Biomedical subjects

E A Kidd

Publications and source records attributed to E A Kidd.

At least 37 records · Page 2Linked to original sources

PubMed1998

Detection, diagnosing, monitoring and logical treatment of occlusal caries in relation to lesion activity and severity: an in vivo examination with histological validation.

The aims of the present study were to investigate the ability of 3 experienced clinicians to detect occlusal carious lesions, assess their depth, diagnose their activity and define a logical management for each lesion. The material consisted of 35 third molars scheduled for extraction or surgical removal making it possible to validate the accuracy of the clinical recordings histologically. Examinations were carried out at baseline and after 4 months in order to monitor lesion progression. At the first visit a radiograph was taken; the number of filled surfaces was counted and the oral hygiene assessed generally and by disclosing occlusal plaque of the tooth under examination. After cleaning the occlusal surface caries was recorded in a selected investigation site using a visual ranked caries scoring system, as well as an electrical conductance recording (ECM). Apart from counting fillings and taking new radiographs the same procedure was performed at the second visit, which then was followed by extraction of the tooth. After sectioning the tooth lesion depth was recorded, and lesion activity, based on acid production, was assessed using methyl red dye. Lesion activity was also judged by means of polarized light microscopic examinations of the sections. Results showed strong relationships between the visual, ECM and radiographic assessments and both lesion depth and lesion activity. In contrast, all other parameters were poorly related to lesion activity. Changes in visual assessments and in conductance readings from first to second examination were poorly associated with lesion activity. In conclusion, clinicians are able to detect lesions, predict activity and severity and define a logical management of occlusal caries on the basis of a single examination.

Acids↗

PubMed1998

Assessment of caries risk.

This paper examines the importance of caries risk assessment, identifies relevant risk factors, including clinical evidence, which has been considered to be the best predictor of caries risk.

DMF Index↗

PubMed1998

The operative management of caries.

In the management of dental caries preventive treatment must always go hand in hand with operative care. This paper looks at the rationale behind operative treatment and gives some guidelines on when to choose restorative intervention.

Dental Caries↗

PubMed1997

An evaluation of the diagnostic yield from bitewing radiographs of small approximal and occlusal carious lesions in a low prevalence sample in vitro using different film types and speeds.

AIM: To compare diagnostic yield in caries diagnosis from D- and E-speed films. DESIGN: A laboratory study. SETTING: A UK dental school between 1992 and 1994. MATERIALS AND METHODS: 96 extracted teeth containing approximal and occlusal lesions, but representing a low caries prevalence sample, were set in occluding dental arches. Bitewing radiographs were taken and interpreted by 5 examiners for the presence or absence of caries. Each examiner was also asked which film image he or she subjectively liked best. MAIN OUTCOME MEASURES: The teeth were subsequently sectioned and histologically examined to validate diagnostic decisions. RESULTS: For all film types the percentage of lesions with caries histologically in dentine correctly identified radiologically (sensitivity) was low (approximal caries 8-22%; occlusal caries 0-30%). The number of sound dentine sites correctly identified (specificity) was high (approximal caries 98-100%; occlusal caries 79-100%). There were no significant differences between D- and E-speed films. Sensitivity was unaffected by each examiner's subjective preference for a particular film. The variation in sensitivity of diagnosis was due to differences between examiners. CONCLUSIONS: The reluctance of many GDPs to use E-speed film because they 'do not like the image' cannot be endorsed or supported. Both E-speed film types examined can be recommended for use in general practice.

Analysis of Variance↗

PubMed1997

Electronic diagnosis of occlusal caries in vitro: adaptation of the technique for epidemiological purposes.

Most studies on electronic diagnosis of occlusal caries have involved taking site-specific conductance measurements. Airflow around the electronic caries monitor probe removes superficial moisture and the conductance measurement reflects the caries status of that part of the fissure beneath the probe tip. This is an appropriate technique for a clinician to use to monitor caries status, and it could be adapted for use in epidemiological studies and clinical trials. The present work investigated an alternative technique using a jelly as a contact medium over the entire fissure system so that the probe might record the overall caries status of the tooth reflecting the worst affected site. Readings were taken on 96 extracted teeth with dye-coloured jelly acting as a contact medium. Readings were repeated on 32 teeth. Histological validation of caries status was carried out by visual examination of serial sections through each tooth to note the deepest lesion. The sensitivity and specificity of the overall electronic caries monitor readings were calculated for all lesions and dentine lesions only using selected resistance cut-off points and presented as a series of Receiver Operating Characteristic (ROC) curves. The optimum sensitivity and specificity values were, for all lesions: 61% and 86%, and for dentine lesions: 76% and 76% respectively. The reproducibility of the readings was acceptable (Kappa values for all lesions = 0.76, for dentine lesions = 0.55). The technique warrants further study as an overall reading may be more appropriate for epidemiological and clinical trial use.

Bicuspid↗

PubMed1997

The effect of fluoridation on the occurrence of hidden caries in clinically sound occlusal surfaces.

It has been suggested that the diagnosis of occlusal dentine carious lesions has become more difficult due to the influence of fluoride on the character of pit and fissure surfaces. The issue pertains to the occurrence of hidden caries exemplified by occlusal surfaces judged as clinically sound but showing a radiolucency on the bite-wing radiograph. The aim of this study was to investigate the influence of water fluoridation on the occurrence of hidden caries in clinically sound occlusal surfaces in young people. The data of 515 persons (15 years of age) collected in 1968/1969 as part of the Dutch longitudinal epidemiological Tiel/Culemborg study were used. The participants in Tiel (F) were exposed to artificially fluoridated drinking water (F-concentration 1.1 ppm F) from birth until the end of the data collection. The participants in Culemborg (NF) were not exposed to extra fluoride (F-concentration 0.1 ppm F). In 1994 the status of occlusal surfaces of the first and second molars, as read from bite-wings made in 1968/1969, were judged by 2 investigators. (Cohen's Kappa intra- and inter-examiner agreement 0.90, 0.83 and 0.85, respectively). The original clinical data of 270 inhabitants of Tiel (F) and 245 of Culemborg (NF) were compared with the radiographic judgements. The children examined in Tiel (F) had a mean of 2.54 clinically sound occlusal surfaces in first and second molars (including surfaces with an enamel demineralization only) of which bite-wing radiographs detected 0.43 surfaces (16.9%) with a radiolucency into dentine. In Culemborg (NF) the children had a mean 0.65 clinically sound judged surfaces of which 0.16 (24.6%) showed a radiolucency on the bite-wing films. The results of the investigation show a proportional reduction of surfaces with hidden caries among clinically sound surfaces in the fluoridated area compared to the control.

Adolescent↗

PubMed1997

Relevance of the use of rubber dam in microbiological sampling of carious dentine.

The aim of this study was to determine the role of rubber dam isolation and the influence of salivary contamination during cavity preparation on the collection of samples of dentine for microbiological examination. Cavities were prepared in 23 carious teeth. Access to caries was gained and a sample of soft, stained demineralized tissue was taken with a round bur. After removing the rubber dam each cavity was flooded with saliva and after thorough washing and drying a second dentine sample was taken. Cavity preparation was completed and the cavity flooded with saliva. After thorough washing and drying a final sample was taken. A data set from another study served as a control for bacterial contamination at the end of cavity preparation where a rubber dam remained in place throughout. There were no significant differences in the numbers of bacteria in dentine samples gathered with and without rubber dam, which implies that salivary contamination can be removed by thorough washing and drying of the cavity.

Adult↗

PubMed1997

The effect of chlorhexidine/xylitol chewing-gum on cariogenic salivary microflora: a clinical trial in elderly patients.

The effects of 14-day use of either a chlorhexidine/xylitol or a xylitol chewing gum on salivary levels of mutans streptococci, lactobacilli, and yeasts were determined for 53 subjects (mean age 79.49 +/- 7.7 years) participating in this randomised, double-blind, placebo-controlled trial. Salivary flow rates and enamel staining were measured and the attitudes of the subjects to gum chewing were evaluated by the use of structured questionnaires. The chlorhexidine/xylitol gum significantly reduced the salivary levels of mutans streptococci (p < 0.0001) lactobacilli (p < 0.05) and yeasts (p < 0.05) while the xylitol placebo gum produced significant reductions in mutans streptococci (p < 0.01) only. The study population found chewing gum twice per day for 10 min an acceptable method of receiving medication and improving oral health. Prior to gum use participants recognised persistent symptoms of dry mouth and their subjective evaluation of dry mouth was significantly (p < 0.001) related to the number of prescribed medications with xerostomic side-effects. The desire to continue gum use was significantly related to the subjects' evaluation of their oral dryness at baseline and to their perceived oral health gain from gum usage. Only those participants with stained enamel at baseline exhibited increased enamel staining following chlorhexidine/xylitol gum usage.

Aged↗

PubMed1997

The effect of airflow on site-specific electrical conductance measurements used in the diagnosis of pit and fissure caries in vitro.

There has been renewed interest in the electronic diagnosis of occlusal caries using measurement of conductance or impedance. One of two previously manufactured electronic caries detectors (the Vanguard electronic caries detector, Massachusetts Manufacturing Corporation, Cambridge, Mass., USA) had a probe tip with an integral air supply. Airflow is essential for removing superficial moisture and preventing surface conduction to the gingival margin. The aim of this study was to determine the effect of airflow on electronic diagnosis of occlusal caries using a prototype electronic caries meter (ECM II. LODE, Groningen, The Netherlands) fitted with a flow meter. Stable conductance readings were taken at 76 discrete sites on 32 extracted teeth with no visible signs of cavitation, at 3 airflows: 5, 7.5 and 10 litres/min. The stable conductance scale was a continuous scale from -0.45 to 13.25 and set by the manufacturer. Histological validation was carried out on macroradiographs of sections cut to include each sample site. The histological picture was compared with the stable conductance readings taken at various airflows. Sensitivity and specificity were calculated using different conductance readings to differentiate sound and carious sites, and receiver operating characteristic (ROC) curves constructed. Of the sites, 32% had enamel and dentine caries and 33% had enamel caries. The ROC curves showed airflow to be highly relevant. An airflow of 5 litres/min was shown to be inadequate and led to large numbers of false-positive diagnoses. A minimum airflow of 7.5 litres/min was required to achieve optimum sensitivity (92%) and specificity (87%) for dentine caries diagnosis.

Air Movements↗

PubMed1997

The electronic diagnosis of caries in pits and fissures: site-specific stable conductance readings or cumulative resistance readings?

A prototype electronic caries meter (ECM II; LODE, Groningen. The Netherlands) was designed to deliver a conductance reading when the reading had remained stable for 3 consecutive seconds. The aim of this study was to determine whether this type of stable conductance reading was optimal for caries diagnosis. The ECM II was connected to a graphic recorder which enabled the continuous resistance to be recorded. The graphic recording was calibrated using a standard, variable resistance box. Stable conductance readings were taken for 76 sites on 32 extracted teeth with no visible sign of cavitation at an airflow of 7.5 l/min. Simultaneous graphic recording of resistance was continued for 10 s and cumulative resistance measurements were calculated by adding the resistance values at 1-second intervals. Histological validation of caries status was carried out on macroradiographs of sections cut to include sample sites. The histological picture was compared with the stable conductance reading and the cumulative resistance value for each site. Sensitivity and specificity values were calculated by randomly choosing stable conductance and cumulative resistance values to differentiate sound and carious sites. The results were presented as a series of receiver operating characteristics (ROC) curves and the optimum sensitivity and specificity values determined. 33% of sites had enamel caries and 32% had enamel and dentine caries. Results showed that both stable conductance readings and cumulative resistance measurements gave high and comparable sensitivity and specificity values for the diagnosis of dentine caries (sens. 92%, spec. 87% and sens. 88%, spec. 81%, respectively). However, when intra-examiner reproducibility was checked, stable conductance readings were more repeatable and achieved in shorter clinical time. In conclusion, stable conductance readings appear to be the most suitable for occlusal caries diagnosis.

Air Movements↗

PubMed1997

Reproducibility and accuracy of three methods for assessment of demineralization depth of the occlusal surface: an in vitro examination.

This laboratory study of 100 occlusal surfaces investigated the reproducibility and accuracy of a visual ranked caries scoring system, an electronic caries scoring system (ECM) using a continuous conductance scale, and a radiographic ranked caries scoring system. Histological examination of the teeth served as a gold standard to validate the ability of each system to assess lesion depth and predict softened, demineralized dentine. After training, 3 examiners carried out each scoring system on two separate occasions. Kappa values for visual, ECM and radiographic ranked scoring systems showed good inter- and intra-examiner reproducibility levels and acceptable limits of agreement for ECM readings. When scoring systems were tabulated against histological scores there was a high correlation between the visual and ECM methods and lesion depth in both enamel and dentine, but radiographic examination could not detect enamel caries. When compared to the histological scoring, the Spearman correlation coefficients for the visual scoring ranged between 0.87 and 0.93, for the ECM between 0.80 and 0.85 and for the radiographic scoring system between 0.76 and 0.78. No tooth scored as visually sound had histological evidence of dentine caries. Soft dentine corresponded to demineralization involving the middle third of the dentine or more which was related to visual cavity formation or an ECM reading above 9 (score 3 or 4). The radiograph was an excellent predictor of soft dentine. In conclusion, the new visual system appears promising, but takes time to learn. The reproducibility and accuracy for the ECM is acceptable while radiographs miss early occlusal lesions.

Bicuspid↗

PubMed1997

A caries control programme for adult patients.

This paper concerns the management of an adult patient with a caries problem. Once a dentist has decided the patient is at high risk to dental decay, involvement of the patient in the management of the problem is essential because it is the patient who will control caries, not the dentist. It is essential to determine why the patient is at risk so that risk factors may be modified appropriately. All members of the dental team have a role to play.

Adult↗

PubMed1996

Criteria for caries removal at the enamel-dentine junction: a clinical and microbiological study.

In the UK cavity preparation at the enamel-dentine junction (EDJ) is considered complete when all soft and/or stained tissue is removed. The aim of the present work was to link the clinical criteria of dentine consistency and dentine colour with the microbiological status of the tissue. Cavities were prepared in 564 teeth. Under rubber dam, access to the EDJ was gained and the sample sites selected (n = 847). Their consistency was noted as hard or soft and wet or dry when probed. The colour of the site was noted as stain-free or stained. Dentine was sampled using a round bur. After microbiological processing the total anaerobic count and counts of mutans streptococci and lactobacilli were expressed as log10 [CFU per sample]. Soft sites harboured significantly more bacteria than hard sites (P < 0.001). Soft and wet sites harboured significantly more bacteria than soft and dry sites (P < 0.001). Stained and hard sites harboured more bacteria than stain-free and hard sites (P < 0.05) but this difference was not considered to be clinically relevant. The relatively simple clinical criteria used here correlated significantly with the microbial findings. All soft dentine must be removed at the EDJ to ensure minimal infection of the underlying hard dentine. However, it may not be necessary to continue preparation until the EDJ is also stain-free.

Adult↗

PubMed1996

Histological validation of electrical resistance measurements in the diagnosis of occlusal caries.

Diagnosis of occlusal caries is difficult from visual and radiographic examination. The use of electrical resistance measurement has been described previously and reported to be a potentially sensitive alternative technique. This is possibly due to the decreased resistance of carious pits and fissures. The aim of this study was to validate a prototype electrical caries monitor for the diagnosis of caries in pits and fissures in vitro using a microfocal radiographic technique. Thirty discrete sites were investigated in 10 extracted molar teeth. Electrical resistance measurements were recorded at each site and thick sections (approximately 0.65 mm) prepared for microfocal radiography. Microfocal radiography indicated that six sites were sound, 10 had enamel caries and 14 dentine caries. At a resistance value of 2.2 M(OMEGA), below which a site was regarded as carious and above which it was regarded as sound, electrical resistance measurements proved sensitive (92%) and specific (100%). Quantification of mineral content indicated that mineral loss in enamel may influence resistance measurement more than lesion depth.

Adult↗

PubMed1996

Prediction of secondary caries around tooth-colored restorations: a clinical and microbiological study.

Caries at the margins of restorations is difficult to diagnose, and the relevance of staining and ditching around tooth-colored fillings is unclear. This clinical study questions the relevance of marginal color change and marginal ditching to the level of infection of the dentin beneath the margins of tooth-colored restorations. Clinically visible sites (197) on the tooth/restoration margin were selected in 113 teeth. The filling margin and the enamel adjacent to each site were noted as stained or stain-free, and sites were graded as intact, having a narrow ditch, or having a wide ditch. Thirty sites with frankly carious lesions were also included. Plaque was sampled at the tooth-restoration margin and the filling removed. The enamel-dentin junction (EDJ) at each sample site was noted as hard or soft when probed, and the dentin was sampled. Samples were vortexed, diluted, and cultured for total anaerobic counts, mutans streptococci, and lactobacilli. There were more bacteria in the plaque over frankly carious cavities, and the dentin was soft and heavily infected. Only 38 out of 167 sites without frankly carious cavities had soft dentin at the EDJ. Both the plaque and dentin in these sites harbored more micro-organisms. However, none of the clinical criteria chosen would reliably predict the presence of this soft dentin. In this study, only a frankly carious lesion at the margin of the filling constituted a reliable diagnosis of secondary caries.

Adult↗

PubMed1995

Operative and microbiological validation of visual, radiographic and electronic diagnosis of occlusal caries in non-cavitated teeth judged to be in need of operative care.

The diagnosis of occlusal caries depends upon the correct identification of demineralised enamel and dentine. However, tissue demineralisation precedes bacterial infection so that dentine may be demineralised but uninfected. The presence of a bacterial infection of dentine may be a more relevant factor to be considered when planning to restore a carious lesion. The aim of this clinical study was to validate three techniques for the diagnosis of occlusal caries as demineralised tissue and as infected demineralised tissue during cavity preparation. The study sample was 82 non-cavitated occlusal lesions, judged by various dentists to be in need of operative care. The diagnostic techniques used by the single operator were vision, bitewing radiography and electronic caries diagnosis. The validating techniques were a caries detector dye to stain demineralised tissue, microbiological sampling to determine the level of infection of the dentine and clinical assessment of the dentine at operation. The caries detector dye showed demineralised dentine in 96% of the referred lesions. This demineralisation was reliably predicted by the electronic readings. However, the dentine samples from many teeth yielded only small numbers of bacteria indicating no, or only a very low level of bacterial infection. Neither vision nor electronic readings reliably predict heavily infected dentine. Radiographic evidence of dentine demineralisation was significantly associated with heavily infected dentine and this dentine was soft and wet at operation.

Adolescent↗

PubMed1995

A re-evaluation of electrical resistance measurements for the diagnosis of occlusal caries.

Clinical and radiographic diagnosis of occlusal caries is difficult. Resistance measurements in pits and fissures have shown better sensitivity compared with the more conventional methods of diagnosis. Two machines have been manufactured for this purpose: the Vanguard and the Caries Meter L. The aims of this study were to calibrate the readouts of these machines against a variable standard resistance box and use the Vanguard to compare readings taken in vivo and in vitro after extraction of the teeth. The diagnostic accuracy of clinical, radiographic, Vanguard and Caries Meter L diagnoses were also assessed. One hundred occlusal sites in 40 teeth of 20 patients were investigated in vivo with the Vanguard, noting clinical and radiographic appearances. The teeth were then extracted and the Vanguard readings repeated in vitro, together with Caries Meter L readings. The in vivo/in vitro comparison between Vanguard readings showed excellent reproducibility (Cohen's Kappa = 0.80). The sensitivity and specificity for the different examination techniques at the enamel level of diagnosis were 27% and 89% for visual, 6% and 100% for radiographic, 81% and 78% for the Vanguard and 74% and 74% for the Caries Meter L. In conclusion, this study supports the renewed interest in resistance measurements as a diagnostic technique and indicates that the in vitro model used gives results comparable to those in vivo.

Adolescent↗

PubMed1995

Clinical and radiographic diagnosis of occlusal caries: a study in vitro.

Various methods of diagnosing occlusal caries have been described, but only visual, clinical examination and radiographic examination are commonly used in dental practice. This laboratory study investigated the ability of 12 examiners to detect the presence or absence of occlusal caries in 48 extracted molar teeth using these two techniques. The presence or absence of caries was subsequently verified by sectioning the teeth. Diagnosis from visual examination was poor, only 48.7% of lesions in dentine being detected. Radiographic diagnosis was better with 62.2% of dentine lesions being found. However, this increase in sensitivity of the diagnosis was accompanied by a decrease in specificity with the number of false positive diagnoses increasing when the radiograph was used. Therefore, although the bite-wing radiograph may be regarded as a safety net for the diagnosis of occlusal caries, it must be interpreted with caution bearing in mind the possibility of false positive diagnoses.

Dental Caries↗