Observer variations in the interpretation of periapical osseous structures: a comparison between xeroradiography and conventional radiography

Comparative analysis of different periapical index systems used in cone-beam computed tomography

This study aimed to compare the three index systems designed for cone-beam computed tomography (CBCT) in terms of intra- and inter-observer agreement. 117 root-filled teeth with or without periapical radiolucency from 77 of already existing CBCT images were chosen randomly. Two observers evaluated the periapical status of the selected teeth and graded the scores twice using CBCT periapical index (CBCTPAI), endodontic radiolucency index (ERI) and complex periapical index (COPI) part of the periapical and endodontic status scale (PESS), respectively. The researchers' self-agreement kappa values ranged from substantial to almost perfect. A moderate inter-observer agreement was present for the COPI and ERI, whereas a fair agreement was present for CBCTPAI. The researchers' ICC for the inter-observer reliability of CBCTPAI, ERI and COPI was 0.75, 0.77 and 0.80, respectively. COPI had the highest self-agreement and inter-observer reliability. ERI showed the highest intra-observer variation, whereas CBCTPAI showed the highest inter-observer variation.

Endodontic Procedural Errors by Students in Two Saudi Dental Schools

Objective:

To explore endodontic procedural errors committed by undergraduate dental students in King Khalid University (KKU), Abha and AlFarabi dental college, Riyadh.

Methods:

In this cross sectional study, a questionnaire was distributed to 500 dental students from both schools and of both genders in the 5th and 6th levels in the academic year 2016–2017. Participants were asked to record their endodontic procedural error(s) that had occurred during training.

Results:

Returned and eligible questionnaires were 469 (93.8% response rate) and were almost equally distributed by university (KKU and Alfarabi). The participants’ age ranged from 22 to 24 years, and approximately 47% of them were female students and 65% were 6th level students. Almost 56% of the sample reported at least one endodontic procedural error during their training. Female students reported errors (65%) more frequently than the male students (49%; P=0.002). Up to 54% of these errors were in the posterior teeth and 65% were in teeth with curved roots. Most common error during access cavity preparation was gouging (68%) and due to instrumentation was ledge formation (47%), during obturation was voids (41%). There were no differences in the reported endodontic errors between the two universities.

Conclusion:

The frequency of reported endodontic procedural errors by senior dental students in both schools, more specifically those in the 6th year, is high. Ledge formation and voids in the root canal filling are the most frequently reported endodontic errors.

Technical quality of root canal treatment performed by undergraduate students using hand instrumentation: a meta-analysis

The technical quality of root canal treatment (RCT) may impact on the outcome. The quality of education received during undergraduate school may be linked to the quality of treatment provided in general dental practice. In this context, the aim of this systematic review was to answer the following focused questions: (i) What is the frequency of acceptable technical quality of root fillings, assessed radiographically, performed by undergraduate students? (ii) What are the most common errors assessed radiographically and reported in these treatments? For this purpose, articles that evaluated the quality of root fillings performed by undergraduate students were selected. Data were collected based on predetermined criteria. The key features from the included studies were extracted. GRADE-tool assessed the quality of the evidence. MAStARI evaluated the methodological quality, and a meta-analysis on all studies was conducted. At the end of the screening, 24 articles were identified. Overall frequency of acceptable technical quality of root fillings was 48%. From this total, 52% related to anterior teeth, 49% to premolars and 26% to molars. The main procedural errors reported were ledge formation, furcation perforation, apical transportation and apical perforation. The heterogeneity amongst the studies was high (84-99%). Five studies had a high risk of bias, eight had a moderate risk, and 11 had low risk. The overall quality of evidence identified was very low. The conclusion was that technical quality of root fillings performed by undergraduate students is low, which may reveal that endodontic education has limited achievement at undergraduate level. A plan to improve the quality of root fillings, and by extrapolation the overall quality of root canal treatment, should be discussed by the staff responsible for endodontic education and training.

Pre-operative diagnostic radiograph interpretation by general dental practitioners for root canal treatment

OBJECTIVES

The aim of this study was to evaluate which radicular radiographic features general dentists want to interpret, determine which of the radicular radiographic features general dentists interpret and which ones they miss in a diagnostic radiograph and correlate how accurately general dentists are able to interpret radiographic features.

METHODS

20 general dental practitioners were selected and given 2 sets of questionnaires. The first set asked them to fill out the findings they would elucidate in a diagnostic radiograph while the second set consisted of 30 randomly selected intraoral radiographs to interpret.

RESULTS

In the first set of questionnaires, more than 50% of dentists said they would interpret periapical changes, calcification, root curvature and the number of root canals. Less than 50% said they would interpret canal morphology, open apex, resorption, fracture, number of roots and lamina dura. In the second set of questionnaires, more than 90% missed grade 1 or 2 periapical changes (according to periapical index scoring), resorption and canal calcification. More than 80% of dentists missed extra roots and root curvature buccally while no dentists were able to interpret the periodontal ligament width changes, lamina dura and canal variation (C-shape). Using a paired t-test, there was significant variation in answers between the first set and second set of questionnaires.

CONCLUSION

It is concluded from this study that general dental practitioners are able to detect radiographic changes when they are extensive but they miss periodontal ligament width and lamina dura changes.

Image processing for enhanced observer agreement in the evaluation of periapical bone changes

AIM

The aim of the present study was to evaluate the effect of root canal treatment on periapical lesions by conventional and subtracted digital radiographic images of clinical cases.

METHODOLOGY

Eleven patients who exhibited clinical or radiological signs of periapical pathology received root canal treatment. Periapical radiographs were obtained immediately postoperatively and recall radiographs at intervals of 3, 6, 9 and 12 months postoperatively were obtained. Identical exposure geometry was maintained. From the standardized radiographs digitized images were produced. Four experienced practitioners interpreted the radiographs and the digitized images. They assessed 59 pairs of images projected at random using a slide projector. On the left side, there was a reference image with no lesion, and on the right an image either with or without a lesion. Each reader was asked to rate each pair of images on a three-point scale: yes, absolutely sure that gain or loss was present; uncertain, if there was gain or loss; no, absolutely sure that no gain or loss was present. There was no time limit for each decision. Inter- and intra-examiner agreement was analyzed using the kappa-statistic for the diagnosis of periapical bone density changes in the periapical region at the different time points either in conventional pairs of radiographs or using digital subtraction images.

RESULTS

The inter-examiner agreement (P < 0.001) and the intra-examiner agreement (P = 0.02) when digital pictures where evaluated were significantly higher than with conventional radiographs.

CONCLUSIONS

A highly significantly better observer agreement was achieved by digital subtraction radiography during the evaluation of the outcome of root canal treatment on periapical lesions.

The sensitivity, specificity, and reliability of radiographic periapical diagnosis of posterior teeth

PURPOSE

The purpose of this study was to define the percent accuracy, sensitivity, specificity, and reliability of periapical radiographic diagnosis of periapical inflammatory disease.

METHOD

A total of 140 cases were reviewed under ideal viewing conditions by 6 observers. For each case, observers determined whether periapical disease was evident and rated the confidence of their interpretation.

RESULTS

The mean percent accuracy was 70.2%. The mean sensitivity and specificity were 0.65 and 0.78, respectively. The intraclass correlation coefficients for intraobserver and interobserver reliability were 0.66 and 0.54, respectively.

CONCLUSION

Specificity of periapical radiographic diagnosis is higher than sensitivity. These results support the current guideline for selective use of periapical views based on patient symptoms and clinical signs. Finally, dentists have a good degree of reliability on repeated evaluations, but only fair agreement when compared with other dentists reading the same radiograph.

Retreatment decisions--a comparison between general practitioners and endodontic postgraduates

One of the most subjective areas with regard to interexaminer variations is the dental radiograph. The variations in radiographic interpretation lead to differences in treatment planning decisions. This study compared the endodontic retreatment planning decisions for endodontically treated teeth between 12 general practitioners and 12 endodontic postgraduate students. Utilizing dental radiographs of completed cases, both groups were asked to make treatment choices based on two hypothetical ages of a case: 1 or 3 yr postoperatively. General practitioners chose to initiate treatment at an earlier date and also chose more extensive treatment modalities. The age of the root filling was looked on as more important in treatment planning by the endodontics postgraduates.

Evaluation of X-ray beam angulation for successful twin canal identification in mandibular incisors

This study was undertaken to determine the most effective horizontal beam angulation for the diagnosis of twin canals in mandibular incisors. Two hundred extracted mandibular incisor teeth, in groups of four, were aligned in the form of a lower dental arch and radiographed using a beam alignment device at 10 degrees intervals between 0 degree and 50 degrees from both right and left sides. Five observers with varying degrees of experience were asked to assess the number of canals in each of the four teeth from these radiographs. A further radiograph of each individual tooth was taken at 90 degrees through the mesio-distal plane to identify the number of twin canals present. A random sample of 10% of the radiographs were viewed for a second time 3 months later to assess intra-observer variation. The 20 degrees right and 30 degrees left horizontal beam angulations showed significantly more accurate diagnosis of twin canals than the ortho-radial view (0 degree) by all five observers. Analysis of the inter-observer results suggests that the experienced viewers were no better but more consistent at identifying twin canals in mandibular incisors.

Methods of reducing observer variation in age estimation from panoramic radiographs

OBJECTIVE

To compare inter- and intra-observer variation in age estimation using subjective and objective methods.

METHODS

Fifty-six panoramic radiographs of patients aged 13 to 25 years were assessed subjectively twice by four observers for the stage of root development of the lower third molars on a seven-point scale. Two of the observers were calibrated before the first evaluation, and the other two before the second. The same observers also digitized predefined reference points in a subsample of the third molars ten times by means of a computer-based digitizer system. Observer variation in classifying different root stages and in digitizing coordinates and measuring root lengths were studied.

RESULTS

Significant systematic differences existed between two of the observers in the subjective assessment. One non-pre-calibrated observer changed her pattern most. Scattergrams from the digitizer measurements showed a good precision within and between observers with no significant differences in calculating root lengths. When, however, the teeth were analysed separately, some significant differences were found.

CONCLUSIONS

The overall observer agreement was best using the objective method on several teeth. With only one tooth there were some significant differences. Subjective evaluation was improved by prior calibration.

Detailed tomography of periapical and periodontal lesions. Diagnostic accuracy compared with periapical radiography

OBJECTIVE

To compare the diagnostic accuracy of detailed tomography using the Scanora system with that of conventional periapical radiography for detecting periapical and periodontal lesions.

METHODS

We selected for comparison 243 periapical and 322 periodontal sites in 177 patients. Five observers independently assessed radiographs for the presence or absence of the following lesions: periapical bone changes, widening of apical and marginal ligament space, crestal erosion, vertical bone loss, furcation involvement and calculus.

RESULTS

ROC analysis demonstrated no significant differences in the overall interpretation of either disease. Periapical radiography was superior (p < 0.05) to tomography for the detection of calculus. The sensitivity of tomography for periapical pathology was 87%, and 70% for periapical radiography. Sensitivities for periodontal diseases were 84% and 77%. Specificities were 81%, 90%, 77% and 79%, respectively. Differences for sensitivity and specificity were significant (p < 0.05) in relation to periapical pathology. The energy imparted during tomography was 0.92 mJ.

CONCLUSION

Detailed tomography and periapical radiography performed equally well for the overall diagnosis of periapical and periodontal lesions. Tomograms differed substantially from periapical radiographs in both sensitivity and specificity for detecting periapical lesions in posterior regions. The energy imparted during detailed tomography is similar to that from two D-speed films.

A comparison of detailed zonography with periapical radiography for the detection of periapical lesions

The diagnostic accuracy of detailed zonography using the Scanora multimodal X-ray system was compared with that of periapical radiography. The study was based on the detection of periapical bone lesions at 259 dental sites distributed evenly throughout the dentitions of 164 patients. Each site was examined by periapical radiography and zonography, in parallel. The zonograms consisted of four detailed images that could also be read as stereopairs, in either the horizontal or vertical direction. Five observers evaluated the sites for the presence or absence of periapical osteolysis or sclerosis and apical widening of the periodontal ligament space for the whole dentition, and for three dental regions. ROC analysis revealed no significant overall or regional differences between the diagnostic accuracies of the periapical and zonographic techniques, regardless of whether the zonograms were read as sets of four images (multiview) or stereoscopic images. The sensitivity of periapical radiography was 72%, that of multiview zonography 88%, and that of stereoscopic zonography 85%. Specificities were 93%, 84% and 89%, respectively. The energy imparted during detailed zonography was 0.98 mJ. It is concluded that zonography is as good as periapical radiography for the detection of periapical pathology.

Radiographic detectability of bone loss in the bifurcation of mandibular molars: an experimental study

The aim of this study was to evaluate observer performance in the diagnosis of bone loss in the bifurcation of mandibular molars on conventional radiographs. Standardized radiographs were obtained of the first and second molars in 10 dry hemimandibles at baseline and after preparation of bony defects corresponding to degree I and degree II buccal furcation involvements. The radiographs were randomly presented to 12 observers who were asked to determine the presence or absence of bone loss. Receiver operating characteristic (ROC) curve analysis was used for evaluation. The mean AZ-value of all observers was 81% for the first molar and 80% for the second. As the degree of furcation involvement increased, the mean AZ-value of the observers also improved from 68% (furcation involvement degree I) to 86% (degree II). Multiple regression analysis revealed that lesion depth was the factor which most strongly influenced the observers' diagnostic performance.

Comparison of periapical and detailed narrow-beam radiography for diagnosis of periapical bone lesions

The diagnostic performance of the detailed narrow-beam (DNB) technique of the Scanora multimodal radiography system was compared for periapical radiography for the detection of periapical bone lesions at 262 dental sites in 144 patients. Receiver operating characteristics (ROC) of both imaging modalities were analysed in relation to the ratings of five observers for the whole dentition, three dental regions, and two types of periapical lesions. ROC analysis demonstrated no overall or regional significant differences in the diagnostic performance of the two imaging modalities. The sensitivity for periapical radiography was 72% and for DNB radiography 90%, and the specificities 89% and 88%, respectively. It is concluded that DNB radiography performs as well as periapical radiography for detecting periapical bone lesions.

Comparison of panoramic and intraoral radiography for the diagnosis of caries and periapical pathology

Panoramic and intraoral radiographs from 400 consecutive patients were compared for their ability to demonstrate periapical pathology and caries. Two hundred panoramic radiographs were exposed with the rotational technique and 200 with the intraoral X-ray tube technique. Periapical osteolytic and sclerotic lesions as well as approximal caries were recorded independently by two observes. Agreement with intraoral radiographs for periapical osteolytic lesions was, on average, 63% for the rotational and 55% for the intraoral X-ray tube technique and for sclerotic lesions 40% and 36%, respectively. The agreement varied with tooth type and lesion size. When teeth without periapical lesions were also included in the comparisons, the values for agreement were over 96%. Interobserver agreement for periapical osteolytic lesions was 61% for the rotational and 56% for the intraoral X-ray tube technique. The corresponding values for sclerotic lesions were 29% and 23%. Intraobserver agreement for periapical osteolytic lesions was 71% for the rotational and 67% for the intraoral X-ray tube technique. The corresponding values for sclerotic lesions were 46% and 56%. Agreement with intraoral radiographs for enamel caries was, on average, 21% for the rotational and 27% for the intraoral X-ray tube technique and for dentinal lesions 44% and 53%, respectively. When caries-free approximal surfaces were also included in the comparisons, the values for agreement were over 95%. It is concluded that panoramic and intraoral radiography perform equally well as diagnostic tools for the detection of periapical lesions, although the results are not identical.(ABSTRACT TRUNCATED AT 250 WORDS)

A five-year study of Hydron root canal fillings

A prospective clinical and radiographic study was conducted in order to compare Hydron and laterally condensed gutta-percha/AH-26 root canal fillings. Paralleling technique periapical radiographs were taken preoperatively, postoperatively and at recall appointments at post-treatment intervals of 6 months, 1 year, 2 years, 3 years and 5 years. Clinical examination at the recall appointments revealed no adverse signs or symptoms amongst all the patients who attended (mean attendance 44.5% at each interval). Radiographs were scored according to the periapical status of the treated root, and comparable bone healing rates were observed between the two root-filling materials. Among the patients attending recall appointments, there were no radiographic signs of failure of any of the 39 gutta-percha/AH-26 root canal fillings. However, three of the 35 canals filled with Hydron were classified as failures, and four required further assessment after the 5-year recall appointment. This study indicated that Hydron and gutta-percha/AH-26 root canal fillings were well accepted but, on the basis of radiographic assessment, success with gutta-percha/AH-26 was more predictable.

Observer performance in the assessment of periapical pathology: a comparison of panoramic with periapical radiography

Observer performance in the assessment of the periapical pathology from panoramic and periapical radiography was examined. Five endodontists, five general practitioners and five oral radiologists were asked to assess the periapical status of 117 teeth. The observers assessed the panoramic and periapical radiographs of the teeth, which were evenly distributed throughout the jaws with a 50% probability that either an osteolytic or sclerotic lesion was present. The results of the comparison between panoramic and periapical radiography were influenced by the selection of observers. When the oral radiologists acted as observers, the mean P(A) value for periapical radiography was higher than for panoramic radiography (P less than 0.001), resulting in periapical radiography presenting a higher overall diagnostic accuracy than panoramic radiography for all 15 observers (P less than 0.01). There was, however, no difference between panoramic and periapical radiography when the two groups of endodontists and general practitioners acted as observers. The comparison of the three groups of observers showed no difference between their diagnostic accuracy when assessing panoramic radiographs. With periapical radiography, the oral radiologists demonstrated a higher diagnostic accuracy than the endodontists (P less than 0.05). The observers in each group with the highest diagnostic accuracy also had the highest intra-observer agreement. The mean intra-observer agreement of the five general practitioners was higher than those of the other two groups of observers for panoramic radiography. For periapical radiography, the mean agreement rates of the groups were comparable.

Comparison between panoramic and periapical radiography in the diagnosis of periapical bone lesions

The diagnostic accuracy of panoramic and periapical radiography was compared by five oral radiologists who assessed the periapical status of 117 teeth evenly distributed throughout the jaws with a 50% probability that either an osteolytic or sclerotic lesion was present. Receiver operating characteristic (ROC) analysis demonstrated no overall significant difference between panoramic and periapical radiography. However, for sclerotic lesions and for all lesions on maxillary premolars and mandibular molars periapical radiography was significantly superior (P less than 0.001); it was also superior for osteolytic lesions in the maxilla as well as for the lesions on mandibular premolars but with a smaller significant difference (P less than 0.05).

Xeroradiography and its application to dentistry

Xeroradiography is a highly accurate electrostatic imaging technique. In this technique a conventional single-phase dental x-ray unit is used as an x-ray source, but instead of a silver-halide film image, a uniformly charged selenium alloy plate housed in a light-proof cassette is used. In this article the equipment, procedure, properties and artifacts related to the xeroradiographic technique are described. An evaluation of the xeroradiographic images is also presented. Xeroradiography, which requires only about one-third of the dose required for conventional radiographs, is a valuable alternative to conventional radiography for detecting carious lesions, calculus deposits and periodontal disease. It is also of value in interpreting periapical structures.

A comparison between xeroradiography and conventional radiography in the diagnosis of endodontic lesions

Detection of periapical bone pathosis is an important part of the diagnostic process in dentistry. Xeroradiographs and E-speed films were taken to evaluate and to compare the diagnostic value for the radiographic interpretation of periapical lesions. Thirty-four patients undergoing endodontic treatment were chosen. Simultaneous exposures of the radiographic film and the xeroradiographic plates were made. The samples were viewed and categorized by the examiners using the following scores: 0 = unacceptably poor, 1 = poor but diagnostic, 2 = adequate for diagnostic information, and 3 = optimal for diagnostic information. A paired sample t test was performed on the result of the evaluation by the two examiners, and both showed that there were no significant difference at p less than 0.05 between xeroradiography and conventional radiography. A two-sample t test was performed on the means of the two examiner's evaluation, and there was no significant difference at p less than 0.05 between the means.

Use of a "sandwich" technique to control image geometry in clinical studies comparing intraoral xeroradiographs and E-speed films

A method of superimposing a film on a xeroradiographic (XR) cassette for simultaneous intraoral exposure is evaluated for use as an imaging technique in clinical studies comparing Ektaspeed film and XR images. Sandwich images were indistinguishable from those produced by conventional technique. Pilot studies were conducted with 104 patients who had symptomatic dental problems. No significant differences were found in diagnostic usefulness or image quality between XR and film radiographs when sign test analysis was used. The sandwich technique yielded film and XR images with duplicate image geometry while reducing patient exposures to one half of that used in conventional image comparison protocols.

Endodontic retreatment decision making among a group of general practitioners

Large interindividual variations have been demonstrated when dentists suggest clinical management of endodontically treated teeth. Since variations also have been shown in radiographic diagnosis of the periapical tissues, a hypothesis was tested that explains variation in treatment as a function of variation in diagnosis. Fifty-four general practitioners suggested diagnosis and management of 32 endodontically treated roots. Spearman's rank correlation coefficient reached 0.298 when the examiners were definitely sure of the presence of a periapical lesion, and 0.356 when probable lesions also were included. Conclusively, the hypothesis seemed to have a limited value in explaining why dentists carry out retreatment. Instead a multi-aspect approach to this problem is suggested.

Examiner agreement in estimating changes in periodontal bone from conventional and subtraction radiographs

It has previously been shown that computer-assisted subtraction of serially-obtained radiographs yields a higher degree of accuracy in the detection of small changes in the marginal periodontal bone than conventional radiographs. This study concerns another important aspect of such diagnostic methods, namely the intra- and inter-examiner agreement rates. On 10 patients with moderate to severe periodontal bone loss involved in a clinical trial to evaluate the effectiveness of subgingival antimicrobial irrigation, conventional radiographs were taken at baseline and after 32 and 52 weeks. The changes in terms of gain or loss of bone occurring between the examination at baseline and that after 32 weeks, as well as those occurring between the examination performed after 32 weeks and that made after 52 weeks, were evaluated by means of conventional radiographs and by subtraction images. Both types of image were interpreted by each of 4 observers. The images were read a 2nd time after a period of at least 2 weeks. The inter-observer as well as the intra-observer agreement were assessed by calculating 3 different measures of agreement: the overall agreement, the specific agreement and the kappa value. Regardless of measure, higher inter-observer agreement rates were found for all observers when the subtraction technique was employed. A similar pattern was found with respect to the intra-observer agreement rates.