Dental Press

More documents

Recommendations

Info

$Assessment of flexural strength and fracture of ... - Dental Press$

[ original article ] Effect of intracanal posts on dimensions of cone beam computed tomography images of endodontically treated teeth0.2 mm 0.6 mm 1 mm 3 mm 5 mmFigure 7. CBCT images of root canal filling with Gold Alloy Post, in different slice thickness (0.2 mm, 0.6 mm, 1 mm, 3 mm, and 5 mm) in coronalview showing metallic artifact in some slices.DiscussionThe 3D visualization of a tooth and oral structures usingCBCT imaging represents an impressive advance indentistry. In the past, 3D structures were superimposedon periapical radiographs; today, they may be perfectlyassessed using CBCT scans. 2,5,8,9,10,24,29 Periapicalradiographs are the standard method to evaluate rootcanal filling and ICP. However, several authors havedescribed their limitations. 8,9,10 At the same time, highdensity materials may produce image artifacts, whichmay limit interpretation, reduce image quality, and inducediagnostic errors conditions. 3,4,7,12,13,14,16-21,26,27,28Few studies have evaluated imaging artifacts associatedwith ICP. Our findings showed that dimensionalvalues measured on CBCT scans of gold and silver alloyposts are greater than the original specimen measurements(Tables 1 and 2). Beam hardening effectsmay be seen depending of the type of ICP. These resultshave important clinical implications, particularlywhen artifacts cover parts of the root and simulate ormask root pathologies. Therefore, the interpretation ofCBCT scans of teeth reconstructed with ICP must becautiously made, which justifies the use of periapicalradiographs as a reference for endodontic diagnoses.Clinical examinations should always be used as a supportto imaging diagnoses.CBCT measurement tools provide satisfactory informationabout linear distances within an anatomicvolume. 1,8,9,10,15,23,30 However, metal ICP may generateartifacts on reconstructed images, which may affectCBCT measurements. Our results did not show anysignificant differences between gold alloy and silver alloyposts; however, differences between metal, glassfiber and carbon fiber posts were significant (Table 2).The occurrence of imaging artifacts on CBCT scansof metal ICP should always be suspected becauseartifacts may limit image interpretation and characterizepotential risks of misdiagnosis. No significantdimensional differences were found in this studywhen different slice thicknesses were used (Table 2).CBCT reconstructions may have greater image dimensionalvalues, as well as lack of image homogeneityand definition. Other studies have already discussedsimilar findings. 1,4,7,15,17-20,30© 2011 Dental Press Endodontics 34Dental Press Endod. 2011 apr-june;1(1):28-36
Estrela C, Bueno MR, Silva JA, Porto OCL, Leles CR, Azevedo BCCBCT scans of endodontically treated teeth and ICPshould be carefully examined because of the higher densityof metal posts and their capacity to generate imageartifacts. Density artifacts affect diagnostic procedures, 28and beam hardening correction methods have alreadybeen evaluated. Artifacts appear as cupping, streaks,dark bands, or flare artifacts, and are associated withspecial absorption of low-energy photons. 4,7,16-21,26,27,28 Arecent study 3 suggested that the use of a harder energybeam during scanning may result in less artifact formation.The effects of beam hardening-induced cuppingartifacts may also be reduced by using beam filtration. 22Further studies should evaluate the clinical implicationsof metallic artifacts and the strategies tominimize them. Our results revealed that the dimensionsof gold-alloy and silver-alloy ICPs were greateron CBCT scan measurements than on the actualspecimen.AcknowledgmentsThis study was supported in part by grants fromthe National Council for Scientific and TechnologicalDevelopment (CNPq grants #302875/2008-5 andCNPq grants #474642/2009 to C.E.).References1. Anbu R, Nandini S, Velmurugan N. Volumetric analysis of root fillingsusing spiral computed tomography: an in vitro study. Int Endod J.2010;43:64-8.2. Arai Y, Tammisalo E, Iwai K, Hashimoto K, Shinoda K. Developmentof a compact computed tomographic apparatus for dental use.Dentomaxillofac Radiol. 1999;28(4):245-8.3. Azevedo B, Lee R, Shintaku W, Noujeim M, Nummikoski P. Influenceof the beam hardness on artifacts in cone-beam CT. Oral Surg OralMed Oral Pathol Oral Radiol Endod. 2008;105(4):e48.4. Barrett JF, Keat N. Artifacts in CT: recognition and avoidance.Radiographics. 2004;24(6):1679-91.5. Cotton TP, Geisler TM, Holden DT, Schwartz SA, Schindler WG.Endodontic applications of cone-beam volumetric tomography. JEndod. 2007;33:1121-32.6. Demarchi MG, Sato EF. Leakage of interim post and cores used duringlaboratory fabrication of custom posts. J Endod. 2002;28:328-9.7. Duerinckx AJ, Macovski A. Polychromatic streak artifacts incomputed tomography images. J Comput Assist Tomogr.1978;2(4):481-7.8. Estrela C, Bueno MR, Alencar AH, Mattar R, Valladares JNeto, Azevedo BC, et al. Method to evaluate inflammatory rootresorption by using Cone Beam Computed Tomography. J Endod.2009;35(11):1491-7.9. Estrela C, Bueno MR, Azevedo BC, Azevedo JR, Pécora JD. A newperiapical index based on cone beam computed tomography. JEndod. 2008; 34:1325-33.10. Estrela C, Bueno MR, Leles CR, Azevedo B, Azevedo JR. Accuracyof cone beam computed tomography and panoramic andperiapical radiography for detection of apical periodontitis. J Endod.2008;34:273-9.11. Estrela C, Bueno MR, Porto OCL, Rodrigues CD, Pécora JD.Influence of intracanal post on apical periodontitis identified by conebeam computed tomography. Braz Dent J. 2009;20:370-5.12. Haristoy RA, Valiyaparambil JV, Mallya SM. Correlation of CBCT grayscale values with bone densities. Oral Surg Oral Med Oral Pathol OralRadiol Endod. 2009;107(4):e28.13. Herman GT. Image reconstruction from projections: the fundamentalsof computerized tomography. New York: Academic Publishers; 1980.14. Hunter A, McDavid D. Analyzing the Beam Hardening Artifact inthe Planmeca ProMax. Oral Surg Oral Med Oral Pathol Oral RadiolEndod. 2009;107(4):e28-e29.15. Huybrechts B, Bud M, Bergmans L, Lambrechts P, Jacobs R. Voiddetection in root fillings using intraoral analogue, intraoral digital andcone beam CT images. Int Endod J. 2009;42:675-85.© 2011 Dental Press Endodontics 35Dental Press Endod. 2011 apr-june;1(1):28-36
Page 5 and 6: editorialRevolution in scientific i
Page 7: 64. Location of the apical foramen
Page 16 and 17: Endo in EndoOrthodontic treatment d
Page 18 and 19: [ endo in endo ]Orthodontic treatme
Page 24 and 25: [ original article ] A NiTi rotary
Page 30 and 31: original articleEffect of intracana
Page 32 and 33: [ original article ] Effect of intr
Page 40 and 41: [ original article ] Efficacy of ch
Page 48 and 49: original articleIn vitro determinat
Page 50 and 51: [ original article ] In vitro deter
Page 52 and 53: [ original article ] In vitro deter
Page 54 and 55: original articleAnalysis of forces
Page 56 and 57: [ original article ] Analysis of fo
Page 58 and 59: [ original article ] Analysis of fo
Page 60 and 61: original articleRoot canal filling
Page 62 and 63: [ original article ] Root canal fil
Page 64 and 65: [ original article ] Root canal fil
Page 66 and 67: original articleLocation of the api
Page 68 and 69: [ original article ] Location of th
Page 70 and 71: [ original article ] Location of th
Page 72 and 73: [ original article ] In vitro evalu
Page 80 and 81: [ original article ] The persistenc
Page 82 and 83: [ original article ] The persistenc
Page 84 and 85: original articleSEM and microbiolog
Page 86 and 87:
[ original article ] SEM and microb
Page 88 and 89:
[ original article ] SEM and microb
Page 90 and 91:
[ case report ] Influence of cone b
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Information for authors— Dental P
Page 98:
Information for authors1. Registrat
show all

Dental Press

Create successful ePaper yourself

Delete template?

Save as template?