Biomedical subjects

D J Evans

Publications and source records attributed to D J Evans.

At least 37 records · Page 2Linked to original sources

PubMed2001

Gold as an oral corticosteroid sparing agent in stable asthma.

BACKGROUND: Patients with chronic severe asthma are often dependent on the long term prescription of oral corticosteroids. The use of steroids is associated with serious side effects. Physicians treating such patients continue to search for alternative therapies that reduce the need for chronic dosing with oral steroids. Gold compounds are immunosuppressive agents and have benefits in the treatment of a number of inflammatory disorders. They have therefore been identified as an potentially useful agents in the treatment of chronic severe asthma both in terms of possible efficacy and as steroid sparing agents. OBJECTIVES: The objective of this review was to assess the effects of adding gold to oral steroids in the treatment of chronic steroid dependent asthmatics. SEARCH STRATEGY: The Cochrane Airways Group trials register and reference lists of identified articles were searched. SELECTION CRITERIA: Randomised trials looking at the addition of gold compared to placebo in adult steroid dependent asthmatics. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data extraction was carried out by two reviewers independently. Study authors were contacted for missing information. MAIN RESULTS: Three trials fulfilled the criteria for inclusion in the review and a total of 376 patients were recruited into these studies. Data from 311 patients could be analysed. There was a small but significant treatment effect for gold in terms of steroid dose reduction (Peto Odds Ratio 0.51, 95% confidence intervals 0.31,0.83). No meta-analysis could be done for measures of lung function although overall there were few changes suggesting a positive benefit for gold. There were trends suggestive of adverse effects but no significant changes for gold treated patients with respect to proteinuria (Peto Odds Ratio 1.4, 95% confidence intervals 0.6, 3.3) dermatitis/eczema Peto Odds Ratio 2.1, 95% confidence intervals 0.9, 4.7). REVIEWER'S CONCLUSIONS: The changes seen in these trials are small and probably of limited clinical significance. Given the side effects of gold and necessity for monitoring the use of gold as a steroid sparing agent in asthma cannot be recommended.

Adrenal Cortex Hormones↗

PubMed2001

Troleandomycin as an oral corticosteroid steroid sparing agent in stable asthma.

BACKGROUND: Patients with chronic severe asthma are often dependent on the long term prescription of oral corticosteroids. The use of steroids is associated with serious side effects. Physicians treating such patients continue to search for alternative therapies that reduce the need for chronic dosing with oral steroids. troleandomycin is a compound that is established as an effective antibiotic but may also have non antibacterial actions that may be useful in the treatment of asthma. OBJECTIVES: The objective of this review was to assess the effects of adding troleandomycin to oral steroids in the treatment of chronic steroid dependent asthmatics. SEARCH STRATEGY: The Cochrane Airways Group trials register and reference lists of identified articles were searched. SELECTION CRITERIA: Randomised trials looking at the addition of troleandomycin compared to placebo in adult steroid dependent asthmatics. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data extraction was carried out by two reviewers independently. Study authors were contacted for missing information. MAIN RESULTS: Three trials fulfilled the criteria for inclusion in the review and a total of 112 patients were recruited into these studies. Data from 90 patients were analysed. There was no treatment effect for troleandomycin in terms of steroid dose reduction (SMD -0.29, 95% CI -0.75, 0.17). For measures of lung function a meta-analysis of data derived from two of the included studies showed no benefits for added troleandomycin (SMD 0.06 95% CI -0.8, 0.9). REVIEWER'S CONCLUSIONS: There is insufficient evidence to support the use of troleandomycin in the treatment of steroid dependent asthma.

Administration, Oral↗

PubMed2001

Cyclosporin as an oral corticosteroid sparing agent in stable asthma.

BACKGROUND: Patients with chronic severe asthma are often dependent on the long term prescription of oral corticosteroids. The use of steroids is associated with serious side effects. Physicians treating such patients continue to search for alternative therapies that reduce the need for chronic dosing with oral steroids. Cyclosporin is an immunosuppressive agent and has benefits in the treatment of a number of inflammatory disorders. It has therefore been identified as an potentially useful agent in the treatment of chronic severe asthma both in terms of possible efficacy and as a steroid sparing agent. OBJECTIVES: The objective of this review was to assess the effects of adding cyclosporin to oral steroids in the treatment of chronic steroid dependent asthmatics. SEARCH STRATEGY: The Cochrane Airways Group trials register and reference lists of identified articles were searched. SELECTION CRITERIA: Randomised trials looking at the addition of cyclosporin compared to placebo in adult steroid dependent asthmatics. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data extraction was carried out by two reviewers independently. Study authors were contacted for missing information. MAIN RESULTS: Three trials fulfilled the criteria for inclusion in the review and a total of 106 patients were recruited into these studies. Data from 98 patients could be analysed. There was a small but significant treatment effect for cyclosporin in terms of steroid dose reduction (SMD -0.5, 95% CI -1.0, -0.04). No meta-analyses could be performed for measures of lung function although one study showed small, but significant improvements in lung spirometry. REVIEWER'S CONCLUSIONS: The changes with cyclosporin are small and of questionable clinical significance. Given the side effects of cyclosporin, the evidence available does not recommend routine use of this drug in the treatment of oral corticosteroid dependent asthma.

Administration, Oral↗

PubMed2001

The variable P5 proteins of typeable and non-typeable Haemophilus influenzae target human CEACAM1.

Haemophilus influenzae, a commensal of the human respiratory mucosa, is an important cause of localized and systemic infections. We have recently shown that numerous strains of capsulate (typeable) and acapsulate (non-typeable) H. influenzae target the carcinoembryonic antigen (CEA) family of cell adhesion molecules (CEACAMs). Moreover, the ligands appeared to be antigenically variable and, when using viable typeable bacteria, their adhesive functions were inhibited by the presence of capsule. In this report, we show that the antigenically variable outer membrane protein, P5, expressed by typeable and non-typeable H. influenzae targets human CEACAM1. Variants and mutants lacking the expression of P5 of all strains tested were unable to target purified soluble receptors. A non-typeable strain that did not interact with CEACAM1 was made adherent to both the soluble receptors and CEACAM1-transfected Chinese hamster ovary cells by transformation with the P5 gene derived from the adherent typeable strain Rd. However, several H. influenzae mutants lacking P5 expression continued to bind the cell-bound CEACAM1 receptors. These observations suggest that (i) CEACAM1 alone can support P5 interactions and (ii) some strains contain additional ligands with the property to target CEACAM1 but require the receptor in the cellular context. The identification of a common ligand in diverse strains of H. influenzae and the presence of multiple ligands for the same receptor suggests that targeting of members of the CEACAM family of receptors may be of primary significance in colonization and pathogenesis of H. influenzae strains.

Animals↗

PubMed2001

Helicobacter pylori CagA: analysis of sequence diversity in relation to phosphorylation motifs and implications for the role of CagA as a virulence factor.

CagA is transported into host target cells and subsequently phosphorylated. Clearly this is a mechanism by which Helicobacter pylori could take control of one or more host cell signal transduction pathways. Presumably the end result of this interaction favors survival of H. pylori, irrespective of eventual damage to the host cell. CagA is noted for its amino acid (AA) sequence diversity, both within and outside the variable region of the molecule. The primary purpose of this review is to examine how variation in the type and number of CagA phosphorylation sites might determine the outcome of infection by different strains of H. pylori. The answer to this question could help to explain the widely disparate results obtained when H. pylori CagA status has been compared to type and severity of disease outcome in different populations, that is in different countries. Analysis of all available CagA sequences revealed that CagA contains both tyrosine phosphorylation motifs (TPMs) and cyclic-AMP-dependent phosphorylation motifs (CPMs). There are two potential CPMs near the N-terminus of CagA and at least two in the repeat region; these are not all equally well conserved. We also defined a 48-residue AA sequence, which includes the N-terminal TPM at tyrosine (Y)-122, which distinguishes between Eastern (Hong Kong-Taiwan-Japan-Thailand) H. pylori isolates and those from the West (Europe-Africa-the Americas-Australia). All 28 of the Eastern type CagA proteins have a functional N-terminal TPM whereas 11 of 47 (23.4%) of the Western type contain an inactive motif, with threonine (T) replacing the critical aspartic acid (D) residue. Only 13 of 24 (54%) known CagA sequences have an active TPM in the repeat region and only one has two TPMs in this region. The potential TPM near the C-terminus of CagA is not likely to be important since only 3 of 24 (12.5%) sequences were found to be intact. Protein database searches revealed that the AA sequence immediately following the TPM at Y-122 in CagA is homologous with a pair of PDZ domains which are common in signal transducing proteins, particularly tyrosine phosphatases. This provides a theoretical link between CagA and many of the observed responses of host cells to H. pylori. In summary, not all CagA proteins are equal in their potential for initiating host cell responses via signal transduction pathways. The degree of functional diversity of this protein depends upon which phosphorylation motifs are critical to the biological activity of CagA.

Amino Acid Motifs↗

PubMed2001

Association of mesangial IgM with IgM deposits in the macula densa: an indication of non-specific macromolecule transport rather than immune reactant?

BACKGROUND: We observed IgM deposits in the macula densa of the distal convoluted tubule in some renal biopsies with mesangial IgM deposits and did a systematic study to investigate the frequency of this phenomenon. We compared the findings with those in IgA disease. METHODS: A total of 30 renal biopsies with either isolated predominantly mesangial IgM, or mesangial IgA (+/-IgM) deposition, were retrieved from the files and reviewed independently by both authors. RESULTS: Eight showed strong macula densa IgM deposits and another three showed weak deposits in the macula densa on immunoperoxidase staining. A total of 14 biopsies also showed mesangial IgA deposition but IgA was not seen in the macula densa. CONCLUSIONS: These results confirm the association of IgM deposits in the macula densa with mesangial IgM, and suggest that mesangial IgM deposits may be a reflection of non-specific macromolecule transport rather than an immune reactant.

Biological Transport↗

PubMed2001

Echoviruses bind heparan sulfate at the cell surface.

Some echoviruses (EV) that bind decay-accelerating factor (DAF) also bind cells of human and murine origins in a DAF-independent manner. Pretreatment of cells with heparinase 1 or heparin blocks the binding of radiolabeled virus to the cell surface, and heparin prevents infection of rhabdomyosarcoma cells by certain EV, including several low-passage clinical isolates of EV 6 and some EV that do not bind DAF. These studies suggest that heparan sulfate may be of in vivo relevance as an attachment molecule for EV.

3T3 Cells↗

PubMed2001

Neonatal catecholamine levels and neurodevelopmental outcome: a cohort study.

AIMS: To determine whether neonatal plasma catecholamine concentrations can be used to predict (a) death plus disability and (b) motor and cognitive impairment at 5 years of age. METHODS: A cohort comprised 136 preterm infants from two randomised controlled trials of neonatal sedation (1989-1992). Adrenaline (epinephrine) and noradrenaline (norepinephrine) were measured at baseline (first day) and 24 hours later. Intelligence and motor ability were assessed at 5-6 years. RESULTS: Infants who died or sustained disability had significantly higher plasma noradrenaline levels on the second day of life. Noradrenaline levels above 9.0 nmol/l were most predictive of death (likelihood ratio 3.27; 95% confidence interval 1.48 to 7.23) and death plus disability (likelihood ratio 3. 55; 95% confidence interval 1.77 to 7.10). There was no correlation between neonatal catecholamine levels and cognitive or motor impairment at 5-6 years. CONCLUSIONS: Elevated noradrenaline levels are associated with adverse outcome in preterm infants; however, the power to predict death or disability is limited and they are not predictive of later motor or cognitive impairment.

Biomarkers↗

PubMed2001

Evidence of selection bias in preterm survival studies: a systematic review.

OBJECTIVE: To determine by how much selection bias in preterm infant cohort studies results in an overestimate of survival. DESIGN: Systematic review of studies reporting survival in infants less than 28 weeks of gestation published 1978-1998. Studies were graded according to cohort definition: A, stillbirths and live births; B, live births; C, neonatal unit admissions. Proportions of infants surviving to discharge were calculated for each week of gestation. RESULTS: Sixty seven studies report data on 55 cohorts (16 grade A, 23 grade B, 16 grade C). Studies that are more selective report significantly higher survival between 23 and 26 weeks of gestation (grade C > grade B > grade A, p < 0.01), exaggerating survival by 100% and 56% at 23 and 24 weeks respectively. CONCLUSION: To minimise the potential for overestimating survival around the limits of viability, future studies should endeavour to report the outcome of all pregnancies for each week of gestation (terminations, miscarriages, stillbirths, and all live births).

Cohort Studies↗

PubMed2001

An investigation into the use of a structured clinical operative test for the assessment of a clinical skill.

AIM: This study was designed to investigate the level of agreement between a group of assessors observing students undertaking a structured clinical operative test. METHOD: 3 assessors agreed a series of criteria to assess the performance of undergraduate students in the recording of a dental impression. Guidelines for assessing whether the students adequately performed in relation to each criteria were also agreed. Following preliminary validation between the assessors, 2 assessors independently scored the performance of each student by reference to the agreed criteria, and the levels of agreement between assessors were compared. The 3 assessors worked in pairs with each other on three groups of students who were in the early stages of their clinical course. RESULTS: A total of 39 clinical dental students were assessed in the recording of a dental impression. The 3 pairs of assessors had satisfactory levels of agreement in the study with similar judgements being made on 90% or more of the 12 criteria assessed. Some differences existed between the pairs of assessors. Certain criteria were more easily judged than others and this was reflected in the level of agreement seen. For over 90% of the criteria, positive assessments were made by each of the 3 assessors, and although there were minor variations between the pairs of assessors, this may have reflected the ability of the groups of students studied. CONCLUSION: The study showed that different assessors were generally able to make agreed judgements on performance criteria in a structured clinical operative test. In setting up performance assessment it is necessary to have close collaboration between assessors to make clearly defined criteria so that judgements are not too subjective. Furthermore, for the assessment of more complex clinical skills, great care is needed in assembling criteria that can be used reproducibly, and sufficient preparation time for the assessors is critical.

Clinical Competence↗

PubMed2001

The dental caries experience of 5-year-old children in Great Britain. Surveys coordinated by the British Association for the Study of Community Dentistry in 1999/2000.

OBJECTIVE: This paper reports the results of standardised clinical caries examinations of 199,440 5-year-old children from across Great Britain. These 1999/2000 coordinated surveys are the latest in a series which seek to monitor the dental health of children and to assess the delivery of dental services. METHOD: The criteria and conventions of the British Association for the Study of Community Dentistry were used. Representative samples were drawn from participating health authorities and boards and caries was diagnosed at the caries into dentine threshold using a visual method without radiography or fibre-optic transillumination. RESULTS: The results again demonstrated a wide variation in prevalence across Britain, with mean values for d3mft for the current English regions (of the National Health Service) and for Wales and Scotland ranging from 0.94 in the West Midlands to 2.55 in Scotland. Mean d3mft across Great Britain was 1.57 (d3t=1.14. mt=0.22, ft=0.21). Overall, 40% of children had evidence of dentinal caries experience (d3mft>0), although the means ranged between 30% (West Midlands) and 55% (Scotland). The distribution of caries was highly skewed. Thus the British mean caries experience for those with the disease was 3.88, as opposed to the overall mean of 1.57. Trends over time demonstrate a modest improvement of 4% in overall d3mft for Britain since 1997/98, compared with the 8.6% improvement seen for the two previous years. All three components with dmft have also fallen. The care index has remained virtually unchanged in Britain as a whole (13.6% in 1999/2000, compared to 13.9% in 1997/8). Regional/country means for 1999/2000 ranged from 8-20%. This indicator has not, however, regained the levels seen in the past. CONCLUSION: There has been some improvement in the dental health of 5-year-old children. Overall, the provision of operative care for those with dental decay has not changed; significant groups remain within the population of 5-year-old children who have dental disease and who are in need of dental care.

Child, Preschool↗

PubMed2001

Black copper phosphate cement: does it have a future?

The aim of this study was to compare the in vitro compressive strength and solubility of a black copper cement with one established restorative material (a conventional glass ionomer cement) and two temporary restorative materials (a zinc phosphate and a zinc polycarboxylate cement). The mean compressive strength of black copper cement varied with the powder: liquid ratio, with an intermediate ratio having a comparable strength to that of the zinc polycarboxylate cement (the best material in this respect). The solubility of the black copper cement at all mixing ratios was significantly greater than that of all other test materials.

Algorithms↗

PubMed2001

Referral of children to a general anaesthetic dental service in Tayside.

OBJECTIVE: To determine the adequacy of child referral for dental general anaesthesia (DGA) by local dental practitioners, given the recent guidance document to dentists from the General Dental Council and in addition, to determine the subsequent treatment and factors which influence treatment selection. DESIGN: A prospective study. SETTING: Department of Paediatric Dentistry, Dundee Dental Hospital, Dundee. SUBJECTS: Children [n = 84] who were referred for dental extractions under general anaesthetic over a three month period. RESULTS: Non-surgical dental extractions under general anaesthetic were requested in nearly 90% of referrals. In the majority of cases, the referral was deemed inadequate; e.g. the medical history was not mentioned in the majority of cases (85.7%) despite nearly one-fifth of patients having a relevant medical history. In general, referring practitioners under-estimated the extent of disease, requiring treatment plans to be changed in 76% of cases; all changes represented an increase in the number of dental extractions undertaken. The most common reasons for general anaesthetic use were: multiple dental extractions (73.8%); the patient's anxiety (63.1%); and patient's age (41.7%). As an alternative to general anaesthesia, treatment was undertaken successfully using inhalation sedation in nearly 15% of cases. CONCLUSION: Dental extractions under general anaesthetic are still a common reason for referral. Referring practitioners frequently provide inadequate information, in addition to under-estimating the treatment required. Alternative forms of anxiety management are available and should be considered for children requiring dental extractions.

Adolescent↗

PubMed2001

Restoration of primary teeth: a study of copper phosphate cement.

OBJECTIVE: To determine the survival of 'PD' Black Copper Cement when used as a dental filling material in carious primary teeth. DESIGN: A prospective study. SETTING: Dundee Dental Hospital, Dundee. SUBJECTS: Fifty children with carious primary molars had 82 dental restorations placed in the initial study. For the follow-up study, 45 restorations were available. RESULTS: Over 65% of the Black Copper Cement restorations placed in the initial study failed. Modification of restoration technique reduced the total loss of filling material to 18% of cases. CONCLUSION: To take advantage of the cariostatic properties of black copper cement may require it to be used as a lining under a less soluble restorative material.

Child↗

PubMed2000

Dental fluorosis in permanent incisor teeth in relation to water fluoridation, social deprivation and toothpaste use in infancy.

OBJECTIVES: To determine the prevalence and severity of fluorosis in permanent incisor teeth in young children in a fluoridated and a fluoride-deficient community and to establish what relationship, if any, there was between the occurrence of dental fluorosis and the reported use of fluoride toothpaste in childhood. DESIGN: A prevalence study of children aged 8-9 years who had been continuous residents in fluoridated Newcastle or fluoride-deficient Northumberland. METHOD: The permanent maxillary central incisor teeth were examined clinically and photographically by one examiner using the Thylstrup-Fejerskov index; the photographs were read blind to child identity and clinical score. A closed-response questionnaire enquired into the child's early experiences of toothbrushing and use of fluoride toothpastes. Social deprivation was measured by a Jarman score. The study took place in 1998. OUTCOME MEASURE: Prevalence of dental fluorosis measured by the Thylstrup-Fejerskov index. RESULTS: Complete data were available for 78% (n = 409) and 79% (n = 403) of eligible sampled children in the two areas, respectively. Clinical and photographic results agreed closely and had high reproducibility. The prevalence of fluorosis was 54% in the fluoridated area and 23% in the fluoride-deficient area when all grades (> 0) of fluorosis were included; percentage prevalence of mild to moderate fluorosis (> or = 3) was 3% and 0.5% in the two areas, respectively. Multivariate analysis indicated that area of residence (odds ratio = 4.5), Jarman score (odds ratio = 0.99 per Jarman unit) and type of toothpaste (odds ratio = 1.6) were statistically significantly related to presence or absence of fluorosis: the risk factors were--fluoridated area, affluence, and use of adult toothpaste. CONCLUSIONS AND RECOMMENDATIONS: The prevalence of aesthetically important dental fluorosis was low, although higher in the fluoridated area. Use of a child's toothpaste (with lower fluoride concentration) could decrease risk in a fluoridated area. Adherence to the guidelines published by the British Society of Paediatric Dentistry is recommended.

Child↗

PubMed2000

A clinical evaluation of an Erbium:YAG laser for dental cavity preparation.

OBJECTIVE: A randomised controlled trial to determine the acceptability to dentists and patients of cavity preparation with an Erbium:YAG laser as compared with conventional handpieces. METHODS: Fifteen dentists (9 GDPs, 1 community dentist and 5 hospital dentists) treated 77 patients (age range 3.5-68 years old) who had two matched cavities, in a split mouth, randomised trial. One cavity was prepared conventionally, the other with the laser, with dentist and patient preference determined by questionnaire. RESULTS: In the majority of cases, where dentists expressed a preference, it was for conventional cavity preparation, and this was significant (P < 0.001). In more than half of the laser appointments, dentists had to use conventional handpieces to complete the cavity. Principle difficulties reported with the laser were access (25 cases) and slow speed of cutting (11 cases). Patients aged > or = 10 years who expressed a preference, preferred laser treatment, and this was significant (P < 0.001). Patients aged < 10 years, assessed using a simplified pictorial questionnaire, did not show a significant preference for either technique. CONCLUSIONS: Dentists preferred conventional handpieces for cavity preparation while patients aged > or = 10 years old preferred laser treatment. Patients < 10 years old did not express a preference.

Adolescent↗

PubMed2000

Anticonvulsants for preventing mortality and morbidity in full term newborns with perinatal asphyxia.

OBJECTIVES: To assess the benefits and harm of administering anticonvulsants to infants of 37 weeks gestation or more following perinatal asphyxia with the primary aims of prevention of death or subsequent severe neurodevelopmental disability and/or the prevention of seizures. SEARCH STRATEGY: Relevant randomised controlled trials were identified using a combination of electronic database searches (MEDLINE), hand searches and a search of the Neonatal Review Group trials register. SELECTION CRITERIA: All randomised, or quasi-randomised, controlled clinical trials with reported data comparing the following outcomes: mortality, neurodevelopmental disability, neonatal seizures and adverse events, following anticonvulsant therapy in term infants (37 weeks or more), compared to controls with or without placebo, following perinatal asphyxia. DATA COLLECTION AND ANALYSIS: Methodological quality and validity of studies were assessed without consideration of the results. Data relevant to the outcome were extracted and analysed. MAIN RESULTS: Five randomised or quasi-randomised controlled trials which met the selection criteria were identified. No studies were of sufficient methodological quality and size to demonstrate a valid, clinically significant change in the risk of mortality or severe neurodevelopmental disability. A meta-analysis combining three studies comparing barbiturates with conventional therapy following perinatal asphyxia demonstrated no difference in risks of death, severe neurodevelopmental disability, or death or severe neurodevelopmental disability. REVIEWER'S CONCLUSIONS: At the present time, anticonvulsant therapy to term infants in the immediate period following perinatal asphyxia cannot be recommended for routine clinical practice, other than in the treatment of prolonged or frequent clinical seizures. Any future studies should be of high quality: randomised control trials with allocation concealment, performance and outcome assessment blinding. Such studies should be of sufficient size, with minimal attrition, to have the power to detect clinically important reductions in mortality and severe neurodevelopmental disability, as the primary outcome measures.

Anticonvulsants↗

PubMed2000

The effect of wavelength, bandwidth, and probe design and position on assessing the vitality of anterior teeth with laser Doppler flowmetry.

OBJECTIVES: To investigate the effect of four variables: wavelength (633 nm and 780 nm), bandwidth filter (3 kHz, 15 kHz, 22 kHz), probe fibre separation (250 microns) and 500 microns) and distance of the probe from the gingival margin (2-3 mm and 4-5 mm) when assessing the vitality of anterior teeth with a laser Doppler flowmetry system. DESIGN: Split-mouth cohort clinical trial. SETTING: Childrens dental clinic, Glasgow Dental Hospital and School. SAMPLE AND METHODS: Sample included 11 non-vital maxillary incisors with necrotic pulps in 10 patients (mean age 12.25 years old). Recordings were taken from the non-vital tooth and from a vital maxillary incisor from the same patient, using all 24 combinations of the recording variables listed above. The vital/non-vital ratios of the signals from the 11 pairs of teeth were calculated and discriminant analysis applied to the data. RESULTS: Of the variables investigated, the combination of a 633 nm laser source with a 3 kHz bandwidth filter using a probe with a 500 microns fibre separation placed 2-3 mm from the gingival margin was the most reliable, with 10 out of a possible 11 true positives for pulpal necrosis, no false positives, and one equivocal diagnosis, and was the only combination that recorded a smaller blood flow from the non-vital tooth compared with the vital control tooth for all 11 pairs of teeth investigated. CONCLUSIONS: It was concluded, therefore, that laser Doppler flowmetry can be of use in assessing the vitality of anterior teeth and that this is the preferred combination of recording variables for further investigations.

Adolescent↗