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Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
Computed tomographic imaging in endodontics a short literatue review
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Computed tomographic imaging in endodontics a short literatue review

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  • 1. REVIEW n 27 pyrig No Co ht t fo rP by N ub Q ui lica tio te not nLalit Boruah, Atool Bhuyan, Shashi Tyagi ss e n c e fo rComputed tomographic imaging in endodontics:a short literature review Lalit Boruah, MDS Department of Endodontics, Kothiwal Dental College and Research Centre, Morada- Key words coherence tomography, computed tomography, cone-beam computed tomography, micro- bad, India computed tomography, optical tuned-aperture computed tomography, spiral computed Atool Bhuyan, MDS tomography Professor of Endodontics Department of Endodontics, Regional Dental College, Guwahati, India This paper reviews the literature concerning computed tomography and other modalities such as spiral computed tomography, micro-computed tomography, cone-beam computed tomography, Shashi Tyagi, MDS Professor of Endodontics tuned-aperture computed tomography and optical coherence tomography in endodontics. Among Department of Endodontics, the plethora of imaging modalities currently available, these recent imaging systems tend to draw Kothiwal Dental College and Research Centre, Morada- attention from the clinicians. But still there is a lack of evidence-based data on the radiation dose bad, India and patient selection criteria for these imaging modalities, which calls for a set of guidelines to be Correspondence to: introduced for their use in clinical practice in the future. Lalit Boruah Department of Endodontics Kothiwal Dental College and Research Centre Kanth Road Moradabad – 244001 India Tel: 0591 2452994/5 0975 881 8222 Email: drlalitboruah@gmail.comn Introduction including conventional and spiral micro-CT, CBCT (cone-beam computed tomography), OCT (opticalWithin the last 20 years, diagnostic digital imag- coherence tomography) and TACT (tuned-apertureing modalities in dentistry, including periapical, computed tomography). Recently, these modalitiesbitewing, panoramic and cephalometric imaging, have been used in diagnosis of endodontic lesion,have been replacing conventional (film-based) identification of root canal systems and postopera-radiography. Drawbacks of two-dimensional (2-D) tive evaluation1,2.imaging include: inherent magnification, distortionand overlap of anatomy. As early as the 1920s,manufacturers attempted to overcome the inherent n Computed tomographyproblems of 2-D imaging by devising movementof the receptor and source in opposite directions Computed tomography uses a fan-shaped beam andto produce tomographic ‘slices’ of oral and max- a multiple exposure around an object to reveal itsillofacial anatomy. This process is termed ‘linear’ internal architecture. In this way the clinician canor ‘multidirectional tomography’, and it led to view morphologic features as well as pathology fromthe introduction of CT (computed tomography), different three-dimensional perspectives3. ENDO (Lond Engl) 2010;4(1):27–40
  • 2. 28 n Boruah et al CT imaging in endodontics pyrig No Co ht t fo rP by N CT in endodontic applications was first reported instrumentation with different rotary nickel-titanium ub Q ui by Tachibana and Matsumoto in 19904. They (NiTi) systems lica 11. However, if radio-opaque materials ti reported that CT had only limited usefulness in are present, there can be scattering and creation of on te ot n endodontics owing to inadequate image detail and fo r artefacts, which can significantly hamper e n c e ss visualisa- high cost. However, one distinct advantage of CT tion3. CT used to evaluate root canals prepared by is that it allows for 3-D reconstruction of root canal nickel titanium and stainless steel hand endodontic systems (RCSs)5. Three-dimensional information, instruments showed that the imaging system used along with tactile feedback during instrumentation, in this study provided a repeatable non-invasive gives the clinician a more thorough understanding of method of evaluating certain aspects of endodontic the true morphology of RCSs. instrumentation12. Some CT software programs add colour-enhance- Spiral CT used for volumetric analysis of root fill- ment features to highlight pathologic lesions from ing concluded that the greatest percentage of obtu- normal anatomic structures. CT images have the rated volume was obtained with System B (93.3%) ability to show slices of a given tissue, with each and Thermafil® (93.7%) as compared to Obtura II slice thickness and location chosen by the operator; (84.8%) and lateral compaction (80.4%)13. therefore CT would enable the operator to look at Another study that compared high-resolution CT multiple slices of tooth roots and their RCSs3. CT has with conventional radiography in regard to detection been suggested as the preferential imaging modal- of endodontic lesions and their relation to impor- ity in difficult situations demanding localisation and tant anatomic structures such as mandibular canal description of RCSs because of its ability to render concluded that use of CT provides additional 3-D 3-D information6. information14. Robinson et al6 evaluated mandibular first premo- Three-dimensional images from spiral computed lars on 120 routine dental CT images for variations in tomography (CT) aided in evaluating the close rela- root/RCS morphology. They identified two RCSs in 16 tionship between maxillary sinus disease and adja- mandibular first premolars. Panoramic evaluation of cent periodontal defects and their treatment15. The the same teeth demonstrated that five of these teeth possibility of using low-dose, low-cost CT to obtain appeared uniformly radio-opaque at all root levels, anatomic information to plan periradicular surgery which might suggest the presence of only one RCS. via the vestibular approach was explored success- They reported that CT images identified a greater fully16. number of morphologic variations than did a pano- CT may play an important role in optimising ramic radiograph. Their suggestion was that anatomic palatal root-end surgery through vestibular access information and unusual RCS configuration should with regard to precision and preventing complica- always be presented whenever a report on dental tions and with relatively low biological and eco- CT is performed. A high correlation was established nomic cost. It may also contribute to the affirma- between the shape of the root canal and the corre- tion of the new surgical procedure. Ebihara et al sponding root and different instrumentations7,8. incorporated 3-D reconstruction in the diagnosis Spiral computed tomography has proved to be and monitoring of a case of Garee’s osteomyelitis useful in accurate diagnosis of a case of dens invagi- managed by root canal treatment of a mandibular natus and its successful management9. Spiral CT has second molar17. been found to be very useful in detection of radix Traditional radiographs could only determine the entomolaris cases (Figs 1–3). mesiodistal extent of the pathology and not the buc- Peripheral quantitative computed tomography colingual extent18. Trope et al used CT scans for the (pQCT) for qualitative and quantitative analysis of first time in 1989 in the differentiation of radicular root canal anatomy and for assessing the extent of cysts and granulomas. A cyst could be differentiated canal enlargement during root canal instrumentation from periapical granulomas by CT scans because of a shows promise10. marked difference in density between the content of Computed tomography (CT) has been used to the cyst cavity and granulomatous tissue19. Another compare the volume of root canals before and after recent study attempted to investigate the course of ENDO (Lond Engl) 2010;4(1):27–40
  • 3. Boruah et al CT imaging in endodontics n 29 pyrig No Co ht t fo rP by N ub Q ui lica tio te otn n ss e n c e fo rFig 1 Intraoral periapical radiograph of tooth 36. Fig 2 Digital radiograph of tooth 36. a bFig 3a and b Spiral CT images of tooth 36 showing an extra distal root (radix entomolaris).the inferior alveolar canal within the alveolar process n Micro-computed tomographyusing panoramic radiography and CT, with ground (micro-CT)truth determined by cadaveric dissection. CT wasfound to be accurate20. Micro-CT has been evaluated in endodontic imag- Nair and Nair21 and Cotton et al22 reviewed the ing. Comparision of the effects of biomechanicaluse of CT scans in the diagnosis of periapical lesions. preparation on canal volume on reconstructed rootA major concern with the use of CT scanning is its canals in vitro using micro-CT has been shown tohigh radiation dosage. In a study23, guidelines by assist with characterisation of morphological changesCristoph et al24 were used. With these, effective radi- associated with these techniques16,25.ation dosage reduced to 0.56 0.06 mGy, which is Micro-CT evaluation of morphological changesequivalent to a standard panoramic radiograph. The in the apical third of root canals using three instru-results of the study indicate that CT scanning and mentation techniques concluded that stainless steelultrasound with power Doppler flowmetry can pro- hand preparation was less conservative of apicalvide an additional or alternative, but more accurate, dentine, and also there is less canal transportationdiagnosis of periapical lesion with validity equivalent with rotary nickel-titanium (ProFile®, ProTaper® andto histopathological diagnosis. FlexMaster®) files26. ENDO (Lond Engl) 2010;4(1):27–40
  • 4. 30 n Boruah et al CT imaging in endodontics pyrig No Co ht t fo rP by N ub Q ui lica tio te ot n n ss e n c e fo r Fig 4 i-CAT® CBCT system (Imaging Sciences Interna- Fig 5 3-D Accuitomo CBCT system (J. Morita USA, Inc., tional, Hatfield, USA). Irvine, USA). Gu et al investigated the anatomic features of In vitro evaluation of the relative performance the isthmus in the mesial root of mandibular first of FlexMaster® nickel-titanium instruments in shap- molars using micro-computed tomography scans in ing maxillary molar root canals, employing micro- a Chinese population. Each tooth was scanned and computed tomography (micro-CT) at a resolution reconstructed, and then the prevalence and type of of 36 micrometres, was done to find out prepara- isthmus were recorded in three different age groups. tion errors32.The behaviour of the instrument under It was observed that the percentage of isthmuses bending or torsional loads was analysed on the decreased with increasing age27. basis of 3-D images produced by micro-CT scanned Investigation of the apical anatomy of C-shaped images33. canal systems in mandibular second molars by micro- Cutting behaviour of nickel-titanium rotary computed tomography (micro-CT) and stereomicro- instruments with and without irrigation was evalu- scopy concluded that apical anatomy of C-shaped ated in a bovine bone model. Irrigation increased root canal systems in mandibular second molars is the cutting efficiency of the instruments significantly, extremely complex with many anatomical varia- except for Liberator. The cutting behaviour of NiTi tions28. rotary instruments depends on experimental set-up, Micro-computed tomography is a new and instrument design and cutting condition34. objective means of quantitative evaluation of root Micro-CT data were used to compare the effects canal instrumentation29. A study using non-destruc- of four preparation techniques on canal volume and tive high-resolution scanning tomography to assess surface area using three-dimensionally reconstructed changes in the canals’ paths after preparation con- root canals in extracted human maxillary molars. cluded that the variations in canal geometry before Within the limitations of the micro-CT system, there preparation had more influence on the changes dur- were few differences between the four canal instru- ing preparation than the techniques themselves30. mentation techniques used35. The availability of 3-D information and a relatively Measurement of the remaining filling volume of high resolution and significantly lower dose makes it different obturation materials from root-filled teeth, the imaging modality of choice in challenging situ- extracted using two removal techniques, were as ations demanding localisation and characterisation follows: teeth were scanned with a micro-computed of root canals. Potential applications in endodontics tomography scan and then root fillings were removed include diagnosis and evaluation of most aspects of by using ProTaper® retreatment files or hand K-files. endodontic treatment, such as determination of the Teeth were scanned again, and volume measure- configuration and length of root canals and the pres- ments were carried out with micro-computed tom- ence of accessory canals31. ography software. The study showed that all tested ENDO (Lond Engl) 2010;4(1):27–40
  • 5. Boruah et al CT imaging in endodontics n 31 pyrig No Co ht t fo rP by Nfilling materials were not completely removed during ufacturer into as many as 512 axial-slice images. ub Q uiretreatment by using hand or rotary files36. These images are in the Digital Imaging and Com- lica tio Comparision of the volumetric expansion of munications in Medicine (DICOM) data format. t ess c e n ot n fo rgutta-percha in the presence of eugenol or physi- DICOM is a standard for handling, storing, printing enologic saline over time was studied on the basis of and transmitting information in medical imaging.images scanned by micro-CT to determine their total During a single rotation of the source and receptor,volume and surface area. Sealers that incorporate the receptor captures the entire volume of anatomyeugenol could be attributed to gutta-percha volu- within the field of view40,41.metric expansion over time, thereby creating a better CBCT can be seen as a highly useful and indis-seal of the obturation material37. pensable part of the dental imaging armamentar- Micro-CT imaging of filled root canals showed it ium1,42. It appears to be an effective and safe wayto be a highly accurate and non-destructive method to overcome some of the problems associated withof evaluation of root canal fillings and their constitu- conventional radiography43.ents. Qualitative and quantitative correlation between Perhaps the greatest improvement in the spe-histological and micro-CT examination of root canal cialty, relative to treatment planning endodonticfillings was high27,38,39. A micro-CT study compared failures, is the advent of cone-beam computedthe volume of hard tissue change following endodon- tomography (CBCT) imaging. The traditional pro-tic procedure and post space preparation. It concluded jection radiograph is a two-dimensional shadow ofthat access cavity and post space preparation results in a Z Plane object. Three-dimensional imaging over-the largest loss of hard tissue, which is larger for cast comes this major limitation by allowing us to visu-post than fibre post preparation40. alise the third dimension, while at the same time The broad-based use of high-quality free soft- eliminating superimpositions. CBCT, also called dig-ware and the resulting exchange of experience might ital volume tomography, is a new technique thathelp to improve the quality of endodontic research produces 3-D digital imaging at reduced cost withwith micro-computed tomography41. less radiation for the patient in comparison with tra- ditional CT scans1. It also delivers faster and easier image acquisition42.n Cone-beam computed Ludlow and colleagues reported that the effec- tive dose equivalent measured after an exposure tomography (CBCT) using indirect digital panoramic imaging was 6–7Volumetric CT or CBCT, a relatively new diagnos- microSieverts. The effective dose equivalent istic imaging modality, has been used in endodontic the amount of radiation received after taking intoimaging recently. This modality uses a cone beam account the tissue’s sensitivity to radiation. Theinstead of a fan-shaped beam, acquiring images of effective dose equivalent measured using CBCT isentire volume. The radiation beam, is 3-D in shape between 30 and 400 μSv, depending on the manu-and similar in photon energy to that used in conven- facturer and technical factors involved. This com-tional and digital radiography. The receptor captures pares with an effective dose equivalent of 2100 μSv2-D images and is solid-state (digital) or an image from a conventional medical CT scan of the maxillaintensifier. Solid-state receptors absorb photons that and mandible43.are converted to an electric charge, which is meas- An outstanding review by Cotton et al reportedured by the computer. Image intensifiers capture on the many possible endodontic applications ofphotons and convert them to electrons that con- CBCT22. It offers relatively high resolution and iso-tact a fluorescent screen that emits light captured tropic images for effective evaluation of root canalby a charge-coupled device camera. As the source morphology44. In a comparative study, Huybrechtsand receptor orbit once around the object, many et al reported that CBCT can detect voids in root fill-exposures are made, ranging in duration from 8.9 to ings that were larger than 300 μm. For smaller void40 seconds. The software ‘reconstructs’ the sum of detection, all digital intraoral techniques performedthe exposures via algorithms specified by the man- better than CBCT imaging45. ENDO (Lond Engl) 2010;4(1):27–40
  • 6. 32 n Boruah et al CT imaging in endodontics pyrig No Co ht t fo r in by N The value of cone-beam tomographyPu clinical bi Q ui endodontics for identification of complex root lcanal cat anatomy is increasing47. ion te ot n ss e n e fo r Simons et al reported that the CBCT mightcpro- vide more accurate diagnostic information than biopsy and histology when evaluating large periapi- cal lesions24. Rigolone et al used CBCT technology to measure the mean distance of the palatal root of the max- illary molar from the external vestibular cortex of the maxilla. They concluded that CBCT might have an important role in the decision to perform peri- radicular surgery on the palatal root of the maxillary molar through a vestibular-vs-palatal approach16. The anatomical structures, such as root canals and side canals, and communications between different root canals, as well as denticles, could be detectedFig 6a CBCT image of maxillary molar (3-D Accuitomo. i-dixel. One Data Viewer – precisely with FD-VCT (flat-panel-detector volume-J. Morita USA). computed tomography). The length of curved root canals was also determined accurately. The spatial CBCT has been used successfully in endodon- resolution of the system is around 140 μm. None tics for different purposes including study of root of the side canals, shown with FD-VCT, was detect- canal anatomy; external and internal macro-mor- able on conventional X-rays48. It is possible to calcu- phology in 3-D reconstruction of the teeth; evalu- late root-curvature radius in both apical and coronal ation of root canal preparation, obturation, retreat- directions with the help of CBCT-aided methods. ment and coronal micro-leakage; detection of bone That is easy to perform, reproducible, and more reli- lesion; and experimental endodontology46. able and predictable than endodontic planning49. In endodontics, it is difficult at times for clinicians to evaluate the extent of inferior cortical border ero- sion of the maxillary sinus, or of associated mucosal thickening extending to the periapical region of the roots of maxillary teeth, using 2-D periapical imaging, owing to superimposition of structures. At spatial resolutions of 300 μm (0.3 mm) and less, images produced with CBCT show the position of the apexes of roots of maxillary teeth extending to the nasal cavity and maxillary sinus, as well as corti- cal border erosion of these structures resulting from apical rarefying osteitis43. A large number of studies with different diag- nostic methods, including CBCT, have evaluated the type and incidence of periapical lesions, root fractures, root canal anatomy and the nature of the alveolar bone topography around teeth19,50–53. Sci- entific consensus has been reached about the fact that apical periodontitis (AP) is identified accuratelyFig 6b CBCT image of maxillary molar – X axis revolutions (3-D Accuitomo. i-dixel. by histologic analyses. Few studies have comparedOne Data Viewer – J. Morita USA). the difference in AP image interpretation by using ENDO (Lond Engl) 2010;4(1):27–40
  • 7. Boruah et al CT imaging in endodontics n 33 pyrig No Co ht t fo rP by NCBCT conventional periapical radiography or digital ub Q uiradiography. CBCT has provided promising results lica tiowith more accurate detection of apical periodon- te ot n ntitis14,22,54. Estrela et al compared periapical radi- ss e n c e fo rography and CBCT scanning for the preoperativediagnosis of apical periodontitis and concluded thata tomographic scan more accurately identified theapical periodontitis55. The findings of an investigation demonstratedthat CBCT images present high accuracy for thedetection of apical periodontitis (AP). CBCT imagestend to offer higher scores than periapical and pan-oramic radiographs, suggesting that diagnosis ofgraduation of AP with conventional images is fre-quently underestimated. AP was correctly identifiedin 54.5% of the cases with periapical radiograph and27.8% with panoramic radiograph. Accuracy of peri-apical radiograph was significantly higher than that Fig 6c CBCT image of maxillary molar – Z axis revolutions (3-D Accuitomo. i-dixel. One Data Viewer – J. Morita USA) (images courtesy of Prof V. Kumar).of panoramic radiograph. AP was correctly identifiedwith conventional methods when a severe conditionwas present55, 56. Influence of root canal obturationon apical periodontitis at different levels detected by be useful in the evaluation of inflammatory rootperiapical radiography and CBCT showed that AP resorption and its diagnosis performance was bet-was detected more frequently by CBCT57. CBCT cor- ter (100%) compared with periapical radiographyrectly identified periapical lesions in 100% of cases, (68.8%)62.as compared to 24.8% with intraoral conventional The diagnosis and three-dimensional imagingradiography, of artificial periapical bone defects in assessment of the resorption is important in order todry human jaws58. Simon et al, in 2006, used Gray determine the treatment complexity and expectedvalues obtained by cone-beam CT scans to differen- outcome based on the location and extension of thetially diagnose 17 large periapical lesions and dem- root defect with the potential use of the NewTom 3Gonstrated that cone-beam computed tomography (CBCT system) for root resorption63.can determine the difference in density between the Computed tomography, magnetic resonancecystic cavity content and the granulomatous tissue, imaging and cone-beam computed tomography arefavouring the choice of a non-invasive diagnosis59. among the most commonly used systems for dental Unfavourable outcomes occurred more fre- and maxillofacial surgery. CBCT, in particular, hasquently after one-visit therapy than two-visit ther- potential in the diagnosis and treatment of dento-apy when determined by CBCT scans60. alveolar traumatic injuries64. Velvart et al correlated the information gathered CBCT scans are desirable to assess posteriorfrom standard dental radiography and resolution teeth prior to periapical surgery, as the thickness ofCBCT scans to the findings obtained during surgery the cortical and cancellous bone can be determinedregarding the presence of endodontic lesions in 50 accurately, as can the inclination of roots in relationpatients. All 78 lesions diagnosed during surgery to the surrounding jaw. The relationship of anatomi-were also visible with CBCT scans. In contrast, only cal structures such as the maxillary sinus and inferior61 (78.2%) lesions were identified by conventional dental nerve to the root apices may also be clearlyradiographs14. visualised50,65. Another study demonstrated the application of Using the FD-VCT, vertical root fractures or crackcone-beam computed tomography in the diagno- lines could be detected clearly in different views, depic-sis of iatrogenic root perforation61. CBCT seems to tion modes and cross-sections at a spatial resolution of ENDO (Lond Engl) 2010;4(1):27–40
  • 8. 34 n Boruah et al CT imaging in endodontics pyrig No Co ht t fo rP by N 140 μm. The evaluation of the fracture lines and teeth the irradiation doses and costs are negligible, the ub Q ui could be performed in three-dimensional views66. VCT cost–benefit ratio could swing in favour of this ltech- ica tio was used to visualise vertical root fractures in extracted nology16. te ot n n teeth. Vertical root fractures were successfully detected ss e n c e fo r In conclusion, evaluation of CBCT images always at a spatial resolution of 140 μm66. resulted in a greater number of RCSs identified than CBCT was better than conventional radiography evaluation with PSP or CCD images in vitro56. for the diagnosis of root fractures, thereby constitut- Examples of currently available CBCT units include: ing an excellent alternative for diagnosis67. 3D Accuitomo FPD XYZ Slice View Tomograph® Comparison of the accuracy of CBCT scans and (J. Morita USA, Inc., Irvine, USA), 3D X-ray CT Scan- periapical radiographs in detecting vertical root frac- ner Alphard series (Asahi Roentgen Industrial Co., tures (VRFs) and to assess the influence of root canal Kyoto, Japan) and Quolis Alphard-3030-Cone- filling (RCF) on fracture visibility showed an overall Beam (Belmont Equipment, Somerset, USA). In addi- higher accuracy for CBCT (0.86) scans than for PRs tion, some digital panoramic radiographic systems (0.66) for detecting VRFs68. include CBCT technology43. Stavropoulos and Wenzel verified intraoral digital and conventional film radiography in mechanically cre- ated periapical defects in pig jaws. The results showed n Optical coherence tomography that the NewTom 3G has a higher sensitivity69. (OCT) Regarding CBCT images, the presence of intra- canal metallic post might lead to equivocated OCT is a new diagnostic imaging technology that interpretation as a result of artefact formations56. was first introduced in 199172. Modern imaging Lofthag-Hansen et al reported that when metallic techniques are clinically applied during root canal objects are present in either the tooth of interest or treatment, as important information about inner the adjacent one, artefacts can pose difficulties in the canal anatomy and dentine thickness is still limited analysis of images. In these cases periapical radio- to in vitro observations. graphs are helpful to complement the diagnosis70. One difficulty in treating oval or curved canals A positive factor in the choice of CBCT is the like lower incisors is the chance of strip perforations production of high-resolution images. CBCT images because of the short distance between the inner provide the clinician with submillimetre spatial resolu- canal wall and the periodontal ligament. In these tion images of high quality with relatively short scan- zones, clinicians often face the challenge of cleaning ning times (10–70 s) and a radiation dose equivalent and enlarging the root canal space sufficiently, while to that needed for 4–15 panoramic radiographs. not perforating the mesial or distal walls. OCT com- However, image quality might vary according to the bines the principles of an ultrasound with the imag- CBCT source56. ing performance of a microscope, although ultra- A great advantage of using CBCT in endodontics sound produces images from back-scattered sound is its usefulness in aiding identification of periapical echoes. OCT uses infrared light waves that reflect lesions, and a differential diagnosis with a non-inva- off the internal microstructure within the biological sive technique with high accuracy concluded that the tissues. Using the principle of low-coherence inter- prevalence of AP was significantly higher with CBCT ferometry, it achieves depth resolution of the order in comparison with periapical and panoramic radio- of 10 μm and in a plane resolution similar to the graphs. In an advanced stage, CBCT was demon- optical microscope. By scanning the probe along the strated to be an accurate diagnostic method for iden- imaged specimen while acquiring image lines, a two- tifying AP56. Simonton et al used CBCT to evaluate dimensional or three-dimensional image is built up. age- and gender-related differences in the position of The OCT light source has a wavelength of 1300 nm. the inferior alveolar nerve, and it was concluded that Visible light that has a shorter wavelength is prone the overall width of mandibular bone decreased in to a higher level of scattering and absorption and both genders from the third to the sixth decade of life produces shallower imaging depth36. The frequency (P < .01)71. Rigolone et al suggested that although and bandwidths of infrared light are significantly ENDO (Lond Engl) 2010;4(1):27–40
  • 9. Boruah et al CT imaging in endodontics n 35 pyrig No Co ht t fo rP by Nhigher than medical ultrasound signals, resulting in were successfully shown with different computed ub Q uiincreased image resolution53,73. In endoscopic OCT tomographic techniques. These methods use ionis- lica tioimaging, near-infrared lighting is delivered to the ing radiation, which could be harmful at higher doses t ess c e n ot n fo rimaging site (usually blood vessels) through a thin when used in vivo. enfibre. The imaging tip contains a lens prism assembly Furthermore, two major disadvantages are limit-to focus the beam and direct it towards the vessel ing the successful application of these methods forwall. The fibre can be retracted inside the catheter intracranial imaging. First, the resolution is usually notsheath to perform a so-called ‘pullback’, allowing suitable for microscopic-level imaging; digital dentalthe user to make a stack of cross-sections, scanning radiography systems have a pixel size approachingthe investigated vessels lengthwise. Modern OCT 100 μm. Second, the probe sizes are usually muchsystems reach a 6 mm imaging depth, with 8-μm bigger than a root canal. These methods are alsoresolution at 50 to 80 frames per second74. time-consuming and often require the interpretation OCT potential in dentistry was not overlooked. of thousands of images. In contrast, OCT combinesOCT images of hard and soft tissues in the oral cavity a very narrow optical fibre measuring 0.5 mm inwere compared with the histologic images using an diameter with high-resolution capacities, enablinganimal model showing an excellent match75. A study imaging of the object measuring a few micrometres,to directly position the tip of the endoscope fibre in and does not involve ionising radiation. The imagingthe root canal via a navigation system concluded that wire can be deployed independently or integratedthe application of the endoscopic navigation system straightforwardly into existing therapeutic or imag-could increase the success rate for root canal treat- ing catheters. Furthermore, it can easily fit into a pre-ments with recalcitrant lesions76. pared root canal and is flexible, allowing penetration In another study, Otis et al discussed the clear through curvatures. The optical probe rotates insidedepiction of periodontal tissues contour, sulcular depth, the image vessel so that adjacent lines in each rota-connective tissue attachment and marginal adaptation tion compose a frame showing a cross-section of theof restorative material to dentine, concluding that OCT tissue architecture in the wall; thus scanning is quickis a powerful method for generating high-resolution and takes 15 s for a 15-mm-long root74.cross-sectional images of oral structure77. Amaechi et aland Baumgartner et al described the recognition of car-ies with OCT78,79. OCT could provide the dentist with n Tuned-aperture computedan unprecedented level of image resolution to assist in tomography (TACT)the evaluation of periodontal disease, dental restora-tions and detection of caries. Commercial development TACT is a flexible 3-D imaging method that convertsof a chair-side OCT dental system is already underway any number of 3-D projections produced from any(www.lantislaser.com)74. Excellent correlation between number of arbitrary or unknown projection sourcethe histologic images and the OCT output is observed positions and angles into a true 3-D image. Thefrom results of a study74. OCT images provided the image produced is similar to viewing the originalinsight into dentinal substrate about 0.65 mm deep and object with unlimited visual access through a win-can generate images of the boundaries of pulp and its dow or aperture whose size is determined by therelation to dentine. original projection. It is a software-driven imaging OCT can be used in the future to prevent iatro- innovation for intra- and extraoral procedures, whichgenic exposure of pulp, complementing other exist- can produce 3-D concepts of the teeth or structuresing methods, and will permit a more predictive prog- within the recorded region. Such 3-D displays couldnosis of treatments80. be useful for caries/demineralisation detection. The New computed tomography methods prove to be displays are useful in the determination of root frac-more accurate in the evaluation of the bone lesions tures, especially vertical fractures. Such sophisticatedthan conventional radiography8. Similarly, canal mor- techniques will also allow better perception of signifi-phology44, root fracture46, tooth anatomy31 and the cant periodontal lesions. Three-dimensional technol-interface between the root canal and filling materials ogy enables reconstructions, with suitable enhance- ENDO (Lond Engl) 2010;4(1):27–40
  • 10. 36 n Boruah et al CT imaging in endodontics pyrig No Co ht t fo rP by NTable 1 Comparative Machine name ub Q uianalysis of currently licaavailable CBCT systems tio(as mentioned by man- Machine Next Classic NewTom NewTom VG ILUMA Kodak 9000 3D te not nufacturers – Imaging name generation i-CAT 30047 ULTRA CBCT ss e n c e fo rSciences International, i-CAT@Hatfield, USA)86. Manufacturer Imaging Imaging Dent-X / Dent-X / IMTEC / IMTEC / Kodak Sciences Sciences AFP Imaging AFP Imaging Kodak Dental Dental Systems International International Systems Gray scale 14 bit 14 bit 12 bit 14 bit 14 bit 14 bit Footprint 1.2 m x H 1.83 m x H 1.5m x H 2.28m x H 1.06m x L 2.3m x 1.16 m W 1.12 m x W 1.9m x W 1.14m x W 1.42m x W 1.15m x D 1.27 m D 2.5m D 1.49m D 2.15m D 1.75m Image detec- Amorphous Amorphous l.l. + CCD Amorphous Amorphous CMOS sensor tor silicon flat silicon flat camera silicon flat silicon flat with optical panel panel panel panel fibre 20 cm x 5 cm Rotation single single single 360° single 360° single 360° single 360° per scan rotation rotation rotation rotation Patient posi- seated seated supine sitting/ seated standing tioning standing/ wheelchair Pre-installed i-CAT Xron Cat NNT Dolphin ILUMA Kodak imaging software visionTM Vision & imaging & Vision 3D software 3DVR 3 DVR NNT Scan time 8.5 s 20 s 36 s 18 s 20–40 s 130 – standard scan standard 13.9 s Scan 8.23 cm 16 cm 20–15–10 cm 16 cm 17–19 cm 5 cm diameter diameter field of view Scan 4–17 cm 13 / 22 cm 20 cm 14 cm 10–19 cm 3.8 cm height height field of view Scan 0–1.25 mm 0.12–0.4 mm 0.1 – 0.2–0.5 mm 0.09 mm 0.076 mm thickness – 0.4 mm 0.5 mm (0.3 type) ENDO (Lond Engl) 2010;4(1):27–40
  • 11. Boruah et al CT imaging in endodontics n 37 pyrig No Co ht t fo rP by N Machine name ub Q ui lica tioCB Mercu- Gendex 3D Accui- Prexion Planmeca Galileos Picasso Picasso te ot n n Masterss e n c eRay GXCB- tomo 3D Promex 3D Trio SC fo r 500TM StandardHitachi Gendex J. Morita Prexion Inc. Planmeca Sirona EWOO Tech- EWOO TechnologiesMedical USA Dental nologiesSystems Systems12 bit 14 bit 12 bit 16 bit 12 bit 12 bit 12 bit 14 bitH 2.25m x 1.2m x H 2.08m x H 2m x H 1.53m x H 2.00m x H 2.2m x H 1.9m xW 1.96m x 1.6m W 1.62m x W 1.49m x W 1.07m x W 1.60m x W 1.8m x W 1.3m xD 1.9m D 1.2m D 0.99m D 1.25m D 1.60m D 1.1m D 1.5mImage inten- Amorphous CMOS flat Csl flat panel CMOS Proprietary Csl coated Amorphoussifier CCD silicon flat panel flat panel Seimens CMOS flat silicon flat panel technique panel panelsingle single single single single 200° single single 360° single 360° 360° shots rotation rotationseated seated seated seated seated / standing / standing seated standing sittingCB Works i-CAT i-Dixel Tera Recon Romexis/ SIDEXIS / Easy Dent Easy Dent visionTM Xtrillion N-Liten GALAXIS Ezimplant Ezimplant IC 3DVR10 s 8.9 s stand- 18 s or less 19 cm – 2.5–18.7 s 14 s 15 s / 24 s 24 s ard scan 360° scan, 37 cm 9s25 cm 8–14 cm field 6/4 cm 8 cm 8 cm 15 cm 12 cm 20 cm of view15–30 cm 4–8cm height 6 / 4 cm 8 cm 8 cm 15 cm 7 cm 19 cm field of view0.1–0.5 mm 0.125 mm – 0.09 mm 0.1 mm variable isotropic 0.1 mm – 0.1 mm – 0.4 mm & up starting at voxel size: 1.0 mm 1.0 mm 16 mm 0, 3/ 0, 15 mm ENDO (Lond Engl) 2010;4(1):27–40
  • 12. 38 n Boruah et al CT imaging in endodontics pyrig No Co ht t fo Grande NM, Plotino G, Pecci R, Bedini R,r Pameijer CH, by N ment and refining of the digital image, from up to 8. Pu bli Q ui Somma F. Micro-computerized tomographic analysis of seven images of the region of interest at different radicular and canal morphology of premolars with longcoval ati angles. At the moment, the development of TACT canals. Oral Surg Oral Med Oral Pathol Oral Radiol Endod on te ot n in dentistry is centred on using a panoramic system 2008;106:70-76. ss e n c e fo r 9. Reddy YP, Karpagavinayagam K, Subbarao CV. Manage- as the radiation source81,82,83. ment of dens invaginatus diagnosed by spiral computed tomography: a case report. J Endod 2008;34:1138-1142. TACT is a relatively new 3-D imaging modality 10. Sberna MT, Rizzo G, Zacchi E, Capparè P, Rubinacci A. A with the significant advantages that the doses are preliminary study of the use of peripheral quantitative com- relatively low; no expensive equipment is required; puted tomography for investigating root canal anatomy. Int Endod J 2009; 42:66-75. image acquisition is relatively simple; artefacts 11. Ozgur Uyanik M, Cehreli ZC, Ozgen Mocan B, Tasman associated with CT, such as starburst patterns Dagli F. Comparative evaluation of three nickel-titanium instrumentation systems in human teeth using computed seen with metallic restorations, do not exist; and tomography. J Endod 2006; 32:668-671. resolution is as good as conventional 2-D radio- 12. Gambill JM, Alder M, del Rio CE. Comparision of nickel- titanium and stainless steel hand-file instrumentation using graphs. It was noted that root canals were easier computed tomography. J Endod 1996;22:369-375. to detect on TACT images than on conventional 13. Anbu R, Nandini S, Velmurugan N. Volumetric analysis of root fillings using spiral computed tomography: an in vitro radiographs84. study. Int Endod J 2010;43:64-68. 14. Velvart P, Hecker H, Tilinger G. Detection of apical lesion and mandibular canal in conventional radiography and com- puted tomography. Oral Surg Oral Med Oral Pathol Oral n Conclusion 15. Radiol Endod 2001;92:682-688 Huang CH, Brunsvold MA. Maxillary sinusitis and peri- apical abscess following periodontal therapy: a case Several advanced radiography techniques for the report using three-dimensional evaluation. J Periodontol precise detection of lesions and root canal systems 2006;77:129-134. 16. Rigolone M, Pasqualini D, Bianchi L, Berutti E, Bianchi SD. have been in use in endodontics, namely CT, CBCT, Vestibular surgical access to the palatine root of the superior TACT and micro-CT for in vitro studies and OCT first molar. ’Low-dose cone-beam’ CT analysis of the path- way and its anatomic variations. J Endod 2003;29:773-775. (experimental). The use of these novel imaging tech- 17. Ebihara A, Yoshioka T, Suda H. Garre’s osteomyelitis man- niques is gaining a lot of attention in the field of aged by root canal treatment of mandibular second molar: incorporation of computed tomography with 3D reconstruc- endodontics85, but the need of the hour is to develop tion in diagnosis and monitoring of the disease. Int Endod J a cost-effective, chair-side, three-dimensional imag- 2005;38:255-261. 18. Kaffe I, Gratt BM. Variation in radiographic interpretation of ing system for routine use with standard radiation periapical dental lesion. J Endod 1988; 14:330-334. dose protocols and clinical guidelines. 19. Trope M, Pettigrew J, Petras J et al. Differentiation of radicu- lar cyst and granuloma using computerized tomography. Endod Dent Traumatol 1989;5:69-72. 20. Sato I, Ueno R, Kawai T, Yosue T. Rare courses of the man- dibular canal in the molar regions of the human mandible: a n References cadaveric study. Okajimas Folia Anat Jpn 2005;82:95-101. 1. Tyndall DA, Rathore S. Cone-beam CT diagnostic applica- 21. Nair MK, Nair UP. Digital and advanced imaging in endo- tions: caries, periodontal bone assessment, and endodontic dontics: a review. J Endod 2007;33:1-6. applications. Dent Clin North Am 2008;52:825-841. 22. Cotton TP, Geisler TM, Holden DT, Schwartz SA, Schindler 2. Nielsen AB, Alayssin AM, Peters DD, Carnes DL, Lancster WG. Endodontic application of cone beam volumetric tom- J. Microcomputed tomography: an advanced system for ography. J Endod 2007;33;1121-1132. detailed endodontic research. J Endod 1995;21:561-568. 23. Agarwal V, Logani A, Shah N. Evaluation of computed tom- 3. Brooks SL. Computed tomography. Dent Clin North Am ography scans and ultrasound in the differential diagnosis of 1993;37:575-590. periapical lesions. J Endod 2008;34:1312-1332. 4. Tachibana H, Matsumutu K. Applicability of X-ray compu- 24. Christoph GD, Wilfried GH, Britta R et al. Must radiation terized tomography in endodontics. Endod Dent Traumatol dose for CT of the maxilla and mandible be higher than 1990;6:16-20. that for panoramic radiography? Am Soc Neuroradiol 5. Peters OA, Laib A, Ruegsegger P, Barbakow F. Three-dimen- 1996;96:1709-1758. sional analysis of root canal geometry using high resolution 25. Jung M, Lommel D, Klimek J. The imaging of root canal computed tomgraphy. J Dent Res 2007;79:1405-1409. obturation using micro-CT. Int Endod J 2005;38:617-626. 6. Robinson S, Czerny C, Gahleinter A, Bernhart T et al. Dental 26. Moore J, Fitz-Walter P, Parashos P. A micro-comput- CT evaluation of mandibular first premolar root configura- ed tomographic evaluation of apical root canal prepara- tions and canal variation. Oral Surg Oral Med Oral Pathol tion using three instrumentation techniques. Int Endod J Oral Radiol Endod 2002;93:328-332. 2009;42:1057-1064. 7. Dowker SEP, Davis GR, Elliot JC. X-ray microtomography: 27. Gu L, Wei X, Ling J, Huang X. A microcomputed tomo- n1on-destructive three-dimensional imaging for in vitro graphic study of canal isthmuses in the mesial root of endodontic studies. Oral Surg Oral Med Oral Pathol Oral mandibular first molars in a Chinese population. J Endod Radiol Endod 1997;83:510-516. 2009;35:353-356. ENDO (Lond Engl) 2010;4(1):27–40
  • 13. Boruah et al CT imaging in endodontics n 39 pyrig No Co ht t fo rP by N28. Cheung GS, Yang J, Fan B. Morphometric study of the api- 49. Estrela C, Bueno MR, Sousa-Neto MD, Pécora JD. Method for ub Q ui cal anatomy of C-shaped root canal systems in mandibular determination of root curvature radius using cone-beam com- lica second molars. Int Endod J 2007;40:239-246. puted tomography images. Braz Dent J 2008;19:114-118. tio29. Bergmans L, Van Cleynenbreugel J, Wevers M, Lambrechts 50. Yousseef S, Gahleitner A, Dorffner R et al. Dental verti- t ess c e n ot n PA. Methodology for quantitative evaluation of root canal cal root fracture: value of CT in detection. Radiology fo r instrumentation using microcomputed tomography. Int 1999;210:545-549. en Endod J 2001;34:390-398. 51. Nair PNR, Pajarola G, Schroeder HE. Types and inci-30. Peters OA, Laib A, Göhring TN, Barbakow F. Changes in dence of human periapical lesions obtained with extracted root canal geometry after preparation assessed by high- teeth. Oral Surg Oral Med Oral Pathol Oral Radiol Endod resolution computed tomography. J Endod 2001;27:1-6. 1996;81:93-102.31. Plotino G, Grande NM, Pecci R et al. Three-dimensional 52. Laux M, Abott PV, Nair PNR, Pajarola G. Apical inflamma- imaging using micro-computed tomography for studying tory root resorption: a correlative radiographic and histologi- macromorphology. J Am Dent Assoc 2006;137:1555-1561. cal assessment. Int Endod J 2003;33:483-488.32. Hübscher W, Barbakow F, Peters OA. Root-canal preparation 53. Low AF, Tearney GJ, Bouma BE, Jang JK. Technology with FlexMaster: canal shapes analysed by micro-computed insight: optical coherence tomography: current status tomography. Int Endod J 2003;36:740-747. and future development. Nat Clin Pract Cardivasc Med33. Kim TO, Cheung GS, Lee JM, Kim BM, Hur B, Kim HC. 2006;3:154-164. Stress distribution of three NiTi rotary files under bending 54. Nataka K, Naitoh M, Izumi M, Inamoto K, Ariji E, Naka- and torsional conditions using a mathematic analysis. Int mura H. Effectiveness of dental computed tomography Endod J 2009;42:14-21. in diagnostic imaging of periradicular lesion of each root of34. Shen Y, Haapasalo MJ. Three-dimensional analysis of cutting a multirooted tooth: a case report. J Endod 2006; behavior of nickel-titanium rotary instruments by microcom- 32:583-586. puted tomography. J Endod 2008;34:606-610. 55. Estrela C, Bueno MR, Leles CR et al. Accuracy of cone beam35. Peters OA, Schönenberger K, Laib A. Effects of four Ni-Ti prep- computed tomography for detection of apical periodontitis. aration techniques on root canal geometry assessed by micro- J Endod 2008;34:273-279. computed tomography. Int Endod J 2001;34:221-230. 56. Matherene R, Angelopolous C, Kulild JC. Use of cone beam36. Hammad M, Qualtrough A, Silikas N. Three-dimensional computed tomography to identify root canal system in vitro. evaluation of effectiveness of hand and rotary instrumenta- J Endod 2008;34:87-89. tion for retreatment of canals filled with different materials. 57. Moura MS, Guedes OA, De Alencar AH et al. Influence J Endod 2008;34:1370-1373. of length of root canal obturation on apical periodontitis37. Michaud RA, Burgess J, Barfield RD, Cakir D, McNeal SF, detected by periapical radiography and cone beam com- Eleazer PD. Volumetric expansion of gutta-percha in contact puted tomography. J Endod 2009;35:805-809. with eugenol. J Endod 2008;34:1528-1532. 58. Patel S, Dawood A, Mannocci F, Wilson R, Pitt Ford T.38. Gullaume B, Lacoste JP, Gabroit N et al. Microcomputed Detection of periapical bone defects in human jaws using tomography used in the analysis of morphology of root cone beam computed tomography and intraoral radiogra- canals in extracted wisdom teeth. Br J Oral Maxillofac Surg phy. Int Endod J 2009; 42:507-515. 2006;44:240-244. 59. Simon JH, Enciso R, Malfaz JM et al. Differential diagnosis of39. Cotti E, Campisi G. Advanced radiographic techniques for detec- large periapical lesion using cone beam computed tomogra- tion of lesions in bone. Endodontic Topics 2004;7:52-57. phy and biopsy. J Endod 2006;32:833-837.40. Ikram OH, Patel S, Sauro S, Mannocci F. Micro-computed 60. Garcia de Paula-Silva FW, Hassan B, Bezerra da Silva LA, tomography of tooth tissue volume changes following Leonardo MR, Wu MK. Outcome of root canal treatment in endodontic procedures and post space preparation. Int dogs determined by periapical radiography and cone-beam Endod J 2009;42:1071-1076. computed tomography scans. J Endod 2009;35:723-726.41. Gao Y, Peters OA, Wu H, Zhou X. An application framework 61. Young GR. Contemporary management of lateral root per- of three-dimensional reconstruction and measurement for foration diagnosed with the aid of dental computed tomog- endodontic research. J Endod 2009;35:269-274. raphy. Aust Endod J 2007;33:112-118.42. Buchanan LS. Ahead of the curve: future directions in endo- 62. Estrela C, Bueno MR, De Alencar AHG, Mattar R, Neto VJ, dontics. Dent Today 2009;28:110-114. Azevedo BC, Estrela De Arauzo CR. Method to evaluate43. Patel S, Dawood A, Whaites E, Pitt Ford T. New dimensions inflammatory root resorption by using cone beam computed in endodontic imaging. Part 1: Conventional and alternative tomography. J Endod 2009;35:1491-1497. radiographic systems. Int Endod J 2009;42:447-462. 63. Cohenca N, Simon JH, Mathur A, Malfaz JM. Clinical indi-44. Taylor C, Geisler TM, Holden DT et al. Endodontic appli- cations for digital imaging in dento-alveolar trauma. Part 2: cation of cone beam volumetric tomography. J Endod root resorption. Dent Traumatol 2007;23:105-113. 2007;33:1121-1132. 64. Cohenca N, Simon JH, Roges R, Morag Y, Malfaz JM.45. Huybrechts B, Bud M, Bergmans L, Lambrechts P, Jacobs R. Void Clinical indications for digital imaging in dento-alveo- detection in root fillings using intraoral analogue, intraoral digital lar trauma. Part 1: traumatic injuries. Dent Traumatol and cone beam CT images. Int Endod J 2009;42:675-685. 2007;23:95-104.46. Eder A, Kantor M, Nell A et al. Root canal system of 65. Patel S, Dawood A, Ford TP, Whaites E. The potential applica- mesiobuccal root of maxillary first molar: an in vitro com- tions of cone beam computed tomography in the management parison of computed tomography and histology. Dentomax- of endodontic problems. Int Endod J 2007;40:818-830. illofac Radiol 2006;35:175-177. 66. Hannig C, Dullin C, Hülsmann M, Heidrich G. Three-47. Cleghorn BM, Christie WH, Dong CC. Anomalous mandibu- dimensional, non-destructive visualization of vertical root lar premolars: a mandibular first premolar with three roots fractures using flat panel volume detector computer and a mandibular second premolar with a C-shaped canal tomography: an ex vivo in vitro case report. Int Endod J system. Int Endod J 2008;41:1005-1014. 2005;38:904-913.48. Heidrich G, Hassepass F, Dullin C, Attin T, Grabbe E, Han- 67. Bernardes RA, de Moraes IG, Duarte MA, Azevedo BC, nig C. [Non-destructive, preclinical evaluation of root canal de Azevedo JR, Bramante CM. Use of cone-beam volumetric anatomy of human teeth with flat-panel detector volume CT tomography in the diagnosis of root fractures. Oral Surg Oral (FD-VCT)]. Rofo 2005;177:1683-1690. [article in German] Med Oral Pathol Oral Radiol Endod 2009;7:904-913. ENDO (Lond Engl) 2010;4(1):27–40
  • 14. 40 n Boruah et al CT imaging in endodontics pyrig No Co ht t fo r Rogers JA, by N 68. Hassan B, Metska ME, Ozok AR, van der Stelt P, Wesselink 78. Amaechi BT, Higham SM, Podoleanu AG, P ub Q ui PR. Detection of vertical root fractures in endodontically Jackson DA. Use of optical coherence tomography for li Oral treated teeth by a cone beam computed tomography scan. assessment of dental caries: quantitative procedure. cat J Endod 2009;35:719-722. Rehabil 2001;28:1092-1093. ion te ot n 69. Stavropoulos A, Wenzel A. Accuracy of cone beam dental 79. Baumgartner A, Dichtl S, Hitzenberger CK et al.s e n c e s Polarization- fo r CT, intraoral digital and conventional radiography for the sensitive optical coherence tomography of dental structures. detection of periapical lesions: an ex-vivo study in pig jaws. Caries Res 2003;34:59-69. Clin Oral Investig 2007;11:101-106. 80. Braz Ana KS, Kyotoku Bernado BC, Gomes Anderson SL. 70. Lofthag-Hansen S, Hummonen S, Grondahl H-G. Limited In vitro tomographic image of human pulp-dentin com- cone beam CT and intraoral radiography for the diagnosis of plex: optical coherence tomography and histology. J Endod periapical pathology. Oral Surg Oral Med Oral Pathol Oral 2009;35:1218-1221. Radiol Endod 2007;92:682-688. 81. Webber RL, Messura JK. An in vivo comparision of diag- 71. Simonton JD, Schindler WG, Hargreaves KM. Age and gen- nostic information obtained from tuned aperture computed der-related differences in the position of the inferior alveolar tomography and conventional dental radiographic imaging nerve by using cone beam computed tomography. J Endod modalities. Oral Surg Oral Med Oral Pathol Oral Radiol 2009;35:944-949. Endod 2003;96:223-228. 72. Huang D, Swanson EA, Lin CP et al. Optical coherence tom- 82. Nance R, Tyndall D, Levin LG. Identification of root canals in ography. Science 1991;254:1178-1181. molars by tuned aperture computed tomography. Int Endod 73. Schmitt JM. Optical coherence tomography (OCT): a review. J 2000;33:392-396. IEEE J Sel Top Quantum Electron 1999;5:1205-1215. 83. Nair MK, Nair UDP, Grondahl HG et al. Detection of artifi- 74. Shamesh H, Soest GV, Wu MK et al. The ability of optical cially induced vertical radicular fractures using tuned aperture coherence tomography to characterize the root canal walls. computed tomography. Eur J Oral Sci 2001;109:375-379. J Endod 2007;33:1369-1373. 84. Nair MK. Diagnostic accuracy of tuned aperture computed 75. Colston BW Jr, Everett MJ, Sathyam US et al. Imaging of the tomography (TACT). Swed Dent J Suppl 2003;159:1-93. oral cavity using optical coherence tomography. Monogr 85. Howerton WB Jr, Mora MA. Advancements in digital imag- Oral Sci 2000;17:32-55. ing: what is new and on the horizon? J Am Dent Assoc 76. Yamazaki Y, Ozawa T, Ogawa T et al. Treatments. Stud 2008;139:20S-24S. Health Technol Inform 2008;132:562-564. 86. Cone Beam Newsletter. Comparison between currently 77. Ottis LL, Everett MJ, Sathyam US, Colston BW Jr. Optical available CBCT systems. www.conebeam.com. coherence tomography: a new imaging technology for den- tistry. J Am Dent Assoc 2000;131:511-514. ENDO (Lond Engl) 2010;4(1):27–40

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