Evaluation of the radiopacity and physical-chemistry properties of the root canal filling materials

Orientadores: Lourenço Correr Sobrinho, Manoel D. Sousa NetoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: No presente estudo, dois experimentos, com base na Especificação n° 57 para materiais obturadores de canais radiculares da American National Standardl American Dental Association (ANSI/ADA), foram realizados. No primeiro experimento, foi avaliada a radiopacidade dos cimentos AR PlusTM, Endofill@, EndoREZTM e EpiphanyTM, e de cones de guta-percha Dentsply-Maillefer@ e ResilonTM, por meio da digitalização direta de imagens (sistema de imagem digital Digora). Placas de acrílico, contendo 6 orificios (5 mm de diâmetro x 1 mm de espessura), foram preenchidas com os materiais, posicionadas juntamente com um penetrômetro de alumínio, padronizada pela Especificação n° 57 da ANSI/ADA, e radiografadas a uma distância foco-objeto de 30 em, com tempo de exposição de 0,2 s. As médias- das densidades radiográficas de cada material foram obtidas em escala de cinza. Os valores decrescentes de densidade radiográfica dos materiais estudados foram: ResilonTM (214,28), AR PlusTM (206,42), gutta-percha (199,04), EpiphanyTM (188,04), Endofill@ (180,34) e EndoREZTM (178,18). No segundo experimento, foi avaliado se a redução do volume de material obturador de canal radicular necessário para a confecção de corpos-de-prova para os testes de solubilidade e alteração dimensional pós-presa possibilitaria a execução dos testes e-atenderia as exigências da Especificação n° 57 da ANSI/ADA. Inicialmente, determinou-se a densidade dos corpos-de-prova padronizados (ANSI/ADA), para o teste de solubilidade e para o teste de alteração dimensional pós-presa, utilizando-se o cimento EndofiU@. Após a determinação da densidade, moldes, de menores dimensões, foram confeccionados e divididos em 6 grupos para cada um dos testes. Os moldes originais, padronizados pela Especificação n° 57 da ANSI/ADA, foram utilizados como grupo controle. Para a confecção dos corpos-de-prova, foram utilizados os cimentos AR PlusTM e Endofill@. Para solubilidade, os corpos-de-prova foram divididos em grupos, sendo estes imersos em volumes de água destilada e deionizada diferenciados, de acordo com a massa do corpo-de-prova: GSl (20 x 1,5 mm, imerso em 50 ml de água destilada, estabelecido pela ANSI/ADA); GS2 (14,14 x 1,5 mm, 25 ml); GS3 (10 x 1,5 mm, 12,5 ml); GS4 (8,94 x 1,5 nurí, 10 ml); GS5 (7,75 x 1,5 mm, 7,5 ml); GS6 (6,32 xl,5 mm, 5 rnl); GS7 (4,47 x 1,5 mm, 2,5 rnl). Dois corpos-de-prova, de cada grupo, foram pesados, em conjunto, antes. de serem imersos em água destilada e deionizada, e armazenados a 37°C, por 24 h. Após esse período, foram secos e pesados novamente. A solubilidade foi calculada pela perda de massa do conjunto (em %) e a água destilada utilizada foi submetida à espectrofotometria de absorção atômica, para análise da presença dos íons Zn e Ca. Para alteração dimensional pós-presa, os seguintes grupos foram formados: GADl (12 x 6 mm, imerso em 30 ml de água destilada, estabelecido pela ANSI/ADA); GAD2 (6,09 x 6 mm, 15,22 rnl); GAD3 (4,48 x 6 mm, 11,19 ml); GAD4 (3,58 x 6 mm, 8,96 ml); GAD5 (6,04 x 4 mm, 6,72 rnl); GAD6 (4,03 x 4mm, 4,48 ml); GAD7 (3,58 x 3 mm, 2,24 ml). Após a mensuração do comprimento, com micrômetro, as amostras foram imersas em água destilada a 37°C, por 30 dias, removidas, secas e mensuradas novamente. Com os comprimentos iniciais e finais, determinou-se a variação percentual para cada grupo. Para o teste de solubilidade, houve correlação entre a massa inicial e a diferença entre massas inicial e final para os diferentes grupos. O cimento . Endofill@ apresentou valor médio de solubilidade estatisticamente superior ao AR PlusTM é (1,55% e 0,06%, respectivamente). Para alteração dimensional pós-presa, houve correlação entre o comprimento inicial e a diferença entre comprimentos inicial e final para os diferentes grupos. O cimento Endofill@ apresentou contração (0,56%) e o AR PlusTM, expansão (0,62%). Concluiu-se que os cimentos AR PlusTM, Endofill@, EndoREZTM e EpiphanyTM, e de cones de guta-percha Dentsply-Maillefer@ e ResilonTM, apresent~ram radiopacidade superior aos 3 mm de alumínio, determinados pela Especificação n° 57 da ANSI/ADA e que a redução do volume de material obturador de canal radicular necessário para a confecção de corpos-de-prova para os testes de solubilidade e alteração dimensional pós-presa, possibilitou a execução dos testes, atendendo as exigências da Especificação n° 57 da ANSI/ADAAbstract: In the present study, two experiments, according to American National Standardl American Dental Association (ANSI/ ADA) Specification No. 57 for endodontic sealing materiaIs, were performed. In the first experiment, the radiopacity of AR PlusTM, Endofilf~, EndoREZTM, and EpiphanyTM sealers, and gutta-percha (Dentsply-Maillefer) and ResilonTM cones were evaluated using direct digital image processing (digital image DigoraTM system). Acrylic plates, containing 6 wells (1 mm in depth and 5 mm in diameter), were filled with the materiaIs, positioned together with an aluminum stepwedge, according to ANSI/ADA Specification 57, and radiographed on an object-to-focus distance of 30 cm, with exposure time of 0.2 s. The averages of radiographic densities for each material were obtained using gray scale values. The decreasing values of radiographic density of the studied materiaIs were: ResilonTM (214.28), AR PlusTM (206.42), guttapercha (199.04), EpiphanyTM (188.04), Endofill@ (180.34), and EndoREZTM (178.18). In the second experiment, it was evaluated the possibility of decreasing the volume of material necessary for the production of test samples for solubility and dimensional change following setting tests, which comply with ANSI/ADA Specification No. 57, without committing the accuracy of the results of these methods. Initially, it was obtained the density of the standard test samples (ANSI/ADA), for solubility, and dimensional ch~nge following setting tests, using Endofill@ sealer. Once original density was determined, moulds, with smaller dimensions, were prepared and divided into 6 groups, ITom each <me of the test. The moulds standardized to ANSI/ ADA Specification 57 were used as control group. To preparing of test samples, it was used AR PlusTM and Endofill@ sealers. For solubility test, the test samples were divided into groups, being the samples immersed into volumes of distilIed and deionized water, according to the mass ofthe test sample: GS1 (20 mm x 1.5 mm, immersed into 50 rnL distilled water, according to ANSI/ADA); GS2 (14.14 mm x 1.5 mm, 25 rnL); GS3 (10 mm x 1.5 mm, 12.5 rnL); GS4 (8.94 mm x 1.5 mm, 10 mL); GS5 (7.75 mm x 1.5 mm, 7.5 rnL); GS6 (6.32 mm x 1.5 mm, 5 rnL); GS7 (4.47 mm x 1.5 mm, 2.5 rnL). Two test samples of eaclí group, were weighted, in set, before being immersed in distilled and deionized water, and stored at 37°C, for 24 h. After this time, they were dried and weighted again. The solubility was calculated using the weight loss (%) and the distilled water was evaluated through atomic absorption spectrometry analysis, to verify the presence ofZn, and Ca ions. For dimensional change following setting test, the following groups were performed: GDC1 (12 x 6 mm, immersed into 30 rnL distilled water, according to ANSI/ADA); GDC2 (6.09 x 6 mm, 15.22 rnL); GDC3 (4.48 x 6 mm, 11.19 rnL); GDC4 (3.58 x 6 mm, 8.96 rnL); GDC5 (6.04 x 4 mm, 6.72 rnL); GDC6 (4.03 x 4mm, 4.48 rnL); GDC7 (3.58 x 3 mm, 2.24 rnL). After height measurement using amicrometer, the test samples were immersed into distilled water, and stored at 37°C, for 30 days, removed, dried and measured again. With initial and final heights, it was established the percentage variation for each group. For solubility test, there was correlation between the initial mass and the difference among initial and final masses for the different groups. The Endofilfi) sealer present~d mean value significant1y higher than AR PlusTM sealer (1.55% and 0.06%, respectively). For dimensional change following setting, there was . correlation between the initial height and the difference among initial and final heights for the different groups. The Endofill@ sealer presented 'shrinkage (0.56%) and AR PlusTM sealer, expansion (0.62%). It can be conc1uded that AR PlusTM, Endofill@, EndoREZTM, and EpiphanyTM sealers, and gutta-percha (Dentsply-Maillefer) and ResilonTM cones showed radiopacity above the 3 mm of aluminum reco.mmended by ANSI/ADA Specification 57. In addition, the volume reduction of root canal filling material necessary for the production of test samples for solubility and dimensional change following setting tests made possible the execution ofthe tests, following the recommendations of ANSI/ADA Specification 57DoutoradoMateriais DentariosDoutor em Materiais Dentário

In vitro study of the effect of Er: YAG laser irradiation on the apical sealing of different root canal sealers

OBJECTIVES: The aim of this study was to determine the effect of Er:YAG laser irradiation used to clean dentinal walls on the apical sealing of root canals filled with different types of sealers. Background Data: Laser application to the dentinal walls removed debris, rendering the root canals free of smear layers and leaving the dentinal canaliculi open. METHODS: Sixty-four maxillary canines obtained from laboratory files were instrumented with K-files (Dentsply, Maillefer, Ballaigues, Switzerland) using the crown-down technique, and irrigated with a 0.5% sodium hypochlorite solution. The specimens were divided into two groups of 32 teeth each. In group I, the teeth were instrumented and irrigated with sodium hypochlorite solution, and divided into four subgroups to be sealed with the different materials (Endofill, N-Rickert, Sealapex and Sealer 26). In group II, the root canals were subjected to Er:YAG laser irradiation (200 mJ, 7 Hz and 60 J total energy), followed by root canal sealing as in group I. RESULTS: The data showed lower levels of apical microleakage in the teeth filled with N-Rickert, Sealapex and Sealer 26 cements than in those sealed with Endofill (p ; 0.05). CONCLUSIONS: The Er:YAG laser irradiation applied to the root canal walls was not able to prevent apical microleakage.OBJETIVOS: Avaliou-se a infiltração marginal apical em caninos superiores, obturados com quatro tipos diferentes de cimento, os quais foram imersos em tinta nanquim e mantidos a uma temperatura de 37º C por 96 horas, descalcificados em solução de ácido clorídrico a 5%, desidratados em série crescente de álcoois e diafanizados em salicilato de metila. MÉTODOS: Para isto, 64 dentes de estoque foram instrumentados pela técnica "crown-down", irrigados com solução de hipoclorito de sódio a 0,5% e divididos em dois grupos experimentais. Os dentes do Grupo I foram subdivididos em quatro sub-grupos de oito elementos e obturados cada um deles com os cimentos Endofill®, N-Rickert®, Sealapex® e Sealer 26®. Os dentes do Grupo II receberam aplicação adicional de laser Er:YAG, tendo seus canais radiculares obturados como aqueles do grupo I. RESULTADOS: A infiltração marginal apical apresentou valores estatisticamente maiores e significantes (p ; 0,05), quanto à infiltração marginal apical, nos dentes do Grupo I, preparados somente com a solução de hipoclorito de sódio a 0,5%, e naqueles do Grupo II, que foram irradiados com laser Er: YAG. CONCLUSÕES: A irradiação de laser Er:YAG aplicada nas paredes do canal radicular não foi capaz de prevenir a infiltração marginal apical

Periradicular repair after single- and two-visit root canal treatments using ultrasonic irrigant activation and calcium hydroxide dressing of teeth with apical periodontitis: study protocol for randomized controlled trials

Abstract Background In certain clinical situations, root canal treatment in teeth with apical periodontitis is performed in multiple visits, with the use of intracanal dressing between visits, aiming to reduce microorganisms and their by-products of the root canal system prior to filling. However, in recent years, discussions have been growing about the real need for the use of intracanal dressing in these cases. The use of ultrasonic activation of the auxiliary chemical substance has increased the potential for decontamination promoted during the chemomechanical preparation of the root canal. Thus, this study is designed to explore whether the use of intracanal dressing between visits during endodontic treatment favors periradicular repair in teeth with apical periodontitis. Methods This is a randomized, prospective, double-blinded, controlled clinical trial designed to evaluate 3 distinct clinical approaches used during endodontic therapy: group 1—root canal treatment in a single visit (RCT-SV); group 2—root canal treatment in two visits with intracanal dressing (RCT-TVWD); and group 3—root canal treatment in two visits without intracanal dressing (RCT-TVWOD). A total of 150 adult patients aged 18 to 60, with at least one tooth diagnosed with asymptomatic apical periodontitis and periradicular lesion (confirmed with a cone beam computed tomography (CBCT)), will be randomized and will undergo one of the types of clinical approaches during endodontic therapy. Patients’ postoperative pain levels will also be recorded in periods of 24, 48, and 72 h and 7 days. Subsequently, clinical findings and long-term follow-up evaluations, with periradicular repair, will be performed at 6 and 12 months by intraoral periapical radiograph (IOPAR) and CBCT at the 24-month follow-up. Discussion This study will evaluate the periradicular repair of mandibular molar teeth with apical periodontitis, providing information about the efficacy, benefits, and safety of performing the endodontic treatment in a single and two visits, with and without the use of calcium hydroxide dressing. All endodontic therapy procedures will be performed under a dental operating microscope and using ultrasonic activation of auxiliary chemical substances. These results may contribute to changes in the clinical approaches adopted during endodontic therapy of teeth with apical periodontitis and reveal the potential of complementary approaches that aim to enhance the decontamination of the root canal system during the preparation stage. Trial registration ClinicalTrials.gov NCT05256667. Registered on 24 February 202