Dental undergraduate students' ability in the diagnosis of root fractures: Comparative analysis of different imaging methods.

OBJECTIVE: The aim of this study was to evaluate the diagnostic ability of dental undergraduate students to detect horizontal and oblique root fractures (ORFs) using different imaging techniques. MATERIALS AND METHODS: Nine teeth were selected and randomly divided in three groups in order to create a fracture line without fragments separation: control (without fracture), horizontal root fracture (HRF), and ORF. The root fracture was created using perpendicular force and was confirmed by transillumination. A model with two adjacent teeth was created, and different imaging techniques were performed: conventional periapical radiograph; mesially and distally shifted periapical radiographs; cone-beam computer tomography (CBCT). Twenty students that had participation on dental trauma clinic at the year of 2019 were invited to identify root fractures by a five-point scale: (i) fracture definitely not present, (ii) fracture probably not present, (iii) uncertain whether fracture is present or not, (iv) fracture probably present, and (v) fracture definitely present. Data were analyzed by Kappa test for agreement evaluation. RESULTS: Comparing each student to the gold standard, there was a variation in reproducibility and performance from poor to substantial (0.042-0.667). Reproducibility values ranged from poor to good for all periapical radiographs both in the diagnosis of ORF (-0.33-0.667) and in HRF (0-1). CONCLUSIONS: In CBCT images, the students' ability was lower in HRF detection in comparison with the oblique ones. The students showed limited capacity to diagnose root fractures; however when CBCT was used, the performance was more satisfactory than when periapical radiographs were used.

Effect of Resin Cement Mixing and Insertion Method into the Root Canal on Cement Porosity and Fiberglass Post Bond Strength.

PURPOSE: To evaluate the method of resin cement mixing and insertion into the root canal on resin cement porosity and fiberglass-post push-out bond strength (PBS). MATERIALS AND METHODS: One hundred twenty human single-rooted teeth were sectioned to a length of 15 mm, en-do-dontically filled, and received a fiberglass post cemented with 3 self-adhesive resin cements (RelyX U200, seT, Panavia SA) using 4 mixing methods/insertion techniques (handmix/endodontic file, handmix/Centrix syringe, automix/conventional tip, automix/endo tip). The samples were scanned using micro-CT. Two slices from the cervical, middle, and apical thirds were submitted to push-out bond strength (PBS) testing, and failure modes were classified. The PBS, volume of resin cement, and porosity data were analyzed using ANOVA and Tukey's test. RESULTS: The porosity was lowest in the cervical third and highest in the apical third, irrespective of the resin cement. The porosity was lower in the the automix/endo tip group compared to the handmix/endodontic file group. The use of Centrix or endo tip reduced the porosity and increased the PBS in the apical third compared with the use of endodontic files. The root canal depth reduced the PBS for U200 and seT when handmix/endodontic files were used. U200 and seT using the automix method increased the PBS, thus eliminating the effect of root region, irrespective of the insertion technique. In general, U200 showed higher PBS and Panavia lower PBS. Adhesive failure between root dentin and resin cement was predominant. CONCLUSIONS: Automixing the cement and using an endo tip produces fewer voids and increased the bond strengths.

Three-dimensional finite element stress analysis of teeth adjacent to a traumatized incisor.

BACKGROUND/AIMS: Dental trauma is the cause of several consequences to the injured tooth. However, the stresses and strains at adjacent teeth non-directly impacted as a possible cause of sequelae are still unknown. The aim of this study was to evaluate the stress distribution in incisors adjacent to an upper central incisor when it suffers a frontal impact in order to identify a potential explanation for sequelae in non-traumatized teeth. MATERIALS AND METHODS: A three-dimensional (3D) finite element model of the maxillary central incisors, lateral incisors and canines was created from a cone-beam scan of a patient with normal occlusion. Non-linear dynamic impact analysis was performed, simulating the right central incisor being impacted by a steel ball with a velocity of 10 m/s. A functional chewing load (100 N) on the palatal surface of the central incisor was simulated for comparison. Displacements, strains and modified von Mises stresses were calculated for the adjacent teeth. RESULTS: During impact on the central incisor, the adjacent teeth showed root displacement. Considerable stress concentrations were observed on the palatal surfaces, proximal and labial surfaces of teeth adjacent to the traumatized incisor. Stresses in the adjacent teeth were higher than stresses calculated during functional biting. Compressive stresses were concentrated at the proximal areas of the adjacent incisors. High levels of deformation were found in the root dentin of adjacent teeth during the traumatic event. CONCLUSIONS: A frontal impact on an anterior tooth generated stresses at the roots of adjacent teeth. These stresses may play a role in clinically observed sequelae of teeth adjacent to traumatized teeth.

Dental trauma on primary teeth at different root resorption stages-A dynamic finite element impact analysis of the effect on the permanent tooth germ.

BACKGROUND/AIM: Dental trauma is a common emergency in children with primary teeth. The aim of this study was to determine stress propagation to the permanent tooth germ and surrounding bone and soft tissues during dental trauma to primary central incisors with three levels of physiological root resorption. MATERIAL AND METHODS: Stresses were determined using finite element analysis (FEA). Cross-sectional models were created using cone-beam computed tomography images of 3.5, 5, and 6 years olds, representing three different physiological root resorption stages of a maxillary primary central incisor. The models included periodontal ligament, bone, and soft tissues. An impact with an asphalt block moving at 1 m/s,was simulated for two impact two directions, frontal on the labial tooth surface, and on the incisal edge. Stresses and strains were recorded during impact. RESULTS: The impact caused stress concentrations in the surrounding bone and soft tissues and permanent tooth germ, regardless of the direction of impact and the primary tooth resorption stage. Impact stresses in dental follicles and surrounding bone increased in models with more physiological root resorption of the primary tooth. Incisal impact generated higher stress concentrations in surrounding bone and soft tissues and permanent tooth germ regardless of physiological root resorption stage. The primary incisor with no physiological root resorption showed high stress concentrations at its root apex. CONCLUSION: During impact to a primary incisor, stresses most significant for potential damage to the formation of permanent enamel and dentin were at the dental follicle and surrounding bone tissue with the three levels of physiological root resorption.

Effects of Lectin (ScLL) on osteoclast-like multinucleated giant cells' maturation-A preliminary in vitro study.

BACKGROUND/AIM: Lectin (ScLL) has been recently evaluated in the oral cavity due to its anti-inflammatory activities. ScLL could be a promising agent for blocking osteoclast activity and preventing root resorption. The aim of this study was to evaluate the effect of ScLL on the viability of the RAW 264.7 macrophage lineage, osteoclast-like maturation and the release of TNF-α and nitric oxide (NO). MATERIALS AND METHODS: The viability of RAW 264.7 cells was determined by MTT and Alamar Blue assays after ScLL treatment for 24 hours. ScLL effects on RANKL-induced osteoclast-like maturation were assessed by tartrate-resistant acid phosphatase (TRAP) staining and F-actin ring formation. The supernatant was collected to detect the release of TNF-α using ELISA and NO using a nitrite assay. RESULTS: ScLL suppressed osteoclast-like maturation by decreasing TRAP activity as well as F-actin ring formation. ScLL at 10 µg/mL showed the highest values of NO release compared with all other groups (P < .05). Lower levels of TNF-α were found for the negative control. CONCLUSIONS: ScLL at 5 µg/mL suppressed osteoclast-like maturation in vitro and had no cytotoxic effect on RAW cell cultures.

Restaurações diretas em resina composta transcirúrgicas em dentes traumatizados: acompanhamento de série de casos na clínica de traumatismo dento-alveolar da FOUFU / Transurgical direct composite restoration in traumatized teeth: case series support of clínica de traumatismo dento-alveolar da FOUFU

Objetivo: apresentar caso clínico de restauração em resina composta transcirúrgica em dente com fratura dental, demonstrando desempenho clínico por proservação de até 2 anos de procedimentos transcirúrgicos realizados na Clínica de Traumatismo Dentoalveolar/FOUFU. Materiais e métodos: Foram avaliados 7 casos clínicos, do total de 21 casos de restauração transcirúrgica de fratura dento-alveolar realizados nos últimos 2 anos. Os acompanhamentos clínicos foram realizados 6 meses após os procedimentos transcirúrgicos descrevendo o uso de pinos de fibra de vidro, tracionamento ortodôntico, assim como presença de edema, profundidade de sondagem, sangramento gengival, lisura superficial e perfil de emergência da restauração, além da relação oclusal. Para ilustrar esta série de casos reavaliados, foi inserido relato de protocolo transcirúrgico restaurador direto, com restabelecimento de distância biológica, associada à cimentação de pino de vibra de vidro com acompanhamento de 4 anos. Resultados: Apenas 42% dos pacientes retornaram para acompanhamento. Exceto em pacientes com higiene oral deficiente, não foram relatados edema e sangramento gengival à sondagem. O perfil de emergência das restaurações apresentou- -se adequado, assim como o acabamento e polimento superficial. Conclusão: Restaurações diretas transcirúrgicas utilizando resinas compostas constituem opção confiável e economicamente viável para a restauração de dentes fraturados com invasão de espaço biológico, principalmente no ambiente do serviço público promove resultados eficazes. Esforços constantes precisam ser realizados para que os pacientes se conscientizem da necessidade de retornos periódicos para acompanhamento realizados em ambientes universitários onde o serviço está vinculado a geração de conhecimento.

Aim: present a case report of a transsurgical composite resin restoration in a fractured tooth, demonstrating clinical performance by proservation of up to 2 years of transsurgical procedures performed at the Dentoalveolar Trauma Clinic / FOUFU. Materials and methods: 7 clinical cases were evaluated, in a 21 total cases of transsurgical restoration of dentoalveolar fractures performed in the last 2 years. The clinical follow-ups were realized 6 months after the transsurgical procedures describing the use of glass fiber posts, orthodontic traction, as the presence of edema, probing pocket depth, gingival bleeding index, surface smoothness and emergence profile of restoration, also occlusal relationship. To illustrate this reavaluated case series, it was inserted a report of a direct transsurgical restorative protocol, with reestablishment of biological distance associated with cementation of glass fiber post with 4 years of follow-up. Results: Only 42% of pacients return to follow-up. Except in pacients with poor oral hygiene, it was not report edema or bleeding on probing. The emergence profile of restorations presented appropriate as the superficial finishing and polishing. Conclusion: Transsurgical direct restorations using composite resins are a confinable option and viable economical for restoration of fracture tooth with invasion of biological space, mainly in public service it can promote effective results. Constants efforts need to be realized for the conscientization of the patients of the periodical return for follow-up made in universitary environment where the service ar connect with knowledge generation.

Mono or polycrystalline alumina-modified hybrid ceramics.

OBJECTIVES: This study evaluated the effect of addition of alumina particles (polycrystalline or monocrystalline), with or without silica coating, on the optical and mechanical properties of a porcelain. METHODS: Groups tested were: control (C), polycrystalline alumina (PA), polycrystalline alumina-silica (PAS), monocrystalline alumina (MA), monocrystalline alumina-silica (MAS). Polycrystalline alumina powder was synthesized using a polymeric precursor method; a commercially available monocrystalline alumina powder (sapphire) was acquired. Silica coating was obtained by immersing alumina powders in a tetraethylorthosilicate solution, followed by heat-treatment. Electrostatic stable suspension method was used to ensure homogenous dispersion of the alumina particles within the porcelain powder. The ceramic specimens were obtained by heat-pressing. Microstructure, translucency parameter, contrast ratio, opalescence index, porosity, biaxial flexural strength, roughness, and elastic constants were characterized. RESULTS: A better interaction between glass matrix and silica coated crystalline particles is suggested in some analyses, yet further investigation is needed to confirm it. The materials did not present significant differences in biaxial flexural strength, due to the presence of higher porosity in the groups with alumina addition. Elastic modulus was higher for MA and MAS groups. Also, these were the groups with optical qualities and roughness closer to control. The PA and PAS groups were considerably more opaque as well as rougher. SIGNIFICANCE: Porcelains with addition of monocrystalline particles presented superior esthetic qualities compared to those with polycrystalline particles. In order to eliminate the porosity in the ceramic materials investigated herein, processing parameters need to be optimized as well as different glass frites should be tested.

A multidisciplinary direct restorative approach for recovering crown-root fractures in young patients: a case report / Tratamento multidisciplinar restaurador direto para reabilitação de fraturas corono-radiculares em pacientes jovens: relato de caso

The aim of this article is to describe a step-by-step protocol for emergency care of a young patient with multidisciplinary direct restorative approach for recovering crown-root fractures. Fractures of maxillary incisors are a frequent consequence of trauma in children and teenagers. Glass fiber post associated with composite resin restoration represents a conservative approach for this rehabilitation. This paper presents a case of a 14-year-old male patient with a crown-root fracture in a left maxillary lateral incisor. The patient was submitted to a periodontal surgery for coronal lengthening. After that, the post luting and restoration technique was performed. Finally, a mouthguard was made for preventing new trauma. The multidisciplinary treatment described for crown-root fracture rehabilitation is simple, providing esthetics and function with a conservative approach in younger patients.

O objetivo deste artigo é descrever passo a passo, um protocolo para tratamento de emergência de pacientes jovens, com abordagem multidisciplinar e restauração direta em resina composta para a reabilitação de fraturas corono-radiculares. Fraturas de incisivos superiores são uma consequência frequente de traumas em crianças e adolescentes. Pinos de fibra de vidro associados às restaurações em resina composta representam abordagem conservadora para este tipo de situação. Este artigo apresenta caso clinico de um paciente do sexo masculino de 14 anos de idade, com fratura corono- radicular em incisivo lateral superior esquerdo. Inicialmente,o paciente foi submetido à cirurgia periodontal para aumento de coroa clínica. Depois, foi realizada cimentação do pino de fibra de vidro, seguido de restauração direta em resina composta. Por fim, um protetor bucal foi confeccionado para prevenir novo trauma. O tratamento multidisciplinar descrito para reabilitação de fraturas corono-radiculares é simples, proporcionando estética e função com uma abordagem conservadora em pacientes jovens.

Uso de coroa em cerâmica pura associada a pino de fibra de vidro na reabilitação estética do sorriso: relato de caso / All ceramic crown associated to fiberglass post: a clinical case report

Restauração de dentes tratados endodonticamente constituidesafio permanente na odontologia, uma vez que aspectos biomecânicos,estéticos e complexidade de execução técnica podemresultar em insucesso com consequente perda do elemento dentário.Geralmente dentes tratados endodonticamente se encontramenfraquecidos devido à perda de estrutura dentária o queresulta em redução de resistência mecânica da dentina. Estesfatores resultando em maiores riscos de falhas biomecânicasquando comparados aos dentes com vitalidade pulpar. Este trabalhotem por objetivo apresentar procedimentos clínicos reabilitadorespara devolução de harmonia estética com ênfase emprocedimentos realizados em incisivo central superior com extensaperda de estrutura coronária e restauração em resina compostainsatisfatória. Foi empregada a associação de pino de fibrade vidro (Exacto, Ângelus) e resina composta para reconstruçãointerna seguido de coroa em cerâmica pura (In Ceram Alumina,Vita). São destacados os passos clínicos e breve revisão de aspectosbiomecânicos e estéticos desta alternativa reabilitadora.

Restoration of endodontically treated teeth is a challenge inoperative dentistry, since the biomechanical, aesthetic and complexityof the technique can result in failure with subsequenttooth loss. Generally endodontically treated teeth are weakeneddue to loss of tooth structure and reduce the mechanicalstrength of dentin. These factors result in a higher risk of biomechanicalfailure when compared to teeth with pulp vitality.This paper aims to present clinical rehabilitation procedures torecover the smile harmony with an emphasis on aesthetic proceduresperformed in the maxillary central incisor with extensiveloss of coronal tooth tissue and unsatisfactory compositeresin restoration. It was employed the combination of fiberglasspost (Exacto, Angelus) and coronal reconstruction with compositeresin followed by all ceramic alumina crown (In CeramAlumina, Vita). Highlights the clinical steps and brief review ofbiomechanical and aesthetic rehabilitation of this alternative aredescribed.