Basic Research—TechnologyDetection of Horizontal Root Fracture with Small-volumeCone-Beam Computed Tomography in the Prese...
Basic Research—Technologyindividually placed in the empty mandibular sockets of 20 human dry                because the ob...
Basic Research—TechnologyTABLE 1. The Number of True (T) and False (F) Diagnoses of Horizontal Root                       ...
Basic Research—Technology                           Acknowledgments                                                  13. H...
Upcoming SlideShare
Loading in …5

Detection of horizontal root fracture with small volume cone-beam computed tomography in the presence and absence of intracanal metallic post


Published on

  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Detection of horizontal root fracture with small volume cone-beam computed tomography in the presence and absence of intracanal metallic post

  1. 1. Basic Research—TechnologyDetection of Horizontal Root Fracture with Small-volumeCone-Beam Computed Tomography in the Presence andAbsence of Intracanal Metallic PostFelipe Ferreira Costa, DDS, Bruno Felipe Gaia, DDS, Otavio Shoiti Umetsubo, DDS, MS,and Marcelo Gusm~ o Paraiso Cavalcanti, DDS, MS, PhD aAbstractIntroduction: The aim of the present study was to testthe accuracy of small-volume cone-beam computedtomography (CBCT) scanning in the detection of hori- A ccurate diagnosis of horizontal root fractures is of fundamental importance in endodontics. However, it is still a challenge because of the restrictions of the clinical examination. Although x-ray examination is indicated for this purpose, bidimensionalzontal root fractures and to assess the influence of techniques have limitations. They are caused by distortion and superimposition of othera metallic post. Methods: Forty teeth were divided structures that preclude root fractures to be visualized.into four groups based on the presence of metallic posts Cone-beam computed tomography (CBCT) scanning was adapted for use inand horizontal root fracture. The teeth were examined by dentistry by Arai et al (1) in 1999. This three-dimensional technique has several appli-small-volume CBCT scanning at 0.2-mm voxel resolu- cations in endodontics (2–7), such as the detection of root fractures (8). One of thetion. Three observers analyzed the samples for the pres- major advantages of CBCT scans over computed tomography (CT) scans is the signif-ence of a horizontal root fracture. Sensitivity and icantly lower effective radiation dose (9).specificity were calculated. Results: High values for The restoration of teeth submitted to endodontic treatment often requires theaccuracy (73%–88%) were obtained in the groups insertion of an intracanal post. Metallic objects can cause artifacts that seriously impairwithout a metallic post, and statistically significant the quality of CT images and are represented by radiopaque, radiolucent, and brightdifferences were found when the group with a metallic tracks that can overlap the teeth root and mimic root fractures. It can occur in bothpost has been observed (55%–70%). Intraobserver CT and CBCT examinations, sometimes making them diagnostically unusable. This isagreement also showed statistically significant differ- because of the fact that x-rays are composed of photons with a range of energies.ences in the groups with a metallic post. Conclusions: Because polychromatic radiation passes through an object, its energy increases inSmall-volume CBCT scanning showed high accuracy in the spectrum because low-energy photons are absorbed more frequently than high-detecting horizontal root fracture without a metallic energy photons. Therefore, the aims of the present study were to (1) test the accuracypost. However, the presence of a metallic post signifi- of small-volume CBCT scanning in detecting horizontal root fracture and (2) investigatecantly reduced the specificity and sensitivity of this the influence of a metallic post in the visual detection of horizontal root fracture. Theexamination. (J Endod 2011;37:1456–1459) null hypothesis was that no significant difference exists between small-volume CBCT observations of fracture in teeth with or without metallic posts.Key WordsCone-beam computed tomography scanning, diagnosis, Materials and Methodshorizontal root fracture Preparation of Samples Extracted single-rooted human premolar teeth (n = 40) with no root reabsorp- tion, crack, caries, or fracture were selected. The anatomic crowns of all teeth were sectioned perpendicularly to the long axis at the cementoenamel junction by using From University of S~o Paulo, S~o Paulo, S~o Paulo, Brazil. a a a water-cooled diamond burs propelled by an air turbine (300,000 rpm). Supported by Conselho Nacional de DesenvolvimentoCient e Tecnolgico (CNPq) National Council for Research, ıfico o For all teeth, the same operator, who was not involved in interpreting the images,Research Productivity Scholarship grant No. 303847/2009-3, performed endodontic treatment (using Gates Glidden drills sizes 2 and 3 and Nitiflexand Universal Research Project grant No. 472895/2009-5 files; Dentsply Maillefer, Ballaigues, Switzerland) and obturation (Pulp Canal Sealer;(M.G.P.C.) and Coordenac~o de Aperfeicoamento de Pessoal ¸a ¸ Sybron Endo, Orange, CA). All fillings were removed from the root canals up to twode N ıvel Superior (CAPES) PhD Scholarships (F.F.C. andB.F.G.) and Master Degree Scholarship (O.S.U.). thirds of their length. Subsequently, a post was modeled within each root canal. Address requests for reprints to Dr Felipe Ferreira Costa, Root fracture was then caused in the teeth (n = 20) by applying a mechanical forceAv Professor Lineu Prestes, 2227 Cidade Universitria, FOUSP, a on their horizontal plane. A hammer was used for this purpose, and the teeth wereCEP 05508-900, S~o Paulo, Brazil. E-mail address: felipecosta@ a placed on a soft foundation as previously described by Hassan et al (8) and and Kirkevang (10). Both fragments were then assembled and glued without displace-0099-2399/$ - see front matter Copyright ª 2011 American Association of Endodontists. ment. Teeth roots (n = 6) that were broken in more than two fragments were replaceddoi:10.1016/j.joen.2011.05.040 according to the inclusion criteria. The entire sample was kept hydrated during the process except during the fracture induction. Image Acquisition A water-filled plastic recipient was used as the head phantom to be imaged. A CBCT (PaX Uni3D; Gnatus/Vatech, Suwon, Korea) scan was performed for each tooth1456 Costa et al. JOE — Volume 37, Number 10, October 2011
  2. 2. Basic Research—Technologyindividually placed in the empty mandibular sockets of 20 human dry because the observers did not remember the previous image interpre-mandibles. The limits of the imaging area consisted of a 50-mm height tation. The presence of a fracture line was diagnosed by a dichotomousand 50-mm diameter cylinder. The voxel size was 0.2 mm, and the gray- (yes/no) evaluation: correct identification of a nonfractured root (truescale range of the acquired images was 16 bits. The region of interest negative [TN]) and a fracture in a fractured root (true positive [TP])was positioned at the center of the field of view (FOV). Subsequently, and the identification of a fracture in a nonfractured root (false posi-the metallic posts were inserted into the root canals, and the teeth tive [FP]) and failure to identify a fracture in a fractured root (falsewere scanned again following the same protocols. negative [FN]). Then, sensitivity = (TP/TP) and specificity = (TN/ Thus, 40 CBCT scans of roots with a metallic post and an equal TN) + FP were calculated. Statistical analyses were performed usingnumber of images of roots without a metallic post (each group contain- the validity and kappa tests. The k coefficients were calculated toing 20 teeth with fracture and 20 without fracture) were obtained. Those assess the degree of intra- and interobserver agreement and scoredscans were coded and divided into four groups of teeth: without both as weak (0.20–0.39), moderate (0.40–0.59), and relevant (0.60–a metal post and fracture (G1), without a metal post and with horizontal 0.79) (11). It allowed us to check the agreement between the tomo-root fracture (G2), with a metal post and without fracture (G3), and graphic diagnosis and the gold standard. The level of significance waswith both a metal post and a horizontal root fracture (G4). Therefore, set at a = 0.05. Data were analyzed using SPSS software (v 17.0.0;each of the three double-blinded observers, experienced oral and SPSS Inc, Chicago, IL).maxillofacial radiologists who were also trained and calibrated ontomographic features of horizontal root fracture, analyzed 80 CBCTscans in each observation. Results After image acquisition, data were stored in a Digital Imaging Table 1 shows the overall TP and FP and TN and FN results forCommunication in Medicine (DICOM) file format and imported into the diagnosis of horizontal root fracture. The values for sensitivity anda specially designed open-source DICOM viewer for MacOS X Apple specificity on the diagnosis of horizontal root fracture in teeth withoutComputer OsiriX 3.8.1 version (Pixmeo, Geneva, Switzerland; http:// and with metallic posts are shown in Table 2. Significant values The entire volume of each sample was accuracy (P .05) were observed in teeth of groups 1 and 2analyzed by the observers who used multiplanar reconstructed axial, (73%–88%) in which the metallic post was not present. However,coronal, and sagittal images. Subsequently, parasagittal and circumfer- accuracy rates were significantly reduced (P .05) in teeth ofential images (slice thickness: 0.2 mm; interval between slices: 0.4 mm) groups 3 and 4 (55%–70%) in which the metallic post was presentwere observed. They could use the visualization tools options (contrast, (Table 2).magnification, and window width and level) available. The sequence of The values for intraobserver agreement on the diagnosis of hori-observations was randomized by software (Randomness 1.5.2; Andrew zontal root fractures in teeth of groups G1 and G2 (without a metallicMerenbach, Los Angeles, CA) (Fig. 1). post) varied from moderate to very high (k: 0.56–0.82); in teeth of The interpretation time was not restricted, and the same image groups G3 and G4 (with a metallic post), the values for intraobserverwas analyzed repeatedly in a 2-week interval. This was performed agreement varied from weak to moderate (k: 0.36–0.39) (Table 2).Figure 1. Circumferential CBCT images: (A) a sample with a horizontal root fracture (arrow) and a metallic post, (B) a sample without a horizontal root fracturewith a radiolucent image caused by a metallic artifact (arrow), and (C) a sample with a horizontal root fracture (arrow) without a metallic post.JOE — Volume 37, Number 10, October 2011 Horizontal Root Fracture in CBCT 1457
  3. 3. Basic Research—TechnologyTABLE 1. The Number of True (T) and False (F) Diagnoses of Horizontal Root a ‘‘beam hardening’’ or x-ray ‘‘hardening’’ effect, is responsible for theFractures as Identified in Each Group Performed without and with Metallic appearance of dark bands and lines between two dense objects in radio-Posts graphic images. High values for accuracy rates were found in the groups Observer 1 Observer 2 Observer 3 Total in which a metallic post was not present. The values for accuracy in Groups groups G1 and G2 are similar to those found in the in vivo study of of teeth T F T F T F T F Youssefzadeh et al (18), who analyzed 42 teeth of patients with a radic- G1 27 13 39 1 30 10 96 24 ular fracture by CT scans. G2 32 8 24 16 37 3 93 27 The values of accuracy found in the present study were slightly G3 20 20 22 18 29 11 71 49 lower than those found in the in vitro studies of Kamburoglu et al G4 27 13 28 12 19 21 74 46 (12), Wenzel et al (15), and Ozer (19). A possible cause for this differ-G1, group without both a metal post and a fracture; G2, group without a metal post and with a hori- ence is that in the present study, a water-filled plastic cylinder 150 mmzontal root fracture; G3, group with a metal post and without a fracture; G4, group with both a metal in diameter  100 mm high and the samples were immersed before thepost and a horizontal root fracture. CBCT examination. This device, which was also used in other studies (20–22), was intended to cause beam attenuation, and, thus, it is likely that its use has leveled those values to the clinic levels.The interobserver agreement on the diagnosis of horizontal root frac- The values for accuracy rates were significantly reduced in groupsture in teeth of groups G1 and G2 was considered moderate to relevant G3 and G4 and exhibited statistically significant differences relative to(k: 0.543–0.645). However, when teeth of groups G3 and G4 were those in groups G1 and G2. These results are similar to those foundanalyzed, the interobserver agreement was considered weak to in the studies of Iikubo et al (14) and Youssefzadeh et al (18) in whichmoderate (k: 0.157–0.453). conventional periapical radiographs were used. In addition, the exami- nation of teeth in these groups was shown to lead to diagnoses with lower Discussion accuracy than in other studies (10, 12, 17, 23) in which digital periapical radiograph systems were used. This is due to artifacts caused by metallic Subtle fractures without separation of the adjacent segments are posts that made it difficult to distinguish the ‘‘beam hardening’’ effectsometimes not detectable using intraoral radiography because of clin- caused by the metallic material inserted within the root from the linesical conditions overlapping anatomic structures and artifacts that can of horizontal fracture in CBCT examination.mimic or hide the fracture lines (12). For this reason, in this In addition to radiographic images, other signals (eg, a change inin vitro study, the root fragments were glued in their original position space corresponding to the periodontal ligament, root-associatedafter induced horizontal fracture. This procedure made the appearance bone loss, and sensitivity during mastication) that can lead to the diag-of the fracture lines similar to that observed in immediate post-trauma nosis of radicular fracture have to be taken into account in clinicalcases and thus difficult to be detected. Recent studies (13, 14) have conditions. Draenert et al (24) stated that the OsiriX software isshown that small-volume CBCT scanning has a high sensitivity and spec- able to produce good-quality images of cancellous bones in theirificity for the detection of root fractures. The influence of FOV during in vivo and in vitro study. After comparison among similar software,CBCT scan is important. This selection is directly related to the voxel Yamauchi et al (25) considered OsiriX a highly functional DICOMsize and influences spatial and contrast resolution (15). Large FOV viewer, which is an important tool for preoperative planning in spineprovides less resolution and contrast in comparison with small FOV surgery. No study was performed with this software in the analysis of(13, 16). This observation confirms our results that showed high radicular fractures.accuracy in samples without a metallic post. However, the intraobserver agreement found in samples withoutmetallic post values was moderate to very high. This variation can be Conclusionexplained by the difficulty of diagnosing this fracture, where there is Our study confirmed that small-volume CBCT has good accuracy inno separation of fragments, even in a small-volume CBCT examination. the detection of horizontal root fracture without metallic posts (valuesOther studies such as those of Wenzel et al (15) and Kamburoglu et al ranging from 73% to 88%). However, their presence significantly(17) compared different voxel sizes, and they also found better results reduced the accuracy (55%–63%). This research found statisticallyin diagnostic accuracy when the smallest voxel size of CBCT was used. significant differences between small-volume CBCT observations of frac-Studies taking into account the interference of metallic objects in small- ture in teeth with or without metallic posts. For this reason, the nullvolume CBCT scans were not yet published. A metallic artifact, especially hypothesis was rejected.TABLE 2. Sensitivity and Specificity Coefficients and Accuracy Rates Calculated on the Diagnosis of a Horizontal Root Fracture in Groups of Teeth without and withMetallic Posts First reading Second reading Observer 1 Observer 2 Observer 3 Observer 1 Observer 2 Observer 3 Sensitivity G1 e G2 0.70 0.65 0.85 0.90 0.55 1 G3 e G4 0.65 0.65 0.40 0.70 0.75 0.55 Specificity G1 e G2 0.60 0.95 0.90 0.75 1 0.60 G3 e G4 0.60 0.45 0.85 0.40 0.65 0.60 Accuracy (%) G1 e G2 73 80 88 75 78 80 G3 e G4 63 55 63 55 70 581458 Costa et al. JOE — Volume 37, Number 10, October 2011
  4. 4. Basic Research—Technology Acknowledgments 13. Hassan B, Metska ME, Ozok AR, van der Stelt P, Wesselink PR. Comparison of five cone beam computed tomography systems for the detection of vertical root frac- The authors deny any conflicts of interest related to this study. tures. J Endod 2010;36:126–9. 14. Iikubo M, Kobayashi K, Mishima A, et al. Accuracy of intraoral radiography, multi- detector helical CT, and limited cone-beam CT for the detection of horizontal tooth root fracture. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; References 108:E70–4. 1. Arai Y, Tammisalo E, Iwai K, Hashimoto K, Shinoda K. Development of a compact 15. Wenzel A, Haiter-Neto F, Frydenberg M, Kirkevang LL. Variable-resolution cone-beam computed tomographic apparatus for dental use. Dentomaxillofac Radiol 1999; computerized tomography with enhancement filtration compared with intraoral pho- 28:245–8. tostimulable phosphor radiography in detection of transverse root fractures in an 2. Tu MG, Huang HL, Hsue SS, et al. Detection of permanent three-rooted mandibular in vitro model. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:939–45. first molars by cone-beam computed tomography imaging in Taiwanese individuals. 16. Use of cone-beam computed tomography in endodontics Joint Position Statement of J Endod 2009;35:503–7. the American Association of Endodontists and the American Academy of Oral and 3. Baratto Filho F, Zaitter S, Haragushiku GA, de Campos EA, Abuabara A, Correr GM. Maxillofacial Radiology. Oral Surg Oral Med Oral Pathol Oral Radiol Endod Analysis of the internal anatomy of maxillary first molars by using different methods. 2011;111:234–7. J Endod 2009;35:337–42. 17. Kamburoglu K, Murat S, Yuksel SP, Cebeci AR, Horasan S. Detection of vertical root 4. Nakata K, Naitoh M, Izumi M, Inamoto K, Ariji E, Nakamura H. Effectiveness of dental fracture using cone-beam computerized tomography: an in vitro assessment. Oral computed tomography in diagnostic imaging of periradicular lesion of each root of Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:e74–81. a multirooted tooth: a case report. J Endod 2006;32:583–7. 18. Youssefzadeh S, Gahleitner A, Dorffner R, Bernhart T, Kainberger FM. Dental vertical 5. Simon JH, Enciso R, Malfaz JM, Roges R, Bailey-Perry M, Patel A. Differential diag- root fractures: value of CT in detection. Radiology 1999;210:545–9. nosis of large periapical lesions using cone-beam computed tomography measure- 19. Ozer SY. Detection of vertical root fractures by using cone beam computed tomog- ments and biopsy. J Endod 2006;32:833–7. raphy with variable voxel sizes in an in vitro model. J Endod 2011;37:75–9. 6. de Paula-Silva FW, Wu MK, Leonardo MR, da Silva LA, Wesselink PR. Accuracy of 20. Katsumata A, Hirukawa A, Okumura S, et al. Relationship between density variability periapical radiography and cone-beam computed tomography scans in diagnosing and imaging volume size in cone-beam computerized tomographic scanning of apical periodontitis using histopathological findings as a gold standard. J Endod maxillofacial region: an in vitro study. Oral Surg Oral Med Oral Pathol Oral Radiol 2009;35:1009–12. Endod 2009;107:420–5. 7. Tsurumachi T, Honda K. A new cone beam computerized tomography system for use 21. Katsumata A, Hirukawa A, Okumura S, et al. Effects of image artifacts on gray-value in endodontic surgery. Int Endod J 2007;40:224–32. density in limited-volume cone-beam computerized tomography. Oral Surg Oral 8. Hassan B, Metska ME, Ozok AR, van der Stelt P, Wesselink PR. Detection of vertical Med Oral Pathol Oral Radiol Endod 2007;104:829–36. root fractures in endodontically treated teeth by a cone beam computed tomography 22. Moreira CR, Sales MA, Lopes PM, Cavalcanti MG. Assessment of linear and angular scan. J Endod 2009;35:719–22. measurements on three-dimensional cone-beam computed tomographic images. 9. Patel S. New dimensions in endodontic imaging: part 2. Cone beam computed Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:430–6. tomography. Int Endod J 2009;42:463–75. 23. Bornstein MM, Wolner-Hanssen AB, Sendi P, von Arx T. Comparison of intraoral10. Wenzel A, Kirkevang LL. High resolution charge-coupled device sensor vs. medium radiography and limited cone beam computed tomography for the assessment of resolution photostimulable phosphor plate digital receptors for detection of root root-fractured permanent teeth. Dent Traumatol 2009;25:571–7. fractures in vitro. Dent. Traumatol 2005;21:32–6. 24. Draenert FG, Gebhart F, Berthold M, Gosau M, Wagner W. Evaluation of deminer-11. Landis JR, Koch GG. Measurement of observer agreement for categorical data. alized bone and bone transplants in vitro and in vivo with cone beam computed Biometrics 1977;33:159–74. tomography imaging. Dentomaxillofac Radiol 2010;39:264–9.12. Kamburoglu K, Cebeci ARI, Grondahl HG. Effectiveness of limited cone-beam 25. Yamauchi T, Yamazaki M, Okawa A, et al. Efficacy and reliability of highly functional computed tomography in the detection of horizontal root fracture. Dent Traumatol open source DICOM software (OsiriX) in spine surgery. J Clin Neurosci 2010;17: 2009;25:256–61. 756–75.JOE — Volume 37, Number 10, October 2011 Horizontal Root Fracture in CBCT 1459