ACTA ODONTOLOGICA LATINOAMERICANAactaodontologicalat.com/wp-content/uploads/2020/06/331.pdfRicardo...

ACTA ODONTOLOGICALATINOAMERICANAVol. 33 Nº 1 2020

ISSN 1852-4834 on line versionversión electrónica

Scientific EditorsEditores CientíficosMaría E. ItoizRicardo Macchi(Universidad de Buenos Aires, Argentina)

Associate EditorsEditores AsociadosAngela M. Ubios(Universidad de Buenos Aires, Argentina)Amanda E. Schwint(Comisión Nacional de Energía Atómica, Argentina)

Assistant EditorsEditores AsistentesPatricia MandalunisSandra J. Renou(Universidad de Buenos Aires, Argentina)

Technical and Scientific AdvisorsAsesores TécnicoCientíficosLilian Jara TracchiaLuciana M. SánchezTammy SteimetzDelia Takara(Universidad de Buenos Aires, Argentina)

Editorial BoardMesa EditorialEnri S. Borda (Universidad de Buenos Aires, Argentina)Noemí E. Bordoni (Universidad de Buenos Aires, Argentina)

Fermín A. Carranza (University of California, Los Angeles, USA)

José Carlos Elgoyhen (Universidad del Salvador, Argentina)

Andrea Kaplan (Universidad de Buenos Aires, Argentina)Andrés J.P. KleinSzanto (Fox Chase Cancer Center, Philadelphia, USA)

Susana Piovano (Universidad de Buenos Aires, Argentina)Guillermo Raiden (Universidad Nacional de Tucumán, Argentina)

Sigmar de Mello Rode (Universidade Estadual Paulista,Brazil)

Hugo Romanelli (Universidad Maimónides, Argentina)Cassiano K. Rösing (Federal University of Rio Grande do Sul, Brazil)

PublisherProducción Gráfica y PublicitariaImageGraf / email: [email protected]

Acta Odontológica Latinoamericana is the officialpublication of the Argentine Division of the InternationalAssociation for Dental Research.

Revista de edición argentina inscripta en el RegistroNacional de la Propiedad Intelectual bajo el N° 284335.Todos los derechos reservados.Copyright by:ACTA ODONTOLOGICA LATINOAMERICANAwww.actaodontologicalat.com

ACTA ODONTOLÓGICA LATINOAMERICANAAn International Journal of Applied and Basic Dental Research

POLÍTICA EDITORIAL

El objetivo de Acta OdontológicaLatinoamericana (AOL) es ofrecer a lacomunidad científica un medio adecuadopara la difusión internacional de los trabajos de investigación, realizados preferentemente en Latinoamérica, dentro delcampo odontológico y áreas estrechamente relacionadas. Publicará trabajos originales de investigación básica, clínica yepidemiológica, tanto del campo biológico como del área de materiales dentales ytécnicas especiales. La publicación de trabajos clínicos será considerada siempreque tengan contenido original y no seanmeras presentaciones de casos o series. Enprincipio, no se aceptarán trabajos de revisión bibliográfica, si bien los editorespodrán solicitar revisiones de temas departicular interés. Las ComunicacionesBreves, dentro del área de interés de AOL,serán consideradas para su publicación.Solamente se aceptarán trabajos no publicados anteriormente, los cuales no podránser luego publicados en otro medio sinexpreso consen timiento de los editores.

Dos revisores, seleccionados por lamesa editorial dentro de especialistas encada tema, harán el estudio crítico de losmanuscritos presentados, a fin de lograr elmejor nivel posible del contenido científico de la revista.

Para facilitar la difusión internacional,se publicarán los trabajos escritos eninglés, con un resumen en castellano o portugués. La revista publicará, dentro de laslimitaciones presupuestarias, toda información considerada de interés que se lehaga llegar relativa a actividades conexasa la investigación odontológica del árealatinoamericana.

EDITORIAL POLICY

Although Acta Odontológica Lati noamericana (AOL) will accept originalpapers from around the world, the principal aim of this journal is to be an instrumentof communication for and among LatinAmerican investigators in the field of dental research and closely related areas.

AOL will be devoted to original articlesdealing with basic, clinic and epidemiological research in biological areas or thoseconnected with dental materials and/orspecial techniques.

Clinical papers will be published aslong as their content is original and notrestricted to the presentation of singlecases or series.

Bibliographic reviews on subjects ofspecial interest will only be published byspecial request of the journal.

Short communications which fall within the scope of the journal may also besubmitted. Submission of a paper to thejournal will be taken to imply that it presents original unpublished work, not underconsideration for publication elsewhere.

By submitting a manuscript the authorsagree that the copyright for their article istransferred to the publisher if and whenthe article is accepted for publication. Toachieve the highest possible standard inscientific content, all articles will be refereed by two specialists appointed by theEditorial Board. To favour internationaldiffusion of the journal, articles will bepublished in English with an abstract inSpanish or Portuguese.

The journal will publish, within budgetlimitations, any data of interest in fieldsconnected with basic or clinical odontological research in the Latin America area.

Este número se terminó de editar el mes de Junio de 2020

Vol. 33 Nº 1 / 2020 ISSN 1852-4834 Acta Odontol. Latinoam. 2020

CONTENTS / ÍNDICE

Precision and accuracy of four current 3D Printers to achieve models for Fixed Dental ProsthesisPrecisão de quatro impressoras 3D para obtenção de modelos para prótese fixaBianca S. Reis, Fernando F. Portella, Elken G. Rivaldo ................................................................................................................................................................................................................................................ 3

Use of Antibiotics in early Childhood and Dental Enamel Defects in 6 to 12yearold Children in Primary Health CareUso de antibióticos na primeira infância e defeitos de esmalte dentário em crianças de 6 a 12 anos na Atenção Primária à SaúdeDaniel D. FaustinoSilva, Ariston F. Rocha, Bruno S. da Rocha, Caroline Stein.......................................................................................................................................................................................................... 6

Radiographic Diagnosis of Simulated External Root Resorption in MultiRooted Teeth: The Influence of Spatial ResolutionDiagnóstico radiográfico de reabsorção externa simulada em dentes multiradiculares: influência da resolução especialMariane F. L. S. Lacerda, Rafael B. Junqueira, Thaísa M. G. Lima, Carolina O. Lima, Caroline F. M. Girelli, Francielle S. Verner.......................................................................................................................... 14

Vestibular Alveolar bone height measurement: Accuracy and Correlation between direct and indirect techniquesMedición de la altura del hueso alveolar vestibular: precisión y correlación entre técnicas directa e indirectaGuillermo PérezSánchez, Maykel GonzálezTorres, Mario A. GuzmánEspinosa, Víctor HernándezVidal, Bernardo TeutleCoyotecatl, Luz V. MendozaGarcía, Angeles MoyahoBernal.............................. 22

Is it necessary to pretreat Dentine before GIC Restorations? Evidence from an in Vitro StudyÉ necessário pré tratar a dentina antes das restaurações de CIV? Evidência de um estudo in vitroJulio C. Bassi, Tamara K. Tedesco, Daniela P. Raggio, Ana Maria A. Santos, Renata M. D. Bianchi, Giselle R. de Sant’Anna ................................................................................................................................ 27

Internal Lower Incisor Morphology revealed by Computerized MicrotomographyMorfologia interna de incisivos inferiores reveladas por microtomografía computadorizadaCarolina O. Lima, Lorena T. A. Magalhães, Marília F. MarcelianoAlves, Patrícia Y. de Oliveira, Mariane F. L. S. Lacerda .................................................................................................................................... 33

Odontogenic Infection and dental Pain negatively impact Schoolchildren’s Quality of LifeInfecção odontogênica e odontalgia impactam negativamente a qualidade de vida de crianças escolaresRenata M. LamenhaLins, Maria C. CavalcantiCampêlo, Cláudia R. CavalcanteSilva, Kelly RodriguesMota, Carlos V. LeãoOliveira, Patrícia B. LopesNascimento, Mônica VilelaHeimer, Valdeci E. SantosJúnior .......................................................................................................................................................................................................................................................... 38

Decontamination of Guttapercha Cones employed in EndodonticsDescontaminação de cones de gutapercha empregados em endodontiaClairde S. Carvalho, Moara S. C. Pinto, Samuel F. Batista, Patrick V. Quelemes, Carlos A. M. Falcão, Maria A. A. L. Ferraz.................................................................................................................................. 45

Effect of Obesity and/or Ligatureinduced Periodontitis on Aortic Wall Thickness in Wistar RatsEfeito da obesidade e/ou periodontite induzida por ligadura na espessura da parede da aorta em ratos wistarAndressa G. Moreira, Alessandra C. Nicolini, Eduardo J. Gaio, Fernanda Visioli, Cassiano K. Rösing, Juliano Cavagni .......................................................................................................................................... 50

Acta Odontol. Latinoam. 2020 ISSN 1852-4834 Vol. 33 Nº 1 / 2020

ACTA ODONTOLÓGICA LATINOAMERICANAAn International Journal of Applied and Basic Dental Research

Contact us Contactos: Cátedra de Anatomía Patológica, Facultad de Odontología, Universidad de Buenos Aires.M.T. de Alvear 2142 (C1122AAH) Buenos Aires, Argentina.http://www.actaodontologicalat.com/[email protected]

ACTA ODONTOLÓGICA LATINOAMERICANAA partir del Volumen 27 (2014) AOL se edita en formato digital con el Sistema de Gestión de Revistas Electrónicas (Open Journal System, OJS). La revista es de accesoabierto (Open Access). Esta nueva modalidad no implica un aumento en los costos de publicación para los autores.

Comité Editorial

ACTA ODONTOLÓGICA LATINOAMERICANAFrom volume 27 (2014) AOL is published in digital format with the Open Journal System (OJS). The journal is Open Access. This new modality does not implyan increase in the publication fees.

Editorial Board

RESUMOO objetivo desse trabalho foi comparar a acurácia e a precisãode impressoras 3D utilizadas para a obtenção de modelos paraprótese fixa. Um preparo para prótese fixa foi escaneado ereproduzido por 4 impressoras 3D: RapidShape 3D, Asiga MAX,Varseo e Photon. As impressões foram novamente escaneadas, eo dataset escaneado foi comparado ao original. Os esca neamentos foram sobrepostos digitalmente e determinada adiscrepância entre os modelos original e impresso. A discre

pância média (µm) entre os modelos foi de foi 52,97±20,48(RapidShape 3D), 68,27±43,53 (Asiga MAX), 62,22±56,21(Varseo) e 80,03±28,67 (Photon). Não houve diferença(p=0,314) entre os valores médios, os quais representam aacurácia; entretanto, o desvio padrão dessas foi diferente(0,015), indicando diferença na precisão das impressoras 3D.

Palavraschave: modelos dentários, prótese dentária, impressãotridimensional.

INTRODUCTIONThe use of digital workflow in rehabilitationtreatments is rapidly increasing. Given the practi cality, biological safety, and comfort for the patientand health professional, this technology hasgradually been replacing conventional workflowusing stone models. Additive manufacturing (3Dprinting) enables the fabrication of provisionalrestorations and reliable preparations1. The accuracyand precision of these models are related to the finalfit of prosthetic parts and, consequently, to thelongevity of the restoration. Threedimensionalprinters using the Direct Light Processing (DLP)technique have demonstrated good precision inobtaining dental models2. The impressions shouldbe identical to the preparations (accuracy) and, ifrepeatedly printed, they should always have thesame dimensions (precision). Recently, a wide

variety of 3D printers has been introduced on thedental market, requiring technical assessments3.The present study was therefore designed tocompare the accuracy and precision of four 3Dprinters used to obtain models of fixed dentalprostheses.

MATERIAL AND METHODSAn acrylic resin model of a maxillary canine wasprepared for a complete crown and then scanned(Trios, 3Shape S/A, Copenhagen, Denmark). Basedon the generated dataset file (STL), models of thetooth were obtained from the impressions createdusing four 3D printers (Table 1). The specimens(n=8 for each printer) were scanned with a highprecision scanner (S600 ARTI, Zirkonzahn GmbH,Gais, Italy). The STLs that generated the impressionswere superimposed on the STLs of the printed

ABSTRACTThe aim of this study was to compare the accuracy and precisionof 3D printers used to obtain models of fixed dental prostheses. Afixed dental prosthesis preparation was scanned and reproducedby four 3D printers: RapidShape P40, Asiga MAX, Varseo, andPhoton. The impressions were scanned again, and the datasetwas compared to the original dataset. Mean discrepancies (µm)were 52.97±20.48 (RapidShape P40), 68.27±43.53 (Asiga MAX),

62.22±56.21 (Varseo), and 80.03±28.67 (Photon). There was nodifference (p=0.314) in accuracy; however, the precision differed(p=0.015) among the 3D printers. The printers had distinctprecision but did not differ in accuracy.Received: November 2019; Accepted March 2020.

Keywords: dental models, dental prosthesis, threedimensionalprinting.

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Vol. 33 Nº 1 / 2020 / 3-5 ISSN 1852-4834 Acta Odontol. Latinoam. 2020

Precision and accuracy of four current 3D Printers to achieve models for Fixed Dental Prosthesis

Bianca S. Reis1, Fernando F. Portella2, Elken G. Rivaldo1

1 Universidade Luterana do Brasil. Graduate Program in Dentistry, Canoas, RS, Brazil.2 Universidade Feevale, Novo Hamburgo, RS, Brazil.

Precisão de quatro impressoras 3D para obtenção de modelos para prótese fixa

models using a specific software system (MeshLab2016.12, Visual Computing Laboratory, Italy).Based on the overall superimposition preparedtooth, the discrepancies between the measurementswere calculated by the Hausdorff method4 and then qualitatively categorized according to theirlocation. Incisal, mesial, distal, buccal and lingual

areas were inspected for presence or absence ofmisfit (dichotomously, independently of the misfitarea) and data were described in terms of misfitprevalence on each surface. The misfit was definedby the presence of red areas on superimposedimages of original STL and STL of the printedmodels. Red areas mean that printed models arelarger than original tooth. The mean overalldiscrepancy values of the 3D printed models werecompared by KruskalWallis test. The homogeneityof discrepancy variance was analyzed by theLevene test; differences in this analysis refer to theprecision of the printer. The level of significancewas set at 5% for all analyses.

RESULTSThe mean discrepancy (µm) and standard deviationsamong the models were 52.97±20.48 (RapidShapeP40), 68.27±43.53 (Asiga MAX), 62.22±56.21(Varseo), and 80.03±28.67 (Photon), as shown inFig. 1. Discrepancy values present a nonGaussiandistribution, and are shown in Table 1. There was no difference (p=0.314) in mean values, which

4 Bianca S. Reis, et al.

Acta Odontol. Latinoam. 2020 ISSN 1852-4834 Vol. 33 Nº 1 / 2020 / 3-5

Fig. 1: Discrepancies (µm) ± standard deviation according to3D printer. The circle indicates the mean value (accuracy) andthe whiskers indicate the 95% confidence interval (precision).There was no difference in accuracy (p=0.587), but precisionvaried among printers (p=0.015).

Fig. 2: Example of misfit (red areas) of models. A. no misfit; B.discrete misfit on the proximal surface; C. severe misfit on thebuccal and proximal surfaces.

Fig. 3: Misfit (%) of models according to 3D printer and toothsurface.

Table 1: Detailed discrepancy values measured according printer evaluated.

Printer Mean* ± sd# Minimum discrepancy measured (µm) Maximum discrepancy measured (µm)

RapidShape P40 52.97±20.48 31.86 84.65

Asiga MAX 68.27±43.53 29.59 126.57

Varseo 62.22±56.21 19.42 156.83

Photon 80.03±28.67 43.75 115.06

*arithmetic mean; #standard deviation of mean

represent accuracy; however, the standard deviationdistribution was distinct (0.015), which means that precision was different among the 3D printers.Fig. 2 shows images of superimposed original STLfiles on 3D printed models. Colors close to greenindicate minimal discrepancy, while red areasindicate regions of greater superimposition. Fig. 3shows the prevalence of discrepancies according totooth surface.

DISCUSSIONAccuracy did not differ among the tested 3Dprinters, ranging from 52.97±20.48 to 80.03±28.67µm. These values are consistent with the resolutionsindicated by the manufacturers. Considering thedistribution of these values, we can infer that ispossible that all 3D printers can reproduce detailsin accordance with the ISO 6873 requirements for dental gypsum products, which establish aminimum detail reproduction of 75±8 µm for types1 and 2 dental materials and of 50±8 µm for gypsumtypes 3, 4, and 5. The variability, given by thestandard deviation, refers to the precision of the 3D printers, indicating that the most precise printer(the one with the lowest standard deviation for themean value of discrepancy among models revealedby Levene test) was the one manufactured byStraumann.The differences in precision could be related to thedistinct resolutions, especially in the Z plane4.

Larger deviations associated with the 3D printedmodel may be due to the thickness and shrinkagebetween the layers of the material that occur in theZ plane and to contraction of the material causedby postcuring4. The shrinkage in the Z plane mayalso be the cause of the higher prevalence of discre pancies on the incisal surface of the preparation.Positive discrepancies in this region, even withoutcausing marginal misfit of prosthetic parts, maycompromise the longevity of the restoration as aresult of greater thickness of the cement line.The large standard deviations of discrepancy valuesshould be considered upon evaluation of the datapresented. They are related to the precision of theprinter, but random errors of methods used couldalso be present. Thus, the data presented in thisstudy should be considered cautiously. Futureclinical studies are welcome to evaluate the efficacyof oral rehabilitations where digital workflow ispart of treatment.Overall, all tested 3D printers appear to havesufficient accuracy and precision to be used in thedigital workflow for patient rehabilitation. However,it should be noted that 3D printers with lowerprecision are more likely to lead to the misfit ofprosthetic parts and consequently, to rework.

CONCLUSIONThe printers had distinct precision but did not differin accuracy.

Precision and accuracy of four dental 3D printers 5


FUNDINGNone

CORRESPONDENCEDr. Fernando PortellaRua Residencial Village 7B, Esteio, RS, Brazil. CEP [email protected]

REFERENCES1. Barazanchi A, Li KC, AlAmleh, B, Lyons K, Waddell JN.

Additive Technology: Update on Current Materials andApplications in Dentistry. J Prosthodont 2016; 26:156163.

2. Kim SY, Shin YS, Jung HD, Hwang CJ, Baik HS, Cha JY.Precision and trueness of dental models manufactured withdifferent 3dimensional printing techniques. Am J OrthodDentofacial Orthop 2018; 153:144153.

3. Alharbi N, Wismeijer D, Osman RB. Additive Manu facturing Techniques in Prosthodontics: Where Do WeCurrently Stand? A Critical Review. Int J Prosthodont 2017;30:474484.

4. Sim JY, Jang Y, Kim WC, Kim HY, Lee DH, Kim JH.Comparing the accuracy (trueness and precision) of modelsof fixed dental prostheses fabricated by digital andconventional workflows. J Prosthodont Res 2019; 63:2530.

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RESUMOOs defeitos do esmalte dentário (DED) são lesões que ocorremdevido a vários fatores e é necessária atenção para promoverseu tratamento e prevenção. O objetivo foi avaliar a ocorrênciade DED em dentes permanentes de crianças que usaramantimicrobianos nos primeiros quatro anos de vida. Tratasede um estudo transversal realizado em um serviço de AtençãoPrimária à Saúde (APS), que incluiu crianças de seis a 12 anosde idade. A DED foi avaliada por dados de exames bucais, eos dados sobre o uso de antimicrobiano na primeira infânciaforam coletados com base em prontuários médicos. A análisefoi realizada com o teste do quiquadrado e o teste exato deFisher. A amostra foi composta por 144 crianças. Em relação

ao DED, 50%(72) e 20,1%(29) apresentaram opacidade ehipoplasia, respectivamente. A amoxicilina foi o medicamentoprescrito com mais freqüência, seguido pelo sulfametoxazol+trimetoprim. Entre as crianças, 78,5%(113) receberam medica mentos antimicrobianos pelo menos uma vez nos primeiros 4 anos de vida e 55%(79) deles apresentaram algum tipo de DED. Não houve associação estatisticamente significanteentre as variáveis analisadas. Em conclusão, houve uma altaprevalência de crianças com DED e a amoxicilina foi oantibiótico mais comumente prescrito.

Palavraschave: hipoplasia do esmalte dentário, atençãoprimária à saúde, antibacterianos, amoxicilina, saúde bucal.

INTRODUCTIONOnce dental enamel has formed, it lacks metabolicactivity, which means that any disorders that occurduring its development may be manifested as

permanent defects in erupted teeth1. Such enameldefects are changes that may affect one tooth onlyor a group of similar teeth, in both dentitions2.Disorders in the early secretory phase of the

ABSTRACTDental enamel defects (DED) are lesions that occur due severalfactors. Proper care is needed to promote their treatment and prevention. The aim of this study was to evaluate theoccurrence of DED in permanent teeth of children who usedantimicrobial drugs in the first four years of life. This is a crosssectional study carried out in a Primary Health Care (PHC)service, which included children from six to 12 years of age.DED were evaluated by oral examination, and data on the useof antimicrobials in early childhood were collected based onmedical records. Data were analyzed with the chisquare testand Fisher’s exact test. The sample included 144 children. Inrelation to DED, 50% (72) and 20.1% (29) presented opacity

and hypoplasia, respectively. Amoxicillin was the mostfrequently prescribed drug, followed by sulfamethoxazole +trimethoprim. Among the children, 78.5% (113) were prescribedantimicrobial drugs at least once during the first 4 years of life,and 55% (79) of them presented some type of DED. There wasno statistically significant association between the variablesanalyzed. In conclusion, there was high prevalence of childrenwith DED, and amoxicillin was the most commonly prescribedantibiotic. Received: December 2019; Accepted: January 2020

Keywords: dental enamel hypoplasia, primary health care,antibacterial agents, amoxicillin, oral health.

Use of Antibiotics in early Childhood and Dental Enamel Defects in 6- to 12-year-old Children in Primary Health Care

Daniel D. Faustino-Silva1, Ariston F. Rocha1, Bruno S. da Rocha2, Caroline Stein3

1 Grupo Hospitalar Conceição – Serviço de Saúde Comunitária; Programa de Pós-Graduação em Avaliação de Tecnologias para o Sistema Único de Saúde (SUS), Rio Grande do Sul, Brasil.

2 Universidade Federal do Rio Grande do Sul, Hospital de Clínicas de Porto Alegre, Programa de Pós-graduação em Ciências Médicas: Endocrinologia, Rio Grande do Sul, Brasil.

3 Universidade Federal do Rio Grande do Sul, Programa de Pós-graduação em Odontologia, Rio Grande do Sul, Brasil.

Uso de antibióticos na primeira infância e defeitos de esmalte dentário em crianças de 6 a 12 anos na Atenção Primária à Saúde

amelogenesis matrix are likely to appear asquantitative or morphological defects (hypoplasia),whereas interruptions in the processes of calcifi cation or maturation may produce morphologicallynormal enamel which is nevertheless structurally or qualitatively defective (hypomineralization/hypomaturation)1. Any systemic, local or geneticfactor that may affect the ameloblasts may causedefects on the surface of the dental enamel3.A major change is MolarIncisor Hypomineralization(MIH), defined as a change in systemic etiology thataffects one, two, three or all first permanent molars andpermanent incisors2. Clinically, hypomineralization isseen as translucency and opacity of the enamel, welldefined and not diffuse, which distinguishes it fromfluorosis. Hypomineralized enamel has a porous,smooth, chalklike consistency. Defect in coloringranges from white to yellowbrown and may beeasily differentiated from normal enamel3. Theexact systemic nature of the lesion has not beenfully explained, but disorders during pregnancy,some childhood illnesses and the frequent use of antimicrobials are conditions that are involved in this process. In addition, recent studies haveconcluded that genetic variations related toamelogenesis are associated with the possibility of developing MIH4,5. It should be noted thatameloblasts are very sensitive cells and theoccurrence of any change during enamel maturationmay lead to loss of tissue quality, causing defectssuch as hypomineralization6.The investigation of MIH etiology has focused onenvironmental accidents that occur during the 3 firstyears of life, which is the critical period for theformation of permanent molars and incisors6.Children with enamel defects have 15fold higherchances of developing cavities than patients without this type of defect7. In addition, the firsthypomineralized permanent molars are subject toenamel breakage after tooth eruption due to chewingforces8. Hypersensitivity is another common compli cation of MIH, making oral hygiene and eating more difficult, in addition to further compromisingdefective teeth, and possibly compromising theclinical management of MIH9. Solving this problemand its possible consequences can be a majorchallenge involving complex treatments.Some studies show an association between the useof medicines, especially antimicrobials, and thedevelopment of MIH. One study investigated a

disease related to MIH, to ascertain whether thisassociation is due to the disease itself or to the drugused to treat it, finding an association between theuse of amoxicillin in children and the developmentof MIH10. Another study also suggested thisassociation, reporting that the use of amoxicillinfrom 6 weeks to 3 months and from 3 to 6 monthssignificantly increases the risk of enamel defects inprimary second molars, but that additional studiesare needed to prove this association11.It is therefore important to investigate the use ofmedicines in early childhood in relation to dentalalterations, as amoxicillin is one of the mostcommonly used antibiotics in pediatric patients,including the context of Primary Health Care(PHC). Thus, the aim of this study was to evaluatethe association between the occurrence of dentalenamel defects (DED) in permanent teeth of 6 to12yearold children who used antibiotics in thefirst 4 years of life at a Primary Health Care service.

MATERIALS AND METHODSThis is a crosssectional study carried out in 2014at two Basic Health Units of the Community HealthService of Conceição Hospital Group (SSCGHC),located in the city of Porto Alegre, Rio Grande doSul, Brazil. The present study used oral examinationdata for DED from another study carried out in 2012with 228 children with the aim of evaluating theassociation between asthma and occurrence ofcaries, erosion, and enamel defects in children 12.The research project was approved by the GHCResearch Ethics Committee under the CAAEnumber 26083614.7.0000.5530, and the authorsabide by the universal declarations and regulationsof Brazil (CNS Resolution 466/12). The study included children aged 6 to 12 yearsregistered at the Health Units, and excluded anychildren who did not have regular followup in theirrespective units during the first four years of life, orany whose medical records were not found, eitherbecause they moved elsewhere or because care tothe family was interrupted. All participants providedwritten informed consent.In the original study in 201212, prevalence wasestimated by considering the main oral changes,such as dental caries and enamel defects, found inprevious studies13,14. Considering the statisticalpower of 80% and a pvalue for rejection of the nullhypothesis of p

children was obtained. Out of 1,278 children, 362children were selected at random and 228 wereexamined. In 2014, the medical records of 144children were examined in order to gatherinformation about the use of medicines and theoccurrence of infections in early childhood. The World Health Organization criteria for DED15

were used. The modified DED index is a scale of 0to 9 which considers enamel normality, presence ofopacity (marked, diffuse, or both), presence/ absenceof hypoplasia, presence of other defects, presence ofall conditions simultaneously or possibility of nonexistent records, according to the following codes:(0) Normal, (1) Marked opacity, (2) Diffuse opacity,(3) Hypoplasia, (4) Other defects, (5) Marked anddiffuse opacities, (6) Marked opacity and hypoplasia,(7) Diffuse opacity and hypoplasia, (8) All threeconditions and (9) No record. Two dental surgeons were trained and then calibratedusing photographs of the clinical conditions understudy16,17. The Kappa correlation coefficient was used

in the two calibrations to assess concordancebetween the images evaluated by the same examinerand between examiners. Intraexaminer 1, intraexaminer 2 and interexaminer Kappa values were1.00, 0.85 and 0.70, respectively. The examinations were performed at the HealthUnits or at home visits with the aid of a mouthmirror under artificial lighting. To assess thefrequency of infections and use of medicines, datawere collected from the medical records of thechildren examined who had at least one visit at theirhealth unit from the first months of life and overtheir first 4 years. Data were collected by a pharmacist in 2014 fromhardcopy medical records at the health units. Astructured instrument was used to collect appointmentdata, patient age at the time of the appointment,drugs used according to the Anatomical TherapeuticChemical international coding; defined dailydosage; and time of treatment (when reported in themedical record). Information on the reasons for

8 Daniel D. Faustino-Silva, et al.


Table 1: Frequency of drug prescription in the first 4 years of life of 6- to 12-year old children in Primary Health Care, Porto Alegre - RS, 2014 (n = 144).

Drug 1st year N(%) 2nd year N(%) 3rd year N(%) 4th year N(%)

Amoxicillin 45 (31.2) 52 (36.1) 33 (22.9) 42 (29.2)

Amoxicillin + clavulanate 4 (2.8) 1 (0.7) 3 (2.1) 1 (0.7)

Ampicillin 4 (2.8) 1 (0.7) 4 (2.8) 1 (0.7)

Azithromycin 3 (2.1) 2 (1.4) 7 (4.9) 11 (7.6)

Benzylpenicillinbenzathine 3 (2.1) 6 (4.2) 8 (5.6) 7 (4.9)

Benzylpenicillin potassium 1 (0.7) 1 (0.7) 2 (1.4) 1 (0.7)

Benzylpenicillin procaine 3 (2.1) 2 (1.4) 2 (1.4) 2 (1.4)

Cefaclor 1 (0.7) 0 (0.0) 0 (0.0) 2 (1.4)

Cefadroxil 2 (1.4) 1 (0.7) 1 (0.7) 0 (0.0)

Cephalexin 6 (4.2) 2 (1.4) 3 (2.1) 2 (1.4)

Ceftriaxone 1 (0.7) 0 (0.0) 0 (0,0) 0 (0,0)

Cefuroxime 1 (0.7) 0 (0.0) 1 (0.7) 0 (0.0)

Ciprofloxacin 1 (0.7) 0 (0.0) 1 (0.7) 0 (0.0)

Erythromycin 4 (2.8) 6 (4.2) 11 (7.6) 5 (3.5)

Gentamicin 1 (0.7) 0 (0.0) 0 (0.0) 0 (0.0)

Metronidazole 0 (0.0) 4 (2.8) 4 (2.8) 4 (2.8)

Nystatin* 19 (13.2) 8 (5.6) 1 (0.7) 0 (0.0)

Nitrofurantoin 2 (1.4) 0 (0.0) 0 (0.0) 1 (0.7)

Oxacillin 2 (1.4) 0 (0.0) 0 (0.0) 0 (0.0)

Sulfamethoxazole + trimethoprim 12 (8.3) 17 (11.8) 16 (11.1) 10 (6.9)

*Topical use drug, but prescribed for oral mucosal infections, being included due to this reason.

appointments within the children’s first 4 years oflife was also included. Concerning enamel defects, the children wereclassified as having normal teeth, presentingopacities (demarcated and/or diffuse) or presentingenamel hypoplasia. Conditions 4 (other defects) and9 (No record) were not found among the childrenselected for the study. To verify the association between exposure tomedicines and the development of DED, chisquareand Fisher’s exact tests were used. Associationswith p values

hypoplasia in each age group. In all age groups, thepresence of opacity (demarcated and/or diffuse)was not related to the prescription of antimicrobialdrugs (Table 2). In the cumulative analysis of antibiotic prescriptions,78.5% (113) of the children had used antibiotics atleast once, and among these, 37.5% (54) hadopacities (demarcated and/or diffuse) and 17.4% (25)presented hypoplasia (Table 2). Table 3 shows that among patients with defects inenamel development, the most frequently prescribedantimicrobial drug was amoxicillin, with at least 6patients having used it more than 6 times during theirfirst 4 years of life. Sulfamethoxazole associated withtrimethoprim was also prescribed more than 6 timesin this age group in at least 1 patient. It is also worthmentioning that amoxicillin was the medicine mostfrequently used by patients without enamel defects.

DISCUSSIONThis study was carried out in the context of PrimaryHealth Care, which provides a children’s health

program with free access to medical and dentalappointments. There are few evaluations of thistype in the context of PHC with calibratedexaminers for oral evaluation of the patients usinga random sample. More than half the patientsanalyzed presented DED, with opacities andhypoplasia being the most prevalent. In addition toevaluating the prescription of antimicrobials, thestudy originally intended to evaluate medicationtiming and dosage. However, one of the difficultiesof reviewing medical records is precisely thequality of the records, which can be considered aconstraint of the study. Nevertheless, medicalrecords provide more reliable data than the selfreported data provided by mothers regarding themedications used, which would be limited bymemory bias.The international literature reports widely varyingprevalence of enamel defects around the world. Onestudy mapped the occurrence of molarincisorhypomineralization (MIH) in Europe through aquestionnaire sent to members of the European



Table 3: Relationship between enamel defects and the frequency of the main antimicrobial drug prescription in the first 4 years of life of 6- to 12-year-old children in Primary Health Care, Porto Alegre - RS, 2014 (n = 144).

Infectious disease Total Normal teething Opacities (demarcated Hypoplasia P*

and/or diffuse) N (%)

Amoxicillin 144 43 72 29 0.442

Less than 4 times 114 35 55 24

From 4 to 6 times 22 6 14 2

More than 6 times 8 2 3 3

Cephalosporin 144 43 72 29 -


Penicillin 144 43 72 29 0.698



Sulfamethoxazole 144 43 72 29 0.595+ trimethoprim



More than 6 times 1 0 1 0

Azithromycin 144 43 72 29 0.45



Erythromycin 144 43 72 29 -


Academy of Pediatric Dentistry18. Prevalenceranged from 3.6 to 25%, with the great majority ofdata coming from northern Europe18. Another studyevaluated the prevalence of enamel defects inpermanent teeth of portuguese children of 6 (n =799) and 12 years of age (n = 800) in 1999, findingthat 7.3% of 6yearolds and 7.1% of 12yearoldsshowed demarcated opacities. Numbers were lowerfor hypoplasia (0.3% and 0.6%, respectively)19.A Brazilian study showed that the prevalence ofmolarincisor hypomineralization (MIH) among 5to 12yearolds was approximately 20% in bothteething periods. In another study in Brazil, thatprevalence was 24.4% in 3 to 5yearolds20. Thesedata show a trend to higher prevalence of DED inthe Brazilian population compared to the European,which may be associated to different exposure toetiological factors. Conflicting results can beexplained by certain factors such as ethnicity,disease history, socioeconomic level, diet, patientage and presence of pollutants in the region20. Inaddition, a recent study in Brazil with 8 to 12yearolds found that enamel defects were common in this population, but found no association with pre, peri and postnatal factors21. In our country,developmental defects of dental enamel have notbeen sufficiently studied, even though they causeaesthetic problems, dental sensitivity, and arefactors leading to predisposition to caries22. The occurrence of infectious disease episodes in the6 to 12yearold age group is quite common. In allage groups evaluated, most patients had had someinfectious disease in this period resulting in the useof antimicrobial drugs for treatment. In the presentstudy, the most frequently prescribed medicine wasamoxicillin, which has been introduced as a broadspectrum antimicrobial drug and has been availablein the Brazilian public health system23 for the pastdecades, which coincides with the age of thechildren participating in the study. Amoxicillin isone of the most commonly used antibiotics inpediatric patients for the treatment of upperrespiratory tract infections and especially acuteotitis, a common childhood disease that affectsmore than 80% of children at least once before theyare 3 years old24. In addition, otitis was the mostcommon reason for prescription of antibiotics.Amoxicillin was the most frequently prescribedantibiotic for children, followed by cephalosporins andsulfamethoxazoletrimethoprim25. The widespread

use of amoxicillin during childhood may have asignificant impact on oral health26.These results are in line with our study, in whichcephalosporins and sulfamethoxazoletrimethoprimwere among the most commonly prescribed drugs for children in the first 4 years of life.Sulfamethoxazoletrimethoprim was found to havebeen prescribed 4 to 6 times in at least 3 patientswho developed opacities, and more than 6 times inone patient. However, it was not possible toestablish a statistically significant association in anyof the cases, which may be because the final samplewas reduced by the exclusion criteria. A study inPakistan evaluated the exposure of 367 children topenicillins and cephalosporins, which are widelyused in children and considered lowrisk for thedevelopment of amelogenesis27. The authors foundout that 15.4% of those exposed to amoxicillin and 29.2% of those exposed to cephalosporinspresented hypermineralization of permanent teethand that the increase in the use of these medicinesin the past had a statistically significant association(p < 0.002), especially among those who had usedit more than 8 times. Another study with 147 children with average age 10.7 years investigated whether the use ofamoxicillin, penicillin V, cephalosporins, macrolidesand sulfamethoxazoletrimethoprim could beassociated with the development of molarincisorhypomineralization (MIH). It found that 52.2% ofthe children with molarincisor hypomineralization(MIH) had used antibiotics in the first year of life,and the condition was more common amongchildren who had used amoxicillin or erythromycinthan among those who had not used these drugs. In addition, the use of cephalosporins orsulfamethoxazoletrimethoprim was not correlatedwith molarincisor hypomineralization (MIH)10. Inparallel to the present work, we notice that amongthe 70 children who had used antibiotics in the firstyear of life, 49 (70%) presented some enamel defectand amoxicillin was the most frequently prescribedmedicine, having been used in 31.2% of the cases. Small sample size may be a limiting factor in thestudy, related to nonstatistically significantassociations between exposure and the outcomesstudied, even though other papers in the literaturealso show this lack of association6. The currentstudy included 144 children whose average age was8.7 years, and found no significant difference

Antibiotics and dental enamel defects 11


between groups regarding use of antibiotics, age atwhich antibiotics were used for the first time, oraverage number of treatments. Moreover, there wasno significant difference among those who usedonly erythromycin, penicillin, trimethoprim orsome other unspecified antibiotic 6. However,longitudinal studies with more robust samples maybe necessary in order to ascertain such associationsand to determine outcomes with the otherantimicrobials mentioned in this study, since theliterature does not present very consistent data, ingeneral terms, that could support a definitiverelationship. It is possible to conclude that there was a highprevalence of children with DED, mainly opacities.It is therefore extremely important to reinforce theoral health care of this population with preventiveand educational actions, since defects in the

development of enamel can lead to the formation ofcavities in the long term and thereby a significantloss of dental function, as well as causing aestheticdiscomfort. Amoxicillin was the most frequentlyprescribed antibiotic for infectious diseasesaffecting children in early childhood, and its use was related, even though not statisticallysignificantly, to the development of opacities andhypoplasia. Amoxicillin is known to be effective inthe treatment of several infections, mainly those inthe respiratory tract and the ear, and has been widelyused in Primary Health Care during the pastdecades. When it is prescribed, therefore, attentionshould be given to any potential side effects thatmay arise, such as the development of enameldefects. Based on this information, physiciansshould take into account this possible associationupon considering the riskbenefit ratio in each case.



ACKNOWLEDGMENTSWe thank the Community Health Service at Grupo HospitalarConceição for their availability and support in conducting thisstudy, and the Graduate Dentistry Program at Federal University of Rio Grande do Sul. CS received financial support fromthe Coordination for the Improvement of Higher EducationPersonnel, CAPESBrazil.

FUNDINGThe present study was supported by Grupo Hospitalar Conceição,Serviço de Saúde Comunitária, Rio Grande do Sul, Brazil.

CORRESPONDENCEDr. Daniel Demétrio FaustinoSilva Av. Francisco Trein nº596, Porto Alegre, RS, Brazil CEP 91350200. [email protected]

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3. Takahashi K, Correia A de SC, Cunha RF. Molar incisorhypomineralization. J Clin Pediatr Dent 2009; 33:193197.

4. Jeremias F, Pierri RAG, Souza JF, Fragelli CMBet al.FamilyBased Genetic Association for MolarIncisorHypomineralization. Caries Res 2016; 50:310318.

5. Jeremias F, Koruyucu M, Kuchler EC, Bayram M, et al.Genes expressed in dental enamel development areassociated with molarincisor hypomineralization. Arch OralBiol 2013; 58:14341442.

6. Whatling R, Fearne JM. Molar incisor hypomineralization:a study of aetiological factors in a group of UK children. IntJ Paediatr Dent 2008; 18:155162.

7. Oliveira AFB, Chaves AMB, Rosenblatt A. The influence ofenamel defects on the development of early childhood cariesin a population with low socioeconomic status: alongitudinal study. Caries Res 2006; 40:296302.

8. William V, Messer LB, Burrow MF. Molar incisorhypomine ralization: review and recommendations forclinical management. Pediatr Dent 2006; 28:224232.

9. Daly D, Waldron JM. Molar incisor hypomineralisation:clinical management of the young patient. J Ir Dent Assoc2009; 55:8386.

10. Laisi S, Ess A, Sahlberg C, Arvio P, et al. Amoxicillin maycause molar incisor hypomineralization. J Dent Res 2009;88:132136.

11. Hong L, Levy SM, Warren JJ, Bergus GR, et al. Primarytooth fluorosis and amoxicillin use during infancy. J PublicHealth Dent 2004; 64:3844.

12. Rezende G, dos Santos NML, Stein C, Hilgert JB et al.Asthma and oral changes in children: associated factors ina community of southern Brazil. Int J Paediatr Dent 2019;29:456463.

13. Allazzam SM, Alaki SM, El Meligy OAS. Molar incisorhypomineralization, prevalence, and etiology. Int J Dent2014; 234508.

14. Hoffmann RHS, de Sousa M da LR, Cypriano S. Prevalenceof enamel defects and the relationship to dental caries indeciduous and permanent dentition in Indaiatuba, SaoPaulo, Brazil. Cad Saude Publica 2007; 23:435444.

15. WHO. Oral health surveys: basic methods. World HealthOrganization. Geneva: 4th; 1997. https://apps.who.int/iris/handle/10665/41905

16. Ministry of Health. Examiner Calibration Manual. Brasília:Secretaria de Atenção à Saúde/Secretaria de Vigilância emSaúde. Departamento de Atenção Básica. CoordenaçãoGeral de Saúde Bucal. SB Brasil 2010; 2010. http://bvsms.saude.gov.br/bvs/publicacoes/pesquisa_nacional_saude_bucal.pdf

17. Alves JC, da Silva RP, Cortellazzi KL, Vazquez F de L, et al.Oral cancer calibration and diagnosis among professionalsfrom the public health in Sao Paulo, Brazil. Stomatologija2013; 15:7883.

18. Weerheijm KL, Mejare I. Molar incisor hypominera lization: a questionnaire inventory of its occurrence inmember countries of the European Academy of PaediatricDentistry (EAPD). Int J Paediatr Dent 2003; 13:411416.

19. de Almeida CM, Petersen PE, Andre SJ, Toscano A. Changingoral health status of 6 and 12yearold schoolchildren inPortugal. Community Dent Health 2003; 20:211216.

20. Lunardelli SE, Peres MA. Prevalence and distribution ofdevelopmental enamel defects in the primary dentition ofpreschool children. Braz Oral Res 2005; 19:144149.

21. VargasFerreira F, Peres MA, Dumith SC, Thomson WM etal. Association of Pre Peri and Postnatal Factors withDevelopmental Defects of Enamel in Schoolchildren. J ClinPediatr Dent 2018; 42:125134.

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23. Secretary of Health. Municipal list of essential medicines REMUME. Porto Alegre: Coordenação de AssistênciaFarmacêutica; 2012. 4 p.

24. Klein JO. Is acute otitis media a treatable disease? Vol. 364,The New England Journal of Medicine. 2011. p. 168–169.

25. McCaig LF, Hughes JM. Trends in antimicrobial drugprescribing among officebased physicians in the UnitedStates. JAMA 1995; 273:214219.

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27. Tariq A, Alam Ansari M, Owais Ismail M, Memon Z.Association of the use of bacterial cell wall synthesisInhibitor drugs in early childhood with the DevelopmentalDefects of Enamel. Pakistan J Med Sci 2014; 30:393397.

Antibiotics and dental enamel defects 13


14


RESUMOO objetivo deste estudo foi avaliar a influência do número depares de linhas em radiografia intraoral digital, na precisãoda detecção de reabsorção radicular externa. Quarenta molaresinferiores (n=80 raízes) foram submetidos ao preparo químicomecânico e em então, metade da amostra foi obturada. Emseguida, as raízes dos dentes foram aleatoriamente divididasde acordo com o tamanho da reabsorção radicular a sersimulada e com a presença e ausência de tratamentoendodôntico. As RRE foram realizadas com brocas esféricasdiamantadas de tamanhos 1/2, 1, 2. Executouse radiografiasdigitais por meio do sistema de aquisição semidireto com autilização de placas de fósforo fotoestimuladas (PSP). Em cadadente, incidências orto, mésio e distorradial foram repetidasquatro vezes, para que pudessem ser digitalizadas comresoluções de 10, 20, 25, 40 pl/mm. Após análise, verificouse

que dentes obturados apresentaram menores valores desensibilidade com 10, 20 e 25 pl/mm e maiores valores deespecificidade e acurácia para as mesmas resoluções. Dentessem obturação registraram maiores valores de sensibilidadepara resolução 20 e menor para 40; no entanto, a especificidadee a acurácia, foram maiores com 40 e menores em 10. Em RRE pequena, as resoluções 10 e 25 pl/mm foram respecti vamente menos e mais acuradas; RRE média, foi maior com 40 pl/mm e RRE grandes foram melhores identificadas com 25.Correlacionando acertos no diagnóstico com localização dasRRE, verificouse que o terço cervical apresentouse menosdetectável. Concluiuse que resolução espacial influenciou adetecção de RRE simuladas em radiografias periapicais digitais.

Palavraschave: radiografia dentária digital, reabsorção da raiz,diagnóstico por imagem, endodontia.

ABSTRACTThe aim of this study was to evaluate the influence of spatialresolution (line pairs per millimetre – lp/mm) on the diagnosisof simulated external root resorption (ERR) in multirootedteeth by using digital periapical radiography. Forty humanmandibular molars (80 roots) were used. The roots weredivided into the following groups (n = 10): control without rootfilling (WORF), control with root filling (WRF), small ERRWORF, small ERRWRF, moderate ERRWORF, moderateERRWRF, extensive ERRWORF and extensive ERRWRF.Four digital radiographs (phosphor storage plates – PSPsystem) were taken of each tooth in three angulations. The PSPswere scanned with 10, 20, 25 and 40 lp/mm. All images wereassessed by three endodontists who used a fivepoint scale forpresence and absence of ERR and classified its location(cervical, middle or apical third). ROC curves and oneway

ANOVA were performed (p < 0.01). Diagnosis of ERR in nonrootfilled teeth showed higher values of sensitivity for 20lp/mm and higher values of both specificity and accuracy for40 lp/mm. In rootfilled teeth, sensitivity and accuracy werehigher for 25 lp/mm and spatial resolution had no influence onspecificity. The best resolution for diagnosis of small andextensive ERR was 25 lp/mm, whereas for moderate ERR, itwas 40 lp/mm. Cervical ERR was the most difficult to diagnose,regardless of the spatial resolution. Higher spatial resolutionshave improved the radiographic diagnosis of simulated ERR inmultirooted teeth and this should be considered whenperforming digital radiographs.Received: December 2019; Accepted: January 2020.

Keywords: digital dental radiography, root resorption, diagnosticimaging, endodontics.

Radiographic Diagnosis of Simulated External Root Resorption in Multi-Rooted Teeth: The Influence of Spatial Resolution

Mariane F. L. S. Lacerda1, Rafael B. Junqueira1, Thaísa M. G. Lima1, Carolina O. Lima2, Caroline F. M. Girelli3, Francielle S. Verner1

1 Universidade Federal de Juiz de Fora, Departamento de Odontologia, Campus GV, Governador Valadares, Minas Gerais, Brasil.

2 Universidade Estadual do Rio de Janeiro, Departamento de Endodontia, Rio de Janeiro, Brasil.

3 Associação Brasileira de Odontologia, Governador Valadares, Minas Gerais, Brasil.

Diagnóstico radiográfico de reabsorção externa simulada em dentes multiradiculares: influência da resolução especial

INTRODUCTIONExternal root resorption (ERR) is defined as the lossof dental mineral tissue, such as cement anddentine, as result of various factors (pathological orphysiological) predisposing to alterations inosteoclast activity. Some of these factors areperiapical lesions, orthodontic movements, toothreimplantation, trauma, pressure from adjacenterupting teeth, and odontogenic and nonodontogenic cysts and tumours1,2. In general, ERRpresents no clinical signal or symptom and islargely detected by means of routine radiographicexaminations, being characterised by reduced rootlength or root surface defects. However, in mostcases, these lesions are only diagnosed at anadvanced stage, thus compromising the treatmentitself3, 4. Early diagnosis is therefore key topreserving the teeth involved, which makesradiographic detection of ERR very important forthe dental surgeon5. Digital radiographic systems have recently replacedradiographic films, as they emit lower radiationlevels, use no chemical process, reduce work time,facilitate image acquisition/storage and enableimage reuse, in addition to improving bothpractitionerpatient visual communication and theimage itself4,6,7.Phosphor storage plates (PSP) are a type of digitalimage receptor commonly used intraorally, whichresemble conventional periapical films in size andthickness. The choice of the ideal system dependson factors related to the digital image which candirectly influence image resolution and quality.Among these factors, we can highlight spatialresolution, which is directly related to the numberof line pairs per millimetre (lp/mm) in the digitalreceptors. According to the manufacturers, thehigher the number of lp/mm, the better the imageresolution8. To date, studies assessing the influence of thenumber of lp/mm on the diagnostic accuracy ofradiography have been limited to the diagnosis ofroot fractures7,9 and caries lesions10. Considering that it is challenging to diagnose ERRcorrectly on periapical radiographs, especially inmultirooted teeth, we can highlight the importanceof performing studies to investigate digital systemresources in order to improve the diagnosis of thisendodontic complication. Thus, the aim of thepresent study was to assess the influence of spatial

resolution on the diagnosis of simulated ERR inmultirooted teeth by using digital periapicalradiography. The null hypothesis to be tested wasthat spatial resolution does not influence thediagnosis of ERR.

MATERIALS AND METHODSThis research was approved by the HumanResearch Ethics Committee by protocol number1.998.579/2017. It followed the recommendationsof the National Health Council of the Ministry ofHealth for research in human subjects.Sample Selection and PreparationForty newlyextracted lower molars (n=80 roots)were selected for reasons not inherent to the studyand stored in formalin solution 10% at atemperature of 6o C. The teeth were clinically andradiographically inspected for further selection.Tworooted lower molars with healthy roots wereincluded, whereas those teeth with incomplete rootformation, fused roots, supernumerary roots,obliterated root canals, root resorption (external orinternal), fractured file inside the root canal, intraradicular posts and pulp calcifications or which hadbeen endodontically treated were excluded. Teethwith cracks and root fractures, which wereconfirmed by using transillumination techniquewith highpower LED at 1200 mW/cm2 (Radii Cal,SDI, Victoria, Australia), were also excluded, In order to eliminate the identification of each toothby the examiners, all crowns were sectioned at thecementoenamel junction with a doublesided steeldisc (#6702, Fava, São Paulo, Brazil) attached to amicromotor (Beltec LB100, Araraquara, SP,Brazil). The sample of roots was randomly divided into twogroups, one (n = 40) without endodontic treatment(WORF) and other (n = 40) with endodontictreatment (WRF), which was performed inappropriate laboratory by a single endodonticspecialist. Working length (WL) was determined 1mm beyond the apical foramen by using a #’10 Kfile (Dentsply/Maillefer, Ballaigues, Switzerland).Roots were instrumented with Protaper system byusing files SX, S1, S2, F1 and F2 (Dentsply/Maillefer, Ballaigues, Switzerland), with the fourlatter being used until the WL was reached. A 2.5%sodium hypochlorite solution was used forirrigation of the root canals, which were then driedwith absorbent paper points F2 (Protaper Point

Spatial resolution and external root resorption 15


Maillefer, Dentsply) before being filled with theTagger’s hybrid technique using guttapercha F2(Dentsply/Maillefer, Ballaigues, Switzerland) andendodontic cement (Endofill, Dentsply/Maillefer,Petropolis, RJ, Brazil).The roots were randomly divided into experimentalgroups for simulations of ERR, which wereperformed by using spherical diamond burs sizes1/2, 1 and 2 (KG Sorensen, Cotia, São Paulo,Brazil) to create small (n = 20), moderate (n = 20)and extensive (n = 20) defects, respectively. Theburs were mounted on a highspeed motor (Kavo,Joinville, Brazil), positioned, and placed perpen dicularly on the root surface to simulate ERRs withsymmetrical depths. Each molar root received onlyone defect on its surface, with location (i.e. cervical,middle or apical third and buccal, lingual or distalface) defined randomly by using Excel 16.0software (Office 2016, Microsoft Corporation,USA). Each group had the same amount of mesialand distal roots and the same number of ERR onradicular thirds.Experimental groups were defined as follows:control without root filling (WORF) (n = 10),control with root filling (WRF) (n = 10), smallERRWORF (n = 10), small ERRWRF (n = 10),moderate ERRWORF (n = 10), moderate ERRWRF (n = 10), extensive ERRWORF (n = 10) andextensive ERRWRF (n = 10).In order to simulate the radiographic appearance ofthe periodontal ligament of the tooth within thealveolus, the entire root was covered with specificplastic wax (Plástica Kotaimp Art’s, São Paulo, SP,Brazil), resulting in a layer 0.3 mm thick. Thicknesswas confirmed using a digital calliper (Starrett®799A, Starret, Itu, SP, Brazil). The teeth wereplaced individually and randomly into the residualalveoli of a macerated mandible.

Image Acquisition Digital radiographs were taken by means of a semidirect digital imaging system with the use ofphotostimulable phosphor plates (PSP) (Vista Scan®

(Dürr Dental, BeitigheimBissingen, Germany).Kilovoltage peak (kVp) and milliamperage (mA)were the acquisition parameters set according to thecharacteristics of the equipment (Gendex DentalSystems, Lake Zurich, IL, USA), namely, 70 kVpand 7 mA. Exposure time of 0.10 seconds (32.7mGy.com2) was determined for diagnosis after

images with ideal contrast and density were obtainedin pilot studies. This exposure time was usedthroughout the study. The distance between focusand PSP was standardised at 40 cm and followed thetechnique of parallelism by using an acrylic apparatusspecially developed for periapical radiographs in vitro and soft tissue simulation. All images wereobtained at ortho, mesial and distal angulations,ranging by 15° in relation to the horizontalangulation. The angulations were repeated fourtimes in each tooth so that the PSPs could bedigitalised with a scanner (VistaScan Mini View®,Dürr Dental, BietigheimBissingen, Germany) atdifferent resolutions of line pairs per millimetre: 10lp/mm (500 dpi), 20 lp/mm (1000 dpi), 25 lp/mm(1270 dpi) and 40 lp/mm (2000 dpi).

Image Evaluation After obtaining 480 radiographs, the imagesdigitalised with different line pairs per millimetrewere randomised in order to improve assessmentreliability. The images were assessed by three endo dontic specialists who were previously instructedregarding the assessments and blinded to thestudy’s methodology. They examined the imagesindividually for presence or absence of ERR ineach root according to a 5point scale, namely: 1 –totally absent; 2 – probably absent; 3 – uncertain;4 – probably present; and 5 – totally present. Forcases in which the examiners considered presenceof ERR (scores 4 and 5), it was further ratedaccording to its location in the root thirds, i.e.,cervical, middle or apical. Any discordant caseswere jointly reassessed by all three examiners sothat agreement was achieved between at least twoof them, thereby enabling the calculation of theresponse mode. Periapical radiographs were assessed on Windows®

photo viewer before being exported to .TIFF fileformat (uncompressed) by using the system’s imageacquisition software (DBS Win, Dürr Dental,BietigheimBissingen, Germany). All assessmentswere performed on a 24inch LCD monitor (MDRC2124 (Barco Inc. Duluth, GA, USA) under ideallight conditions. Zoom, brightness and contrasttools could be used to improve the images. After 30 days, a period considered to be longenough for the examiners to forget the images, 20%of the sample was reassessed in order to calculateintra and interrater reliability11.

16 Mariane F. L. S. Lacerda, et al.


Statistical Analysis Statistical analysis was carried out using the SPSSstatistics software version 21.0 (IBM Corp,Armonk, New York, USA) at a significance levelof 1%. Weighted kappa test was used for intra andinterrater reproducibility. For comparison of the results of the images obtained at differentresolutions (lp/mm) with the gold standard, ROC(receiver operating characteristics) curves werebuilt to determine the values of sensitivity,specificity and areas under ROC curve (accuracy).Oneway analysis of variance (ANOVA) and posthoc Tukey’s test were used to compare the areavalues.

RESULTSKappa test showed that values for intra and interrater reliability ranged from significant to almostperfect agreement12 (0.66 to 0.81 and 0.77 to 0.86),respectively.ROC curves were calculated for each spatialresolution in the WORF and WRF groups. Thevalues of sensitivity, specificity and areas under theROC curves are shown in Table 1.

Analysis of diagnostic tests showed that spatialresolution and presence of root filling materialsignificantly influenced the detection of simulatedexternal root resorptions on digital periapicalradiographs. Fig. 1 shows periapical radiographs ofmandibular molars with and without endodontictreatment and presence of simulated RRE indifferent thirds of root canal. By comparing the values of sensitivity, specificityand accuracy between the WORF and WRF groupsregarding the different spatial resolutions, it wasobserved that rootfilled teeth had lower values ofsensitivity at resolutions of 10, 20 and 25 lp/mm (P < 0.001) and higher values of specificity andaccuracy at the same resolutions (P < 0.001). Onthe other hand, by comparing the values ofsensitivity, specificity and accuracy obtained ateach spatial resolution, it was found that the WORFgroup presented higher values of sensitivity at aresolution of 20 lp/mm (0.917) and lower values at40 lp/mm (0.611). Moreover, nonrootfilled teethhad higher values of specificity and accuracy at aresolution of 40 lp/mm, respectively 1.00 and0.873, and lower values at 10 lp/mm, respectively,



Fig. 1: Periapical radiographs of mandibular molars. (A) Absence of endodontic treatment and presence of simulated RRE in themiddle third of the mesial root, 10 lp/mm. (B) Presence of endodontic treatment and simulated RRE in the middle third of thedistal root and in apical third of the mesial root, 10 lp/mm. (C) and (D) Spatial resolution 20 lp/mm. (E) and (F) Spatialresolution 25 lp/mm. (G) and (H) Spatial resolution 40 lp/m (white arrows).

0.714 and 0.823. For rootfilled teeth, the values ofsensitivity and accuracy at a resolution of 25 lp/mmwere higher, 0.769 and 0.887 respectively, whereasno difference was found in specificity betweendifferent spatial resolutions (Table 1). With regard to the extent of ERR, it was found thatdifferent types of spatial resolution produceddifferent results (P < 0.001). For small ERRs,spatial resolution of 10 lp/mm was less accurate(0.755) than that of 25 lp/mm (0.848). For moderateERRs, on the other hand, accuracy was higher at a

resolution of 40 lp/mm (0.885) than at otherresolutions. Extensive ERRs were significantlybetter identified at a resolution of 25 lp/mm (0.891),whereas a resolution of 40 lp/mm enabled lessaccurate identification (0.876) (Table 2).By correlating the percentage of diagnostic hits tolocalization of ERR at different spatial resolutions, itwas possible to verify that the percentage of hits waslower in the cervical third than that in the other thirdsfor all resolutions tested, whereas ERRs located inthe middle third were more easily detected (Table 3).



Table 1: Values of diagnostic tests for the different spatial resolutions, in the presence and absence of root filling.

Spatial Resolution

10 lp/mm 20 lp/mm 25 lp/mm 40 lp/mm P Value

Sensitivity WORF 0.889A,a 0.917B,a 0.806C,a 0.611D,a P < 0.001

WRF 0.718A,b 0.744B,b 0.769C,b 0.744B,b P < 0.001

Specificity WORF 0.714A,a 0.857B,a 0.786C,a 1.000D,a P < 0.001

WRF 0.923A,b 0.923A,b 0.923A,b 0.923A,b P = 1.000

AZ WORF 0.823A,a 0.836B,a 0.832C,a 0.873D,a P < 0.001

WRF 0.841A,b 0.848B,b 0.887C,b 0.864D,b P < 0.001

AZ, Area under the ROC curves. Lp/mm, line/pair per millimetre. WORF, Without root filling. WRF, With root filling. For each diagnostic parameter value, different capital letters indicate significant difference (P < .01) between the different spatial resolutions, in the WORF and WRF conditions.For each diagnostic parameter value, different lowercase letters indicate significant difference (P < .01) between the WORF and WRF conditions.

Table 2: AZ values for the different sizes of simulated external root resorption in the different spatial resolutions.

Spatial Resolution

Size of ERR 10 lp/mm 20 lp/mm 25 lp/mm 40 lp/mm P Value

Small ERR 0.755A 0.827B 0.848C 0.831B P < 0,001

Medium ERR 0.833A 0.829A 0.826A 0.885B P < 0,001

Extensive ERR 0.876A 0.849B 0.891C 0.847B P < 0,001

ERR, external root resorption. Lp/mm, line/pair per millimetre.P Value, One-way ANOVA, Tukey Post-Hoc (P < 0.01).Different capital letters indicate significant difference (P < 0.01) between the different spatial resolutions for the three sizes of simulated ERR.

Table 3: Relative frequency of correct diagnosis of the location of the simulated external root resorptions in the different spatial resolutions.

Spatial Resolution

Location of ERR 10 lp/mm 20 lp/mm 25 lp/mm 40 lp/mm

Absence of ERR 88.90% 92.60% 85.20% 88.90%

Cervical third ERR 45.80% 41.70% 45.80% 41.70%

Middle third ERR 77.80% 88.90% 96.30% 85.20%

Apical third ERR 45.80% 50.00% 50.00% 58.00%

DISCUSSIONThe aim of the present study was to ascertainwhether spatial resolution (line pairs per millimetre)has any influence on the diagnosis of simulatedERRs in multirooted teeth by using digital periapicalradiography. The results show that both spatial resolution anddifferent root canal conditions (i.e. rootfilled ornonrootfilled) had a significant influence on thedetection of simulated ERRs on digital periapicalradiographs. Based on the diagnostic efficacy of spatial reso lution for detection of simulated EERs on digitalradiographs, high spatial resolutions were expectedto have higher values of specificity, sensitivity andaccuracy. For nonrootfilled teeth, however, theseexpected results were found for specificity andaccuracy as they were higher at a resolution of 40lp/mm and lower at 10 lp/mm.These findings corroborate the literature, showingthat images acquired at high spatial resolutionsenable better detection of radiographic details9,10,13,14. Nevertheless, contrary to our expectations, betterresults for accuracy were found for rootfilled teethat a resolution of 25 lp/mm. This finding isimportant because it shows that it is possible tomake a precise diagnosis without spending a longtime on scanning, as occurs during the use of linepairs in high spatial resolution imaging. Anotherinherent advantage is small image file size, whichalso enables easy data export.No statistical difference was observed for specificityin rootfilled teeth. Although it is not feasible toperform a direct comparison due to methodologicaldifferences, a previous study corroborated ourfinding by demonstrating that different systems withdifferent spatial resolutions showed no statisticaldifference in the detection of vertical root fracture15. On the other hand, analysis of sensitivity showedbetter results in nonroot filled teeth at a resolutionof 20 lp/mm, whereas higher sensitivity was foundin rootfilled teeth at a resolution of 25 lp/mm. Forthis reason, considering the diagnostic difficultiesminimised due to the lack of filling material, theuse of a lower resolution was enough for a precisediagnosis, whereas a higher resolution enabled saferdiagnosis in teeth whose images were affected bythe filling material.These data are similar to those reported by a recentstudy assessing different intraradicular conditions

during the diagnosis process. Teeth filled withguttapercha or restored with intraradicular postswere more poorly diagnosed than those without rootfilling15,16. With regard to the extent of ERRs, the present studyhas demonstrated that higher spatial resolutionsimprove accuracy in detecting small to moderatesized ERRs, although it has been suggested that the higher the spatial resolution, the better theidentification of radiographic details17. Studiesusing different spatial resolutions were alsoperformed to detect morphological alterations suchas vertical root fractures 9 and deep caries lesions18,reporting better results for higher resolutions, whichcorroborates our findings.For extensive ERRs, accuracy was better at aresolution of 25 lp/mm and worse at 40 lp/mm. Thiscan be explained by the fact that an increase inspatial resolution without altering the exposure time,i.e., a proportionally longer exposure is needed for ahigher spatial resolution in order to keep the samequality of the image acquired with lower spatialresolution17. Because extensive ERRs show a greaternumber of radiographic details and the study wasperformed with the same exposure time despite thedifferent spatial resolutions, such details were moreeasily identified at lower resolutions.In addition, greater wear of the root structure leadsto a larger radiolucent area. Therefore, the accuratediagnosis of root resorption was higher for largercavities4. The same finding was reported by a studyon ERR with different sizes, showing that extensiveresorptions were not considered a diagnosticchallenge as they could be easily identified in allmodalities tested19. With regard to the location of ERRs, middle thirdwas the region enabling the most precise diagnosis,whereas the lowest percentage of diagnostic hits was observed in the cervical third for all spatialresolutions. Statistical differences between differentroot thirds have also been reported in the literature5,20,with the middle third enabling the best results5, whichcorroborates our study. These findings can be attributed to a higher densityand greater thickness of the structures superimposedin the cervical region, such as surrounding bone, rootdentine and, in cases of rootfilled teeth, greateramount of filling material. On the other hand, a study using other digitalmethods with PSPs did not show any statistically



significant superiority in detecting ERRs withdifferent sizes and in different sites3. The failure in timely diagnosis of ERR may lead toloss of dental structure and decrease the likelihood ofpreserving the tooth, since resorptive lesions are thefirst ones to be diagnosed on intraoral radiographs.Safe radiographic techniques for diagnosis of suchlesions is therefore necessary6. Spatial resolution, usually expressed as line pairs permillimetre (lp/mm), is a characteristic of digitalreceptors that enables differentiation of imagedetails. To date, however, there is no study describingthe effect of different spatial resolutions using a semidirect digital imaging system (phosphor storageplates) on the detection of ERR.The present study used tworooted lower molarswith healthy roots. Multirooted teeth were selectedbecause their morphology is largely affected bynecessary endodontic procedures, thus posing agreat challenge during the diagnosis of ERR due toroot superimposition, which may result in poortherapeutic outcome. Different intraradicularconditions (i.e. rootfilled and nonrootfilled teeth)were prepared in order to create diagnosticdifficulties resulting from the filling material. In the present study, teeth with simulated resorptioncavities were considered to be the gold standard,which enabled the calculation of the exact percentageof positive and negative readings. It should beemphasised that simulated ERRs have relativelydistinct cavity ridges, making them fairly easy todetect compared to naturally formed ERRs, whichhave more diffuse ridges6.We also decided to simulate ERRs on the wholesurface of the root and in three different regions toreproduce the likelihood of finding them in dentalpractice. Moreover, the teeth were placed within thealveoli of dried mandibles in order to better simulatethe condition of their roots, i.e., surrounded by bonetrabeculae and peripheral bone contour2. In addition,tissue attenuation and xray dispersion were preciselysimulated in the acrylic apparatus21. To follow the ALARA principle (as low as reasonablyachievable), exposure time was determined bymeans of a pilot study in which the image qualitywas obtained for all radiographs and maintained

constant for all exposures, regardless of the spatialresolution. The aims of this procedure were toenable clinical reproducibility in terms of radiationexposure level and to ensure that any statisticaldifferences were exclusively related to spatialchanges. Similarly, based on specific guidelines for radiologicdiagnosis of tooth fractures22, in which at least tworadiographs should be taken for diagnosis, thepresent work has extrapolated this recommendationby performing a radiographic triad for each tooth atdifferent spatial resolutions in order to increasediagnostic sensitivity.ERRs not viewed on orthoradial images were thusmore likely to be detected after altering the horizontalangles23. With regard to image evaluation criteria, it has beenreported that subjective analysis of the image qualityof a digital radiographic system is rather complexbecause it is directly related to sensitivity and dynamicscale of each examiner and related to the importanceof the object of analysis8. In the present study,nevertheless, the examiners were previously trainedand their analyses tested by means of a ROC curve.This approach enabled outlier data to be eliminated inorder to increase the reliability of the study. However, the present study has limitations inherentto the laboratory method and the results should beextrapolated to clinical practice with caution. Inaddition to the fact that simulated ERRs wererelatively sharper than naturally formed ERRs,which tend to be rather diffuse and calcified, dataon painful symptoms, crown colour and patient’sdental history can help contextualise the observa tions made during interpretation of the images.Therefore, further research should be carried out ex vivo by using a methodology similar to ours inorder to precisely compare specificity, sensitivityand accuracy of digital imaging systems in thedetection of ERR, as well as studies using irregularresorption cavities to better simulate clinical features.In conclusion, it has been found that spatialresolution influenced the detection of simulatedERRs on digital periapical radiographs, as well astheir location, size, root canal configuration andpresence of filling material.



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9. Wenzel A, Kirkevang LL. High resolution charge coupleddevice sensor vs. medium resolution photostimulablephosphor plate digital receptors for detection of rootfractures in vitro. Dental Traumatol 2005; 21:3236.

10. Li G, Berkhout WER, Sanderink GCH, Martins M. Stelt PF.Detection of in vitro proximal caries in storage phosphorplate radiographs scanned with different resolutions.Dentomaxillofac Radiol 2008; 37:325329.

11. Ferreira LM, Visconti MAPG, Nascimento HA, DallemolleRR, Ambrosano GM, Freitas DQ. Influence of CBCTenhancement filters on diagnosis of vertical root fractures:a simulation study in endodontically treated teeth with and

without intracanal posts. Dentomaxillofac Radiol 2015;44:16.

12. Landis JR, Koch GG. The measurement of observeragrement for categorical data. Biometrics 1977; 33:159174.

13. Møystad A, Svanaes DB, Risnes S, Larheim TA. Gr€ondahlHG. Detection of approximal caries with a storage phosphorsystem. A comparison of enhanced digital images withdental Xray film. Dentomaxillofac Radiol 1996; 25:202206.

14. Kositbowornchai S, Basiw M, Promwang Y, Moragorn H.Sooksuntisakoonchai N. Accuracy of diagnosing occlusalcaries using enhanced digital images. DentomaxillofacRadiol 2004; 33:236240.

15. Nascimento HA, Neves FS, deAzevedoVaz SL, DuqueTM. Ambrosano GM, Freitas DQ. Impact of root filling andposts on the diagnostic ability of three intraoral digitalradiographic systems in detecting vertical root fractures.Int Endod J 2014; 48:864871.

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FundingNone

CORRESPONDENCEDr. Mariane FLS LacerdaAv. Doutor Raimundo Rezende, 330, Centro, Sala 301, Governador Valadares, Minas Gerais, Brasil. Zip Code: [email protected]

22


RESUMENLa tomografía de haz cónico (CBCT) ha modificado la perspectivade la imagenología en odontología que brinda una imagentridimensional manipulable con una relación 1:1, paciente:imagen. Los tratamientos y diagnósticos se ven modificados ocorroborados por el CBCT; sin embargo, la exactitud que presentaen estructuras delgadas como las corticales óseas ha sidosometida a críticas. El objetivo fue correlacionar la medición dela altura del hueso alveolar vestibular mediante medicionesdirectas y las realizadas con imágenes tomográficas de haz cónicocon resolución de vóxel estándar (SD). Treinta dientes incisivos ypremolares de pacientes sometidos a un curetaje abierto semidieron con un calibrador de alta precisión y una tomografíacomputarizada de haz cónico (CBCT) a una resolución SD de

0,16 mm de vóxeles en un escáner 3D Orthophos XG Sirona. La evaluación intraobservador se realizó utilizando el coeficientede correlación intraclase (ICC), y las mediciones directas y lasmediciones CBCT se correlacionaron utilizando la correlación dePearson (PCC). La diferencia media entre las medicionesindirectas y directas fue de 3,15 mm. La prueba t pareada y elCoeficiente de Correlación de Pearson determinaron que todaslas mediciones fueron estadísticamente diferentes entre sí con unap

for dental use in the year 2000 in Loma LindaUniversity, USA2. This new tool has significantadvantages such as low radiation dose, a 1:1 ratioof bone structures and shorter shooting times than2D Xrays and computed axial tomography (CAT).The companies involved in 3D tomography haveprovided different options to the orthodontist,making it important to analyze each tomogram andcorroborate the accurate measurement of anatomicalstructures. The 1:1 ratio has been demonstrated in many cases; however, when highly accuratemeasurement of thin structures is required forcortical bone, the reliability of 3D tomographydecreases3, 4.The alveolar bone is formed by the projection of theexternal and internal cortical bone and providessupport to the teeth and soft tissues. The determi nation of alveolar bone height helps to establish the limitations in orthodontic treatments, e.g., inbiomechanical expansion or closure of spaces,movements could cause or aggravate fenestrationsor dehiscences in the alveolar crest, especially if thediagnosis was incorrect. Biomechanical andbiological factors are closely related and determinethe collateral effects of potential treatment such asroot resorption, gingival recession, dehiscence andfenestrations5, 6.Threedimensional imaging through a CBCT scanis important because it can reveal fenestrations anddehiscences. These types of alveolar defects arecommon, especially in hyperdivergent patients andincreased lower facial height7,8. A previous study of1872 teeth reported high prevalence of these defectsin hyperdivergent (8.35%) and normodivergent(8.18%)6 subjects. In another study, iCAT™ was performed on 123 scans, showing that thepresence of fenestrations and dehiscences did notvary significantly between skeletal I, II or IIImalocclusion9. In terms of measurements on CBCT, it has beenfound that linear measurements are reliable, but thepresence of soft tissue and voxel size influenced theresults. Even when using a 0.125 mm voxel, the thinvestibular cortex of some external layers is notrepresented, hence, there is a considerable risk ofoverestimating the dehiscences or fenestrationsviewed in a threedimensional image10.The correlation between linear measurementsperformed on a skull and the same measurementstaken from tomographic images analyzed using

Dolphin® software has been assessed in theliterature. It was demonstrated that many of thelinear measurements differed significantly11. Thishighlighted the limitations of using this technologyfor studies in skulls. Several factors can influencethe accuracy of the results, such as the attenuationof soft tissues, metalbased restorations and patientmovement. CBTC scans (0.4 mm voxel) were performed in pigjaws to measure the height of the vestibular alveolarbone in the molar region. The results showed thattomographic images can overestimate alveolar boneloss associated with rapid palatal expansion by 1.5to 2 mm12.The aim of this study was to investigate whetherthere is a significant correlation in the accuracy ofthe vestibular alveolar bone height measurementbetween direct and indirect techniques (0.16 mmvoxel resolution CBCT), with the goal of validatingthis methodology and establishing its limitations. The importance of the present study is theobservation of variables in living patients, andanalysis of the representation of clinical reality inCBCT scans.

MATERIALS AND METHODSThis study was reviewed and approved by theFaculty of Dentistry Research Committee at theBenemérita Universidad Autónoma de Puebla(Mexico). The procedures adhered to ethicalstandards and there was no risk in the investigationaccording to the Regulation of the General HealthLaw on Research and Helsinki Declarationguidelines for research involving human subjects.The intraclass correlation coefficient for thevestibular alveolar bone height measurements ofboth researchers was 0.980. The interresearcher’sPearson’s correlation coefficient for the directtechnique (Vernier caliper measurement) was0.990, and for the indirect technique (CBCT at 0.16 mm) it was 0.986. Thus, direct and indirectmeasurements were consistent and reproducible foreach researcher. Eight patients were invited to participate in thestudy, under informed consent, to receive opencurettage treatments. The protocol included asample of 30 teeth that were exposed to a fullthickness flap during debridement. The studyincluded incisors and premolars of patients of different ages and genders, and excluded

Alveolar bone height measurement 23


teeth with extensive restorations that could affectthe tomographic image. The procedure included patients who required flapelevation for their periodontal procedure whichenabled us to perform the measurements. A copy ofthe CBCT scan was delivered to the specialist whowas treating the patients for diagnostic purposeswithout additional cost. Patients were exposed to one CBCT scan afterclinical procedures. Precautions were taken tominimiz

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