Continuous Wave of Condensation Improves the Filling of Curved Canals: a Micro-CT Study / La condensación de onda contínua mejora el selle de canales curvos: un estudio de micro-CT

Abstract The aim of this study was to compare the filling capacity in curved root canal using a new continuous wave of condensation technique (Termo Pack II, Easy Dental Equipments, Brazil) or lateral compaction. The percentage of voids in the filling of mesial root canals of mandibular molars was assessed by micro-computed tomography (micro-CT). Mesial root canals (n=24) of mandibular molars with a degree of curvature between 20° and 40° were prepared using rotary system (ProDesign Logic, Easy, Brazil) up to #35, .05 taper. The root canals were filled by using the continuous wave of condensation system or lateral compaction and AH Plus sealer (n=12). Scanning at 9 µm was performed after preparation and after filling by using micro-CT SkyScan 1176. The volumetric percentage of filling material and voids (total length and in each root canal third) were calculated. Data were analyzed using ANOVA/ Tukey and Student's t tests (α=0.05). Before the filling techniques, the root canals volume after preparation was similar (p>0.05). The root canals filled by the continuous wave of condensation technique presented the lowest percentage of voids, and the greatest percentage of filling material in total length and thirds (cervical, middle and apical) (p<0.05). Both techniques were not able of completely filling the root canals. The continuous wave of condensation technique Termo Pack II promoted better root canal filling in curved root canals, when compared with lateral compaction.

Resumen El objetivo de este estudio fue comparar la capacidad de obturación en conductos radiculares curvos utilizando una nueva técnica de condensación de onda continua (Termo Pack II, Easy Dental Equipments, Brasil) vs compactación lateral. El porcentaje de brechas en la obturación de los conductos radiculares mesiales de los molares mandibulares se evaluó mediante microtomografía computarizada (micro-CT). Se prepararon conductos radiculares mesiales (n=24) de molares mandibulares con un grado de curvatura entre 20° y 40° utilizando un sistema rotatorio (ProDesign Logic, Easy, Brasil) al #35, conicidad 0,05. Los conductos radiculares se obturaron utilizando un sistema de condensación de onda contínua o compactación lateral y cemento AH Plus (n=12). Se realizó un escaneo de 9 µm después de la preparación y después de la obturación usando el micro-CT SkyScan 1176. Se calculó el porcentaje volumétrico de material de obturación y vacíos (longitud total y en cada tercio del conducto radicular). Los datos se analizaron utilizando las pruebas ANOVA/Tukey y t de Student (α=0,05). Antes de las técnicas de obturación, el volumen de los conductos radiculares después de la preparación fue similar (p>0,05). Los conductos radiculares obturados con la técnica de condensación por onda contínua presentaron el menor porcentaje de vacíos y el mayor porcentaje de material de obturación en longitud total y en tercios (cervical, medio y apical) (p<0,05). Ambas técnicas no fueron capaces de llenar completamente los conductos radiculares. La técnica de condensación de onda contínua Termo Pack II promovió un mejor relleno del conducto radicular en conductos radiculares curvos en comparación con la compactación lateral.

Effect of voxel size of Micro-CT on the assessment of root canal preparation

The aim of this study was to assess the influence of micro-computed tomography (micro-CT) voxel size on evaluation of root canal preparation using rotary heat-treated nickel-titanium files. Curved mesial root canals of mandibular molars were prepared using ProDesign Logic 30/.05 (PDL) or HyFlex EDM 25/.08 (HEDM) (n=12). The specimens were scanned using micro-CT with 5μm of voxel size before and after root canal preparation. Images with sub-resolution of 10 and 20μm voxel sizes were obtained. The percentage of volume increase, debris and uninstrumented root canal surface were analyzed in the different voxel sizes. Data were compared using unpaired Student's t-test and ANOVA statistical tests (α=0.05). No differences were observed for percentage of volume increase, debris and instrumented surface between the root canals prepared by PDL and HEDM (p>0.05). Both systems promoted higher percentage of debris in the apical third compared to the middle third (p0.05). PDL and HEDM had similar root canal preparation capacity. Micro-CT images using different voxel sizes did not influence the results of volume increase and debris evaluation. However, images at 5µm showed greater accuracy to evaluate the percentage of uninstrumented surfaces.

El objetivo de este estudio fue evaluar la influencia del tamaño de vóxel de la microtomografía computarizada (micro-CT) en la evaluación de la preparación del conducto radicular utilizando limas rotatorias de níquel-titanio tratadas térmicamente. Se prepararon conductos radiculares mesiales curvos de molares mandibulares usando ProDesign Logic 30/.05 (PDL) o HyFlex EDM 25/.08 (HEDM) (n=12). Las muestras se escanearon usando micro-CT con un tamaño de vóxel de 5μm antes y después de la preparación del conducto radicular. Se obtuvieron imágenes con subresolución de vóxeles de 10 y 20μm. Se analizó el porcentaje de aumento de volumen, residuos y superficie del conducto radicular no instrumentado en diferentes tamaños de vóxel. Los datos se compararon usando la prueba t de Student no pareada y las pruebas estadísticas ANOVA (α=0,05). No se observaron diferencias en el porcentaje de aumento de volumen, detritus y superficie instrumentada entre los conductos radiculares preparados por PDL y HEDM (p>0,05). Ambos sistemas promovieron un mayor porcentaje de detritos en el tercio apical en comparación con el tercio medio (p0,05). PDL y HEDM tenían una capacidad de preparación del conducto radicular similar. Las imágenes de micro-CT que utilizan diferentes tamaños de vóxel no influyeron en los resultados de la evaluación del volumen y los desechos. Sin embargo, las imágenes de 5µm mostraron una mayor precisión al evaluar el porcentaje de superficies no instrumentadas.

Accuracy of an endodontic rotary motor with integrated apex locator to determine the root canal length / Precisão de um motor rotatório endodôntico com localizador apical integrado para determinação do comprimento radicular

Aim: The purpose of this study was to evaluate the efficacy to determine the root canal length, in vitro,of both the electronic apex locator (M2) and the autostop (AS - M3) functions of the Endus Duo Gnatus endodontic motor (Gnatus, São Paulo, SP, Brazil). Methods: Thirty extracted human single-rooted premolars had their root canal lengths (TLs) up to the apical foramen determined using the Endus Duo Gnatus in two ways: (1) In the stainless steel (SS) control group, the measurement was obtained using a stainless steel hand instrument with the electronic locator mode (M2 function) connected to a stainless-steel hand instrument (K-file #15). In the NiTi rotary instrument (NiTi RI) intervention group, the measurement was obtained during the instrumentation (M3 function) of the root canals with a nickel-titanium rotary instrument (Hyflex CM: Coltene Whaledent, Cuyahoga Falls, OH, USA), size 25/.06. The NiTi manually used instrument (NiTi MUI) Intervention group performed the measurement in locator mode using a Hyflex instrument, placed to true length manually. Statistical analysis was performed using ANOVA followed by the Tukey post-hoc test with a significance level of p < 0.05. Results: The true mean length and standard deviation (SD) of the standardized root canals were 18.40 ± 2.14mm, while the mean lengths and standard deviations (SD) were 18.29 ± 1.89mm, 18.22 ± 1.85mm, and 17.24 ± 2.09mm for the SS, NiTi RI, and NiTi MUI groups, respectively. However, data from the NiTi MUI Intervention group indicated shorter root canal lengths when compared to the SS control group and the NiTi RI Intervention group values, and were significantly shorter than the true canal length (p < 0.001). Conclusions:The use of the motor in NiTi RI Intervention group showed acceptable results. However, the NiTi MUI Intervention group resulted in unacceptable short measurements.

Objetivo: O objetivo deste estudo foi avaliar a eficácia na determinação do comprimento do canal radicular, in vitro, das funções localizador eletrônico foraminal (M2) e auto-parada durante a instrumentação (M3) do motor endodôntico Endus Duo Gnatus ( Gnatus, São Paulo, SP, Brasil). Métodos: Trinta pré-molares humanos uniradiculares extraídos tiveram seus comprimentos de canais radiculares (CRTs) até o forame apical determinados usando o Endus Duo Gnatus de duas maneiras: (1) No grupo controle de aço inoxidável (SS), a medida foi obtida usando um instrumento manual de aço inoxidável com modo de localização eletrônica foraminal (função M2) conectado a um instrumento manual de aço inoxidável (lima tipo K #15). No grupo intervenção instrumento rotatório NiTi (NiTi RI), a medida foi obtida durante a instrumentação (função M3) dos canais radiculares com instrumento rotatório de níquel-titânio (Hyflex CM: Coltene Whaledent, Cuyahoga Falls, OH, EUA), tamanho 25/.06. O grupo de intervenção NiTi instrumento usado manualmente (NiTi MUI) realizou a medição no modo localizador foraminal usando um instrumento Hyflex, colocado manualmente no comprimento real do dente. A análise estatística foi realizada por meio de ANOVA seguida do teste post-hoc de Tukey com nível de significância de p < 0,05. Resultados: Os comprimentos reais médios dos dentes e desvios-padrão (DP) dos canais radiculares padronizados foram 18,40 ± 2,14 mm, enquanto os comprimentos médios e desvios- padrão (DP) foram 18,29 ± 1,89 mm, 18,22 ± 1,85 mm e 17,24 ± 2,09 mm para os grupos SS, NiTi RI e NiTi MUI, respectivamente. No entanto, os dados do grupo de intervenção NiTi MUI indicaram comprimentos de canais radiculares mais curtos quando comparados aos valores do grupo controle SS e do grupo de intervenção NiTi RI, e foram significativamente mais curtos que o comprimento real do canal (p < 0,001). Conclusões: A utilização do motor no grupo Intervenção NiTi RI apresentou resultados aceitáveis. No entanto, o grupo de intervenção NiTi MUI resultou em medições curtas inaceitáveis.

Diamond-coated ultrasonic tip decreases debris and uninstrumented surface after preparation of curved canals with isthmus

Abstract The aim of this study was to evaluate root canal preparation with nickel titanium rotary instruments and complementary preparation with ultrasonic tip in curved canals of mandibular molars with isthmus. Twenty-eight mesial roots of mandibular molars with curvature between 20° and 40° and presence of isthmus throughout the entire extension of the root canals were prepared using ProDesign Logic CM (PDL) up to size 40.05, or HyFlex EDM (HFEDM) up to size 40.04. Complementary preparation was performed in the isthmus region using the ultrasonic insert E18D (Helse, Istmo Diamantada). The root canals were scanned using micro-CT (SkyScan 1176) at 9 µm voxel size before and after each preparation step. Transportation, percentage of increase in volume, debris and uninstrumented surface (UNS) were evaluated. Mann Whitney, Wilcoxon, paired and non-paired t-tests were used for statistical analysis (α = 0.05). The canals prepared with PDL and HFEDM obtained similar results for all the variables assessed before using E18D (p > 0.05). E18D significantly decreased the percentage of debris and UNS values in both Groups (p < 0.05). The complementary preparations with E18D caused a smaller quantity of debris in the isthmus of the canals previously prepared with PDL in comparison with HFEDM (p < 0.05). PDL and HFEDM provided similar root canal preparation. PDL promoted a smaller quantity of Debris in the isthmus than HFEDM after using E18D. E18D significantly improved cleaning, and reduced Debris and UNS.

Comparison of Accuracy Between Pulp/Tooth Ratio and Tooth Coronal Index Methods for Dental Age Estimation Using Digital Panoramic Radiographs

ABSTRACT Objective: To evaluate the reliability and the accuracy of Tooth Coronal Index (TCI) and Pulp/Tooth Ratio (PTR) methods in dental age estimation using digital panoramic radiography. Material and Methods: In this cross-sectional study, 237 dental panoramic images were collected. The two methods (TCI and PTR) were applied to all left mandibular first and second molars based on inclusion and exclusion criteria. In order to analyze the acquired data, statistical methods were used. The estimated ages derived by exclusive formula were compared to the chronological age, and the error ranges for each indicator were measured to determine their accuracy. Results: There were negative correlations between PTR in the first molar (r=-0.89) and in the second molar (r=-0.788), as well as TCI in the first molar (r=-0.587) and in the second molar (r=-.242). In this study, we found that the Pulp/Tooth Ratio (PTR) accuracy rate for mandibular first and second molar teeth was 79.21% and 62.09 %, respectively, although the Tooth Coronal Index (TCI) value for these teeth was 34.45% and 5.85%. Conclusion: Pulp/Tooth Ratio and Tooth Coronal Index are potential age estimation indices. Although PTR was the more accurate one in our study. The results also demonstrated that indices related to the first molar tooth could be used to estimate age with greater accuracy and validity.

Randomized Clinical Study of the Use of MTA and Biodentine™ for Pulpotomy in Primary Teeth

ABSTRACT Objective: To verify, through clinical and radiographic evaluations, the in vivo response of the dentin-pulpal complex of human primary teeth after pulpotomy with MTA and Biodentine™ in a follow-up period of 3, 6, and 12 months. Material and Methods: Thirty teeth were divided into MTA pulpotomy (n = 15) and Biodentine™ pulpotomy (n = 15) from children between 5 and 9 years of age, a randomized clinical trial with simple random sampling. The materials were inserted into the cavity after opening and removing the coronary pulp tissue. The cavity base consisted of glass ionomer cement and light-cured composite resin restoration. Clinical and radiographic analyses were performed after 3, 6, and 12 months. Statistical analysis by Fisher's exact test for dichotomous data at a 5% significance level was utilized. Results: Both materials caused color change after 12 months. However, MTA showed a higher percentage than Biodentine™ (p<0.0001). Pain was detected only with Biodentine™ at six months and mobility at 12 months (p=0.0013). Radiographically, after 12 months, periapical lesions, interradicular lesions, and internal resorption were evidenced in 13% of the cases for Biodentine™-treated teeth (p<0.0013). MTA induced pulp calcification in 13% of cases, unlike Biodentine™ (p<0.0013). Conclusion: BiodentineTM and MTA are suitable for clinical use in pulpotomy treatment, yet both materials lead to tooth discoloration.

Effects of using different root canal sealers and protocols for cleaning intraradicular dentin on the bond strength of a composite resin used to reinforce weakened roots / Efectos del uso de diferentes selladores de conductos radiculares y protocolos para limpiar la dentina intrarradicular sobre la fuerza de unión de una resina compuesta utilizada para reforzar raíces debilitadas

Background: This study evaluated the effects of using different root canal sealers and protocols for cleaning intraradicular dentin on the bond strength of a composite resin used to reinforce weakened roots. Material and Methods: Sixty-four roots of extracted human maxillary canines were weakened, prepared and filled with two different endodontic sealers (Endofill and AH Plus). In half of the sample, set aside for each respective sealer, excess filling material was cleaned. In the other half, the weakened areas were not cleaned, and the excess of sealer was spread on the intraradicular dentin. Intentionally worn areas inside each root were restored with a microhybrid light-cure composite resin (Z100) to reinforce them, with and without acid etching. Prefabricated metal posts were fixed with a dual resin cement (RelyX ARC), and the specimens were submitted to a pull-out test. Statistical analysis was performed by means of Shapiro-Wilk, analysis of variance (one-way ANOVA) and Tukey-Kramer tests (p<0.05). Results: The groups filled with Endofill (GI, GII, GIII, GIV) had the lowest bond strength values, which were similar among each other (p>0.05).The greatest bond strength values were observed in roots filled with AH Plus (GV, GVI, GVII, GVIII), mainly without cleaning of the weakened areas, and followed by acid etching (GVII), and also with cleaning of the weakened areas, however, with no acid etching (GVI) (p<0.05). Conclusion: The greatest bond strength values were observed in roots filled with AH Plus; (1) without cleaning of the weakened areas and with acid etching, and; (2) with cleaning of the weakened areas, but without acid etching.

Antecedentes: este estudio evaluó los efectos del uso de diferentes selladores de conductos radiculares y protocolos para limpiar la dentina intrarradicular sobre la fuerza de unión de una resina compuesta utilizada para reforzar las raíces debilitadas. Material y Métodos: Sesenta y cuatro raíces de caninos maxilares humanos extraídos fueron debilitadas, preparadas y rellenadas con dos selladores endodónticos diferentes (Endofill y AH Plus). En la mitad de la muestra, reservada para cada sellador respectivo, se limpió el exceso de material de relleno. En la otra mitad, las áreas debilitadas no se limpiaron y el exceso de sellador se esparció sobre la dentina intrarradicular. Las áreas desgastadas intencionalmente dentro de cada raíz se restauraron con una resina compuesta fotopolimerizable microhíbrida (Z100) para reforzarlas, con y sin grabado ácido. Los postes metálicos prefabricados se fijaron con un cemento de resina dual (RelyX ARC) y los especímenes se sometieron a una prueba de extracción. El análisis estadístico se realizó mediante Shapiro-Wilk, análisis de varianza (ANOVA de una vía) y pruebas de Tukey-Kramer (p<0,05). Resultados: Los grupos rellenos con Endofill (GI, GII, GIII, GIV) presentaron los valores más bajos de fuerza de unión, los cuales fueron similares entre sí (p>0,05). Los mayores valores de fuerza de unión se observaron en raíces rellenas con AH Plus (GV, GVI, GVII, GVIII), principalmente sin limpieza de las áreas debilitadas, seguido de grabado ácido (GVII), y también con limpieza de las áreas debilitadas aunque sin grabado ácido (GVI) (p<0.05). Conclusión: Los mayores valores de fuerza de unión se observaron en las raíces rellenas con AH Plus; (1) sin limpieza de las áreas debilitadas y con grabado ácido, y; (2) con limpieza de las áreas debilitadas, pero sin grabado ácido.

Técnica endocrown como alternativa restauradora para dentes tratados endodonticamente: relato de caso clínico / Endocrown technique as a restorative alternative for endodontically treated teeth: a case report

Este trabalho teve como objetivo apresentar um relato de caso clínico de uma restauração do tipo coroa endocrown cerâmica em um dente molar tratado endodonticamente. Paciente com 45 anos de idade, sexo feminino, procurou a clínica do Centro Universitário da Serra Gaúcha (FSG) relatando a necessidade de reabilitação protética no primeiro molar inferior do lado esquerdo. Com base no exame radiográfico e exame clínico foi constatado um primeiro molar inferior do lado esquerdo com tratamento endodôntico satisfatório, mas uma extensa destruição coronária. Após a aprovação da paciente e indicações para a utilização da técnica, optou-se pela confecção de uma coroa endocrown em cerâmica reforçada por dissilicato de lítio. Foi realizado o preparo do remanescente dentário, envolvendo a câmara pulpar, com ângulos arredondados e expulsivos e, após a moldagem do mesmo com silicone de adição, utilizando a técnica simultânea e duplo fio. O provisório foi realizado com resina quimicamente ativada na cor 62 e, na sessão seguinte a coroa endocrown foi ajustada e polida. Após receber o protocolo de condicionamento adequado da peça, a mesma foi cimentada com cimento autopolimerizável Multilink N. Pode-se concluir que a alternativa restauradora Endocrown é um tratamento conservador e favorável para dentes com extensa destruição coronária, permitindo adequada estética e função(AU)

This study aimed to present a clinical case report of an endocrown ceramic crown restoration in na endodontically treated molar tooth. A 45-year-old female patient sought the clinic at the Centro Universitário da Serra Gaúcha (FSG), reporting the need for prosthetic rehabilitation on the lower left first molar. Based on the radiographic and clinical examination, the first molar presented satisfactory endodontic treatment, but extensive coronary destruction. After the approval of the patient and indications for the use of the technique, it was decided to make an endocrown with reinforced ceramic by lithium disilicate. The remaining tooth was prepared, involving the pulp chamber, with rounded and expulsive angles and, after the impression with silicone using the simultaneous and double wire technique was taken. The provisional was made with chemically activated resin in color 62 and, in the following session, the endocrown crown was adjusted and polished. After receiving the proper conditioning protocol, it was lutted with Multilink N self-curing cement. It can be concluded that the Endocrown restorative alternative is a conservative and favorable treatment for teeth with extensive coronary destruction, allowing adequate aesthetics and function(AU)

XP Endo Finisher-R and PUI as supplementary methods to remove root filling materials from curved canals

Abstract: This study assessed the ability of XP-endo Finisher R (FKG, La Chaux-de-Fonds, Switzerland) to remove filling remnants from curved mesiobuccal canals of maxillary molars, using the passive ultrasonic irrigation (PUI) technique as a comparison. Twenty-four curved main mesiobuccal canals (MB1) of maxillary molars were instrumented with Wave One (#25/07) and filled with gutta-percha points and AH Plus Sealer. Samples were then re-treated with a standardized protocol with Wave One (#35/06) as the master apical file. Micro-CT scans measured baseline volume of remaining filling material (in mm3). Samples were divided into two groups (n = 12) according to the supplementary cleaning approach: (PUI) or XP-endo Finisher R. Statistics compared baseline and final volume of filling material (within-group); and the percentage of filling material reduction (between-group). Mean baseline volumes, final volumes, and percentages of reduction (%) of filling material for XP-endo Finisher R and PUI were respectively: 0.060 mm3, 0.042 mm3, and 31.28%; and 0.064 mm3, 0.054 mm3, and 16.57%. Both tested protocols reduced the amount of filling material (p < 0.05). XP-endo Finisher R had higher percentage of reduction as compared to PUI (p < 0.05). XP-endo Finisher R and PUI used as supplementary cleaning protocols during re-treatment improved the removal of root filling material in curved canals; but XP-endo Finisher R was approximately twice more efficient. The complete filling material removal during re-treatment procedures is still a challenge. Supplementary cleaning protocols may help to remove the remaining material after the complete mechanical preparation of curved canals. XP-endo Finisher R was approximately twice more efficient than PUI.

Influence of anatomical features in the endodontic treatment planning of maxillary anterior teeth

Abstract This study evaluate the maxillary anterior teeth anatomy by micro-computed tomography (μCT), about relevant characteristic for endodontic treatment planning. Fifty maxillary central incisors (MCI), lateral incisors (MLI) and maxillary canines (MC) were scanned using a μCT device. Two and three-dimensional parameters at 1 to 5mm distance to the apical foramen, external anatomic characteristics of the teeth and qualitative analysis of the internal anatomy was performed. The roundness and form factor values revealed a circular canal in the apical third in the MCI and MC, whereas MLI showed flattening in the apical third. The linear regression test indicated a progressive increase in the major/minor diameters in the five mm assessed (p < 0.001). The 3D analysis revealed the greatest volume and surface area in MC. The SMI showed a cylindrical geometry of root canals. All teeth presented Vertucci's type I root canal configuration. A mild curvature was prevalent in the MCI (45%) and a moderate one in the MLI (50%) and MC (50%). Palatal shoulder volume was smaller in the MLI (11.46 ± 3.09) than in the MCI (14.15 ± 3.85) and MC (13.95 ± 2.55). The most common exit of main apical foramen was in a central (22%), distolingual (30%) and mesiobuccal position (28%) for MCI, MLI and MC, respectively. Radicular grooves were observed in 2% of MCI and 4% of MLI. Two and three-dimensional data obtained by μCT allowed to observe morphological characteristics of internal/external anatomy of the maxillary anterior teeth. These characteristics may affect the endodontic treatment planning.

Cone Beam Computed Tomography Evaluation of Root Morphology of the Premolars in Saudi Arabian Subpopulation

Abstract Objective: To evaluate root canal configuration and morphology of premolar teeth among Saudi subpopulations using cone beam computed tomography (CBCT). Material and Methods: In this retrospective cross-sectional study, CBCT images of 314 patients comprising 346 maxillary and 412 mandibular first premolar (FPM) teeth, 298 maxillary and 387 mandibular second premolar (SPM) teeth were analyzed to evaluate the number of roots, root canal morphology, and configuration based on the Vertucci's classification. The average intra-class correlation coefficient value was 0.931. Results: In the maxillary first premolar, 52.6% were two separate rooted and single rooted teeth, with one canal in 81.2% of the maxillary second premolar. Among the mandibular FPM, 96.6% of the teeth had one root and canal, and 97.9% of mandibular SPM had one root and canal. Type 1 canal configuration was seen as most common in all premolars. The number of roots in mandibular premolars did not reveal the difference among gender. Conclusion: Wide variations in root canal morphology and canal configuration system exists among maxillary and mandibular premolar teeth (AU).

Root canal length changes during mechanical preparation due to different cervical enlargement patterns

Abstract This study aimed to evaluate the root canal real length (RL) changes due to the mechanical instrumentation use with different flaring magnitudes. After access cavity, 60 mesial root canals of mandibular molars were randomly separated in three groups: Hyflex EDM (HF; #25/.12, #10/.05 e #25/~), Reciproc Blue (RB; R25), and MTwo (M2; #10/.04, #15/.05, #20/.06 e #25/.06). The RL was defined as the apical limit, and 2.5% sodium hypochlorite irrigating solution was chosen. After the access cavity (RL 1), cervical flaring (RL 2), and complete chemical-mechanical preparation (RL 3), the RL was evaluated. The RL was evaluated by a blind examiner with the aid of a microscope (16x) placing the endodontic file stop at the coronary reference. When comparing length measurements, the RL was shorter before instrumentation than that after instrumentation. A reduction of 0.65 mm (HF), 0.61 mm (RB), and 0.48 mm (M2) was observed. However, among groups, no statistical differences were found (p > 0.05). Under the conditions tested, it can be inferred that all mechanical systems provoked RL variations, which emphasizes the need for constant verification of the odontometry, mainly before root canal obturation.

Percepção e conhecimento de odontopediatras sobre o uso de coroas pré-fabricadas de aço e zircônia na reabilitação de dentes decíduos / Perception and knowledge of pediatric dentists about the use of prefabricated steel and zirconia crowns in the rehabilitation of deciduous teeth

Objetivo: O presente trabalho tem como objetivo avaliar o conhecimento dos odontopediatras e suas percepções, conhecendo as dificuldades que estes encontram frente ao desafio da reabilitação de dentes decíduos. Métodos: A pesquisa foi realizada por meio da aplicação de questionários on-line e a análise estatística foi descritiva e comparativa, com tabelas de frequência para as variáveis quantitativas. O teste não paramétrico de Qui-quadrado foi utilizado para estimar a associação entre as diferentes categorias dos dados e em todo o estudo, estipulou-se o nível de significância em 5%. Resultados: Os resultados da pesquisa mostraram que a maioria dos entrevistados conhecem as coroas pré-fabricadas de aço, porém sua aplicação em atendimentos de crianças com extensas destruições coronárias limita-se a 34,1% destes profissionais, sendo que a baixa utilização se deve à dificuldade de aquisição do material e falta de habilidade técnica. Já com relação às coroas pré-fabricadas de zircônia, 82,4% das odontopediatras as conhecem, mas a grande maioria não as utiliza devido à dificuldade de aquisição, falta de habilidade técnica e o seu alto custo. Não foi encontrada associação entre a dificuldade de planejamento dos casos e a consideração estética e o âmbito de trabalho do entrevistado, bem como o fato de conhecer as coroas pré-fabricadas e utilizá-las. Conclusão: Conclui-se que os materiais reabilitadores, como coroas pré-fabricadas de aço e de zircônia, são de certa forma bem conhecidos pelos odontopediatras, mas sua utilização em reabilitação de dentes decíduos ainda é limitada.

Aim: The present study aims to evaluate the knowledge of pediatric dentists and their perceptions, knowing the difficulties they face in the challenge to rehabilitate deciduous teeth. Methods: This study was carried out through the application of online questionnaires. The statistical analysis was descriptive and comparative, with frequency tables for the quantitative variables. The non-parametric chi-square test was used to estimate the association between the different categories of data, and the significance level was set at 5%. Results:The survey results showed that most respondents know about prefabricated steel crowns, but their application in the care of children with extensive coronary destruction is limited to 34.1% of these professionals. The low use is due to the difficulty of acquiring the material and the lack of technical skills. It was found that 82.4% of the pediatric dentists have knowledge about prefabricated zirconia crowns, but the vast majority do not use them due to the difficulty of acquisition, their lack of technical skills, and the product's high cost. No association was found between the difficulty of planning the cases and the esthetic consideration and sphere of work of the interviewee, nor regarding the fact of their having knowledge about the prefabricated crowns and using them. Conclusion: It can therefore be concluded that rehabilitation materials, such as prefabricated steel and zirconia crowns, are well-known by pediatric dentists, but their use in the rehabilitation of deciduous teeth is still limited.

Influence of different reciprocating systems on the apical extrusion of debris in flat-oval canals

Aim: To evaluate the apical extrusion of debris in flat-oval canals, using three reciprocating systems at two different working lengths (WL), 0 mm and 1 mm from the apical foramen. Methods: Ninety mandibular incisors were randomly divided into three groups based on the systems: WaveOne Gold #25.07 (WOG), ProDesign R #25.06 (PDR), and X1 Blue #25.06 (X1B). Extruded debris were collected and dried in pre-weighed Eppendorf tubes. Three consecutive weighings were performed for each tube, and the mean was calculated. If the assumptions of normality and homogeneity of variance were not met, the Kruskal-Wallis test was used to analyze the amount of extruded debris between groups with the same WL, and the Mann-Whitney U test was used for comparison within groups for each WL. Results: All groups had extruded debris, with higher median values occurring at 1 mm. No significant difference regarding the amount of debris extrusion was observed at 0 mm (p>0.05) and 1 mm (p>0.05) between groups. However, within the groups, at different WL, there was greater extrusion at 1 mm (p<0.05), with PDR differing significantly from the other systems (p<0.05). Conclusion: The extrusion of debris occurred regardless of the group, with higher values at 1 mm. However, using PDR at 1 mm from the apical foramen showed the highest values of extrusion

Oximetría de pulso y su eficacia para diagnosticar vitalidad pulpar / Pulse oximetry and its use in diagnosing pulp vitality

Objetivo: Identificar y analizar en la literatura científica reciente el uso de la oximetría de pulso como método diagnóstico de vitalidad pulpar. Metodología: En este trabajo se llevó a cabo una revisión de la literatura en las plataformas de PubMed y Google Académico, en la cual se analizó el uso de la oximetría de pulso en el diagnóstico y monitoreo odontológico del estado pulpar. Resultados: Después de una exhaustiva revisión, y de acuerdo con los criterios de inclusión y exclusión, se analizaron 21 artículos. La mayoría de los trabajos consideran la oximetría de pulso un método alternativo de diagnóstico indoloro, seguro y eficaz; sin embargo, la adaptación de un instrumento de uso exclusivo odontológico es necesaria para una medición exacta de la saturación de oxígeno en la pulpa dental. Los avances tecnológicos en el campo clínico de la odontología nos han llevado a la búsqueda de nuevas técnicas diagnósticas clínicas para mejorar la atención y los tratamientos de los pacientes que acuden día con día a recibir una consulta odontológica. Conclusiones: En los últimos años la oximetría de pulso ha demostrado ser una herramienta de diagnóstico eficaz para el diagnóstico de la vitalidad pulpar. El análisis de los artículos incluidos en esta revisión concluye que la oximetría de pulso es una técnica innovadora que puede ser utilizada como una herramienta diagnóstica adyuvante en el diagnóstico de la vitalidad pulpar (AU)

Objective: To identify and analyze in the recent scientific literature the use of pulse oximetry as a diagnostic method for pulp vitality. Methodology: In this work, a literature review was carried out on the PubMed and Google Scholar platforms in which the use of pulse oximetry in the dental diagnosis and monitoring of pulp status was analyzed. Results: After an exhaustive review and in accordance with the inclusion and exclusion criteria, 21 articles were analyzed. Most of the studies consider pulse oximetry an alternative method of painless, safe and effective diagnosis, however, the adaptation of an instrument for exclusive dental use is necessary for an exact measurement of the oxygen saturation in the dental pulp. Technological advances in the clinical field of dentistry have led us to search for new clinical diagnostic techniques to improve the care and treatment of patients who come every day to receive a dental consultation. Conclusions: In recent years, pulse oximetry has proven to be an effective diagnostic tool for the diagnosis of pulp vitality. The analysis of the articles included in this review concludes that pulse oximetry is an innovative technique that can be used as an adjunct diagnostic tool in the diagnosis of pulp vitality (AU)

Bio-c repair - a new bioceramic material for root perforation management: two case reports

Abstract These case reports aimed to describe the management of lateral perforation in the middle cervical third of the root in two maxillary incisors with pulp canal calcification using Bio-C Repair, with safe and viable clinical treatment strategies. Digital radiographic exams were obtained with different angles and analyzed using different filters. Cone-beam computed tomography (CBCT) images were requested to show the actual position of the canal, location of the perforation, and guide the strategic planning of the case. Subsequently, cavity access was prepared with the aid of dental operating microscopy. After perforation was identified, granulation tissue was removed and the original canal was identified and then dressed with calcium hydroxide. In the second visit, the perforation was filled with Bio-C Repair and the canal system filled with gutta-percha points and a root canal sealer (Bio-C Sealer). The teeth were restored with glass fiber post, 4 mm beyond the perforation level, and provisory crowns. Both teeth treated as described above were functional and asymptomatic with a 1-year clinical and radiographic assessment. The Bio-C Repair is suggested as a new cement option for the management of lateral canal perforations, with effective results as observed after a one-year follow-up.

Resumo O presente relato de caso teve como objetivo descrever o manejo da perfuração lateral no terço médio cervical da raiz em dois incisivos superiores com calcificação pulpar utilizando o Bio-C Repair, com estratégias de tratamento clínico seguras e viáveis. Radiografias digitais foram obtidas em diferentes ângulos e analisadas com diferentes filtros. Imagens de tomografia computadorizada de feixe cônico (TCFC) foram solicitadas para mostrar a real posição do canal e a localização da perfuração, e orientar o planejamento estratégico do caso. Posteriormente, o acesso à cavidade foi preparado com auxílio de microscopia cirúrgica. Após a identificação da perfuração, o tecido de granulação foi removido, o canal original foi identificado e, em seguida, recebeu medicação intracanal à base de hidróxido de cálcio. Na segunda visita, a perfuração foi selada com Bio-C Repair e o sistema de canais obturado com cones de guta-percha e cimento endodôntico (Bio-C Sealer). Os dentes foram restaurados com pino de fibra de vidro, 4 mm além do nível da perfuração, e coroas provisórias. Ambos os dentes tratados conforme descrito acima se mostraram funcionais e assintomáticos na avaliação clínica e radiográfica de 1 ano. O Bio-C Repair é sugerido como uma nova opção de cimento endodôntico para o manejo de perfurações laterais, com resultados efetivos observados após um ano de acompanhamento.

Micro-push-out bond strength of mineral­based root canal sealer in canals with different tapers / Fuerza de unión por micro-expulsión del sellador de conductos radiculares a base de minerales en conductos con diferentes ahusamientos

Objective: The aim of this study was to assess the micro-push-out bond strength of a mineral-based root canal sealer, BioRoot RCS in canals prepared by K3XF rotary systems of two different tapers. Material and Methods: Eighty caries free maxillary central incisors were used in this study. The samples were allocated into 4 groups (n=20) according to the root canal sealer and taper of the rotary instruments. The samples were obturated using single cone obturation technique. From each root 1mm thick slices at coronal, middle and apical thirds were collected using hard tissue microtome under continuous water coolant. Push-out tests were done for these sections using a Universal testing machine (INSTRON 8801) at a crosshead speed of 1mm/min. One-way analysis of variance (ANOVA) was used to compare the bond strengths within groups and Tukey's multiple post hoc analysis was used for pair-wise comparison of bond strengths. Results: AH Plus exhibited higher micro-push-out bond strength than BioRootRCS though they did not differ significantly (p>0.05). Preparation of root canals with 6% taper rotary instruments showed higher bond strength than 4% though they did not differ significantly (p>0.05). Conclusion: There was no significant difference between micro-push-out bond strength values of BioRoot RCS and AH Plus. The bond strength values were high in 6% taper canals than 4% canals though the difference was not significant statistically.

Objetivo: El objetivo de este estudio fue evaluar la fuerza de unión por micro-expulsión de un sellador de conductos radiculares de base mineral, BioRoot RCS, en conductos preparados por sistemas rotativos K3XF con dos conos diferentes. Material y Métodos: En este estudio se utilizaron 80 incisivos centrales superiores libres de caries. Las muestras se distribuyeron en cuatro grupos (n = 20) de acuerdo al sellador del conducto radicular y al cono de los instrumentos rotativos. Las muestras se obturaron mediante la técnica de obturación de un solo cono. De cada raíz se recogieron rodajas de 1 mm de grosor en los tercios coronal, medio y apical utilizando un micrótomo de tejido duro con refrigeración continua por agua. Posteriormente, se realizó una prueba de expulsión para estas secciones utilizando una máquina de prueba universal (INSTRON 8801) a una velocidad del cabezal transversal de 1mm/min. Se utilizó el análisis de varianza unidireccional (ANOVA) para comparar las resistencias de la unión dentro de los grupos y el análisis post hoc multiple de Tukey se utilizó para la comparación por pares de las resistencias de la unión. Resultados: AH Plus exhibió una fuerza de unión de micro-expulsión más alta que BioRootRCS, aunque no difirieron significativamente (p>0,05). La preparación de los conductos radiculares con instrumentos rotativos ahusados al 6% mostró una fuerza de unión superior al 4%, aunque no difirieron significativamente (p>0,05). Conclusión: No hubo diferencias significativas entre los valores de fuerza de unión de micro-expulsión de BioRoot RCS y AH Plus. Los valores de la fuerza de unión fueron más altos en canales cónicos al 6% que en canales al 4%, aunque la diferencia no fue significativa estadísticamente.

Micro-CT evaluation of maxillary first molars: interorifice distances and internal anatomy of the mesiobuccal root

Abstract: This study aimed to describe the morphometric relationship of root canal orifices on the pulp floor in the presence/absence of mesiobuccal second canal (MB2) in the maxillary first molars and other aspects of its internal anatomy. Sixty-two maxillary first molars were scanned by micro-CT. The presence of the MB2 canal was verified. The distance between the center points of the MB1, MB2, distobuccal (DB), and palatal (P) canal orifices on the pulp floor were measured (MB1-MB2, MB1-DB, MB2-DB, MB1-P, and DB-P). The MB1-P to DB-P ratio was calculated. The distances between the anatomic apex and the MB1 and MB2 apical foramina were measured. The length of the band-shaped isthmus was also measured. Student's t-test was applied to verify the association between the presence of an MB2 canal, the interorifice distances, and the ratio of the MB1-P to DB-P distance (α = 5%). The MB2 canal was present in 43 roots (69.35%). Statistics showed significant differences when MB2 was present for the largest MB1-P distance (p < 0.05) and higher values for the MB1-P to DB-P ratio (p < 0.05). A band-shaped isthmus was detected in 25.8% of MB roots. The mean distance from the apical foramen to the isthmus floor ranged from 1.74 for MB1 canals to 1.42 for MB2 canals. Canal orifice distances on the pulp floor may predict the presence of MB2 canals. There was a high incidence of isthmus, accessory canals, and apical delta in the critical apical zone in MB roots of maxillary first molars.

Frequency of pulp canal obliteration in primary teeth after traumatic dental injury and its association with related variables / Frequência de obliteração do canal pulpar nos dentes decíduos após traumatismo dentário e sua associação com variáveis relacionadas

ABSTRACT Objective The aim of this study was to determine the frequency of pulp canal obliteration (PCO) after traumatic dental injury (TDI) of primary anterior teeth and to investigate its relation with the related variables. Methods This retrospective study has been done with dental records of patients selected from the Paediatric Dental Trauma Clinic between 2006 and 2016. Those who had PCO in the primary anterior teeth and were aged 0-108 months at the time of trauma were considered eligible. Data related to patients and TDI, such as sex, the child's age at the time of trauma, aetiology, affected teeth, the child's age at the time of the eruption of the permanent successor as well as the presence of crown discoloration were extracted from the dental records. Results Among the 483 children with traumatised teeth, 14.9% had PCO and the most of them exhibited crown discoloration. The average age of the children at the time of the trauma was 38 months and the most common aetiology of the TDI was falls. The average time for the beginning of the PCO process was 13.5 months. There was no statistically significant association between the child's age at the time of trauma and the types of TDI, PCO and the presence of crown discoloration. Conclusions The frequency of PCO was relatively low though the presence of crown discoloration was considerable. There was no association between the child's age at the time of trauma and the studied variable.

RESUMO Objetivo O objetivo desse estudo foi determinar a frequência de obliteração do canal pulpar (OCP) após traumatismo dos dentes decíduos anteriores e investigar sua associação com variáveis relacionadas. Métodos Este estudo retrospectivo foi realizado com base nos prontuários odontológicos de pacientes selecionados da Clínica de Trauma Dentário Pediátrico entre 2006 e 2016. Aqueles que tinham OCP nos dentes decíduos anteriores e tinham entre 0-108 meses no momento do traumatismo foram considerados elegíveis. Dados dos pacientes e dos traumatismos, tais como, sexo, idade da criança no momento do traumatismo, etiologia, dente afetado, idade da criança na época no momento da erupção do sucessor permanente, bem como presença de alteração de cor da coroa foram extraídos dos prontuários. Resultados Dentre as 483 crianças com dentes com traumatismos, 14.9% tinham OCP e a maioria delas apresentava alteração de cor da coroa. A média de idade da criança no momento do traumatismo foi de 38 meses e a etiologia mais comumente associada ao TD foram as quedas. O tempo médio decorrido para o início do processo de OCP foi de 13,5 meses. Não houve associação estatisticamente significativa entre a idade da criança no momento do traumatismo e os tipos de TD, OCP e presença de alteração de cor da coroa. Conclusão A frequência de OCP foi relativamente baixa, embora a presença de alteração da coroa tenha sido considerável. Não foi encontrada associação entre a idade da criança no momento do trauma e as variáveis estudadas.

Influência do acesso minimamente invasivo na fratura de dentes tratados endodonticamente - uma revisão de literatura / Influence of minimally invasive access on fracture of endodonti-cally treated teeth- a literature review

O acesso à cavidade pulpar é a etapa do tratamento endodôntico que tem como objetivo expor a embocadura dos canais radiculares. Por muito tempo, o formato ideal da cavidade era aquele que proporcionasse a criação de uma trajetória reta ao canal, com a remoção completa do teto da câmara pulpar. Porém, nas últimas décadas, foi investigado um desgaste excessivo de dentina que possibilita a redução da resistência do dente. Então, propuseram novo formato de cavidade de acesso, que permite a preservação máxima possível das estruturas de suporte, objetivando aumentar a resistência de dentes tratados endodonticamente. Apesar das vantagens, supostamente atribuídas aos acessos minimamente invasivos, esse formato tem sido questionado por dificultar a visibilidade da entrada dos canais, localização, e possibilidade de deixar áreas intocadas nas paredes dos canais. Diante disso, este trabalho realizou um levantamento bibliográfico a fim de verificar se há consistência científica quanto à interferência do acesso coronário na resistência dentária. Concluiu-se que o acesso minimamente invasivo não apresentou diferença quanto ao aumento da resistência à fratura de dentes tratados endodonticamente quando comparado ao acesso tradicional, entretanto, o tema ainda é relevante e os benefícios dessa técnica devem ser investigados clinicamente a longo prazo.

Access to the pulp cavity is the stage of endodontic treatment that aims to expose the mouth of the root canals. For a long time, creating a straight path to the canal, with the complete removal of the pulp chamber roof, was the ideal cavity format. However, in recent decades, excessive dentin wear, which makes it possible to reduce tooth strength, has been investi-gated. So, a new access cavity format, which allows the maximum possible preservation of the support structures, was proposed to increase the resistance of endodontically treated teeth. Despite the advantages supposedly attributed to minimally invasive accesses, this format has been questioned for hindering the visibility of the entrance to the channels, the location, and the possibility of leaving untouched areas on the walls of the channels. Therefore, this work carried out a bibliographical survey to verify the scientific consistency regarding the interference of coronary access in dental resistance. The minimally inva-sive access showed no difference regarding increased fracture resistance of endodontically treated teeth compared to the traditional access. However, the topic is still relevant, and its benefits, in the long term, should be clinically investigated.