Diagnosis Of Occlusal Caries Research Articles

Stereomicroscopy, Film Radiography, Microradiography and Naked-Eye Inspection of Tooth Sections as Validation for Occlusal Caries Diagnosis

In establishing a trustworthy validation for occlusal caries lesions, various methods have been used after sectioning teeth. The aim of the present study was to compare the accuracy of four such methods: stereomicroscopy (SM), film radiography (FR), microradiography (MR) and naked-eye inspection (NEI) for the detection of caries in occlusal tooth surfaces. Further, the interobserver agreement between three observers' registrations of occlusal caries by these methods was evaluated. The material consisted of 18 unerupted third molars known to be sound with respect to caries, as they were embedded in bone prior to removal, and 20 erupted third molars with an unknown 'true state of disease'. The teeth were serially sectioned, coded and examined blindly for occlusal caries by three independent observers by the four validation methods under study. SM was demonstrated to be the only method by which all observers correctly identified all 18 unerupted teeth as sound, resulting in a specificity of 1.00. By the other three methods, 1 or more of the unerupted teeth were falsely classified as carious. In the erupted teeth, 73, 58, 52 and 32%, respectively, of the teeth were determined carious by SM, MR, NEI and FR. As it was possible by SM to detect caries in nearly three quarters of the erupted teeth and at the same time to identify all unerupted teeth as sound, this method seemed to be the most trustworthy of the validation methods under study.

Variations among dentists in radiographic detection of occlusal caries.

The quality of radiographic diagnosis of occlusal carries was examined with special attention to the diagnosis of lesions in dentin. Eighty-four extracted teeth, most of them with occlusal caries of different severity and some apparently sound, were radiographed. For validation purposes, the lesion depths were recorded during a drilling procedure. Ten dentists interpreted the radiographs. On average, 12% of the sound surfaces were wrongly diagnosed radiographically as having caries (false positives), 33% of the enamel lesions were identified on radiographs, and 62% of the small dentin lesions and 100% of the big dentin lesions were diagnosed radiographically (true positives). There was wide variation in the ability to identify dentin caries correctly between the observers; the sensitivity values ranged from 0.77 to 1.0 (mean 0.90) and the specificity values from 0.45 to 0.93 (mean 0.76). The dentist demonstrating the highest diagnostic quality (measured by the area beneath the receiver operating characteristics curve) had only about 9% false positives (1-specificity), while the dentist who had the lowest diagnostic quality scored caries in about 55% of the teeth in the control group. Both of them had 96% true positives. The tendency to make false-positive registrations in the dentin adjacent to enamel seems to be a major problem in radiographic diagnosis of occlusal caries. The radiograph has significant value in the diagnosis of occlusal dentin caries, but the great variations between observers indicate the need for training and calibration.

Impact of the validator and the validation method on the outcome of occlusal caries diagnosis.

In studies evaluating the performance of caries-diagnostic methods, a validation of the true state of disease is needed. The aim of this study was to evaluate the impact of the validator and the validation system (stereomicroscopy or radiography of tooth sections) on the outcome of diagnostic tests for occlusal caries. The material consisted of 60 extracted third molars which were serially sectioned (500-600 microns thick). Four observers examined the sections by two caries validation methods: stereomicroscopy and film radiography. The presence of caries in the occlusal surfaces of these teeth had previously been recorded by visual inspection and conventional film radiography. The kappa values for interobserver agreement within one validation method ranged from 0.44 to 0.76 for radiography and from 0.47 to 0.60 for microscopy. The intraobserver agreement with the two methods was low (range 0.31-0.49), and by cross-tabulating the data, it was found that the disagreements originated in a consistently deeper lesion score with stereomicroscopy than with radiography by all observers except 1. By use of receiver operating characteristic curve areas, little impact of the validation method was seen when visual inspection was validated (against microscopy mean area = 0.75, against radiography mean area = 0.74). The mean receiver operating characteristic area was higher when diagnostic film radiographs were validated against radiography (0.68) than against microscopy (0.63). The differences between observers within a validation method were larger with microscopy than with radiography. In conclusion, caries validation methods are subject to variability. The outcome of caries--diagnostic tests may be influenced both by the validator and the validation method.

Occlusal caries diagnosis: a changing challenge for clinicians and epidemiologists

The diagnosis of occlusal caries is an integral part of an epidemiologist's task, whether carrying out crosssectional national caries prevalence surveys to assist with planning and the evaluation of service provision, or clinical trials of caries preventive agents. Similarly, the clinician also carries out this same overall diagnostic procedure in order to plan care for individual patients, although he/she will usually have access to improved facilities and diagnostic aids. This paper reviews the different problems now being encountered by both epidemiologists and clinicians in the face of changes in the presentation of the disease at this site and the qualifications which should now be appreciated when extrapolating from the results of surveys employing comparatively gross criteria. It explores recent developments in diagnostic aids and makes suggestions as to how further information might be obtained in future which would aid the valid comparison of diagnoses made by these two groups of dentists.

Performance of electrical resistance measurements adjunct to visual inspection in the early diagnosis of occlusal caries

The detection of small carious lesions at occlusal surfaces is a difficult task, particularly in low caries prevalence populations and individuals. The aim of this study was to evaluate the performance of electrical resistance measurements (ERM) in diagnosing small dentinal lesions at one site per occlusal surface in low caries prevalence populations when used adjunct to visual inspection, and to compare the performance of ERM to that of radiographic examination. The occlusal surfaces of 81 third permanent molar teeth extracted from young adolescents were diagnosed by four examiners, who measured the electrical resistance of enamel on a one measurement per surface basis, and furthermore assessed the occlusal surfaces visually and radiographically. The teeth were sectioned for validation by histological examination. The ERM had the highest sensitivity (0.67), and visual inspection had the highest specificity (0.89). ROC analysis showed no statistically significant differences between the performance of the observers when using visual inspection and ERM ( z-score test; P > 0.05). One examiner performed statistically significantly better by measuring the electrical resistance of enamel than by radiographic examination ( P < 0.05). The average sensitivity and specificity of the three diagnostic systems were used to express the positive and negative predictive values as a function of caries prevalence. At a caries prevalence of 0.2 the negative predictive values for visual inspection, ERM and radiographic examination were 0.88, 0.91 and 0.89, and the positive predictive values were 0.53, 0.48 and 0.42 respectively. It was concluded from the very low positive predictive values that neither ERM used in this way nor radiography aid visual inspection in detecting small occlusal caries lesions, when applied in low caries prevalence populations or individuals.

CO 22 laser and the diagnosis of occlusal caries: in vitro study

The diagnosis of small lesions in pit and fissure sites is becoming increasingly problematical. This study was designed to evaluate, in vitro, the potential use of a carbon dioxide (CO 2) laser technique as an aid to the diagnosis of incipient pit and fissure caries. Vaporization of the organic material in the ‘early’ carious lesion should lead to its carbonization and thus make it more conspicuous. Pilot studies were carried out to identify lasing parameters which produced no visible effect on sound enamel but which caused charring (carbonization) of white spot fissure lesions. Fifty extracted human molars and premolars were air-polished on the occlusal surfaces and independently scored clinically for caries, both before and after lasing. The teeth were subsequently sectioned and examined histologically. Of the 37 sites histologically scored as sound or exhibiting precavitation lesions, eight were correctly scored as sound both prelasing and postlasing. Of the 29 precavitation lesions detected histologically, five were detected clinically prelasing and 11 were detected postlasing. This 21% difference in the sensitivity of caries diagnosis between the prelasing and postlasing examinations was statistically significant (at the 95% level). There were no false-positive caries diagnoses. Further research, in particular the refining of lasing parameters employed, is indicated.

Digital subtraction radiography after stanous fluoride treatment for occlusal caries diagnosis

The material in this study consisted of 38 fully erupted, extracted third molars without clinical cavitation in the occlusal surface. A radiograph was made of each tooth before and after 5, 10, and 20 minutes of stannous fluoride treatment. The radiographs were digitized and subtraction performed between the images obtained after stannous fluoride treatment and the pretreatment image. Two observers assessed the stannous fluoride treated radiographic and the subtraction images on a monitor: 0 = no change, 1 = intensity increase (white area interpreted as a carious lesion) in dentinoenamel area. Caries was assessed on conventional film radiographs made before treatment: 0 = no caries in dentin, 1 = caries in dentin. The presence of caries in dentin was validated histologically. Sensitivity for intensity increase as a sign of caries was overall higher for the subtraction images based on 20-minute treatment than for the radiographic images (0.025 > p > 0.01) but not significantly higher than for the conventional radiographs. However, neither observer gave false-positive scorings in the subtraction images, whereas observer 1 had five false-positive scorings on the conventional films. Observer 2 had none. The subtraction method did not provide a higher sensitivity for dentinal occlusal caries than conventional film radiography, but the intensity increase could be trusted more than the traditional radiolucency as a sign of a dentinal lesion.