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Featured researches published by R.P. Ellwood.


Caries Research | 2003

An in vitro Comparison of a Combined FOTI/Visual Examination of Occlusal Caries with Other Caries Diagnostic Methods and the Effect of Stain on Their Diagnostic Performance

D.F. Côrtes; R.P. Ellwood; K.R. Ekstrand

The aims of this in vitro study were to compare the combination of FOTI and visual inspection to other diagnostic methods for the detection and evaluation of the depth of occlusal caries and assess the effect of stain on diagnostic performance. Five diagnostic methods (combined FOTI/Visual (CFV), Visual, FOTI, DIAGNOdent and Electrical Caries Monitor) were considered. Histological validation was performed in the 152 occlusal molar sites (111 teeth) using 350-µm sections and a stereomicroscope. The rank correlation coefficients with histology ranged from 0.42 (DIAGNOdent) to 0.66 (CFV). The area under the ROC curves (AUC) for enamel lesions ranged from 0.82 (ECM) to 0.88 (CFV) and from 0.81 (DIAGNOdent) to 0.91 (CFV) for dentine lesions. The AUC at the dentine level for CFV and FOTI were similar (p > 0.05), but the AUC for CFV was significantly greater than for visual (p < 0.001), DIAGNOdent (p = 0.005) and the ECM (p = 0.04). FOTI was found to be particularly useful for the detection of dentine lesions. The exclusion of stain and brown spot lesions improved performance for all methods. It is concluded that CFV is useful for the determination of occlusal lesion depth and that in the presence of stain and brown spot lesions different cut-off points may be required for the ECM and DIAGNOdent to identify dentine lesions.


Caries Research | 2006

Efficacy of Sealing Proximal Early Active Lesions: An 18-Month Clinical Study Evaluated by Conventional and Subtraction Radiography

Stefania Martignon; Kim R. Ekstrand; R.P. Ellwood

This study assessed the efficacy of sealing proximal lesions on adult patients using a split-mouth design. Eighty-two 15- to 39-year-olds from the Dental Faculties in Copenhagen and Bogotá participated, each having 2 or more proximal lesions in the following radiographic stages: (1) lesion restricted to the outer half of enamel; (2) lesion from the inner half of enamel including the enamel dentine junction, and (3) lesion restricted to the outer third of dentine. Standardized geometrically aligned baseline and follow-up radiographs were obtained. One randomly selected lesion (test) in each patient was sealed with 1 of 2 resins. The patients were instructed to floss all the proximal lesions 3 times per week. The baseline to 18 months difference in caries lesion progression status was assessed using 3 methods: (1) radiographs were independently assessed visually; (2) radiographs were read in pairs, and (3) using subtraction radiography of digitized images. A total of 72 subjects finished the study (12.2% dropout). The compliance concerning flossing was poor (15%). For the repeated examinations kappa was 0.84 for the visual examination, 0.44 for the paired readings and 0.84 for the subtraction examination. Two test lesions and 1 control lesion were restored. For the independent radiograph assessment method 10 and 26% progressed in the test and control group, respectively (p > 0.05); with the paired radiograph method the corresponding data were 22% in the test and 47% in the control groups (p < 0.01). By subtraction radiography 44% of the test group and 84% of the control were judged to have progressed (p < 0.001). The sealing technique was superior to instructing patients to floss, and subtraction radiography appeared to be the most sensitive method for assessing lesion progression.


Caries Research | 2011

Clinical Studies of Dental Erosion and Erosive Wear

M.C.D.N.J.M. Huysmans; H.P. Chew; R.P. Ellwood

We define erosion as apartial demineralisation of enamel or dentine by intrinsic or extrinsic acidsand erosive tooth wear as the accelerated loss of dental hard tissue through the combined effect of erosion and mechanical wear (abrasion and attrition) on the tooth surface. Most experts believe that during the last decade there has been a significant increase in the prevalence and severity of erosive tooth wear, particularly in adolescents. Even when erosive wear occurs in its milder forms, this is a matter of concern, as it may compromise the integrity of an otherwise healthy dentition in later life. The erosive wear process is complicated and modified by many chemical, behavioural and associated processes in the mouth. If interventions are to be developed it is therefore important that in vivo methods are developed to assess the outcomes of the erosion and erosive wear processes and the effects of interventions upon them. This paper discusses potential methods of investigating erosion and erosive wear in vivo and the difficulties associated with clinical studies.


Community Dentistry and Oral Epidemiology | 2013

Evidence on existing caries risk assessment systems: are they predictive of future caries?

Marisol Tellez; Juliana Gomez; Iain A. Pretty; R.P. Ellwood; Amid I. Ismail

AIM To critically appraise evidence for the prediction of caries using four caries risk assessment (CRA) systems/guidelines (Cariogram, Caries Management by Risk Assessment (CAMBRA), American Dental Association (ADA), and American Academy of Pediatric Dentistry (AAPD)). This review focused on prospective cohort studies or randomized controlled trials. METHODS A systematic search strategy was developed to locate papers published in Medline Ovid and Cochrane databases. The search identified 539 scientific reports, and after title and abstract review, 137 were selected for full review and 14 met the following inclusion criteria: (i) used as validating criterion caries incidence/increment, (ii) involved human subjects and natural carious lesions, and (iii) published in peer-reviewed journals. In addition, papers were excluded if they met one or more of the following criteria: (i) incomplete description of sample selection, outcomes, or small sample size and (ii) not meeting the criteria for best evidence under the prognosis category of the Oxford Centre for Evidence-Based Medicine. RESULTS There are wide variations among the systems in terms of definitions of caries risk categories, type and number of risk factors/markers, and disease indicators. The Cariogram combined sensitivity and specificity for predicting caries in permanent dentition ranges from 110 to 139 and is the only system for which prospective studies have been conducted to assess its validity. The Cariogram had limited prediction utility in preschool children, and a moderate to good performance for sorting out elderly individuals into caries risk groups. One retrospective analysis on CAMBRAs CRA reported higher incidence of cavitated lesions among those assessed as extreme-risk patients when compared with those at low risk. CONCLUSION The evidence on the validity for existing systems for CRA is limited. It is unknown if the identification of high-risk individuals can lead to more effective long-term patient management that prevents caries initiation and arrests or reverses the progression of lesions. There is an urgent need to develop valid and reliable methods for caries risk assessment that are based on best evidence for prediction and disease management rather than opinions of experts.


Journal of Biomedical Optics | 2009

Near-infared hyperspectral imaging of teeth for dental caries detection

Christian Zakian; Iain A. Pretty; R.P. Ellwood

Near-infrared (NIR) is preferred for caries detection compared to visible light imaging because it exhibits low absorption by stain and deeper penetration into teeth. Hyperspectral images from 1000 to 2500 nm have been obtained for a total of 12 extracted teeth (premolars and molars) with different degrees of natural lesion. Analysis of the reflectance spectra suggests that light scattering by porous enamel and absorption by water in dentin can be used to quantify the lesion severity and generate a NIR caries score. Teeth were ground for histological examination after the measurements. The NIR caries score obtained correlates significantly (Spearmans correlation of 0.89, p<0.01) with the corresponding histological score. Results yield a sensitivity of >99% and a specificity of 87.5% for enamel lesions and a sensitivity of 80% and a specificity >99% for dentine lesions. The nature of the technique offers significant advantages, including the ability to map the lesion distribution rather than obtaining single-point measurements, it is also noninvasive, noncontact, and stain insensitive. These results suggest that NIR spectral imaging is a potential clinical technique for quantitative caries diagnosis and can determine the presence of occlusal enamel and dentin lesions.


Caries Research | 2000

An in vitro Comparison of the Ability of Fibre–Optic Transillumination, Visual Inspection and Radiographs to Detect Occlusal Caries and Evaluate Lesion Depth

D.F. Côrtes; Kim R. Ekstrand; A.R. Elias-Boneta; R.P. Ellwood

The aim of this study was to compare the performance of fibre–optic transillumination (FOTI), visual inspection and bite–wing radiographs to detect occlusal caries and estimate the lesion depth. Fifty–nine extracted molars were assessed using FOTI and visual examination by 4 trained examiners and 1 examiner evaluated the bite–wing radiographs. Histological validation was performed using 250–μm sections examined with a stereomicroscope. For the three methods, the correlation between the lesion depth and the histological scores varied from 0.65 to 0.73. For dentinal caries detection, the areas under ROC curves ranged from 0.83 to 0.87. The radiographic method was poor at detecting lesions confined to enamel. FOTI, visual inspection and radiographs showed a good correlation with the histology but had difficulty in distinguishing lesions located deep in enamel or in the outer third of dentine. FOTI was shown to be as accurate as a detailed visual inspection in detecting occlusal caries.


Caries Research | 2013

Two-Year Caries Clinical Study of the Efficacy of Novel Dentifrices Containing 1.5% Arginine, an Insoluble Calcium Compound and 1,450 ppm Fluoride

P. Kraivaphan; C. Amornchat; T. Triratana; L.R. Mateo; R.P. Ellwood; D. Cummins; W. DeVizio; Y.P. Zhang

A 2-year double-blind randomized three-treatment controlled parallel-group clinical study compared the anti-caries efficacy of two dentifrices containing 1.5% arginine, an insoluble calcium compound (di-calcium phosphate or calcium carbonate) and 1,450 ppm fluoride (F), as sodium monofluorophosphate, to a control dentifrice containing 1,450 ppm F, as sodium fluoride, in a silica base. The 6,000 participants were from Bangkok, Thailand and aged 6-12 years initially. They were instructed to brush twice daily, in the morning and evening, with their randomly assigned dentifrice. Three trained and calibrated dentists examined the children at baseline and after 1 and 2 years using the National Institute of Dental Research Diagnostic Procedures and Criteria. The number of decayed, missing and filled teeth (DMFT) and surfaces (DMFS) for the three study groups were very similar at baseline, with no statistically significant differences among groups. After 1 year, there were no statistically significant differences in caries increments among the three groups. After 2 years, the two groups using the dentifrices containing 1.5% arginine, an insoluble calcium compound and 1,450 ppm F had statistically significantly (p < 0.02) lower DMFT increments (21.0 and 17.7% reductions, respectively) and DMFS increments (16.5 and 16.5%) compared to the control dentifrice. The differences between the two groups using the new dentifrices were not statistically significant. The results of this pivotal clinical study support the conclusion that dentifrices containing 1.5% arginine, an insoluble calcium compound and 1,450 ppm F provide significantly greater protection against caries lesion cavitation, in a low to moderate caries risk population, than dentifrices containing 1,450 ppm F alone.


Journal of Dentistry | 2013

In vitro performance of different methods in detecting occlusal caries lesions

Juliana Gomez; Christian Zakian; S. Salsone; S.C.S. Pinto; Andrew Taylor; Iain A. Pretty; R.P. Ellwood

UNLABELLED Early caries detection is essential for the implementation of preventive, therapeutic and intervention strategies within general dental practice. OBJECTIVE The aim of this study was to compare the in vitro performance of the International Caries Detection and Assessment System (ICDAS), digital photographs scored with ICDAS (ICDAS photographs), fibre-optic transillumination (FOTI), optical coherence tomography (OCT), SoproLife(®) camera and two implementations of quantitative light-induced fluorescence a commercial (QLF-Inspektor Research systems) and a custom (QLF-Custom) system, to detect early and intermediate occlusal lesions. METHODS One hundred and twelve permanent extracted teeth were selected and assessed with each detection method. Histological validation was used as a gold standard. The detection methods were compared by means of sensitivity, specificity, areas under receiver operating characteristic (AUROC) curves for enamel and dentine levels and with the Spearmans rank correlation coefficient against histology. RESULTS For any enamel or dentine caries detection, the AUROC curves ranged from 0.86 (OCT) to 0.98 (ICDAS and ICDAS photographs, SoproLife(®) camera) and at the dentine level from 0.83 (OCT) to 0.96 for FOTI. The correlations with histology ranged between 0.65 (OCT) and 0.88 (ICDAS and FOTI). Under in vitro conditions, the assessed detection methods showed excellent intra-examiner reproducibility. All the methods were strongly correlated with histology (p<0.01) except OCT which showed a moderate correlation (0.65). CONCLUSION Even though all methods present similar performance in detecting occlusal caries lesions, visual inspection seems to be sufficient to be used in clinical practice for detection and assessment of lesion depth. Other methods may be useful in monitoring caries lesion behaviour.


Community Dentistry and Oral Epidemiology | 2013

Non-Cavitated Carious Lesions detection methods: a systematic review

Juliana Gomez; Marisol Tellez; Iain A. Pretty; R.P. Ellwood; Amid I. Ismail

The aim of this study was to critically appraise the performance of detection methods for non-cavitated carious lesions (NCCLs). A detailed search of Medline (via OVID), the Cochrane Collaboration, Scielo and EMBASE identified 2054 publications. After title and abstract review by three investigators (JG, MT, AI), 124 publications were selected for further review. The final publications evaluated the following methods: Visual (V), Caries Lesion Activity Assessment (CLAA), Laser Fluorescence (LF), Radiographic (R), Fibre-optic Transillumination (FOTI), Electrical Conductance (EC) and Quantitative Light-induced Fluorescence (QLF). All included studies used histological assessment as a gold standard for in vitro studies or clinical/visual validation for the in vivo designs. They reported outcomes measures such as sensitivity (SE), specificity (SP), area under the receiver operating characteristic curve (AUROC) and reliability. Data were extracted from the selected studies independently by two reviewers and checked for errors. The quality of the studies was evaluated as described by Bader et al. (2002). Of the 124 articles, 42 were included that described 85 clinical assessments. Overall, the quality of evidence on detection methods was rated ‘poor’, except for EC that was rated ‘fair’. The SE rates were as follows: V (0.17–0.96), LF or DIAGNOdent (DD) (0.16–0.96), R (0.12–0.84), FOTI (0.21–0.96), EC (0.61–0.92) and QLF (0.82). The SP rates were as follows: V (0.46–1.0), LF (0.25–1.00), R (0.55–0.99), FOTI (0.74-0.88), EC (0.73–1.0) and QLF (0.92). There is a large variation in SE and SP values for methods and a lack of consistency in definition of disease and analytical methods. EC and QLF seem to be promising for detection of early lesions. For both cost and practicality considerations, visual methods should remain the standard for clinical assessment in dental practice.


BMC Public Health | 2012

The association between social deprivation and the prevalence and severity of dental caries and fluorosis in populations with and without water fluoridation

Michael G McGrady; R.P. Ellwood; A. Maguire; Michaela Goodwin; Nicola Boothman; Iain A Pretty

BackgroundTo determine the association between social deprivation and the prevalence of caries (including caries lesions restricted to enamel) and enamel fluorosis in areas that are served by either fluoridated or non-fluoridated drinking water using clinical scoring, remote blinded, photographic scoring for caries and fluorosis. The study also aimed to explore the use of remote, blinded methodologies to minimize the effect of examiner bias.MethodsSubjects were male and female lifetime residents aged 11–13 years. Clinical assessments of caries and fluorosis were performed on permanent teeth using ICDAS and blind scoring of standardized photographs of maxillary central incisors using TF Index (with cases for fluorosis defined as TF > 0).ResultsData from 1783 subjects were available (910 Newcastle, 873 Manchester). Levels of material deprivation (Index of Multiple Deprivation) were comparable for both populations (Newcastle mean 35.22, range 2.77-78.85; Manchester mean 37.04, range 1.84-84.02). Subjects in the fluoridated population had significantly less caries experience than the non-fluoridated population when assessed by clinical scores or photographic scores across all quintiles of deprivation for white spot lesions: Newcastle mean DMFT 2.94 (clinical); 2.51 (photo), Manchester mean DMFT 4.48 (clinical); 3.44 (photo) and caries into dentine (Newcastle Mean DMFT 0.65 (clinical); 0.58 (photo), Manchester mean DMFT 1.07 (clinical); 0.98 (photo). The only exception being for the least deprived quintile for caries into dentine where there were no significant differences between the cities: Newcastle mean DMFT 0.38 (clinical); 0.36 (photo), Manchester mean DMFT 0.45 (clinical); 0.39 (photo). The odds ratio for white spot caries experience (or worse) in Manchester was 1.9 relative to Newcastle. The odds ratio for caries into dentine in Manchester was 1.8 relative to Newcastle. The odds ratio for developing fluorosis in Newcastle was 3.3 relative to Manchester.ConclusionsWater fluoridation appears to reduce the social class gradient between deprivation and caries experience when considering caries into dentine. However, this was associated with an increased risk of developing mild fluorosis. The use of intra-oral cameras and remote scoring of photographs for caries demonstrated good potential for blinded scoring.

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Iain A. Pretty

University of Manchester

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R.M. Davies

University of Manchester

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Juliana Gomez

University of Manchester

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Andrew Taylor

University of Manchester

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