Lise-Lotte Kirkevang

Variable-resolution cone-beam computerized tomography with enhancement filtration compared with intraoral photostimulable phosphor radiography in detection of transverse root fractures in an in vitro model

OBJECTIVES The aim of this study was to compare the diagnostic accuracy of an intraoral photostimulable storage phosphor (PSP) plate system and cone-beam computerized tomography scanning (CBCT) for detection of experimentally induced transverse root fractures and to evaluate differences between original images and images enhanced with high-pass filters. STUDY DESIGN Sixty-nine extracted human teeth, 34 with root fractures and 35 without, were examined under standardized conditions using an intraoral PSP system (Digora Optime; Soredex). The images were saved in original 8-bit format and in a version sharpened with a high-pass filter. The teeth were examined with CBCT (i-Cat; Imaging Sciences) in 2 resolutions: 0.125 mm and 0.25 mm voxel size. Original images were saved together with images enhanced with 2 high-pass filters, sharpen and angio-sharpen. Six observers scored the presence of a root fracture in all modalities in random order. Sensitivity, specificity, and accuracy [(true positives + true negatives)/all scores] were calculated for each modality and each observer. Differences were estimated by analyzing the binary data, assuming additive effects of observer and modality in a generalized linear model. RESULTS High-resolution original CBCT images had higher sensitivity (P < .05) than lower-resolution images and PSP images (0.125 mm resolution 87%, 0.25 mm resolution 72%, and PSP 74%). Angio-sharpen-filtered images for both CBCT resolutions had higher sensitivities (P < .02) than the original images (0.125 mm resolution: 95% vs. 87%; 0.25 mm resolution: 81% vs. 72%). There was no significant difference between the lower-resolution CBCT and PSP images. Only small differences in specificity were seen between modalities, and accuracy was higher for high-resolution CBCT than for the other modalities (P < .03). CONCLUSIONS High-resolution i-Cat CBCT images resulted in an increase in sensitivity without jeopardizing specificity for detection of transverse root fractures compared with lower-resolution CBCT images, which were not more accurate than periapical PSP images. The angio-sharpen high-pass filter improved sensitivity in the high-resolution CBCT images in this in vitro model.

Marginal adaptation of a low-shrinkage silorane-based composite: 1-year randomized clinical trial

The aim of the present study was to examine the marginal adaptation of a new low-shrinkage silorane-based composite material (Filtek™ Silorane, 3M-Espe) by comparing it with a methacrylate-based composite material (CeramX™, Dentsply DeTrey). In particular, we wanted to test the hypothesis that reduced polymerization shrinkage would improve the marginal adaptation. Seventy-two patients participated in the study. A total of 158 restorations were placed in 80 premolars and 78 molars. Only Class II restorations were included, and each patient could contribute with more than one tooth. The restorations were scored at baseline and after one year. While statistical comparison of marginal adaptation at follow-up indicated better performance of CeramX™ both occlusally and approximally (p = 0.01 and p < 0.01), the low kappa value (32%) reflects the difficulty to assess marginal adaptation clinically. The reduction in polymerization shrinkage demonstrated in the laboratory was not clinically significant in the present study.

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%).

Undergraduate curriculum guidelines for endodontology.

Earlier editions of the ESE undergraduate curriculum guidelines for Endodontology were published in 1992 and 2001 (International Endodontic Journal 25, 169–72; 34, 574–80) and formed a benchmarking reference for dental schools and regulatory bodies. Despite much technological advance and the publication of quality guidelines for endodontic treatment (European Society of Endodontology 2006), studies published during the last decade have continued to show disappointing technical standards of root canal treatment in European populations (Eriksen et al. 2002, Segura-Egea et al. 2004, Tavares et al. 2009, Gencoglu et al. 2010, Peters et al. 2011). Longitudinal observational studies have also reinforced the relationship between treatment quality and persistent disease (Eckerbom et al. 2007, Kirkevang et al. 2007). Although a limited number of European countries have recognized endodontics as a speciality, there is no doubt that the vast proportion of endodontic procedures will continue to be undertaken by general dental practitioners. Evidence suggests that many general practitioners lack sufficient knowledge of the factors important in determining the outcome of root canal treatment (Bjørndal et al. 2007) and that basic principles are often disregarded (Peciuliene et al. 2009). Some of this may reflect the acquisition of foundational knowledge and skills during undergraduate training, where standards remain highly variable (Eleftheriadis & Lambrianidis 2005, Er et al. 2006, Sonntag et al. 2008, Burke et al. 2009, Kelbauskas et al. 2009, Khabbaz et al. 2010). It is therefore important to ensure that undergraduate training is undertaken to a level that encourages deep understanding of the factors important in determining clinical outcome. It is beyond the scope of this pre-amble to provide a detailed critique of all aspects of endodontic practice, but the example of root canal treatment serves to illustrate the motivation of the European Society of Endodontology in promoting standards of scientific education and clinical training across a broad undergraduate curriculum in Endodontology. This includes but is not limited to diagnostic and treatment procedures for the prevention and management of pulpal and periradicular disease, and for the preservation, restoration and monitoring of pulpally compromised teeth that would otherwise be lost. It is implicit that the procedures defined should be exercised within a model of holistic, evidence-based patient care and should be undertaken to support the oral and general health of patients. This document represents a guideline for an undergraduate curriculum and cannot be exhaustive. The underlying principle must be that a minimum level of competence is reached prior to graduation and that an ethos of continuing professional development is instilled in the graduate.

Risk factors for tooth loss in an adult population: a radiographic study

AIM The aim of the present study was to estimate the incidence and identify risk factors for tooth loss during a 5-year period in a randomly selected Danish population. MATERIAL AND METHODS In 1997 and 2003, 473 randomly selected adults received a full-mouth radiographic examination. The total number of teeth was 12,444. For each tooth, the following information was recorded from the radiographs: marginal bone level, filling, crown, root canal post, root filling, apicectomy, periapical status and caries lesion. Unconditional and conditional logistic regression analyses were used to identify risk factors for tooth loss. RESULTS During the study period, 107 teeth in 60 individuals were lost. On the individual level, reduced marginal bone level and apical periodontitis (AP) were highly associated with tooth loss. On the tooth level, a reduced marginal bone level, AP and apicectomy were strongly associated with tooth loss. Canines were not lost often, whereas tooth loss was more frequently observed in molars and premolars than in incisors. CONCLUSIONS A reduced marginal bone level and AP were associated with tooth loss over time. Furthermore, there was a higher risk of tooth loss in the posterior regions than in the anterior region.

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.

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.

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

Abstract 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.

Comparison of images from digital intraoral receptors and cone beam computed tomography scanning for detection of voids in root canal fillings: an in vitro study using micro-computed tomography as validation

OBJECTIVE To compare the diagnostic value of six intraoral digital receptors and a cone beam computed tomography scanning system for detection of voids in root fillings. METHODS Sixty-seven root-filled roots with oval and ribbon-shaped canals were included. Three standardized radiographic examinations were performed for each root with six intraoral digital receptors. Further, the roots were examined using CBCT. Four observers measured the extension of voids in all images. The true extension of voids was recorded in cross-sectional images from micro-computed tomography scans (micro-CT). The proportion of voids observed in the radiographic image validated against micro-CT was calculated for each system. RESULTS All intraoral receptors underestimated the extension of voids, and few false positives were recorded. CBCT resulted in a higher proportion of correctly observed voids, but with several false-positive recordings. CONCLUSIONS The diagnostic value differed little among the six intraoral systems. CBCT overestimated in many cases the proportion of voids in root fillings.