Impact of motion artefacts and motion-artefact correction on diagnostic accuracy of apical periodontitis in CBCT images: an ex vivo study in human cadavers.

AIM: To assess the impact of motion artefacts and motion-artefact correction on diagnostic accuracy of apical periodontitis (AP) in CBCT images. METHODOLOGY: Based on clinical and radiographic inspection of 40 formalin-fixated human jaw specimens, 77 roots in 45 teeth (molars and premolars), with various disease and treatment state, were selected. The specimens were mounted on a robot simulating 3-mm movement types (nodding, lateral rotation and tremor). CBCT images with and without (controls) movements were acquired in four CBCT units: without motion-artefact correction in Cranex 3Dx, Orthophos SL 3D, and Promax 3D Mid, and with motion-artefact correction in Promax 3D Mid and X1. Three observers blindly assessed (i) whether the images were interpretable and (ii) if AP was present (5-step probability index). Histopathology provided the reference standard for presence of AP. Weighted Kappa statistics described inter-observer agreement. Estimates of diagnostic accuracy were assessed by means of receiver operator characteristic (ROC) curve analysis. Area under the curve (AUC) provided a measure of accuracy, and paired-sample AUC difference tests compared differences amongst the CBCT units and movement types. RESULTS: Observer agreement was substantial for control images, moderate for motion-artefact corrected images and fair for images without motion-artefact correction. When movement was present, motion-artefact correction reduced the percentage of images scored as noninterpretable or with uncertain disease state (score 3 in the 5-step probability index). Control images were not perfectly accurate (both false-positive and false-negative results were present; AUC 0.750-0.799). Images acquired with movement and without motion-artefact correction (AUC 0.541-0.709) were associated with significantly lower accuracy than control images (P < 0.05). With motion-artefact correction, accuracy was comparable to that observed in control images (AUC 0.732-0.790). CONCLUSIONS: Diagnostic accuracy of apical periodontitis in CBCT images was dependent on the presence of motion artefacts (i.e. lower accuracy associated with the presence of movement). Motion-artefact correction systems positively influenced image interpretability and diagnostic accuracy.

Self-efficacy of undergraduate dental students in Endodontics within Aarhus and Amsterdam.

AIM: To understand whether the self-efficacy of undergraduates is associated with the extent of the endodontic education they received. METHODOLOGY: Data were obtained from three undergraduate endodontic programmes in two universities: Aarhus University (AU), Denmark and the Academic Centre for Dentistry Amsterdam (ACTA), the Netherlands. Just before their graduations in 2016 or 2017, students completed a questionnaire that contained the Endodontic General Self-Efficacy Scale and questions on how they valued the education they received in Endodontics. The information on the number and type of root canal treatments participants had performed on patients was collected from dental clinic management systems. Data were ana-lysed using non-parametric tests and multiple regression analyses. RESULTS: The median number of treated root canals on patients per student was 5 in the standard programme at ACTA, 10 in AU, and 14.5 in the extended programme at ACTA. Students' self-efficacy increased with the number of treated root canals; however, retreatments and root canal treatments in molars were negatively associated with self-efficacy. All students wanted more experience in performing root canal treatment on patients. CONCLUSIONS: The endodontic self-efficacy of students from the standard programmes of the two participating universities was comparable. Students' self-efficacy was influenced mostly by their clinical experience when performing root canal treatment. It seems that the more root canal treatments students perform on patients, the greater their self-efficacy is at graduation. However, treating difficult cases (molars and retreatments) might reduce their self-efficacy.

Preferred Reporting items for OBservational studies in Endodontics (PROBE) guidelines: a development protocol.

Observational studies have a significant role in establishing the prevalence and incidence of diseases in populations, as well as determining the benefits and risks associated with health-related interventions. Observational studies principally encompass cohort, case-control, case series and cross-sectional designs. Inadequate reporting of observational studies is likely to have a negative impact on decision-making in day-to-day clinical practice; however, no reporting guidelines have been published for observational studies in Endodontics. The aim of this project is to develop reporting guidelines for authors when creating manuscripts describing observational studies in the field of Endodontology in an attempt to improve the quality of publications. The new guidelines for observational studies will be named: 'Preferred Reporting items for OBservational studies in Endodontics (PROBE)'. A steering committee was formed by the project leaders (PD, VN) to develop the guidelines through a five-phase consensus process. The steering committee will review and adapt items from the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) statement and the Clinical and Laboratory Images in Publications (CLIP) principles, as well as identify new items that add value to Endodontics. The steering committee will create a PROBE Delphi Group (PDG), consisting of 30 members across the globe to review and refine the draft checklist items and flowchart. The items will be assessed by the PDG on a nine-point Likert scale for relevance and inclusion. The agreed items will then be discussed by a PROBE Face-to-Face meeting group (PFMG) made up of 20 individuals to further refine the guidelines. After receiving feedback from the PFMG, the steering committee will pilot and finalize the guidelines. The approved PROBE guidelines will be disseminated through publication in relevant journals, and be presented at national and international conferences. The PROBE checklist and flowchart will be available and downloadable from the Preferred Reporting Items for study Designs in Endodontics (PRIDE) website: www.pride-endodonticguidelines.org. The PROBE steering committee encourages clinicians, researchers, editors and peer reviewers to provide feedback on the PROBE guidelines to inform the steering group when the guidelines are updated.

Diagnostic accuracy of cone beam computed tomography used for assessment of apical periodontitis: an ex vivo histopathological study on human cadavers.

AIM: To assess the diagnostic accuracy of Cone Beam Computed Tomography (CBCT) to diagnose apical periodontitis (AP) using histopathology of ex vivo human jaws as the reference standard. METHODOLOGY: Based on periapical radiographs of jaw specimens from human bodies donated for science, a sample of 223 teeth with 340 roots including all tooth groups, and different disease and treatment statuses was selected. Cone Beam Computed Tomography was performed using Cranex® 3Dx (Soredex Oy, Tuusula, Finland), small field-of-view (5 × 5 cm), and isotropic resolution 0.085 mm. Three observers assessed the presence of AP using a probability index. Histopathological examination of the periapical area was used as a reference standard to calculate estimates of diagnostic accuracy. RESULTS: For non-root filled teeth all estimates of diagnostic accuracy; sensitivity (SENS), specificity (SPEC), positive predictive value (PPV) and negative predictive value (NPV) were high. All estimates were lower for root filled teeth. When mild AP was classified as 'AP', SENS, SPEC and NPV were significantly lower in root filled roots (P < 0.001 in all cases). The same tendency was seen when mild AP was classified as 'No AP' but here only the difference in SPEC was significant (P < 0.001). CONCLUSION: The diagnostic accuracy of CBCT used for diagnosis of AP is dependent on the treatment status of the tooth. For non-root filled teeth the diagnostic accuracy of CBCT is high and almost all cases of AP can be diagnosed correctly with only a very small risk of over-diagnosis. All diagnostic accuracy parameters were lower for root filled roots, hence the diagnosis of AP on root filled roots using CBCT was less accurate.

Impact of cone beam computed tomography on periapical assessment and treatment planning five to eleven years after surgical endodontic retreatment.

AIM: To evaluate how additional information from Cone Beam CT (CBCT) impacts on periapical assessment and treatment planning based on clinical examination and periapical radiographs (PR) in cases followed up five to eleven years after surgical endodontic retreatment (SER). METHODOLOGY: Patients receiving SER during 2004-2010 were reinvited for follow-up examination including clinical examination, PR, and CBCT. In total, 108 patients (119 teeth) were reinvited, 74 patients (83 teeth) accepted to participate. Three observers initially assessed PR according to the four-scaled, increasing disease severity criteria by Rud et al. (International Journal of Oral Surgery, 1, 1972 and 195) and Molven et al. (International Journal of Oral and Maxillofacial Surgery, 16, and 432): 'Radiographic assessment A'. By including clinical information 'Treatment plan A' was made as follows: 1) no treatment, 2) further observation, 3) SER reoperation (SER-R), or 4) extraction. Hereafter, the CBCT volume was assessed and the information incorporated for 'Radiographic assessment B' followed by 'Treatment plan B'. Agreement between radiographic assessments and between treatment plans was recorded and assessed statistically by Stuart-Maxwell test for marginal homogeneity. RESULTS: Nine teeth had been extracted; thus, the final analysis included 74 teeth (66 patients). The radiographic assessment was changed as a result of the CBCT evaluation in 38 cases (51.4%), of which 35 (47.3%) were to a higher Rud & Molven score, P < 0.001. The treatment plan was changed for 18 teeth (24.3%). For 14 teeth (18.9%), the change was from no treatment or further observation to a more invasive treatment plan (SER-R or extraction), P = 0.005. CONCLUSION: The use of CBCT for long-term follow-up after SER led to more cases diagnosed with persisting or recurrent apical periodontitis and hence often to the recommendation of a more invasive treatment modality.

Prediction of periapical status and tooth extraction.

AIM: To describe and analyse risk factors associated with prediction of periapical status, assessed using the full-scale Periapical Index (PAI) supplemented with extraction as outcome variable. METHODOLOGY: In 1997-1998, 616 randomly selected individuals from Aarhus County, Denmark, underwent a full-mouth radiographic survey. All 616 were re-invited in 2003-2004 and in 2008-2009, when 473 and 363 persons, respectively, consented and attended a new radiographic examination. The study population of the present investigation included 330 persons who had participated in all three examinations, and 143 persons who had participated in the first and second examination only. Using the full-mouth radiographic survey and interview information, the following variables were assessed: on person level - age, gender, smoking habits and number of teeth; on tooth level - presence of tooth, PAI, root filling, caries, marginal bone level, restoration, jaw and tooth group. The outcome variable was the 5 score PAI supplemented with extraction. The observation period was 5 years. Ordered logistic regression analyses were carried out for root filled and non-root filled teeth separately. The Regional Committee of Ethics approved the study. RESULTS: For both root filled teeth and non-root filled teeth, the baseline PAI score was the most important predictive factor of periapical status and extraction (P < 0.0001). Non-root filled teeth had in general a better outcome than root filled teeth. However, in non-root filled teeth, several other factors had a significant influence on the outcome, and the risk estimates were larger and showed a more pronounced variation between the different categories of predictive factors. For root filled teeth few variables, other than baseline PAI score, influenced the outcome significantly. CONCLUSION: The full-scale PAI was the strongest predictive factor of periapical status or extraction even when adjusted for additional factors, such as marginal bone level. A high baseline PAI score increased the risk for an impaired outcome. The large difference in risk estimates for non-root filled compared to root filled teeth documents the importance of separate analyses/studies for identification and quantification of predictive factors associated with periapical status and extraction of a tooth.

Cone beam computed tomography and periapical lesions: a systematic review analysing studies on diagnostic efficacy by a hierarchical model.

AIM: To evaluate using a systematic review approach the diagnostic efficacy of CBCT for periapical lesions, focusing on the evidence level of the included studies using a six-tiered hierarchical model. METHODOLOGY: The MEDLINE bibliographic database was searched from 2000 to July 2013 for studies evaluating the potential of CBCT imaging in the diagnosis and planning of treatment for periapical lesions. The search strategy was limited to English language publications using the following combined terms in the search strategy: apical pathology or endodontic pathology or periapical or lesion or healing and CBCT or cone beam CT. The diagnostic efficacy level of the studies was assessed independently by four reviewers. RESULTS: The search identified 25 publications that qualitatively or quantitatively assessed the use of CBCT for the diagnosis of periapical lesions, in which the methodology/results comprised at least one of the following parameters: the methods, the imaging protocols or qualitative/quantitative information on how CBCT influenced the diagnosis and/or treatment plan. CONCLUSION: From the assessed studies, it can be concluded that although there is a tendency for a higher accuracy for periapical lesion detection using CBCT compared to two-dimensional imaging methods, no studies have been conducted that justify the standard use of CBCT in diagnosing periapical lesions. In addition, it should be considered that, at the present time, the efficacy of CBCT as the diagnostic imaging method for periapical lesions has been assessed merely at low diagnostic efficacy levels.

Prognostic value of the full-scale Periapical Index.

AIM: To evaluate whether the full-scale Periapical Index (PAI) can predict the periapical status over time in nonroot filled and root filled teeth. METHODOLOGY: Full-mouth radiographic surveys of a random sample from a general population were performed in 1997, 2003 and 2008. The present investigation included 330 persons who participated in all three examinations and 143 persons who participated in the first and second examination. At each examination, the presence or absence of a tooth and of a root filling was recorded, and a PAI score (1-5) was assigned to all teeth. Retreatment of a root filling was recorded for root filled teeth. Statistical analysis was carried out using ordinal logistic regression and logistic regression and computed as Wald's tests. RESULTS: At baseline, nonroot filled teeth had lower PAI scores than root filled teeth (P < 0.0001). A high baseline PAI increased the risk of extraction for both root filled (P < 0.001) and nonroot filled teeth (P < 0.001). At 5-year follow-up, PAI scores were higher when baseline PAI scores had been higher. The overall pattern for root filled and nonroot filled teeth was similar, however, the differences were statistically significant (P < 0.001). In particular, the follow-up PAI score for nonroot filled teeth with baseline PAI score 1 or 2 was significantly lower than that of root filled teeth (P < 0.001). For root filled teeth with baseline PAI score 3, 4 or 5, the trend was reversed as they overall had slightly lower PAI scores at follow-up (P = 0.023). CONCLUSION: Repeated radiographic assessments of teeth using the full-scale PAI reveal that each of the five scores had distinct prognostic value for the course of periapical disease over a 5-year period for both nonroot filled and root filled teeth.

Ten-year follow-up of root filled teeth: a radiographic study of a Danish population.

AIM: To assess the long-term outcome of root filled teeth in a general adult population examined in 1997, 2003 and 2008. METHODOLOGY: The study provides longitudinal, observational information on endodontic status for 327 randomly selected individuals from a general Danish population receiving three consecutive full-mouth radiographic examinations. The association between root filling quality, periapical disease and the long-term outcome of the root filling and the root filled tooth was assessed using GEE methodology and tests for trend. RESULTS: Overall 13% of the root filled teeth had been extracted, 12% had received a revision of the root filling and 42% of root filled teeth present in 2008 had apical periodontitis (AP) after the 10-year follow-up period. The probability of persistent AP was higher if the root filling was either short or long (P = 0.001), if there were voids (P < 0.001), or if there were radiographic signs of overhang or open margin of the restoration (P = 0.01). Further, the probability of extraction was high if there were radiographic signs of overhang or open margin of the restoration (P = 0.008) and if the overall root filling quality was inadequate (test for trend, P = 0.03). CONCLUSIONS: The root filling quality primarily affected the risk of persistent AP and to a smaller extent the risk of extraction, whereas the quality of the coronal restoration primarily affected the risk of extraction and to a smaller extent the risk of persistent AP. If adjusted for AP present at the initial examination, the associations were less pronounced both in relation to extraction and persistence of AP.

Quality of root fillings performed with two root filling techniques. An in vitro study using micro-CT.

OBJECTIVE: The aim of this study was to compare the presence of voids in root fillings performed in oval and ribbon-shaped canals with two root filling techniques, lateral compaction technique (LCT) or hybrid technique (HT), a combination of a gutta-percha masterpoint and thermoplastic gutta-percha. Furthermore, the obturation time for the two techniques was evaluated. MATERIALS AND METHODS: Sixty-seven roots with oval and ribbon-shaped canals were prepared using Profile Ni-Ti rotary files. After preparation, the roots were randomly allocated to two groups according to root filling technique. All roots were filled with AH plus and gutta-percha. Group 1 was filled using LCT (n = 34) and group 2 was filled using HT (n = 33). The obturation time was measured in 30 cases evenly distributed between the two techniques. Voids in relation to the root canal fillings were assessed using cross-section images from Micro-computed Tomography scans. RESULTS: All root canal fillings had voids. Permutation test showed no statistically significant difference between the two root filling techniques in relation to presence of voids (p = 0.092). A statistically significant difference in obturation time between the two techniques was found (p < 0.001). CONCLUSION: The present study found no statistically significant difference in percentage of voids between two root filling techniques. A 40% reduction in obturation time was found for the HT compared to the LCT.

Ten-year follow-up observations of periapical and endodontic status in a Danish population.

AIM: To describe changes in periapical and endodontic status in a general adult Danish population examined in 1997, 2003 and 2008. METHODOLOGY: The study provides longitudinal, observational information on endodontic status for 327 individuals who participated in three consecutive full-mouth radiographic examinations performed with an approximately 5-year interval. The collected data allow changes to be investigated within and between age-cohorts. RESULTS: The median number of teeth declined slightly, but the number of individuals with apical periodontitis (AP) and with root filled teeth increased. The number of teeth with AP and of teeth with root fillings increased, whereas the number of root filled teeth with AP was almost stable. The proportion of individuals who had no AP and the proportion of individuals who had no root fillings decreased during the 10-year observation period. The proportion of teeth with AP/individual increased steadily with age, unaffected by the different time periods. Differences were found between the age groups for the proportion of root filled teeth/individual where the younger age-cohorts had root fillings performed later in life and at a slower rate. In the old age-cohort, the proportion of lost teeth/individual was much larger and showed a stronger increase with age, than in the younger age-cohorts. CONCLUSION: The younger age-cohorts will probably never reach the proportion of root fillings or lost teeth seen in the oldest age-cohort. However, it is disturbing that the proportion of teeth with AP/individual increased steadily with age, completely unaffected by the different time periods.

Incidence of caries lesions in approximal surfaces: a radiographic study of a general adult Danish population.

The aim was to describe the incidence of caries lesions in a randomly selected adult population, and to identify risk factors related to the incidence of caries lesions in approximal surfaces. In 1997, 616 adults participated in a study including a radiographic survey. In 2003 these individuals were contacted again and offered a second radiographic survey; 473 consented and attended this examination. In approximal surfaces, presence/absence of caries lesions and presence and type of coronal fillings were recorded. The incidence of caries lesions in surfaces with no caries lesions in 1997 was studied. Potential risk factors included information at three levels: (1) person, (2) tooth, and (3) surface. The analysis was carried out by multilevel logistic regression. For the analyses 23,701 approximal surfaces were eligible. In 23,243 approximal surfaces no caries lesions were detected in 1997, 17,007 of these were surfaces without fillings, and 6,236 were filled surfaces. In unfilled surfaces several factors affected the risk for development of a caries lesion: young age, high number of fillings, number of teeth and status of the adjacent surface. In filled surfaces few factors affected the incidence of caries lesions: status of the adjacent surface, smoking and distal surfaces. Differences in risk factor patterns for the incidence of caries lesions were found for unfilled and filled surfaces. The study emphasizes the importance of assessing factors related to the incidence of caries lesions in adults. Further it underlines the need to analyse the fate of filled surfaces separately, because once a surface has received a filling it needs continuous attendance.

A protocol for the Development of Core Outcome Sets for Endodontic Treatment modalities (COSET): an international consensus process.

BACKGROUND: The outcome of endodontic treatment is generally assessed using a range of patient and clinician-centred, non-standardised clinical and radiographic outcome measures. This makes it difficult to synthesise evidence for systematic analysis of the literature and the development of clinical guidelines. Core outcome sets (COS) represent a standardised list of outcomes that should be measured and reported in all clinical studies in a particular field. Recently, clinical researchers and guideline developers have focussed on the need for the integration of a patient-reported COS with clinician-centred measures. This study aims to develop a COS that includes both patient-reported outcomes and clinician-centred measures for various endodontic treatment modalities to be used in clinical research and practice. METHODS: To identify reported outcomes (including when and how they are measured), systematic reviews and their included clinical studies, which focus on the outcome of endodontic treatment and were published between 1990 and 2020 will be screened. The COSs will be defined by a consensus process involving key stakeholders using semi-structured interviews and an online Delphi methodology followed by an interactive virtual consensus meeting. A heterogeneous group of key 'stakeholders' including patients, general dental practitioners, endodontists, endodontic teachers, clinical researchers, students and policy-makers will be invited to participate. Patients will establish, via interactive interviews, which outcomes they value and feel should be included in a COS. In the Delphi process, other stakeholders will be asked to prioritise outcomes identified from the literature and patient interviews and will have the opportunity at the end of the first round to add outcomes that are not included, but which they consider relevant. Feedback will be provided in the second round, when participants will be asked to prioritise the list again. If consensus is reached, the remaining outcomes will be discussed at an online meeting and agreement established via defined consensus rules of outcome inclusion. If consensus is not reached after the second round, a third round will be conducted with feedback, followed by the online meeting. Following the identification of a COS, we will proceed to identify how and when these outcomes are measured. DISCUSSION: Using a rigorous methodology, the proposed consensus process aims to develop a COS for endodontic treatment that will be relevant to stakeholders. The results of the study will be shared with participants and COS users. To increase COS uptake, it will also be actively shared with clinical guideline developers, research funders and the editors of general dental and endodontology journals. TRIAL REGISTRATION: COMET 1879. 21 May 2021.

Prevalence and incidence of caries lesions in relation to placement and replacement of fillings: a longitudinal observational radiographic study of an adult Danish population.

The aim was to describe the prevalence and incidence of caries lesions in relation to the placement and replacement of amalgam and non-metal fillings in a randomly selected adult Danish population. In 1997 and in 2003, 470 individuals underwent a full-mouth radiographic survey. All recordings were based on radiographs. A total of 12,361 teeth were examined. Registrations were performed on surfaces: mesial, distal and occlusal or incisal. In 1997 the total number of teeth and the number of unfilled teeth per individual decreased with the age of the individual, whereas the number of caries lesions per individual did not vary systematically with age. In each age group approximately 50% of the individuals had no caries lesions. In 1997 approximately 70% of the filled surfaces were filled with amalgam and 30% with non-metal filling materials. In 2003 60% of the surfaces were amalgam-filled and 40% were non-metal-filled. Overall non-metal filling material was more frequently used than amalgam in both treatments and re-treatments. During the observation period approximately 20% of both amalgam and non-metal-filled surfaces were re-treated. For amalgam fillings this was constant across the tooth groups, but for non-metal fillings the percentage of re-treated surfaces was larger for molars. The percentage of teeth with caries increased from front teeth to posterior teeth. The lowest percentage of surfaces with caries was detected in unfilled surfaces, and the highest in non-metal-filled surfaces. The results from the present study suggest the need for reflection and diligence when using non-metal materials for dental fillings especially in relation to molars.

Randomized clinical trial of root-end resection followed by root-end filling with mineral trioxide aggregate or smoothing of the orthograde gutta-percha root filling--1-year follow-up.

AIM: To compare healing after root-end resection with a root-end filling of mineral trioxide aggregate (MTA) or smoothing of the orthograde gutta-percha (GP) root filling. METHODOLOGY: Forty-four patients (consisting of 52 teeth with periapical infection), average age of 54.6 years (range 30-77) participated in a randomized clinical trial (RCT) comparing the MTA and GP treatment methods. Radiographs produced 1-week and 12 months post-operatively were compared after blinding for treatment method, and healing was assessed as complete, incomplete, uncertain, or unsatisfactory. RESULTS: Six teeth were not available for the 12-month follow-up: three teeth (GP) had been re-operated because of pain and two teeth (one GP, one MTA) had been extracted because of root fracture (these five teeth were classified as failures). One patient (GP) was not available for recall. In the GP group, seven teeth (28%) showed complete healing, six teeth (24%) incomplete healing, six teeth (24%) uncertain healing and two teeth (8%) unsatisfactory healing after 1 year. In the MTA group, 22 teeth (85%) showed complete healing, three teeth (12%) incomplete healing, and none were scored as uncertain or unsatisfactory healing after 1 year. The difference in healing between the GP and the MTA groups was significant (P < 0.001). CONCLUSIONS: The results from this RCT emphasize the importance of placing a root-end filling after root-end resection. Teeth treated with MTA had significantly better healing (96%) than teeth treated by smoothing of the orthograde GP root filling only (52%).

Periapical radiography and cone beam computed tomography for assessment of the periapical bone defect 1 week and 12 months after root-end resection.

OBJECTIVES: Our aim was to compare periapical radiography and cone beam CT (CBCT) for assessment of the periapical bone defect 1 week and 12 months after root-end resection. METHODS: 50 patients (58 teeth) with a persisting apical periodontitis in a root-filled tooth (incisor, canine or premolar) were treated with root-end resection. 1 week and 12 months post-operatively, a CBCT scan (NewTom 3G) and a periapical radiograph (Digora) were obtained. Three observers detected and measured the periapical bone defects on periapical radiographs and CBCT images (coronal and sagittal sections). RESULTS: 1 week post-operatively, a periapical bone defect area was measured in all teeth by all observers. The defect was 10% smaller on periapical radiographs (mean = 12.4 mm2, SD = 8.2) than on the CBCT images measured in the coronal plane (mean = 13.0 mm2, SD = 7.8), a difference which was not statistically significant (P = 0.58). 12 months post-operatively (n = 52), there was considerable variation between the observers' detection of a remaining defect on the periapical radiographs and the CBCT images. The average agreement between the periapical radiograph and the CBCT images in the coronal sections was 67%, and more defects were detected on CBCT than on periapical radiographs. CONCLUSIONS: On average, the periapical bone defect measured on periapical radiographs was approximately 10% smaller than on coronally sectioned CBCT images 1 week post-operatively. More remaining defects were detected 1 year after periapical surgery on CBCT images than on periapical radiographs, but it is uncertain how this information is related to success or failure after root-end resection.

Effect of monitor display on detection of approximal caries lesions in digital radiographs.

OBJECTIVES: The aim was to compare the accuracy of five flat panel monitors for detection of approximal caries lesions. METHODS: Five flat panel monitors, Mermaid Ventura (15 inch, colour flat panel, 1024 x 768, 32 bit, analogue), Olórin VistaLine (19 inch, colour, 1280 x 1024, 32 bit, digital), Samsung SyncMaster 203B (20 inch, colour, 1024 x 768, 32 bit, analogue), Totoku ME251i (21 inch, greyscale, 1400 x 1024, 32 bit, digital) and Eizo FlexScan MX190 (19 inch, colour, 1280 x 1024, 32 bit, digital), were assessed. 160 approximal surfaces of human teeth were examined with a storage phosphor plate system (Digora FMX, Soredex) and assessed by seven observers for the presence of caries lesions. Microscopy of the teeth served as validation for the presence/absence of a lesion. RESULTS: The sensitivities varied between observers (range 7-25%) but the variation between the monitors was not large. The Samsung monitor obtained a significantly higher sensitivity than the Mermaid and Olórin monitors (P<0.02) and a lower specificity than the Eizo and Totoku monitors (P<0.05). There were no significant differences between any other monitors. The percentage of correct scores was highest for the Eizo monitor and significantly higher than for the Mermaid and Olórin monitors (P<0.03). CONCLUSIONS: There was no clear relationship between the diagnostic accuracy and the resolution or price of the monitor. The Eizo monitor was associated with the overall highest percentage of correct scores. The standard analogue flat panel monitor, Samsung, had higher sensitivity and lower specificity than some of the other monitors, but did not differ in overall accuracy for detection of carious lesions.