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Biomedical subjects

D W Bartlett

Publications and source records attributed to D W Bartlett.

At least 19 recordsLinked to original sources
PubMed2003

Retrospective long term monitoring of tooth wear using study models.

OBJECTIVE: Tooth wear is recognised as a common feature of European dentitions. However, little is known about its progression in susceptible patients. The aim of this study was to assess the degree and progression of tooth wear in patients by examining study casts taken of their teeth on two separate occasions. DESIGN: Over 500 sets of study casts taken during an 18-year period from patients referred for a variety of restorative procedures, were examined at Guy's Dental Hospital. Of these, 34 cases were found to have consecutive models taken at two time intervals and these were used to assess the progression of tooth wear. Study models from 19 females and 16 males, with an average age of 26 years (range 18-60) at the time of their first presentation and were all examined by a single operator. The Smith and Knight tooth wear index was used to assess the degree of tooth wear at presentation and then at another time which was a median of 26 months (interquartile range 14 - 50 months) later. RESULTS: The most common initial TWI score per surface was 1, with 54% of surfaces affected at the first assessment and 57% at the second. Score 2 was less common (14% at both assessments) and the scores for 3 and 4 combined were relatively uncommon with 5% of surfaces effected. Minimal progression of tooth wear was observed on study casts with only 7.3% of surfaces involved. CONCLUSION: In this sample, tooth wear was a slow, minimally progressive process.

Adolescent↗
PubMed2001

Experiences and perceptions of vocational training reported by the 1999 cohort of vocational dental practitioners and their trainers in England and Wales.

OBJECTIVE: To assess the self-reported confidence of vocational dental practitioners (VDPs) in clinical procedures together with vocational trainers' perceptions of the VDPs confidence in the same procedures, immediately after qualification and towards the end of the vocational training year. DESIGN: A questionnaire-based cohort study. SETTING: A general practice study carried out in 1999. SUBJECTS: Vocational Dental Practitioners and vocational trainers in England and Wales. METHOD: VDPs and trainers were asked on a single occasion to grade the clinical confidence of the VDP at the beginning and near the end of vocational training as high, satisfactory or low. RESULTS: Questionnaires were sent to 531 VDPs and 555 trainers; 82 per cent of VDPs and trainers responded. Approximately half the VDPs were male and 57 per cent were white, whilst 89 per cent of trainers were male and 81 per cent white. A large proportion of both VDPs and trainers reported low confidence in orthodontics, molar endodontics and surgical extractions at the start of the training year. Towards the end of training, both groups reported improved confidence levels in most clinical procedures. However, a higher proportion of trainers reported low confidence than their VDPs in most clinical procedures at both time points (p<0.001). VDPs appeared to gain most from experience and training in administration/management and interpersonal skills. CONCLUSION: Vocational training appears to satisfy its aim to enhance clinical and administrative confidence.

Clinical Competence↗
PubMed2001

Mesotrione: a new selective herbicide for use in maize.

Mesotrione is a new herbicide being developed for the selective pre- and post-emergence control of a wide range of broad-leaved and grass weeds in maize (Zea mays). It is a member of the benzoylcyclohexane-1,3-dione family of herbicides, which are chemically derived from a natural phytotoxin obtained from the Californian bottlebrush plant, Callistemon citrinus. The compound acts by competitive inhibition of the enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD), a component of the biochemical pathway that converts tyrosine to plastoquinone and alpha-tocopherol. Mesotrione is an extremely potent inhibitor of HPPD from Arabidopsis thaliana, with a Ki value of c 6-18 pM. It is rapidly taken up by weed species following foliar application, and is distributed within the plants by both acropetal and basipetal movement. Maize is tolerant to mesotrione as a consequence of selective metabolism by the crop plant. Slower uptake of mesotrione, relative to susceptible weed species, may also contribute to its utility as a selective herbicide for use in maize.

4-Hydroxyphenylpyruvate Dioxygenase↗
PubMed2001

The measurement and prevention of erosion and abrasion.

OBJECTIVES: To develop a reproducible method to measure tooth wear and assess the protection given by dentine bonding agents in an erosive/abrasive wear regime. METHODS: Seal and Protect (Dentsply, UK) and Optibond Solo (Kerr, UK) were each applied to 20 extracted teeth and subjected to 3000 cycles in a reciprocating erosion/abrasion wear machine. A further 20 teeth, without protection, were subjected to the same wear regime and were either brushed in water or immersed in acid. Impressions were taken by a standardised technique and were scanned with a non-contacting laser profilometer. The amount of erosion was measured at the same co-ordinates before and after erosion using 2mm diameter metal discs as reference points. RESULTS: The amount of wear on Seal and Protect had a mean 24.8 microm (SD 57.4 microm) and for Solo it was 1.4 microm (24.5 microm), and this difference was statistically significant (p=0.02). There was no statistically significant difference in the wear measured on the teeth brushed in water or immersed in acid. The wear measured on the unprotected teeth was 243 microm (SD 120 microm) and was statistically significantly different to the protected surfaces (p=0.001). CONCLUSION: Both Seal and Protect and Solo protected the teeth in this wear regime and the technique could be used clinically for patients with uncontrolled dental erosion.

Analysis of Variance↗
PubMed2001

Comparison of the erosive potential of gastric juice and a carbonated drink in vitro.

The aim of this study was to compare the erosive effect of gastric juice and a carbonated drink on enamel and dentine by measuring release of calcium from 30 hemisectioned teeth in vitro. In addition, the titrable acidity (mL of 0.05 M sodium hydroxide required to neutralize) and pH of the fluids was estimated. The mean pH of the seven gastric acid samples was 2.92 (range 1.2-6.78) and mean titratable acidity 0.68 mL (range 0.03-1.64). Both the pH and the titratable acidity of the gastric juice varied between patients all of whom suffered from symptoms of reflux disease. The carbonated drink had a pH of 2.45 and a titratable acidity of 0.29 mL. The median amount of calcium released by the gastric acids from enamel was 69.6 microg L-1 (interquartile range 5.4-144) and 62.4 microg L-1 (2.2-125.3) from dentine. The carbonated drink released 18.7 microg L-1 (13.4-23.4) and 18.6 microg L-1 (11.9-35.3), respectively. The differences in calcium release by gastric juice and the carbonated drink were statistically significant for both enamel (P < 0.005) and dentine (P < 0.01). It is concluded that gastric juice has a greater potential, per unit time, for erosion than a carbonated drink.

Calcium↗
PubMed2001

Bleaching discoloured teeth.

The bleaching of teeth has encountered some legislative problems over the past few years but it is now possible to use both vital and non-vital bleaching techniques in the UK. Hydrogen peroxide has a long history of use and would appear to be safe to use to change the appearance of discoloured teeth. It is conservative of tooth tissue and may delay the need for more invasive veneers and crowns. This article describes some of the methods of bleaching using hydrogen peroxide that are currently available.

Borates↗
PubMed2000

Oral pH and drinking habit during ingestion of a carbonated drink in a group of adolescents with dental erosion.

OBJECTIVES: To investigate the relationship between dental erosion, oral pH and drinking habit in a group of adolescents. METHODS: Oral pH was measured simultaneously at the surface of four teeth in 11 patients, aged 10-16 years, with erosion and in 10 controls subjects without erosion using antimony electrodes. Measurements were made before, during and after drinking 330 ml of a carbonated drink. The method and timing of drinking the beverage, reported dietary intake of acidic foods and flow rate and buffering capacity of saliva were recorded. RESULTS: The erosion patients reported drinking more carbonated drinks (p<0.01) and drinking directly from a can more frequently than the controls (p<0.05). They also drank twice as quickly (p<0.05). The pH at the buccal surface of a molar remained lower for longer in the erosion patients than in the patients without erosion (p<0.01), whilst the labial surface of the upper central incisor had a longer exposure to low pH in the controls subjects (p<0.05). CONCLUSION: The pattern of oral pH differed between subjects with and without erosion after drinking an acidic beverage. This may be related to observed differences in drinking habit, which could have influenced the pattern of erosion in these subjects.

Adolescent↗
PubMed2000

The role of the esophagus in dental erosion.

OBJECTIVE: The aim of this study was to measure lower esophageal sphincter pressure, sphincter length, and esophageal motility in patients with dental erosion and compare the results with measurements made in patients without gastroesophageal reflux or dental erosion. STUDY DESIGN: Lower esophageal sphincter length and esophageal motility were measured in 39 patients (age range, 15-74 years) with dental erosion through use of static esophageal pressure monitoring; the data were compared with those from 10 control subjects (age range, 26-46 years) with nonparametric statistical tests. RESULTS: Median lower esophageal sphincter pressure was 9 mmHg (range, 0-26 mmHg) in the patients with erosion and 9.5 mmHg (range, 0 -14 mmHg) in the controls; there was no statistically significant difference between the two subject groups. Similarly, there was no statistically significant difference in esophageal length between the subject groups. There was a statistically significant difference between the groups (P =.01) in the measurement of esophageal motility; the median value was 8% (range, 0% to 100%) in the patients with erosion and 0% (range, 0% to 18%) in the controls. CONCLUSIONS: It appears that esophageal motility in patients with dental erosion is more likely to be associated with low amplitude changes than with sphincter pressure alone. Poor esophageal motility may therefore be a risk factor in regurgitation erosion.

Adolescent↗
PubMed2000

A literature review of the techniques to measure tooth wear and erosion.

This paper reviews methods to measure tooth wear especially those more recently introduced as a result of improvements in technology. The review searched methods to measure tooth wear and dental erosion from large epidemiological investigations, in vitro and in vivo studies. There seems to be wide variation in techniques used to measure tooth wear and erosion. In vitro techniques may have little direct clinical relevance but can lead to new and more accurate clinical methods. In vivo studies have problems with reference points and accurate validation of the techniques. There is a need for a simple, reliable technique to quantify tooth wear due to erosion.

Diagnostic Imaging↗
PubMed1999

Dealing with sensitive teeth.

Dental pain is extremely common in the UK and can severely reduce the quality of life when it is associated with eating, drinking or speech. Patients often present complaining of a short, sharp, stabbing pain from hot or cold air, foods or drinks: while this may be caused by tooth decay, failing fillings or cracks in teeth, a major cause is sensitivity from exposed dentine. Treatment varies from dietary control, desensitising toothpastes to protection with dentine-bonding agents and glass ionomers. In extreme cases elective devitalisation is necessary.

Dentin Permeability↗
PubMed1999

The role of saliva in regurgitation erosion.

It has been suggested that salivary characteristics are important in the progression of erosion. The aim of this investigation was to measure salivary parameters in 22 patients with erosion, 10 with normal (non-pathological) levels of reflux (Group I) and 12 with previously diagnosed pathological levels of gastro-oesophageal reflux (Group II). A further 10 subjects without evidence of erosion and no history of reflux disease acted as controls (Group III). No statistically significant differences in salivary flow rate, buffering power or the concentrations of calcium, phosphorus and fluoride were detected. The results suggest that variation in the characteristics of unstimulated and stimulated saliva collected during waking hours do not have a major role in erosion.

Adult↗
PubMed1998

The prevalence of tooth wear in a cluster sample of adolescent schoolchildren and its relationship with potential explanatory factors.

OBJECTIVE: To assess the prevalence of tooth wear in adolescents and its relationship with diet, saliva and gastro-oesophageal reflux. DESIGN: Single centre cluster sample epidemiological study. SETTING: A school in London in the summer of 1996. SUBJECTS: 11-14-year-old schoolchildren. MAIN OUTCOME MEASURES: The Smith and Knight tooth wear index (TWI), salivary factors, diet and symptoms of gastro-oesophageal reflux were recorded for all subjects. RESULTS: Results were obtained from 210 subjects. One subject refused to provide a saliva sample and 11 subjects provided insufficient saliva for analysis of buffering power (n = 198). 57% (95% confidence intervals 50.3-63.7%) of subjects had tooth wear on more than ten teeth and a median 12% (interquartile range 6-18%, 95% confidence intervals 8-14%) of surfaces were affected. However, dentine involvement was rare. The median intake of carbonated drinks was 2 cans (interquartile range 1-3) a day. However, there was no correlation with TWI (r = -0.09, P = 0.19). There was no relationship between tooth wear index (TWI) and salivary flow rate (r = -0.02, P = 0.78) or buffering capacity (r = -0.02, P = 0.76). A trend was observed for those with a reported history of regurgitation (n = 27) to have a higher maxillary TWI (median 8, interquartile range 2-13) compared with those who did not (5, 2-9, P = 0.06). CONCLUSIONS: Tooth wear is common in adolescents and the relationship with dietary acid, salivary buffering and symptoms of gastro-oesophageal reflux is complex and requires further investigation.

Adolescent↗
PubMed1997

Experience of undergraduates from three London dental schools and trainers from the south east of England on interviews for vocational training in 1996.

OBJECTIVE: To assess the current perceptions, motivations and expectations of trainers and vocational dental practitioners (VDPs) of vocational training (VT) interviews. DESIGN: Questionnaire based study. SETTING: General practice study carried out in 1996. SUBJECTS: Undergraduates from three London dental schools and vocational trainers from south-east England. MAIN OUTCOME MEASURES: Perceptions, motivation and experiences were assessed by a questionnaire. RESULTS: 111 questionnaires were posted to trainers with 72 (65%) returned. 108 (70%) were returned from the dental schools after 155 were posted. Graduates employed in hospital training posts, armed forces and community dentistry were eliminated from the results. Most trainers (74%) had previous experience of VT and 89% of trainers thought that a CV was important for their choice of VDPs. However, only 11% of trainers sought references before interviewing. 34% of VDPs preferred jobs close to their dental school but 75% considered location to be vital to their choice. 67% of VDPs made 10 or more applications and 57% visited 10 or more practices for interviews. 78% of VDPs considered that either genderism or racism was likely to or possibly influenced the trainers choice. However, the converse was not true, 62% of trainers considered it unlikely that the VDPs were influenced by their gender or race. CONCLUSIONS: Trainers and VDPs have different perceptions concerning the protocol of interviews for VT.

Adult↗
PubMed1997

Measurement of tooth wear in patients with palatal erosion.

AIM: To develop a reproducible method for the assessment of tooth wear in vivo using a laser profilometer. DESIGN: A controlled study to measure tooth wear. SUBJECTS AND METHODS: Wear was measured over a 6-month period in 13 patients with unexplained palatal dental erosion and compared with a group of 7 controls without any evidence of abnormal wear. MAIN OUTCOME MEASURES: Metal disks were cemented to the tooth surface and impressions taken at 6-month intervals. Wear was estimated by scanning the impressions with a contacting laser profilometer and measuring a change in depth around the disk over a 6-month period using fixed reference points on the metal disks. RESULTS: A statistically significant difference was observed between patients with palatal erosion and the controls. Patients with erosion had a median of 36.5 microns of wear over 6 months (range 17.6-108.2) and the controls had a median of 3.7 microns (range 0.5-15.8). CONCLUSIONS: This paper presents a novel method for measuring erosion using fixed reference points cemented to the palatal surfaces of upper incisor teeth.

Adolescent↗
PubMed1997

The prevalence, etiology and management of tooth wear in the United Kingdom.

STATEMENT OF PROBLEM: Recent epidemiologic evidence suggests that tooth wear is now a significant problem in both children and adults. There is growing evidence that a major cause of severe wear in patients is regurgitation erosion due to a variety of factors including gastroesophageal reflux disease. PURPOSE: The purpose of this article is to discuss the prevalence of tooth wear in the United Kingdom. Emphasis in management should be on accurate diagnosis, and in some patients, long-term monitoring before embarking on any irreversible, interventive treatment. Even when treatment is necessary, a period of monitoring is helpful to assess the rate of progress of the wear, the effectiveness of preventive measures, and therefore the extent of the treatment necessary.

Adolescent↗
PubMed1997

Oral regurgitation after reflux provoking meals: a possible cause of dental erosion?

Certain foods and drinks such as alcohol, heavily spiced or fatty meals are known to provoke gastro-oesophageal reflux (GOR). This may give rise to symptoms of heartburn, epigastric pain and occasionally oral regurgitation of the gastric contents. Oral regurgitation of gastric juice is important in dentistry because of its association with dental erosion. This study measured oesophageal and oral reflux in 12 healthy subjects after a curry meal taken with alcohol 2 h before sleep. Each subject repeated the test with a bland non-reflux provoking control meal. GOR was measured by recording distal and proximal oesophageal pH on a dual channel, portable pH monitor. Oral pH was measured with a pH sensitive radio-telemetry capsule (RTC) held on the palate in a vacuum formed splint. Signals from the RTC were received by an aerial worn around the head. The pH change produced by GOR was estimated as the percentage time that pH (PTpH) was less than 4 in the distal oesophagus. Similarly, the PTpH was estimated < 4 and < 5 in the proximal oesophagus and < 5.5 and < 6 in the mouth over a period of 16 h. All subjects tolerated the monitors overnight with little loss of data and data were collected from all studies. The curry meal provoked GOR in all subjects, but only in six subjects to pathological levels according to international guidelines. The results show that GOR measured as the PTpH < 4 was significantly higher in the distal oesophagus whilst subjects were supine after the curry meal than with the control meal (P = 0.0006) and in the proximal oesophagus in the upright position (P = 0.006). There was a significant difference in the oral PTpH < 5.5 between the two meals for the total study period (P = 0.005). The bland meal provoked pathological levels of reflux in only two subjects. In one of these subjects the bland meal provoked oral regurgitation with a PTpH < 5.5 of 13.5%. In the remaining subjects little oral regurgitation occurred.

Adult↗