the two-year evaluation and the remaining 86 restorations were found to be intact with no secondary caries. A high percentage of optimal scores were recorded for anatomic form and surface roughness. The colour match of two restorations (2%) was recorded as an obvious mismatch, but otherwise no unacceptable scores were recorded. CONCLUSIONS: After two years of clinical service a high proportion (96%) of the Solitaire 2 restorations that were available for re-examination, placed in general dental practice settings, were found to be performing satisfactorily.

Adhesives↗
PubMed2005

The frictional coefficients and associated wear resistance of novel low-shrink resin-based composites.

OBJECTIVES: Frictional forces play a major role in the oral wear process of dental resin-based composites (RBCs) and it would be of interest to consider how the energy from friction is dissipated at the material surface. Consequently, the micromechanical wear properties of conventional methacrylate compared with novel oxirane RBCs were assessed. METHOD: The frictional coefficient (mu), volume loss and Vickers hardness number (VHN) of oxirane (EXL596 and H1) and methacrylate RBCs (Z100 and Filtek Z250) were evaluated. Archard's wear equation was implemented to obtain the wear coefficient (K) and expressed as a 'fraction of friction' (K/micro) to indicate the dissipation of frictional energy that resulted in wear. Scanning electron microscopy (SEM) was used to qualitatively asses the wear facets of each RBC following 50000-cycles. RESULTS: The mean frictional coefficients observed between the oxirane and methacrylate RBCs were not significantly different (P > 0.05). However, the volume loss of EXL596 and H1 (5.9 +/- 0.4 and 4.7 +/- 0.3 x 10(-2) mm(3)) was significantly increased compared with Z100 and Filtek Z250 (1.7 +/- 0.2 and 2.3 +/- 0.3 x 10(-2) mm(3)). The VHN of EXL596 and H1 was either significantly greater (P = 0.021) or similar (P = 0.089) to Filtek Z250, respectively. An increase in K/micro was reported for EXL596 and H1 (34.7 +/- 4.1 and 22.8+ /- 2.4 x 10(-4)) compared with Z100 and Filtek Z250 (8.50 +/- 0.7 x 10(-4) and 8.62 +/- 1.0 x 10(-4)) (P < 0.05). SEM images of the oxirane RBCs exhibited increased surface fatigue and delamination of the surface layers compared with the methacrylate RBC specimens following 50,000-cycles. CONCLUSION: The significant decrease in wear resistance of the oxirane compared with methacrylate RBCs was unexpected since frictional coefficients and/or surface hardness were statistically similar. The decreased wear resistance of EXL596 and H1 compared with Z100 and Filtek Z250 was further explained by the increase in K/micro from wear theory and the associated increase in surface fatigue identified from SEM. The simplistic testing procedure combined with SEM utilized in the current investigation provided a greater insight into the wear mechanism by considering the effect of frictional energy at the specimen surface which may benefit the development of improved wear resistance for experimental RBC materials.

Animals↗
PubMed2005

An assessment of career satisfaction among a group of general dental practitioners in Staffordshire.

OBJECTIVES: To assess the level of job satisfaction among general dental practitioners from one area of England, and to assess the association of various personal and work related factors with job satisfaction. DESIGN: Postal questionnaire survey. SETTING: General dental practices in South Staffordshire, Wolverhampton and Dudley, England. METHOD: An anonymous questionnaire posted to all 396 registered dentists in the above areas. RESULTS: A 75% response rate was achieved. Data were analysed using non-parametric statistics for any significant differences in the scores for stress, respect, overall professional satisfaction, quality of life and overall job satisfaction according to the different demographic groupings of the dentists (alpha =0.05). Dentists with an area of special interest had higher scores in all categories except quality of life. Overall job satisfaction was higher among private dentists, and those in group practices and in non-rural locations. The highest bi-variate correlation occurred between overall job satisfaction and overall professional satisfaction, delivery of care, income, respect and professional time. CONCLUSIONS: Job satisfaction was judged to be good among this group. Stress was the factor associated with the greatest dissatisfaction. This survey produced similar results to preceding US studies, and suggests ways of improving job satisfaction.

Attitude of Health Personnel↗
PubMed2005

Indices.

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Health Status Indicators↗
PubMed2005

Conducting trials.

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Clinical Trials as Topic↗