Influence of Apical Diameter on Filling Material Extrusion during Retreatment - A Micro-CT and CBCT evaluation

Abstract Aim: To investigate whether foraminal widening performed at primary treatment has an effect on the amount of apically extruded obturator material during retreatment and to evaluate the sensitivity of cone beam computed tomography (CBCT) in detecting extruded obturator material. Methods: Forty palatal roots of maxillary molars were selected based on micro-CT and divided into two groups (n=20): with foraminal widening (WE) and without foraminal widening (NE). To standardize the apical foramen, all specimens were instrumented to the foramen using the Protaper Next system, up to instrument X3. The WE group was instrumented to the foramen up to instrument X5, and the NE group was instrumented 1 mm lower. The canals were obturated 1 mm below the apical foramen with gutta-percha and AH Plus and stored for 7 days at 37 °C and 95% humidity. Roots were fixed in microtubes filled with 1.5% agar gel. The obturation material was removed with Reciproc R50. Scans of the teeth and agar were performed using micro-CT and CBCT. Comparison between groups and between methods was performed using Mann-Withney test (p ≤0.05). Results: No statistical difference was found when comparing the extruded material between groups using micro-CT (p = 0.589) or CBCT (p = 0.953). CBCT measured a greater volume of extruded material than micro- CT (p = 0.0004). Conclusion: Foraminal widening had no effect on the extrusion of filling material during retreatment. The CBCT favored the evaluation of apically extruded filling material.

Resumo Objetivo: Investigar se o alargamento do foramen realizado durante o tratamento primário tem um efeito na quantidade de material obturador apicalmente extruído durante oretratamento e verificar a sensibilidade da tomografia computorizada de feixe cônico (TCFC) na detecção de material obturador extruído. Métodos: Quarenta raízes palatinas de molares superiores foram selecionadas de acordo com a microtomografia computorizada, e foram divididas em dois grupos (n=20): com alargamento do foraminal (CA) e sem alargamento do foraminal (SA). Para padronizar o forame apical, todas as amostras foram instrumentadas com o sistema ProTaper Next até ao instrumento X3 até o forame. O grupo CA foi instrumentado até ao instrumento X5 até o forame, e o grupo SA foi instrumentado 1 mm aquém. Os canais foram obturados 1 mm abaixo do forame apical com gutta-percha e AH Plus e armazenados durante 7 dias a 37 °C e 95% de umidade. As raízes foram fixadas em microtubos preenchidos com gel de ágar a 1,5%. O material obturador foi removido com Reciproc R50. Os escaneamentos dos dentes e do ágar foram realizados com micro-CT e CBCT. A comparação entre grupos e entre métodos foi realizada utilizando o teste Mann-Withney (p ≤0.05). Resultados: Não foi encontrada diferença estatística ao comparar o material extruído entre grupos utilizando o Micro-CT (p = 0,589) ou TCFC (p = 0,953). Foi medido um volume maior de material extruído com a TCFC do que com a Micro- CT (p = 0,0004). Conclusão: O alargamento foraminal não teve qualquer efeito na extrusão do material obturador durante o retratamento. A TCFC favoreceu a avaliação do material de obturador apicalmente extruído.

CBCT-based evaluation of integrity of cortical sinus close to periapical lesions

The purpose of the present study was to test the applicability of cone beam computed tomography (CBCT) to evaluate the integrity of the cortical sinus close to periapical lesions. Two observers analyzed samples of 64 alveoli of first molar roots in macerated swine maxillas prepared with perchloric acid to simulate periapical lesions. The specimens were evaluated using CBCT (55-mm high and 100-mm diameter cylinder at 0.2-mm voxel resolution) for the presence of oroantral communication (OAC) caused by the simulated lesions. Sensitivity, specificity, and accuracy were calculated. Fair values were obtained for accuracy (66%-78%) and good values for specificity (70%-98%), whereas the values for sensibility showed relevant variation (41%-78%). For this reason, the interobserver agreement score was weak. CBCT proved capable of evaluating the integrity of the cortical sinus (absence of oroantral communication) when it lies close to an apical periodontitis lesion. However, the low interobserver agreement reflects the difficulty in performing diagnoses when OAC is adjacent to a periapical lesion, using the acquisition protocol adopted in this research. This could be attributed to the high level of image noise.

Detection of horizontal root fracture using four different protocols of cone-beam computed tomography

The purpose of this study was to analyze four different cone-beam computed tomography (CBCT) protocols to identify horizontal root fractures (HRF) in endodontically treated teeth, with or without the presence of a metallic post. Thirty extracted single-rooted human premolars were treated endodontically. Afterwards, an observer induced a horizontal fracture in 15 teeth. Each tooth was inserted in an empty mandibular socket and submitted to a computed tomography scan taken with and without the metallic post. The acquisition followed four different protocols, with different fields of view (FOV) and voxel sizes, as follows: FOV 6X16 cm/0.2 mm voxel; FOV 6X16 cm/0.25 mm voxel; FOV 8X8 cm/0.2 mm voxel; FOV 8X8 cm/0.25 mm voxel. Two observers checked all the acquisitions within a two-week interval, and the values of sensitivity, specificity, accuracy and kappa were calculated. The sensitivity, specificity and accuracy values were better for the 8X8 cm/0.2 mm and 16X6 cm/0.25 mm protocols, ranging from 0.60 to 0.86 and 0.53 to 0.80, respectively. The intra- and interobserver concordance ranged from 0.65 to 0.72. The protocols where FOV and voxel were proportional showed better results. The 8x8 cm/0.2 mm protocol had the least interference from the metallic artifact. All four protocols showed a decline in values in the presence of the metallic artifact.

Congenital epulis with auto-resolution: case report / Epúlide congênita com auto-resolução: relato de caso

Congenital epulis is an uncommon benign lesion that affects the oral cavity of newborns, and presents histological features which are similar to those of granular cell tumor. The origin of this lesion has not been fully elucidated, and many hypotheses are considered due to the large variety of cell types observed in histological sections. Epulis development occurs further in the prenatal period, and is more common in newborn females, frequently in the maxilla. This lesion usually is presentend as a nodule covered by normal oral mucosa, which in some cases, interferes with baby's breathing and feeding. This report describes the case of a two-month-old male baby who presented a pedunculated intraoral lesion in the mandibular alveolar ridge. Histological sections revealed presence of mucosal fragments with atrophic squamous stratified epithelium, and fibrous connective tissue composed of cells with granular and eosinophilic cytoplasm. A few days after initial exam, the lesion detached from alveolar ridge, and healed spontaneously.

A epúlide congênita é uma lesão benigna rara que acomete a cavidade oral de recém-nascidos e apresenta características histológicas semelhantes às do tumor de células granulares. A origem da lesão ainda não foi completamente elucidada, e as muitas hipóteses a respeito de sua histogênese baseiam-se na grande variedade de tipos celulares observados nos cortes histológicos. A epúlide desenvolve-se ainda no período pré-natal, e é mais comum em recém-nascidos do sexo feminino, ocorrendo com mais freqüência na maxila. Esta lesão costuma apresentar-se como um nódulo coberto por mucosa oral normal que, em alguns casos, interfere na respiração e na alimentação do bebê. Esse artigo descreve o caso de um bebê do gênero masculino, leucoderma, de dois meses de idade, que apresentava lesão intra-oral pediculada com implantação débil na região alveolar da mandíbula. Cortes histológicos revelaram a presença de fragmento de mucosa revestido por epitélio pavimentoso estratificado atrófico, e de tecido conjuntivo fibroso composto de células com citoplasma granular e eosinofílico abundante. Alguns dias após o exame inicial, a lesão desprendeu-se do rebordo alveolar, sofrendo resolução espontânea.

Assessment of open source software for CBCT in detecting additional mental foramina

The purpose of this study was to evaluate which post-processing imaging protocol would be better to analyze the additional mental foramen (AMF) in preoperative planning with cone-beam computed tomography (CBCT) exams, and to test reproducibility of measurements, using open source software (OsiriX). The software was used to detect the cases of AMF from among 58 exams for dental implant planning in edentulous mandible areas-three cases were found. The case images were submitted to qualitative analysis using 2D orthogonal MPR, 3D-MPR and 3D volume rendering protocols by two oral and maxillofacial radiologists. Quantitative analysis used the 3D-MPR protocol; the closed polygon tool measured the mental foramen (MF) and the AMF areas; the length tool measured the distance between foramina. The measurements were performed independently by the examiners, at two different times. Intra- and interexaminer agreement was assessed using the intraclass correlation coefficient. The panoramic view did not show the MF and the AMF clearly. The AMF could be detected in the parasagittal view. 2D Orthogonal MPR was effective to observe the AMF in some cases. The 3D-MPR and 3D view protocols were the most effective to locate and analyze the AMF. In conclusion, a 3D view improves visualization when anatomical points are not clearly visible. 3D-MPR was considered a more effective post-processing imaging protocol to observe foramina relationships. The high reproducibility of measurements for anatomical MF variations was established using specific tools featured in open source software for CBCT. OsiriX is realistic and recommended for preoperative planning.

Odontodisplasia regional: relato de caso em maxila com transpasse de linha média / Regional odontodysplasia: case report in maxilla crossing the midline

Odontodisplasia regional é uma afecção rara, não-hereditária, a qual afeta o desenvolvimento do esmalte e dentina na dentição decídua e/ou permanente. A etiologia ainda é desconhecida. Em geral, esta condição é diagnosticada durante exames radiográficos de rotina e muitos casos são diagnosticados erroneamente como dentes malformados ou odontomas. Esta condição afeta duas vezes mais o sexo feminino do que o masculino e envolve com mais frequência à maxila do que a mandíbula. Esta afecção é também mencionada como "dentes fantasmas", uma vez que os dentes afetados, radiograficamente, não apresentam distinção dos limites entre o esmalte e a dentina; e a câmara pulpar se apresenta alargada. Clinicamente os dentes são vistos com uma coloração castanha ou amarelada. O presente trabalho apresenta um caso clínico de odontodisplasia regional, não usual, que cruza a linha média da maxila, em uma criança do sexo feminino de quatro anos de idade. Todos os dentes decíduos e permanentes superiores do lado esquerdo eram displásicos, assim como também os incisivos centrais, decíduo e permanente do lado direito.

Regional odontodysplasia is a rare, nonhereditary condition that affects the development of the enamel and dentin of the deciduous and/or permanent teeth. The etiology is still unknown. In general, this condition is diagnosed during routine radiographic assessments and many cases are mistaken for malformed teeth or odontomas. This condition affects twice as many females as males and is more common in the maxilla than the jaw. This condition is also called "ghost teeth" because the enamel-dentine border of the affected teeth cannot be distinguished in the radiograph and the pulp chambers are wide. Clinically, the teeth are brownish or yellowish. The present study reports an unusual case of maxillary regional odontodysplasia crossing the midline in a 4-year-old female. All deciduous and permanent teeth in the left side of the maxilla and the central incisors in the right side of the maxilla were dysplastic.