Simulated Root Resorption Cavities Research Articles

Accuracy of volumetric measurement of simulated root resorption lacunas based on cone beam computed tomography

To evaluate the accuracy of volumetric measurement of simulated root resorption cavities based on cone beam computed tomography (CBCT), in comparison with that of Micro-computed tomography (Micro-CT) which served as the reference. The State Key Laboratory of Oral Diseases at Sichuan University. Thirty-two bovine teeth were included for standardized CBCT scanning and Micro-CT scanning before and after the simulation of different degrees of root resorption. The teeth were divided into three groups according to the depths of the root resorption cavity (group 1: 0.15, 0.2, 0.3 mm; group 2: 0.6, 1.0 mm; group 3: 1.5, 2.0, 3.0 mm). Each depth included four specimens. Differences in tooth volume before and after simulated root resorption were then calculated from CBCT and Micro-CT scans, respectively. The overall between-method agreement of the measurements was evaluated using the concordance correlation coefficient (CCC). For the first group, the average volume of resorption cavity was 1.07 mm(3) , and the between-method agreement of measurement for the volume changes was low (CCC = 0.098). For the second and third groups, the average volumes of resorption cavities were 3.47 and 6.73 mm(3) respectively, and the between-method agreements were good (CCC = 0.828 and 0.895, respectively). The accuracy of 3-D quantitative volumetric measurement of simulated root resorption based on CBCT was fairly good in detecting simulated resorption cavities larger than 3.47 mm(3), while it was not sufficient for measuring resorption cavities smaller than 1.07 mm(3) . This method could be applied in future studies of root resorption although further studies are required to improve its accuracy.

Comparison of 6 cone-beam computed tomography systems for image quality and detection of simulated canine impaction-induced external root resorption in maxillary lateral incisors

The most frequent adverse effect of canine impaction is resorption of the adjacent incisors. The subjective image quality and the radiographic diagnostic accuracy for detection of simulated canine-induced external root resorption lesions in maxillary lateral incisors were compared among 6 cone-beam computed tomography (CBCT) systems invitro. A child cadaver skull in the early mixed dentition was obtained. This skull had an impacted maxillary left canine and allowed a reliable simulation. Simulated root resorption cavities were created in 8 extracted maxillary left lateral incisors by the sequential use of 0.16-mm diameter round burs in the distopalatal root surface. Cavities of varying depths were drilled in the middle or apical thirds of each tooth root according to 3 setups: slight (0.15, 0.20, and 0.30 mm), moderate (0.60 and 1.00 mm), and severe (1.50, 2.00, and 3.00 mm) resorption. The lateral incisors, including 2 intact teeth, were repositioned individually in the alveolus with approximal contacts to the impacted maxillary left canine. Six sets of radiographic images were obtained with 3D Accuitomo-XYZ Slice View Tomograph (J. Morita, Kyoto, Japan), Scanora 3D CBCT (Soredex, Tuusula, Finland), Galileos 3D Comfort (Sirona Dental Systems, Bensheim, Germany), Picasso Trio (E-WOO Technology, Giheung-gu, Republic of Korea), ProMax 3D (Planmeca OY, Helsinki, Finland), and Kodak 9000 3D (Trophy, Croissy-Beaubourg, France) for each tooth setup. The CBCT images were acquired and subsequently analyzed by 12 observers. Linear models for repeated measures were used to compare the CBCT systems for the image quality and the degree of agreement between the diagnosed severity of root resorption and the true severity. The differences in the image quality between CBCT systems were statistically significant (P<0.001). The root resorption scores between CBCT systems showed a significantly higher score for the ProMax when compared with the Galileos and the Kodak. However, the differences in agreement between the diagnosed severity of root resorption and the true severity for all resorption sizes were not significantly different (P>0.05) among the different CBCT systems. High image quality is important when detecting root resorption. The CBCT systems used in this study had high accuracy with no significant differences between them in the detection of the severity of root resorption.

Editor's Summary and Q&A: In-vitro comparison of 2 cone-beam computed tomography systems and panoramic imaging for detecting simulated canine impaction-induced external root resorption in maxillary lateral incisors

Introduction The introduction of cone-beam computed tomography (CBCT) in dentomaxillofacial radiology has created new diagnostic challenges, including some potential opportunities for evaluating impacted teeth. The diagnostic accuracy for detection of simulated canine-induced external root resorption lesions in maxillary lateral incisors was compared between conventional, 2-dimensional panoramic radiographic imaging and two 3-dimensional CBCT systems. Methods A child cadaver skull in the early mixed dentition was obtained from the Department of Anatomy, Hasselt University, Diepenbeek, Belgium, with ethical approval. This skull had an impacted maxillary left canine and allowed a reliable simulation. Simulated root resorption cavities were created in 8 extracted maxillary left lateral incisors by the sequential use of 0.16 mm diameter round burs in the distopalatal root surface. Cavities of varying depths were drilled in the middle or apical thirds of each tooth root according to 3 setups: slight (0.15, 0.20, and 0.30 mm), moderate (0.60 and 1.00 mm), and severe (1.50, 2.00, and 3.00 mm). The lateral incisors, including 2 intact teeth, were repositioned individually in the alveolus of the pediatric skull with approximal contacts to the impacted maxillary left canine. Three sets of radiographic images were obtained with panoramic Cranex Tome (Soredex, Helsinki, Finland), Accuitomo-XYZ Slice View Tomograph (J. Morita, Kyoto, Japan), and Scanora 3D CBCT (Soredex, Tuusula, Finland) for each tooth setup. Eight observers examined the 3 sets of 10 radiographs for resorption cavities. Results The differences in correct detection of simulated root resorption for all cavity sizes were significantly different ( P Conclusions These results suggest that the CBCT radiographic method is more sensitive than conventional radiography to detect simulated external root resorption cavities.

In-vitro comparison of 2 cone-beam computed tomography systems and panoramic imaging for detecting simulated canine impaction-induced external root resorption in maxillary lateral incisors

The introduction of cone-beam computed tomography (CBCT) in dentomaxillofacial radiology has created new diagnostic challenges, including some potential opportunities for evaluating impacted teeth. The diagnostic accuracy for detection of simulated canine-induced external root resorption lesions in maxillary lateral incisors was compared between conventional 2-dimensional panoramic radiographic imaging and two 3-dimensional CBCT systems. A child cadaver skull in the early mixed dentition was obtained from the Department of Anatomy, Hasselt University, Diepenbeek, Belgium, with ethical approval. This skull had an impacted maxillary left canine and allowed a reliable simulation. Simulated root resorption cavities were created in 8 extracted maxillary left lateral incisors by the sequential use of 0.16 mm diameter round burs in the distopalatal root surface. Cavities of varying depths were drilled in the middle or apical thirds of each tooth root according to 3 setups: slight (0.15, 0.20, and 0.30 mm), moderate (0.60 and 1.00 mm), and severe (1.50, 2.00, and 3.00 mm). The lateral incisors, including 2 intact teeth, were repositioned individually in the alveolus of the pediatric skull with approximal contacts to the impacted maxillary left canine. Three sets of radiographic images were obtained with panoramic Cranex Tome (Soredex, Helsinki, Finland), Accuitomo-XYZ Slice View Tomograph (J. Morita, Kyoto, Japan), and Scanora 3D CBCT (Soredex, Tuusula, Finland) for each tooth setup. Eight observers examined the 3 sets of 10 radiographs for resorption cavities. The differences in correct detection of simulated root resorption for all cavity sizes were significantly different (P <0.05) between the panoramic and both CBCT systems. CBCT imaging performance was significantly better than that of panoramic radiography for determining root resorption in the categories of slight and severe resorption. These results suggest that the CBCT radiographic method is more sensitive than conventional radiography to detect simulated external root resorption cavities.

Film and digital radiography for detection of simulated root resorption cavities

Objectives. The purpose of this study was to evaluate observers' ability to detect simulated root resorption cavities in conventional radiographs and digital radiographs from a charge-coupled device system and a storage phosphor system and to determine whether the detectability was influenced by resorption size and exposure. Study design. In teeth from dry mandibular jaw specimens, resorptive defects 1.2 mm in diameter and at two different depths (0.6 and 0.9 mm) were prepared in the buccal root surface. Each tooth was radiographed at a number of different exposure settings. Observers were asked to rate their confidence that a resorption was or was not present using a five-graded confidence scale. Receiver operating characteristic analysis was used to evaluate the results. Results and conclusion. Given optimal exposures, all systems reached what might be considered clinically acceptable A z values (>0.75). The storage phosphor system reached this value at considerably lower exposures than those required for both the film and charge-coupled device systems. There was a tendency to better detect the deeper lesions and to identify them at lower exposures.

Early radiographic diagnosis of apical root resorption during orthodontic treatment: a study of maxillary incisors.

The purpose of this study was to evaluate the sensitivity of digital radiographs for detection of (i) simulated root resorption cavities in an experimental model and (ii) orthodontically-induced apical root resorption in vivo. The severity of root resorption after 3 and 6 months treatment was studied in relation to root form. The experimental study cavities, drilled in mandibular roots in a dry skull, were recorded in conventional and digital radiographs. In vivo root resorption was evaluated on digital radiographs of 92 maxillary incisors after 3 and 6 months treatment with fixed appliances. The results showed a similar sensitivity for the two methods. Sensitivity increased significantly with cavity size. After 3 months apical root resorption was detected in only a few teeth. The number had increased significantly after 6 months. There was a higher degree of root resorption in teeth with blunt and pipette-shaped apices. In such teeth a 3-month radiographic control is recommended.

Digital subtraction radiography for assessment of simulated root resorption cavities. Performance of conventional and reverse contrast modes.

A previous study of the sensitivity and accuracy of a standardized radiographic technique for the disclosure of root cavities in a cadaver material indicated that it was not possible to perceive small artificial "resorption" cavities. Using the same material, the aim of the present study was to evaluate whether the use of subtraction radiography would improve the detection of root cavities. In an autopsy material of five mandibular blocks each containing two premolars, small, medium, and large cavities were drilled in the cervical, middle, and apical thirds of the proximal and oral root surfaces. Each jaw block was radiographed before (B) and after (A) cavity preparation with three different exposure times resulting in light, medium, and dark film densities. The radiographs were digitized. Digital subtraction was performed between the A- and B images of varying densities by a computer program developed for dental subtraction radiography. Conventional and reverse contrast modes of the subtraction image were assessed independently by four observers. The results showed small inter- and intraobserver differences in diagnostic accuracy for assessment of total number of root cavities. Original film density did not influence the diagnostic performance in the resulting subtraction image. Contrast mode in the subtraction image influenced diagnostic performance as the majority of observers did best with the reverse contrast mode (p < 0.05). Some of the small root cavities were disclosed by the subtraction technique, but overall accuracy was not increased compared to conventional radiography.

Radiographic assessment of simulated root resorption cavities.

Abstract A study into the sensitivity and accuracy of a standardized radiographic technique for the disclosure of root resorption cavities was performed in a cadaver material. Film contrast and horizontal angulation were varied in order to identify factors in radiographic exposure which resulted in the greatest diagnostic reliability. In an autopsy material of 5 jaw blocks containing both mandibular premolars, “small, medium and large” cavities simulating root resorptions of 0.6, 1.2 and 1.8 mm in diameter and 0.3, 0.6 and 0.9 mm in depth, respectively, were drilled at the cervical, middle and apical thirds of the proximal and oral root surfaces of the premolars. Cavity locations were distributed to ensure an equal number of locations with and without cavities and an equal number of cavities of each size. Results of the investigation indicated that the small cavities were never visualized, nor were 6 out of 13 medium cavities nor 1 out of 13 large cavities; that cavities located proximally were more readily seen than those located orally and that there was no clif Terence in cavity visualization between cavities on the apical, middle or cervical thirds of the roots; high density (contrast) films allowed the best cavity visualization. Finally, radiographs from the time of injury (i.e. preresorption radiographs) as well as radiographs taken at various horizontal angulations were found to be of importance in order to increase the possibility of cavity visualization.